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WiMAX簡介Ming-Tsung Huang
Fu Jen Catholic UniversityComputer Science
Outline
bull 1048707 I Introductionbull 1048707 II 80216 Physical Layerbull 1048707 III 80216 MAC Layerbull 1048707 IV QoS Support in IEEE 80216bull 1048707
I Introduction
bull Many new services are based on multimediaapplicationsndash voice over IP (VoIP)ndash video conferencingndash video on demand (VoD)ndash massive online gamingndash peer-to-peer
bull Unlike traditional TCPIP services multimedia applications usually require strict network guarantees
ndash reserved bandwidthndash bounded delays
Broadband wireless Access
bull The International Telecommunication Union (ITU) which reported that Broadband Wireless Access (BWA) although still in the early stage of its growth is one of the most promising solutions for broadband access
bull Standards for BWA are being developed within IEEE 80216
bull To promote 80216-compliant technologies the Worldwide Interoperability for Microwave Access (WiMAX) Forum was founded with more than 300 member companies
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Outline
bull 1048707 I Introductionbull 1048707 II 80216 Physical Layerbull 1048707 III 80216 MAC Layerbull 1048707 IV QoS Support in IEEE 80216bull 1048707
I Introduction
bull Many new services are based on multimediaapplicationsndash voice over IP (VoIP)ndash video conferencingndash video on demand (VoD)ndash massive online gamingndash peer-to-peer
bull Unlike traditional TCPIP services multimedia applications usually require strict network guarantees
ndash reserved bandwidthndash bounded delays
Broadband wireless Access
bull The International Telecommunication Union (ITU) which reported that Broadband Wireless Access (BWA) although still in the early stage of its growth is one of the most promising solutions for broadband access
bull Standards for BWA are being developed within IEEE 80216
bull To promote 80216-compliant technologies the Worldwide Interoperability for Microwave Access (WiMAX) Forum was founded with more than 300 member companies
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
I Introduction
bull Many new services are based on multimediaapplicationsndash voice over IP (VoIP)ndash video conferencingndash video on demand (VoD)ndash massive online gamingndash peer-to-peer
bull Unlike traditional TCPIP services multimedia applications usually require strict network guarantees
ndash reserved bandwidthndash bounded delays
Broadband wireless Access
bull The International Telecommunication Union (ITU) which reported that Broadband Wireless Access (BWA) although still in the early stage of its growth is one of the most promising solutions for broadband access
bull Standards for BWA are being developed within IEEE 80216
bull To promote 80216-compliant technologies the Worldwide Interoperability for Microwave Access (WiMAX) Forum was founded with more than 300 member companies
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Many new services are based on multimediaapplicationsndash voice over IP (VoIP)ndash video conferencingndash video on demand (VoD)ndash massive online gamingndash peer-to-peer
bull Unlike traditional TCPIP services multimedia applications usually require strict network guarantees
ndash reserved bandwidthndash bounded delays
Broadband wireless Access
bull The International Telecommunication Union (ITU) which reported that Broadband Wireless Access (BWA) although still in the early stage of its growth is one of the most promising solutions for broadband access
bull Standards for BWA are being developed within IEEE 80216
bull To promote 80216-compliant technologies the Worldwide Interoperability for Microwave Access (WiMAX) Forum was founded with more than 300 member companies
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Unlike traditional TCPIP services multimedia applications usually require strict network guarantees
ndash reserved bandwidthndash bounded delays
Broadband wireless Access
bull The International Telecommunication Union (ITU) which reported that Broadband Wireless Access (BWA) although still in the early stage of its growth is one of the most promising solutions for broadband access
bull Standards for BWA are being developed within IEEE 80216
bull To promote 80216-compliant technologies the Worldwide Interoperability for Microwave Access (WiMAX) Forum was founded with more than 300 member companies
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Broadband wireless Access
bull The International Telecommunication Union (ITU) which reported that Broadband Wireless Access (BWA) although still in the early stage of its growth is one of the most promising solutions for broadband access
bull Standards for BWA are being developed within IEEE 80216
bull To promote 80216-compliant technologies the Worldwide Interoperability for Microwave Access (WiMAX) Forum was founded with more than 300 member companies
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull To promote 80216-compliant technologies the Worldwide Interoperability for Microwave Access (WiMAX) Forum was founded with more than 300 member companies
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull It is envisaged that the first 80216-compliant products to be deployed will very likely be aimed at providing last-mile Internet access for residential users mainly high-speed Internet access and small and medium-sized enterprises (SMEs)
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull For the SME market 80216 will provide a cost-effective alternative to existing solutions based on very expensive leasedline services
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
80216 family
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Deployment
bull 80216 systems can be deployed effectively wherendash Users are dissatisfied with the current packet
andor network interfacendash Network operators need to reach customers cost
effectivelyndash New service offerings are available for 25G3G
augmentation
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Salient Advantages
bull Some of the more salient advantages of a wireless system for broadband access based on the 80216 standard are as followsndash Bandwidth on demand (BOD)ndash Higher throughputndash Scalable system capacityndash Coveragendash Quality (CBR or UBR)ndash Cost (investment risk and end-user fee)
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
II 80216 Physical Layer
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Physical Layer
bull The physical layer of the IEEE 80216 air interface operatesndash 10ndash66 GHz band for IEEE 80216 (LOS)ndash 2ndash11 GHz band for IEEE 80216a (NLOS)
bull In the 10ndash66 GHz the air interface used for this band is Wireless-SC (single carrier)
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull In the 2ndash11 GHz band three different air interfaces can be used as followsndash WirelessMAN-SCa for single-carrier modulationndash WirelessMAN-OFDM The MAC scheme for the
subscriber stations is TDMAndash WirelessMAN-OFDMA for OFDM-based
transmission using 2048 subcarriers
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
OFDMA
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
III 80216 MAC Layer
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Medium Access Control Layer
bull The 80216 standard specifies two modes for sharing the wireless medium point-to-multipoint (PMP) and mesh (optional)
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull IEEE 80216WiMAX uses a connection-oriented MAC protocol that provides a mechanism for the subscriber stations to request bandwidth from the BS
bull A 16-bit connection identifier (CID) is usedprimarily to identify each connection to the BS
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull 80216 MAC layerndash Sublayer
bull Service Specific Convergence Sublayer (CS)bull MAC-Common Part Sublayer (CPS)bull Privacy Sublayer (PS)
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull On the downlink the BS broadcasts data to allsubscriber stations in its coverage area Eachsubscriber station processes only the MACprotocol data units (PDUs) containing its ownCID and discards the other PDUs
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull For TDD-based access a MAC frame (ie transmissionperiod) is divided into uplink and downlink subframes
bull The lengths of these subframes are determineddynamically by the BS and broadcast to the subscriberstations through downlink and uplink MAP messages(DL-MAP and UL-MAP) at the beginning of each frame
bull The MAC protocol in the standard supports dynamicbandwidth allocation
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
subframe
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Subframe(2)
Ex TDD subframe
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull PMP modendash The BS serves a set of SSs within the same
antenna sector in a broadcast manner
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Mesh Operation Modendash In addition to the single-hop PMP operation
scenario the WiMAX standard (eg IEEE 80216a) also defines the multihop mesh networking scenario among the subscriber stations (ie client meshing)
ndash Meshing among the BSs (ie infrastructure meshing) has not been standardized yet
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull The mesh modetraffic can be routed through other SSs and can occur directly among SSs
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
IV QoS Support in IEEE 80216
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull QoS in wireless networks is usuallymanaged at the medium access control(MAC) layer
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull In PMP mode uplink (from SS to BS) anddownlink (from BS to SS) data transmissions occur in separate time framesndash In the downlink subframe the BS transmits a burst of
MAC protocol data units (PDUs)ndash Since the transmission is broadcast all SSs listen to
the data transmitted by the BSndash In the uplink subframe any SS transmits a burst of
MAC PDUs to the BS in a time-division multiple access (TDMA) manner
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Based on measurements at the physical layerany SS adapts over time the interval usage code (IUC) in use
bull That is modulation rate and forward errorcorrection (FEC) scheme for both downlink(downlink IUC DIUC) and uplink (uplink IUCUIUC) transmissions
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Duplex
bull Downlink and uplink subframes are duplexedusing one of the following techniquesndash Frequency-division duplex (FDD)ndash Time-division duplex (TDD)
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Frame structure with FDD and TDD
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull The MAC protocol is connection-oriented all data communications for both transport and control are in the context of a unidirectional connection
bull At the start of each frame the BS schedules the uplink and downlink grants in order to meet the QoS requirements
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Each SS learns the boundaries of its allocation within the current uplink subframe by decoding the UL-MAP message
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull The DL-MAP message contains the timetable of the downlink grants in the forthcoming downlink subframe Downlink grants directed to SSs with the same DIUC are advertised by the DL-MAP as a single burst
bull Both maps are transmitted by the BS at the beginning of each downlink subframe for both FDD and TDD modes
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
QoS functions within the BS and SSs
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Since the BS controls the access to the medium in the uplink direction bandwidth is granted to SSs on demand
bull Bandwidth-request mechanisms ndash Unsolicited grantingndash Unicast pollndash Broadcast polls
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Unsolicited grantingndash A fixed amount of bandwidth on a periodic basis is
requested during the setup phase of an uplink connection After that phase bandwidth is never explicitly requested
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Unicast pollndash A unicast poll consists of allocating to a polled
uplink connection the bandwidth needed to transmit a bandwidth request
ndash If the polled connection has no data awaiting transmission (backlog for short) or if it has already requested bandwidth for all of its backlog it will not reply to the unicast poll which is thus wasted
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Broadcast polls ndash A collision occurs whenever two or more uplink
connections send a bandwidth request by responding to the same poll in which case a binary exponential backoff algorithm is employed
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Bandwidth requests can be piggybacked on a PDU
bull Bandwidth requests are used on the BS for estimating the residual backlog of uplink connections
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull Although bandwidth requests are per connection the BS nevertheless grants uplink capacity to each SS as a whole
bull When an SS receives an uplink grant it cannot deduce from the grant which of connections it was intended for by the BS
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
bull The 80216 MAC specifies four different scheduling services in order to meet the QoS requirements of multimedia applications UGS rtPS nrtPS and BE
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Unsolicited Grant Service (UGS)
bull UGS is designed to support real-time applications (with strict delay requirements) that generate fixed-size data packets a periodic intervals
bull Ex T1E1 and VoIP without silence suppression
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Unsolicited Grant Service (UGS)
bull The guaranteed service is defined so as to closely follow the packet arrival pattern with the base period equal to the unsolicited grant interval and the offset upper bounded by the tolerated jitter
bull The grant size is computed by the BS based on the minimum reserved traffic rate
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
real-time Polling Service (rtPS)
bull rtPS is designed to support real-time applications (with less stringent delay requirements) that generate variable-size data packets at periodic intervals
bull Ex MPEG video and VoIP with silence suppression
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
real-time Polling Service (rtPS)
bull The key QoS parameters for rtPS connections are the minimum reserved traffic rate and the maximum latency
bull The BS periodically grants unicast polls to rtPS connections
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE are designed for applications that do not have any specific delay requirement
bull The main difference between the two is that nrtPS connections are reserved a minimum amount of bandwidth which can boost performance of bandwidth-intensive applications Ex FTP
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
non-real-time Polling Service (nrtPS) and Best Effort (BE)
bull nrtPS and BE uplink connections request bandwidth by either responding to broadcast polls from the BS or piggybacking a bandwidth request on an outgoing PDU
bull Exndash For nrtPS FTPndash For best-effort HTTP SMTP
Thank you
Thank you
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