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Huawei Confidential. All Rights Reserved
OMQ000001 GPRS Principle
ISSUE 2.0
Internal Use
Internal Use
Internal Use4
GSM Development EvolutionGSM Development Evolution
57.6 kbps
115 kbps
384 kbps
2 Mbps
GSM
HSCSD
GPRS
EDGE
IMT-2000
9.6 kbps
2G
2.5G
3G
Internal Use
General Packet Radio Service (GPRS)
is a packet oriented Mobile Data Service available to users of Global System for Mobile Communications (GSM) and IS-136 mobile phones.
It provides data rates from 56 up to 114 k.bit /s.
GPRS is a technology which is changing the present shape of mobile communication.
2G cellular systems combined with GPRS are often described as "2.5G", that is, a technology between the second (2G) and third (3G) generations of mobile telephony
Internal Use
Internal Use
Internal Use
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Technology of GPRSTechnology of GPRS
Splits data into Internet Protocol (IP) packets Transmitted in packet switching connection Objectives:
give support for bursty traffic use efficiently network and radio resources provide flexible services at relatively low costs possibility for connectivity to the Internet provide fast access time to have and support flexible co-existence with
GSM voice
Internal Use
What is GPRS?What is GPRS?
Bandwidth
share the same bandwidth
be served from a single cell
LIMITED IN REALITY
Speed
Theoretically, maximum speed ~ 144 kbps
Using all eight timeslots at the same time
SPEEDS MUCH LOWER IN REALITY
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Features of GPRSFeatures of GPRS
Key user features of GPRS
IMMEDIACY NEW APPLICATIONS,
BETTER APPLICATIONS
SERVICE ACCESS
Keynetwork features of GPRS
PACKET SWITCHING
SPECTRUM EFFICIENCY
Internal Use
How is GPRS?How is GPRS?
Technology used by GPRSPacket-mode technique over GSM radio
networksOptimizes the use of radio and network
resources
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When is GPRS?When is GPRS?
Figure: GSM migration paths
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OpportunitiesOpportunities
Bridge of the gap for 3GSensible steeping-stone adoptionTest of higher bandwidth services to come
in 3GFirst time non-voice services to mass
market
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Which is GPRS?Which is GPRS?
Application VOICE MAIL SERVICES CHAT TEXTUAL AND VISUAL INFORMATION IMAGES WEB BROWSING DOCUMENT SHARING/ COLLABORATIVE
WORKING
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Which is GPRS?Which is GPRS?
Applications AUDIO CORPORATE EMAIL INTERNET EMAIL VEHICLE POSITIONING REMOTE LAN ACCESS FILE TRANSFER HOME AUTOMATION
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ApplicationsApplications
Personal Digital Assistant (PDA)
Internal Use
Advanced Consumer Advanced Consumer ApplicationsApplications information on demand regarding weather,
traffic, entertainment, stock exchange, flight schedule etc.
bank transactions fast communication with the service
provider to receive administrative information such as statements, bill reminders, or new services
Internal Use
Advanced Business Advanced Business ApplicationsApplications tracking of taxis and credit card validation for
customer payment control over the position of trucks for
transportation companies localization of stolen cars support of security and monitoring systems distribution of specific short messages to
selected groups of users in large corporations
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GSM ArchitectureGSM Architecture
BTSMS
BTS
BTS
MS
BSC
BSC
MSC
GMSC
MS
EIR
VLR
HLR
AUC
PSTNPDN
ISDN
Internal Use
GPRS ArchitectureGPRS Architecture
BTS
BTSMS
BSC Gb
SGSN
Gf
GsGr
DEIR
MSC/VLR
HLR
Gc
Gn
GGSNGi
PDN
Gp GGSN
Other GPRS
PLMN
Internal Use22
Network interface types Network interface types
GPRS backbone network
SGSNSGSN
SGSNSGSNGGSNGGSNGn
IP interface
SS7 interface
BSS MSCSMS-GMSC
AUm
PDP network (IP/X.25)
Gi
TE
MT
MS
HLR
Gs
Gr
Gd
Gc
Gb
Internal Use23
Key Elements Of GPRS NetworkKey Elements Of GPRS Network
SGSN- Serving GPRS Support Node
GGSN- Gateway GPRS support Node
PCU Packet Control Unit
ADDITIONAL ELEMENTS OF THE GPRS CG ( Charging Gateway)
NMS ( Network Management Center)
BG (Border Gateway)
LIG (Legal Interception Gateway)
DNS
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BSS GPRS MODIFICATIONBSS GPRS MODIFICATION
24
BTS Requires Software up gradation
Inclusion of CCU in the BTS
BSC requires software upgrade and addition of PCUSN
PCUSN can contain PCUs
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Packet Control Unit (PCU) Functions Packet Control Unit (PCU) Functions
25
Provides physical and logical data interface out of the BSS for
packet data traffic
ARQ functions
Radio channel management
LLC layer PDU segmentation/reassembly
Packet data transfer scheduling
Internal Use
CHANNEL CODING UNITCHANNEL CODING UNIT
26
Channel Coding functions
FEC
Interleaving
Radio channel functions
Internal Use27
Position of PCUPosition of PCU
CCU
CCU
CCU=Channel Codec UnitPCU= Packet Control Unit
CCUPCU
BTS BSC GSN
AGb
Um
CCU
CCUPCU
BTS BSC GSN
B
CCUPCU
BTS BSC GSN
C
Abis
Gb
Gb
Internal Use28
Position of Huawei PCUPosition of Huawei PCU
CCU
CCU
BSCBTS
SGSN
Um
Abis
GbBSC
Pb
CCU
CCU
PCU
BTS
Internal Use29
GPRS(BSS side) upgrade to EDGEGPRS(BSS side) upgrade to EDGE
Upgrade BSC software
Upgrade PCU software
upgrade BTS software
Internal Use30
GPRS shares GSM database resources
Databases software upgrades required to accommodate new GPRS
functionality and parameters when interacting with GSM.
EIR/AuC will also require software upgrades for GPRS-specific
authentication/authorization
DATA BASES-VLR/HLRDATA BASES-VLR/HLR
Internal Use31
SGSN “ Packet Switching MSC – delivers packets to and received
packets from MTs
SGSN sends queries to HLR to obtain profile data of GPRS
subscribers.
An SGSN detects new GPRS in its service area, process registration
and authentication and manages ciphering between MTs and SGSN.
It also performs Mobility Management Functions i.e. GPRS location
Area (LA), attach and detach.
Serving GPRS Support Node SGSNServing GPRS Support Node SGSN
Internal Use32
Interface between GPRS back bone and external PDNs such as
the IP-based internet and X.25 networks.
The GGSN also translate between data formats , signaling
protocols and address information between the GPRS network
and differing external networks.
Address Mapping by using DNS
Supports multiple SGSNs
GGSNs maintain routing information
Gate Way GPRS Support Node (GGSN)Gate Way GPRS Support Node (GGSN)
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GPRS Coding SchemesGPRS Coding Schemes
33
CS-1
CS-2
CS-3
CS-4
Internal Use34
Functions of CGFunctions of CG
Real-time collection of GPRS bills
Temporary storage and buffering of GPRS bills
Pre-processing of GPRS bills
Sending GPRS bills to the billing center
Internal Use35
Functions of BGFunctions of BG
BG enables the following protocols necessary for interworking
between operators
Security protocol: IPSec and firewall are recommended
Routing protocol: BGP is recommended
Billing protocol: determined by the operators with negotiation; BG
might be needed in collecting billing information
It is normally based on routers
It can be configured in combination with GGSN
Internal Use36
Functions of MSC/VLRFunctions of MSC/VLR
When Gs interface is installed, MSC/VLR can support Establishment and maintenance of the association between
SGSN and MSC/VLR.
GPRS combined mobility management procedure.
Combined IMSI/GPRS attachment/detachment.
Combined location area/routing area updating.
Circuit paging coordination function.
The wireless resource usage can be greatly improved.
Internal Use37
Functions of HLR/AUCFunctions of HLR/AUC
Saving and updating GPRS subscriber subscription data
User authentication
Providing location/routing information and processing needed
in mobility management and routing, for example:
Saving and updating user service SGSN number and address
GPRS user location deletion indication
Whether MS is reachable.
Subscriber tracing (optional)
Internal Use38
Functions of SMS-GMSC/SMS-IWMSCFunctions of SMS-GMSC/SMS-IWMSC
After Gd interface is installed, short messages can be sent via
GPRS, which reduces the occupation on SDCCH and cuts
down the influence on voice services by SMS services.
The operator can select to send SMS via MSC or SGSN.
Internal Use
EDGEEDGE
39
EDGE can also be known as extended version of GPRS therefore it is also called EGPRS.
EDGE is standardized by 3GPP as part of the GSM family, and it is an upgrade that provides more than three-fold increase in both the capacity and performance of GSM/GPRS networks.
introducing sophisticated methods of coding and transmitting data, delivering higher bit-rates per radio channel.
EDGE can be used for any packet switched application, such as an Internet connection. EDGE-delivered data services create a broadband internet-like experience for the mobile phone user.
Internal Use40
High bandwidth data applications such as video services and other multimedia benefit from EGPRS' increased data capacity.
EDGE was deployed on GSM networks beginning in 2003.
EDGE/EGPRS is implemented as a bolt-on enhancement for 2G and 2.5G GSM and GPRS networks, making it easier for existing GSM carriers to upgrade to it
Internal Use41
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EDGE: TRANSMISSION TECHNIQUEEDGE: TRANSMISSION TECHNIQUE
42
In addition to Gaussian minimum-shift keying (GMSK), EDGE uses higher-order PSK/8 phase shift keying (8PSK) for the upper five of its nine modulation and coding schemes.
EDGE produces a 3-bit word for every change in carrier phase. This effectively triples the gross data rate offered by GSM. EDGE, like GPRS, uses a rate adaptation algorithm that adapts the modulation and coding scheme (MCS) according to the quality of the radio channel, and thus the bit rate and robustness of data transmission. This increases the probability of correct decoding.
EDGE can carry a bandwidth up to 236.8 kbit/s (with end-to-end latency of less than 150 ms) for 4 timeslots (theoretical maximum is 473.6 kbit/s for 8 timeslots) in packet mode. This means it can handle four times as much traffic as standard GPRS.
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EDGE modulation and coding scheme EDGE modulation and coding scheme (MCS)(MCS)
43
Coding and modulation
scheme (MCS)
Bit Rate (kbit/s/slot)
Modulation
MCS-1 8.80 GMSK
MCS-2 11.2 GMSK
MCS-3 14.8 GMSK
MCS-4 17.6 GMSK
MCS-5 22.4 8-PSK
MCS-6 29.6 8-PSK
MCS-7 44.8 8-PSK
MCS-8 54.4 8-PSK
MCS-9 59.2 8-PSK
EDGE is four times as efficient as GPRS. GPRS uses four coding schemes (CS-1 to 4) while EDGE uses nine Modulation and Coding Schemes (MCS-1 to 9).
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