Upload
benjamin-powers
View
222
Download
0
Embed Size (px)
DESCRIPTION
3 Introduction IEEE amendment is known as WiMAX The MAC layer architecture in WiMAX is designed to support multi-service flows Differentiates mainly four types of service classes: Unsolicited Grant Service (UGS) real-time Polling Service (rtPS) non-real time Polling Service (nrtPS) Best Effort (BE)
Citation preview
Applying a Self-Configuring Admission Control Applying a Self-Configuring Admission Control Algorithm in a New QoS Architecture for IEEE Algorithm in a New QoS Architecture for IEEE
802.16 Networks802.16 Networks
Sahar Ghazal1, Yassine Hadjadj Aout2, Jalel Ben Othman1, Farid Nait-Abdesselam2
1 PRiSM- CNRS UMR 8144 2 LIFL - IRCICA - CNRS UMR 8022
ISCC 2008
2
IntroductionIntroduction Introduction Related Work A New Distributed QoS Architecture for WiMAX Adaptive Fuzzy-based Admission Control Simulation and Results Conclusion
3
IntroductionIntroduction
IEEE 802.16-2004 amendment is known as WiMAX
The MAC layer architecture in WiMAX is designed to support multi-service flows
Differentiates mainly four types of service classes: • Unsolicited Grant Service (UGS)• real-time Polling Service (rtPS)• non-real time Polling Service (nrtPS)• Best Effort (BE)
4
Related WorkRelated Work
The IEEE 802.16 standard defines the basic QoS architecture described in Fig 1
5
Related WorkRelated Work
WiMAX protocol is connection oriented• establish a connection
• Dynamic Service Add (DSA)• Dynamic Service Change (DSC)
Two parameters are used when admitting a connection:• the minimum reserved traffic rate• the maximum sustained traffic rate
6
Related WorkRelated Work UGS
• max_sustained_rate
rtPS• min_reserved_rate• max_sustained_rate
nrtPS• min_reserved_rate
BE
7
Related WorkRelated Work
didn't give any details about the admission control algorithm to be applied
based on static resource management and don't consider the real nature of WiMAX networks
8
A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX
9
A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX A. SS QoS Architecture
• Traffic Policing
• SS Uplink Packet Scheduler (SS-ULPS)• 1.Traffic class are scheduled by priority order• 2.connections within the same class of service are scheduled
using perdefined scheduling algorithm
• Queue Manager• Loss ratio(LR) and queue length are recorded for each class o
f service• Queue manager sends those value to BS by Q-Stat message
10
A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX B. BS QoS Architecture
• BS Downlink Packet Scheduler (BS-DLPS)• don’t schedule connections by CID
• BS Uplink Packet Scheduler (BS-ULPS)• connections are scheduled by class of service only
• Queue manager
11
A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX B. BS QoS Architecture
• Bandwidth Allocation Module• Two function
• retrieves bandwidth requirement information of a connection from the queue manager in the BS ULPS module
• send UL-MAP to SS
• Connection Classifier• The connections should be classified for a second
time in the BS
12
A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX B. BS QoS Architecture
• Bandwidth Manager• the SS requests a new connection• records the real-time available bandwidth
• BWAv : available bandwidth• BWTot : the total bandwidth• BWTr : the total reserved bandwidth
• Admission Control module• Our objective is to admit the maximum number of connection
s with their QoS requirements while maintaining the QoS of those already running
13
A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX B. BS QoS Architecture
• Admission Control module• admit the maximum number of connections with their Qo
S requirements • while maintaining the QoS of those already running
• -UL Manager: • Loss ratio (LR), queue length, a bandwidth size, are aggre
gated per SS, and sent to uplink admission contorl
• -Downlink Manager• Loss ratio is recorded by class of service and not for the w
hole SS
14
A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX B. BS QoS Architecture
• Admission Control module (Continue)• -Uplink Admission Control (ULAC):
• Available bandwidth on the UL sub-frame
• -Downlink Admission Control (DLAC)• -Decision module
• ULAC: reject an incoming connectionwithout verifying the DLAC decision
• DLAC: reject the connectionreject it as well
• ULAC: accept the new incoming connectiondecision module will not admit the connectionalso admitted by DLAC
15
Adaptive Fuzzy-based Admission Adaptive Fuzzy-based Admission ControlControl
The blocking probability is determined empirically except for value 0(smallest) and 8(largest)
16
Adaptive Fuzzy-based Admission Adaptive Fuzzy-based Admission ControlControl
x1 = qi-qref
x2: represents the error variation which can be interpreted as prediction horizon
17
Adaptive Fuzzy-based Admission Adaptive Fuzzy-based Admission ControlControl
18
Simulation and ResultsSimulation and Results
Software: OPNET 11.5 One BS
• Buffer size set to 500 packets Three SSs
• 25 clients behind each SS• rtPS and nrtPS
19
Simulation and ResultsSimulation and Results
20
Simulation and ResultsSimulation and Results
21
Simulation and ResultsSimulation and Results
22
Simulation and ResultsSimulation and Results
23
ConclusionConclusion
This paper proposed a new QoS architecture that completes the missed modules and functions in the existing QoS architecture of the IEEE 802.16 standard
Simulation results validate the proposed QoS architecture and showed that • rtPS flows are blocked only in imminent congestion• while nrtPS flows are blocked in order to maintain the
network free from congestions.