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

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IntroductionIntroduction Introduction Related Work A New Distributed QoS Architecture for WiMAX Adaptive Fuzzy-based Admission Control Simulation and Results Conclusion

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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)

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Related WorkRelated Work

The IEEE 802.16 standard defines the basic QoS architecture described in Fig 1

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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

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Related WorkRelated Work UGS

• max_sustained_rate

rtPS• min_reserved_rate• max_sustained_rate

nrtPS• min_reserved_rate

BE

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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

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A New Distributed QoS Architecture for WiMAXA New Distributed QoS Architecture for WiMAX

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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

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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

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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

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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

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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

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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

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Adaptive Fuzzy-based Admission Adaptive Fuzzy-based Admission ControlControl

The blocking probability is determined empirically except for value 0(smallest) and 8(largest)

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Adaptive Fuzzy-based Admission Adaptive Fuzzy-based Admission ControlControl

x1 = qi-qref

x2: represents the error variation which can be interpreted as prediction horizon

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Adaptive Fuzzy-based Admission Adaptive Fuzzy-based Admission ControlControl

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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

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Simulation and ResultsSimulation and Results

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Simulation and ResultsSimulation and Results

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Simulation and ResultsSimulation and Results

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Simulation and ResultsSimulation and Results

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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.