Performance Analysis of the IEEE 802.16 Wireless Metropolitan Area Network

nmgmt.cs.nchu.edu.tw

系統暨網路管理實驗室 Systems & Network Management Lab

Reporter：黃文帥2007/12/4

Proceeding of the First International Conference on Distributed Frameworks for Multimedia Applications (DFMA’05)

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Outline

Introduction1

Proposed QoS Architecture2

Simulation3

Conclusion4

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Introduction

Broadband Wireless Access

IEEE 802.16• Fast deployment.

• Cost saving.

• Support QoS.

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Introduction

Quality of Service

BWA systems are expected to support QoS for real time applications.

IEEE 802.16 standard doesn’t define the QoS based packet-scheduling algorithms.

This paper proposes an efficient QoS architecture, base on priority scheduling and dynamic bandwidth allocation.

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Introduction

Quality of Service

IEEE 802.16 defines four QoS services.• Unsolicited Grant Service (UGS).

• Real-Time Polling Service (rtPS).

• Non-Real-Time Polling Service (nrtPS).

• Best Effort (BE).

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Introduction

Quality of Service

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Introduction

Quality of Service

IEEE 802.16 defines:• The signaling mechanism for information exchange

between BS and SS.

• The uplink scheduling for UGS service flow.

IEEE 802.16 doesn’t define:• The uplink scheduling for rtPS, nrtPS, BE service flow.

• The admission control.

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Proposed QoS Architecture

Modification

At the BS:• Add a detailed description of the Uplink Bandwidth

Allocation Scheduling part.

• Admission Control part

At the SS:• Add a traffic management module.

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Proposed QoS Architecture

Modification

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Proposed QoS Architecture

Connection establishment

Before establish connection:• SS set connection request to BS.

• Admission control part of the BS decides to accept or reject.

• BS provide necessary information to SS.

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Proposed QoS Architecture

Connection establishment

After establish connection:• Enforce the traffic on the contract.

• BS update the traffic management table.

• BS generate UL-MAP in downlink subframe.

• SS transmits packets according to the UL-MAP.

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Proposed QoS Architecture

Uplink Scheduler of SS

For rtPS connection, SS transmits UGS packet to append virtual packet arrival time of rtPS.

Data Packet Analysis Module (DPAM) can find the rtPS deadline information.

BS can determine order of Poll based on deadline information.

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Proposed QoS Architecture

Uplink Scheduler of SS

The nrtPS uses either contention-free or contention mode.

The BE uses only contention mode.

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Proposed QoS Architecture

Uplink BandwidthAllocation Scheduling

DPAM of BS separates UGS data and virtual packets arrival time of rtPS.

Traffic Management Module manages the information to decide the Poll order of next time.

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Proposed QoS Architecture

Analytical model forchannel utilization

Assume k classes of priority queues.

Arrival events are mutual independent.

Let C denote the server capacity and channel utilization for each class i.

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Proposed QoS Architecture

Analytical model forchannel utilization

λk is offered load for class k.

E[τk] is the average service time for class k.

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Simulation

The simulation model

The system model consists one BS and numbers of SSs.

Several assumptions have been made to reduce the complexity of the simulation model.

• The effects of propagation delay are neglected.

• The channel is error-free.

• The BS has the ability to detect collision.

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Simulation

The simulation model

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Simulation

Results

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Simulation

Results

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Conclusion

In this paper authors proposed a new QoS architecture for IEEE 802.16 BWA MAC protocol.

The simulation results show that architecture may provide QoS support for all type of traffic classes.