JOURNAL OF COMMUNICATIONS (JCM)
ISSN : 1796-2021
Volume : 4    Issue : 2    Date : March 2009

Uplink Scheduling Algorithms for QoS Support in Broadband Wireless Access Networks
Mikael Gidlund and Gang Wang
Page(s): 133-142
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Abstract
In order to support different types of multimedia applications, the IEEE 802.16 standard defines
different service classes with their associated Quality of Service (QoS) parameters. The scheduling
algorithm is the crucial point in QoS provisioning over such broadband wireless access (BWA)
network and it is important that the scheduling algorithm have a multi-dimensional objective of
satisfying QoS requirements of the users, maximizing system utilization and ensuring fairness
among users. In this article we present two different scheduling algorithms for the uplink (UL)
connection. One is a combination of legacy scheduling algorithms earliest deadline first (EDF) and
weighted fair queuing (WFQ). The other proposed algorithm is a cross-layer algorithm that pledges
fairness among admitted connections and it also supports all service classes. The proposed
scheduling algorithms are compared to several other scheduling algorithms for UL traffic under
different mixes of traffic and for various characteristics of the IEEE 802.16 MAC layer such as UL
burst preamble, frame length and bandwidth request mechanisms. Simulation results indicate that
legacy scheduling algorithms are not suitable for the multi-class traffic in IEEE 802.16 since they do
not explicitly incorporate the QoS parameters for the given standard.

Index Terms
IEEE 802.16, MAC, scheduling, QoS, fairness, delay.