New Contention Resolution Schemes for WiMAX

Abstract

Abstract-The use of Broadband Wireless Access (BWA) technology is increasing due to the use of Internet and multimedia applications with strict requirements of end-to-end delay and jitter, through wireless devices. The IEEE 802.16 standard, which defines the physical (PHY) and the medium access control (MAC) layers, is one of the BWA standards. Its MAC layer is centralized basis, where the Base Station (BS) is responsible for assigning the needed bandwidth for each Subscriber Station (SS), which requests bandwidth competing between all of them. The standard defines a contention resolution process to resolve the potential occurrence of collisions during the requesting process. In this paper, we propose to modify the contention resolution process to improve the network performance, including end-to-end delay and throughput.

Modeling and optimization of bandwidth request procedure in IEEE 802.16 networks

“…The work [11] presents decision algorithms for scheduling in the base station that optimize either the delay or the bandwidth utilization, but not both of them simultaneously. A modified contention-resolution procedure that distinguishes between the priorities of the different scheduling classes is proposed in [12], yielding to the improvement of their end-toend delays and throughputs.…”

A Study of Bandwidth-Perception Management Mechanisms in IEEE 802.16 Networks

“…To reduce the number of collisions, Delicado et al [13] propose to independently adapt the contention windows (CW) of the SSs. As an extension to the standard, each connection sends its BW-REQs in an adapted (fairly constant) number of frames once the SS finds the adequate size of the CW (i.e., by exponentially increasing the CW).…”