Near optimal fair delay based resource allocation for video traffic over wireless multimedia system M.R.M. Rizk a , M.I. Dessouky b , Sami A. El-Dolil b , Mohammed Abd-Elnaby b, * a Department of Electrical Engineering, Faculty of Engineering, Alexandria University, Alexandria, Egypt b Department of Electrical Communication, Faculty of Electronic Engineering, Menoufia University, B.O. Box 32952, Menouf, Egypt article info Article history: Received 24 April 2007 Received in revised form 23 February 2008 Accepted 23 February 2008 Available online 29 February 2008 Keywords: Wireless resource allocation MAC protocol Quality of service (QoS) Multimedia abstract The major issue related to the realization of wireless multimedia system is the design of suitable medium access control (MAC) protocol. The design challenge is to maximize the utilization of the limited wireless resources while guaranteeing the various quality of service requirements for all traffic classes especially for the stringent real-time constraint of real-time variable bit rate (rt-VBR) video service. In this paper a novel resource allocation algorithm for video traffic is proposed. The proposed allocation algorithm aims to provide fair delay for video packets by minimizing the delay difference among transmitted video pack- ets. At the same time it adaptively controls the allocated resources (bandwidth) for video traffic around the corresponding average bit rate, and has the ability of controlling the quality of service (QoS) offered for video traffic in terms of packet loss probability and average delay. A minimized control overhead of only two bits is needed to increase the utilization efficiency. Simulation results show that the proposed algorithm achieves very high utilization and provides nearly fair delay among video packets. Its efficiency is also investigated under traffic integration condition with voice and data traffic to show that the QoS offered to video traffic does not change in the presence of the highest priority voice traffic while data traf- fic increases the channel utilization to 98% by using the remaining bandwidth after voice and video traffic while a good QoS is offered to voice and data traffic. Ó 2008 Elsevier B.V. All rights reserved. 1. Introduction In wireless multimedia system, the medium access control (MAC) protocol should play a central role in providing a statisti- cally multiplexing capability over the wireless access interface and maximizing the utilization of limited wireless resources. Its design objective is to maximize the multiplexing gain over the wireless interface while guaranteeing the various QoS require- ments for all multimedia traffic classes, especially for the stringent real-time constraint of real-time variable bit rate (rt-VBR) video service [1]. The dynamic slot assignment become essential for achieving the statistically multiplexing gain among the various types of ser- vice classes with different traffic characteristics and has been rec- ognized as a useful choice for the variable bit rate (VBR) traffic class, since it simply serves to coordinate the varying traffic de- mands among the independent and spatially distributed wireless terminals [2–4]. Existing MAC protocols are typically involved with an excessive overhead to transmit the buffer state information, e.g., instanta- neous queue length, residual lifetime, or packet arrival rate as the dynamic parameter in a timely accurate manner. Two different types of access schemes are used to transfer the dynamic parame- ter information from the individual distributed wireless terminals to the access point: contention-based and contention less (conten- tion-free) schemes. In the contention-based scheme [5–8] reducing the collision probability and the size of control packet is necessary to reduce wastage of bandwidth in case of collision. On the other hand, the contention-free scheme [9–12] is based on either a piggyback mechanism, which piggybacks the dynamic parameters on the up- link data burst, or polling mechanism, which dynamically assigns an uplink dedicated slot for transferring the dynamic parameters. The piggybacking overhead should be minimized and the polling period should be efficiently adjusted to reduce the wastage of bandwidth. The dynamic reservation TDMA (DR-TDMA) protocol proposed in [8] is one of the most complete and efficient allocation algo- rithms for multimedia traffic over wireless ATM networks. These include, in particular, an efficient rate-based allocation algorithm for variable bit rate (VBR) video traffic, which incorporates a rate 0140-3664/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.comcom.2008.02.020 * Corresponding author. Tel.: +20 483677453; fax: +20 483661334. E-mail addresses: mrmrizk@ieee.org (M.R.M. Rizk), dr_moawad@yahoo.com (M.I. Dessouky), msel_dolil@yahoo.com (S.A. El-Dolil), moh_naby@yahoo.com (M. Abd-Elnaby). Computer Communications 31 (2008) 2360–2366 Contents lists available at ScienceDirect Computer Communications journal homepage: www.elsevier.com/locate/comcom