One of the major challenges in the context of transmitting real-time multimedia data in broadband wireless access (BWA) systems is that the varied bit rate of traffic causes low bandwidth utilization. The conventional uplink scheduling algorithms for variable bit rate (VBR) video traffic transmission in IEEE 802.16 BWA systems have some disadvantages, including waste of uplink bandwidth, MAC overhead, and access delay. To cope with these difficulties, we propose an uplink scheduling algorithm for VBR traffic transmission for IEEE 802.16 BWA systems. In the proposed algorithm, the base station (BS) assigns uplink bandwidth to the video user by considering the traffic state transitions. The uplink bandwidth is equally divided into several intervals where each interval represents a traffic state. Only when the traffic state is changed, the bandwidth request process is incurred. Also, by using two reserved bits in the generic MAC header of IEEE 802.16 BWA systems as piggyback bits, the information about traffic state transition can be sent to the BS without extra overhead. Simulations conducted with QualNet 4.0 show that the bandwidth waste ratio of our proposed algorithm is less than that of the conventional algorithms. That is, the proposed algorithm outperforms the conventional algorithms for VBR traffic transmission in IEEE 802.16 BWA systems in terms of bandwidth utilization.
All Science Journal Classification (ASJC) codes
- Computer Networks and Communications
- Electrical and Electronic Engineering