A Novel Resource Allocation Technique for VBR Video Traffic in the Uplink over WiMAX Networks

WiMAX cellular packet networks have become an attractive solution for many applications these days. One of the main reasons for that, is the QoS support that WiMAX provides. An important part of the WiMAX QoS framework is the scheduling services defined for different types of traffic and the uplink BW allocation mechanism associated with these scheduling services. These 5 uplink scheduling mechanisms are unsolicited grant services (UGS), real-time polling service (rtPS), non-real-time polling service (nrtPS), best effort (BE), in IEEE 802.16d/e and extended real-time polling service (ertPS) in IEEE 802.16e. In this paper, since we study video VBR traffic we are concerned with scheduling algorithms for VBR traffic only, i.e. rtPS and ertPS. There are problems with rtPS and ertPS, which are mainly scheduling MAC overhead and access delay, therefore,we propose a novel uplink resource allocation technique for VBR video traffic that overcomes these problems besides a node scheduler for video traffic that collaborates with it. We will explain why ertPS is suitable only for VBR VoIP but not video. We also give detailed analysis for the operation of our scheme versus rtPS and show with the aid of simulation that our algorithm performs better in terms of overhead, resource utilization and packet loss factor.