Quasi-dedicated access scheme for uplink realtime services in future wireless communication systems

Recently, the uplink contention-free access schemes have been being considered in systems proposed for BWA (Broadband Wireless Access). The assignment of dedicated channels for contention-free access limits the number of users, and the polling service requires some downlink resources for the transmission of polling information. So, both the assignment of dedicated channels and polling service are inadequate to the realtime service with long inter-packet time. In this paper, we propose a concept of the QDA (Quasi-Dedicated Access) which is rather the concept of "mapping and stealing" than the concept of "assignment", and show that this QDA scheme is very adequate to a variety of future uplink realtime services such as VoIP, VoD and video gaming, through computer simulation. Moreover, we introduce the heuristic suboptimal QDCCH (Quasi-dedicated control channel)-stealing ordering scheme which meets access delay bound and can utilize uplink resources flexibly.