Multi-access protocols for wireless multimedia networks

Abstract

This thesis is concerned with multi-access protocols for the third generation mul-timedia wireless personal communication systems (PCS) employing slotted packet code division multiple access (CDMA). First, a protocol is proposed for the in-tegrated voice/data services. The concept of dynamic boundary is adopted in both code and time domains to meet the different requirements of voice and data services. Three channel assignment policies, Horizontal Assignment (HA), Opti-mal Assignment (OA) and Dynamic Assignment (DA) are outlined and compared. A discrete-event simulation and two mathematical methods, namely, Traditional Markov Analysis (TMA) and Transient Fluid Analysis (TFA) are adopted to eval-uate the system performance. The results show that TMA can only be used when the number of voice and data packets that can be accommodated in a frame is small, while TFA does not have such a problem. The results also indicate that an improved performance can be achieved by introducing Dynamic Boundary Scheme(DBS), in which the DA policy, which is easier to be implemented, results in a performance close to the optimal value. Then, the above protocol is extended for the integrated videophone/voice/data services network. The performance is evaluated by both TMA and TFA methods. Suggestions are given to choose the suitable boundaries so as to achieve the desired quality of services.