Multiple access control protocols based on priority service in multimedia WCDMA systems

Abstract

In this dissertation, we propose multiple access control protocols to support voice, data, and video services in wideband code division multiple access (WCDMA) systems. First, we propose an access control scheme with permission probability for common packet channel (CPCH) access procedure. The proposed scheme is based on the channel assignment (CA) scheme early proposed in 3rd Generation Partnership Project (3GPP). The CA scheme maximizes the efficient use of resource but has the problem that uplink interference increases excessively under high-loading conditions, since the number of unnecessary requests increases. How-ever, the proposed scheme provides high throughput, even under high-loading conditions, since the access control algorithm based on channel load prohibits excessive interference. The proposed scheme is analyzed taking multiple access interference into consideration and is compared with the basic (BA) scheme, the channel monitoring (CM) scheme, and the CA scheme, early proposed in 3GPP. Second, we propose an access control scheme with preemption for integrated voice/data services over CPCH. In the proposed scheme, to satisfy the quality of service of voice communications, the base station preempts data transmissions. Therefore, the failure rate in code assignment to voice users is expected to be reduced while the mean data message delay increases. We analyze the proposed scheme and compare its performance with the BA, CM, and CA scheme, in view of the voice packet dropping probability and the average delay of data packet. Finally, we propose access control protocols for integrated voice/data/video CDMA systems with nontransparent data services such as e-mail, file transfer, store-and-forward facsimile, etc. In order to offer multimedia services with different bit rate and quality of service, the total system interference should be below a certain level by scheduling the non-real time data transmissions. To schedule data packet transmissions in slo...