An uplink CDMA system architecture with diverse QoS guarantees for heterogeneous traffic

The uplink access control problems for cellular code-division multiple-acce ss (CDMA) systems that service heterogeneous traffic with various types of quality-of-service (QoS) and use multicode CDMA to support variable bit rat es are addressed. Considering its distinct QoS requirements, class-I real-t ime traffic (e.g., voice and video) is differentiated from class-II non-rea l-time traffic (e.g., data). Connection-oriented transmission is achieved b y assigning mobile-oriented code channels for class-I traffic, where each c orresponding mobile needs to pass an admission test. Class-II traffic is tr ansmitted in a best-effort manner through a transmission-rate request acces s scheme which utilizes the bandwidth left unused by class-I traffic. Whene ver a mobile has class-II messages to transmit, the mobile requests code ch annels via a base station-oriented transmission-request code channel, then, according to the base station scheduling, the transmission is scheduled an d permitted. Addressed are the admission test for class-I connections, tran smission power allocation, and how to maximize the aggregate throughput for class-II traffic. The admission region of voice and video connections and the optimum target signal-to-interference ratio of class-II traffic are der ived numerically. The performance of class-II traffic transmissions in term s of average delay is also evaluated and discussed.