A code assignment scheme for CDMA wireless networks with integrated voice and data traffic

Wireless personal communication requires provision of integrated services of multimedia traffic, such as voice and data, over the radio link. Multiple-access protocols with CDMA have been widely investigated in the recent literature. This paper presents a code assignment scheme for CDMA broadband wireless networks with the integration of voice and data traffic. In our scheme, a voice terminal can reserve a spreading code to transmit packets in multiple talk spurts, while a data terminal can transmit packets by either using the unassigned codes or borrowing the codes from the voice terminals during their silent periods. We build two mathematical models for voice and data subsystems, respectively. Two performance parameters, the average dropping probability for voice packets and the average transmission delay for data packets, are derived based on the equilibrium point analysis (EPA). System performance is discussed by varying the code reservation intervals of voice terminals and it is shown that both dropping probability of voice packets and the transmission delay of data packets can be significantly reduced.