Delay Performance of Enhanced Access Channel in 1xEV-DO Revision A System

In CDMA 1xEV-DO Revision A system, an enhanced access channel (EAC) with multiple transmission data rates is introduced with improved access performance for the general usage of connection setup. Data Over Signaling (DOS) protocol, also introduced in DO Rev. A, allows an access terminal to send short user data messages over the EAC on the reverse link. DOS is useful for delay sensitive applications such as the call setup messages for push-to-talk and VoIP services. In this paper, we investigate the performance of EAC using both analytical and simulation models. In particular, the delay performance of DOS using the EAC with different data rates and message sizes is analyzed and compared. It is shown that the analytical and simulation results match very well. Furthermore, we propose a method for selecting access channel and traffic channel for transmitting data traffic. The proposed method takes better advantage of DOS for reduced latency and also improves the RF coverage.