Performance comparisons of two retransmission protocols for CDMA

We describe a new radio link protocol for CDMA IS-95 circuit-mode data. This protocol, (Protocol S), relies on a single level of recovery and uses a flexible segmentation and recovery (FSAR) sublayer to efficiently pack data frames into physical layer bursts. We next describe Protocol T, that consists of two levels of recovery and compare the performance of Protocol T with Protocol S. Protocol T has been standardized for CDMA circuit-mode data as IS-99. We find that the complexity of the two level recovery mechanism buys higher throughput through reduced overhead. However, the choice of TCP (and its associated congestion control mechanism) as the upper layer of recovery on the link layer, leads to long fade recovery times for Protocol T.