Advances in Random Access Protocols for Satellite Networks

In this paper we review key properties of recently proposed high performance protocols for Random Access (RA) satellite channels for both Time Division and Code Division Multiple Access (TDMA/CDMA) techniques. The proposed protocols by far outperform traditional satellite random access techniques without the need for quick feedback from the gateway. This makes possible to avoid the utilization of demand assigned capacity for the transmission of small/medium size bursts of packets. A fair comparative performance of state-of-the-art TDMA and CDMA RA schemes is provided together with a summary of their key performance results. It is shown that the proposed enhanced RA protocols, although different between TDMA and CDMA, share commonalities as they exploit iterative interference cancellation at the demodulator side and demonstrate to provide even better performance in the presence of received carrier power unbalance. Typical application scenarios of these enhanced random access protocols are then illustrated, as well as possible ways to combine random access and demand assigned protocols.