Single code multiple access for the broadband satellite return channel

Future broadband satellite access networks will provide user connectivity via a return channel from a centralized hub. The forward channel can be embedded into the broadcast channel yielding asymmetric bandwidth ratios of 10:1 or greater. To meet such a bandwidth asymmetry as well as the required quality of service, QoS, selection of multiple access and media access control protocols plays a significant role among other design issues. In most of the recent satellite access networks, the forward traffic is broadcasted to satellite interactive terminals (SITs) using the ETSI specified DVB-S protocol. For the return channel multiple access protocol, options based on multi-frequency time division multiple access (MF-TDMA), code division multiple access (CDMA) and random multiple access (RMA) are available. We present a comparative overview of connection- and contention-oriented multiple access and focus on the use of spread ALOHA by using one single long code.