RLC protocol enhancement for SIP-based session establishment over satellite-UMTS

Session initiation protocol (SIP) has been selected as the official end-to-end IP signalling protocol for establishing multimedia sessions in the IP-based universal mobile telecommunication systems (UMTS) network. Since a satellite component has been identified within UMTS, there is a need also to support SIP-based session establishment over satellite-UMTS (S-UMTS) to achieve an end-to-end seamless IP-based terrestrial/satellite network integration. To improve the session setup performance, a link layer retransmission based on the radio link control acknowledgement mode (RLC-AM) mechanisms is utilised. However the current RLC-AM procedure is found to be inefficient when applied to transactional-based applications such as session establishment. As such this paper proposes a scheme to alleviate this inefficiency and simulation results reveal that this scheme achieves a good compromise between delay and radio resource utilization under various channel conditions.