Change detection mechanism in feedback implosion suppression algorithm for reliable transmission of multicast data over geostationary satellite network

In this paper, we propose a channel change detection mechanism implemented at UE to support feedback implosion suppression algorithm for reliable transmission of multicast data over GEO satellite networks. In this framework, reliability is guaranteed via MFTP that retransmits lost segments to the multicast group. A channel-aware scheduling mechanism is used at the Gateway that behaves like a switch to allow downlink transmissions of MFTP packets. The scheduler uses CSI values collected from group members through the CSI collection policy before making a decision as to whether or not to transmit a multicast packet in the forward link. As such, the scheduling algorithm aims at avoiding unfavorable channel conditions to reduce the forward link resources that would be wasted for retransmissions and to allow downlink transmissions only when users are in good channel condition, in the face of L-band mobile satellite channel conditions. The integration of channel-aware scheduling algorithm and CSI collection policy aims to reduce session duration and traffic volume in the return link by updating only relevant information back to Gateway. In order to achieve this objective, change detection mechanism is proposed. The performance parameters such as change detection rate and downlink resource utilization are analyzed. Two change detection algorithms are compared; it is shown that there is a trade-off in performance, in particular between uplink signalling load and downlink resource utilization. The work presented in this paper is executed within IST SatNEx II (EU IST FP6 - Contract No. 027393), JA2330 "Radio Resource Allocation and Adaptation" activity. Copyright © 2008 by Aduwati Sali.