@conference {
	title = {Return Channel Performance Evaluation of Enhanced SAMA VSAT with FMCSA and ACM Capability},
	author = {Perumal, Senni., Baras, John S., Roy-Chowdhury, Ayan., Petluri, Hemant S., Robinson, Mitch.},
	year = {2011},
	month = {10/2011},
	abstract = {In this paper, we describe our work on developing and evaluating detailed OPNET simulation models of an enhanced Very Small Aperture Terminal (VSAT) satellite Internet gateway and an enhanced satellite hub based on Cerona SkySPAN technology with capacity and latency optimizations in the return channel so as to allow significantly higher number of users and a better user experience. The Cerona SkySPAN technology uses Digital Video Broadcast via Satellite 2nd standard (DVB-S2) in the forward channel and Spread Aloha Multiple Access (SAMA) protocol in the return channel. We augment the SAMA return channel protocol with Fast Multi-Channel Slotted Aloha (FMCSA) protocol and Adaptive Coding and Modulation (ACM). FMCSA combines Multi-Channel Slotted Aloha (MCSA) with packet level forward error correction (FEC) for new messages and scheduled retransmissions for partially received messages. This protocol increases the maximum possible throughput of SAMA, thus supporting higher number of users. FMCSA also reduces the delay of multi-slot short messages (e.g., HTTP requests) while providing more robust delay performance with respect to load fluctuations, thus resulting in a better user experience. We incorporate Adaptive Coding and Modulation in the return channel in order to automatically adapt the coding and modulation to changing channel conditions so as to ensure remote data service irrespective of the channel degradation due to interference, rain fade or other conditions. We show via OPNET simulations that the enhanced SAMA VSAT with FMCSA and ACM improves the throughput, latency and robustness of the SkySPAN SAMA system. We also compare, via OPNET simulations, the enhanced SAMA system (with FMCSA and ACM) with a DVBRCS system to show improvements in user experience.},
	address = {Palermo, Italy},
	booktitle = {17th Ka and Broadband Communications, Navigation and Earth Observation Conference},
	pages = {pp. 417-424}
}
@conference {
	title = {VSAT return Channel Optimizations for Broadband Internet Support in 2-Way Satellite Networks},
	author = {Roy-Chowdhury, Ayan., Baras, John S., Robinson, Mitch.},
	year = {2010},
	month = {10/2010},
	abstract = {In this paper we describe our work on a Very Small Aperture Terminal (VSAT) satellite Internet gateway with capacity and latency optimizations in the return channel so as to allow significantly higher number of users, and a better user experience. The gateway is based on the Cerona SkySPAN technology which uses the Digital Video Broadcast via Satellite 2nd standard (DVB-S2) in the forward channel, and single-channel slotted Aloha protocol in the return channel. In this paper we describe the Spread Aloha Multiple Access (SAMA) protocol which we implement in the return channel. The SAMA protocol promises to deliver high speeds at a third of the latency compared to competing technologies like DVB-RCS (multi-frequency TDMA), while allowing the same number of users in 3MHz bandwidth as is possible in TDMA using 36MHz. We also describe the implementation of the Fast Multi-channel Slotted Aloha (FMCSA) protocol that will co-exist with SAMA in the return channel. FMCSA combines slotted Aloha random access with packet level forward error correction (FEC) for new messages and scheduled retransmissions for partially received messages. Due to the parity packets sent in FMCSA, more load is offered to the channel than in SAMA to achieve the same throughput. The delay performance of FMCSA is also much more robust to load fluctuations than SAMA. The combination of SAMA and FMCSA improves the robustness and throughput of the SkySPAN return channel and reduces the channel latency, while supporting significantly higher number of users, in comparison to the competition.},
	address = {Milan, Italy},
	booktitle = {16th Ka and Broadband Communications Conference},
	pages = {pp. 479-486}
}
