@conference {
	title = {A Multichannel Random Access Protocol for Multislot Short Messages with Delay Constraints},
	author = {Zhou, Xiaoming., Baras, John S.},
	year = {2005},
	month = {03/2005},
	abstract = {A multichannel random access protocol called FMCSA for multislot short messages is proposed in this paper to be used in access networks with large propagation delay. This protocol combines random access with the use of packet level forward error correction coding for new messages and scheduled retransmissions for partially received messages. Analytical and simulation results show that FMCSA can achieve a higher throughput and lower delay than slotted Aloha. When the system is operating in the low load region, the short messages can be delivered in their first attempts with very high probability. With the load increasing, more messages will be received partially in their first attempts and the scheduled retransmission scheme will guarantee the partially received messages to be recovered in their second attempts. Therefore the delay performance of FMCSA is much more robust to the load fluctuation than slot Aloha.},
	address = {Miami, Florida},
	booktitle = {INFOCOM 2005}
}
@conference {
	title = {Adaptive Hierarchical Resource Management for the Hybrid network of MANET-Satellite Internet},
	author = {Liu, Nelson X., Zhou, Xiaoming., Baras, John S.},
	year = {2004},
	month = {09/2004},
	abstract = {MANETs are often deployed in an infrastructure-less or hostile region where the satellite provides the only link for the MANETs to communicate with the rest part of the world. It faces many challenges to support multiple serviced communications between MANETs and Internet through satellite. In this paper we propose an efficient resource management scheme called AHRM to dynamically allocate bandwidths among multiple MANET users and multiple priority and non-priority services sharing a multi-access satellite channel. It uses a flexible hierarchical structure to exploit the channel utility and resolve contention from two levels. A bandwidth adaptation algorithm is designed to adjust the allocation dynamically in response to traffic and link status changes. The algorithm turns out to be in line with reinforcement learning and is a customized version of it for the practical satellite network setting. Implementation issues are discussed. Simulation results are presented, showing that the scheme can guarantee fast delivery of critical messages in spite of channel contention, and significantly improve the performance of multiple services.},
	address = {Los Angeles, California},
	booktitle = {2004 IEEE Vehicular Technology Conference},
	pages = {pp. 4027-4031}
}
@conference {
	title = {Web Access Over a Multiple Access Channel: Evaluations and Improvements},
	author = {Zhou, Xiaoming., Liu, Nelson X., Baras, John S.},
	year = {2004},
	month = {06/2004},
	abstract = {We evaluate Web browsing performance over a multiple access satellite channel for three different MAC layer protocols. A Web user behavior model is used to generate realistic source traffic. A new transport layer protocol called RWBP is proposed to solve the TCP problems inside satellite networks. RWBP uses per-flow queuing, round robin scheduling and receiver window backpressure for congestion control. We compare its performance with TCP over the three multiple access protocols. Our simulation results show that RWBP can reduce the multiple access channel load and at the same time improve the Web page response time when driven by realistic Web traffic. For the MAC layer protocols, combined free demand assignment multiple access (CFDAMA) always performs better than the other two protocols.},
	address = {Paris, France},
	booktitle = {2004 IEEE International Conference on Communications},
	pages = {pp. 4392-4396}
}
@conference {
	title = {TCP over GEO satellite hybrid networks},
	author = {Zhou, Xiaoming., Baras, John S.},
	year = {2002},
	month = {10/2002},
	abstract = {Broadcast satellite networks are going to play an important role in the global information infrastructure. Satellites can provide direct-to-user Internet services and as well as traffic trunks in the middle of the network. About 98\% of Internet traffic is TCP traffic. TCP works well in terrestrial fiber networks, but does not work well in satellite and in hybrid (satellite-terrestrial) networks. We analyze the problems that cause this degraded performance and review the solutions proposed in the literature. Because an end-to-end solution is difficult in the hybrid network, we propose a solution based on connection splitting. While much research has been done on improving TCP throughput for a single connection, we consider the case when multiple connections with different round trip times compete with each other. The crucial part of our scheme is the flow control algorithm at the hybrid gateways (i.e., the interfaces between the satellite and terrestrial networks). Because the end-to-end connection is split at the hybrid gateways, the data packets are buffered at the TCP layer rather than at the IP layer as in a normal router. Furthermore, the TCP layer not only buffers data waiting for transmission, but also buffers data transmitted but not yet acknowledged. The flow control algorithm should avoid stall caused by buffer exhaustion, guarantee fairness among all competing connections and maintain high utilization of the satellite link. A performance evaluation demonstrates that our scheme meets these requirements.},
	address = {Anaheim, CA},
	booktitle = {Military Communications Conference},
	pages = {pp. 29-34}
}
@techreport {
	title = {Interactive Data Services in Wireless Access Networks: Capacity Planning and Protocols},
	author = {Zhou, Xiaoming., Raissi-Dekhordi, Majid.},
	year = {2005},
	month = {01/2005},
	abstract = {In this paper, we study the capacity planning in wireless access network for interactive data services such as web browsing. A closed queuing model has been developed which can capture the bottleneck effects in both the forward and the reverse channels. The model can be used to calculate the average throughput, the average response time and the number of users the system can support. We evaluate the performance of several MAC protocols such as slotted Aloha, static TDMA, Aloha/periodic stream and combined free demand assignment multiple access (CFDAMA) using realistic web traffic models. Based on the performance evaluation, we propose a new MAC protocol and a new transport layer protocol. Our new MAC protocol called combined polling free demand assignment multiple access (CPFDAMA) explores the correlation between forward channel data packets and reverse channel acknowledgement packets. Our new transport layer protocol called RWBP uses per-flow queuing, round robin scheduling and receiver window backpressure for congestion management. RWBP can eliminate congestion losses inside the wireless networks. Our protocol suite outperforms the proposed protocols in term of both channel utilization and response time. Our results can be used for service providers to dimension their networks and provide quality of service to a certain number of users.},
	number = {Number: CSHCN TR 2005-5}
}
@techreport {
	title = {Web access over a multiple access channel: evaluations and improvements},
	author = {Zhou, Xiaoming., Liu, Nelson X.},
	year = {2004},
	month = {01/2004},
	abstract = {We evaluate web browsing performance over a multiple access satellite channel for three different MAC layer protocols. A web user behavior model is used to generate realistic source traffic. A new transport layer protocol called RWBP is proposed to solve the TCP problems inside satellite networks. RWBP uses per-flow queuing, round robin scheduling and receiver window backpressure for congestion control. We compare its performance with TCP over the three multiple access protocols. Our simulation results show that RWBP can reduce the multiple access channel load and at the same time improve the web page response time when driven by realistic web traffic. For the MAC layer protocols, combined free demand assignment multiple access (CFDAMA) always performs better than the other two protocols.},
	number = {Number: CSHCN TR 2004-10}
}
@techreport {
	title = {A Multichannel Random Access Protocol for Multislot Short Messages with Delay Constraints},
	author = {Zhou, Xiaoming.},
	year = {2004},
	month = {01/2004},
	abstract = {A multichannel random access protocol called FMCSA for multislot short messages is proposed in this paper to be used in access networks with large propagation delay. This protocol combines random access with the use of packet level forward error correction coding for new messages and scheduled retransmissions for partially received messages. Analytical and simulation results show that FMCSA can achieve a higher throughput and lower delay than slotted Aloha. When the system is operating at the low load region, the short messages can be delivered in their first attempts with very high probability. With the load increasing, more messages will be received partially in their first attempts and the scheduled retransmission scheme will guarantee the partially received messages to be recovered in their second attempts. Therefore the delay performance of FMCSA is much more robust to the load fluctuation than slot Aloha.},
	number = {Number: CSHCN TR 2004-14}
}
@techreport {
	title = {Congestion management in access networks with long propagation delay},
	author = {Zhou, Xiaoming.},
	year = {2003},
	month = {01/2003},
	abstract = {Satellite networks are going to play an important role in the global information infrastructure. Satellites can be used to provide Internet services to fixed users and to mobile users. However, recent measurements show that the satellite link efficiency is only about 30\%. In order to improve the performance of Internet over satellite, a new protocol called Receiver Window Backpressure Protocol (RWBP) is proposed. RWBP uses per-flow queuing, round robin scheduling and receiver window backpressure for congestion management. Simulation results show that RWBP can maintain high utilization of the satellite link and improve fairness among the competing connections.},
	number = {Number: CSHCN TR 2003-23}
}
@techreport {
	title = {TCP over Satellite Hybrid Networks: A Survey},
	author = {Zhou, Xiaoming.},
	year = {2002},
	month = {01/2002},
	abstract = {Satellite is going to play an important role in the global information infrastructure. Satellite canprovide direct to home Internet service (i.e. DirecPC from Hughes Network System) and it can alsoserve as traffic trunk in the middle of the network. About 98 percent of the Internet traffic is TCPtraffic. TCP works well in the terrestrial fiber network. However, in the satellite hybrid networks,because of the long propagation delay, large bandwidth-delay product, high bit error rate anddownstream/upstream bandwidth asymmetry, TCP performance degrades dramatically. This paperaddresses the problems of TCP in satellite data networks and reviews the proposed solutions in theliterature. For each solution, the advantages and disadvantages are pointed out. In addition,extensive simulations have been done for the proxy based scheme currently used in the industry tofind out how and to what extent the enhancements, such as connection splitting, window scalingand selective acknowledgement, benefit the TCP throughput.},
	number = {Number: CSHCN TR 2002-15}
}
@techreport {
	title = {Flow Control at Satellite Gateways},
	author = {Zhou, Xiaoming., Liu, Xicheng.},
	year = {2002},
	month = {01/2002},
	abstract = {In this paper we analyze the problems that cause this dramatically degradedperformance. Based on the observation that it difficult for an end-to-end solution to solve these problems in this kind of hybrid networks, we propose a connection splitting based solution. A rate-based protocol is designed for the satellite connections and a flow control scheme at the satellite gateways (SGW) used to couple the two split connections together.},
	number = {Number: CSHCN TR 2002-19}
}
