Research Article Distributed Cooperative Transmission with Unreliable and Untrustworthy Relay Channels | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 740912 13 pages doi 2009 740912 Research Article Distributed Cooperative Transmission with Unreliable and Untrustworthy Relay Channels Zhu Han1 and Yan Lindsay Sun2 1Electrical and Computer Engineering Department University of Houston Houston TX 77004 USA 2Electrical and Computer Engineering Department The University of Rhode Island Kingston RI02881 USA Correspondence should be addressed to Zhu Han hanzhu22@ Received 25 January 2009 Revised 13 July 2009 Accepted 12 September 2009 Recommended by Hui Chen Cooperative transmission is an emerging wireless communication technique that improves wireless channel capacity through multiuser cooperation in the physical layer. It is expected to have a profound impact on network performance and design. However cooperative transmission can be vulnerable to selfish behaviors and malicious attacks especially in its current design. In this paper we investigate two fundamental questions Does cooperative transmission provide new opportunities to malicious parties to undermine the network performance Are there new ways to defend wireless networks through physical layer cooperation Particularly we study the security vulnerabilities of the traditional cooperative transmission schemes and show the performance degradation resulting from the misbehaviors of relay nodes. Then we design a trust-assisted cooperative scheme that can detect attacks and has self-healing capability. The proposed scheme performs much better than the traditional schemes when there are malicious selfish nodes or severe channel estimation errors. Finally we investigate the advantage of cooperative transmission in terms of defending against jamming attacks. A reduction in link outage probability is achieved. Copyright 2009 Z. Han and Y. L. Sun. This is an open access article distributed under the Creative Commons Attribution License which .
