Open Access

Capacity of Wireless Ad Hoc Networks with Opportunistic Collaborative Communications

EURASIP Journal on Wireless Communications and Networking20072007:053075

DOI: 10.1155/2007/53075

Received: 17 January 2006

Accepted: 27 December 2006

Published: 7 March 2007


Optimal multihop routing in ad hoc networks requires the exchange of control messages at the MAC and network layer in order to set up the (centralized) optimization problem. Distributed opportunistic space-time collaboration (OST) is a valid alternative that avoids this drawback by enabling opportunistic cooperation with the source at the physical layer. In this paper, the performance of OST is investigated. It is shown analytically that opportunistic collaboration outperforms (centralized) optimal multihop in case spatial reuse (i.e., the simultaneous transmission of more than one data stream) is not allowed by the transmission protocol. Conversely, in case spatial reuse is possible, the relative performance between the two protocols has to be studied case by case in terms of the corresponding capacity regions, given the topology and the physical parameters of network at hand. Simulation results confirm that opportunistic collaborative communication is a promising paradigm for wireless ad hoc networks that deserves further investigation.


Authors’ Affiliations

Dipartimento di Elettronica e Informazione, Politecnico di Milano


  1. Gupta P, Kumar PR: The capacity of wireless networks. IEEE Transactions on Information Theory 2000,46(2):388-404. 10.1109/18.825799MATHMathSciNetView ArticleGoogle Scholar
  2. Toumpis S, Goldsmith AJ: Capacity regions for wireless ad hoc networks. IEEE Transactions on Wireless Communications 2003,2(4):736-748.View ArticleGoogle Scholar
  3. Laneman JN, Tse DNC, Wornell GW: Cooperative diversity in wireless networks: efficient protocols and outage behavior. IEEE Transactions on Information Theory 2004,50(12):3062-3080. 10.1109/TIT.2004.838089MATHMathSciNetView ArticleGoogle Scholar
  4. Qin M, Blum RS: Capacity of wireless ad hoc networks with cooperative diversity: a warning on the interaction of relaying and multi-hop routing. Proceedings of IEEE International Conference on Communications (ICC '05), May 2005, Seoul, South Korea 2: 1128-1131.Google Scholar
  5. Toumpis S, Goldsmith AJ: Performance, optimization, and cross-layer design of media access protocols for wireless ad hoc networks. Proceedings of IEEE International Conference on Communications (ICC '03), May 2003, Anchorage, Alaska, USA 3: 2234-2240.Google Scholar
  6. Mitran P, Ochiai H, Tarokh V: Space-time diversity enhancements using collaborative communications. IEEE Transactions on Information Theory 2005,51(6):2041-2057. 10.1109/TIT.2005.847731MATHMathSciNetView ArticleGoogle Scholar
  7. Scaglione A, Hong Y-W: Opportunistic large arrays: cooperative transmission in wireless multihop ad hoc networks to reach far distances. IEEE Transactions on Signal Processing 2003,51(8):2082-2092. 10.1109/TSP.2003.814519View ArticleGoogle Scholar
  8. Stefanov A, Erkip E: Cooperative coding for wireless networks. IEEE Transactions on Communications 2004,52(9):1470-1476. 10.1109/TCOMM.2004.833070View ArticleGoogle Scholar


© O. Simeone and U. Spagnolini. 2007

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.