Su Yi
ABSTRACT
The capacity of ad hoc wireless networks is constrained by the interference between concurrent transmissions from neighboring nodes. Gupta and Kumar have shown that the capacity of an ad hoc network does not scale well with the increasing number of nodes in the system when using omnidirectional antennas [6]. We investigate the capacity of ad hoc wireless networks using directional antennas. In this work, we consider arbitrary networks and random networks where nodes are assumed to be static.In arbitrary networks, due to the reduction of the interference area, the capacity gain is proven to be √2π/α when using directional transmission and omni reception. Because of the reduced probability of two neighbors pointing to each other, the capacity gain is √2π/β when omni transmission and directional reception are used. Although these two expressions look similar, the proof technique is different. By taking advantage of the above two approaches, the capacity gain is 2π/√αβ when both transmission and reception are directional.For random networks, interfering neighbors are reduced due to the decrease of interference area when directional antennas are used for transmission and/or reception. The throughput improvement factor is 2π/α, 2π/β and 4π2/αβ for directional transmission/omni reception, omni transmission/direc-tional reception, and directional transmission/directional reception, respectively.We have also analyzed hybrid beamform patterns that are a mix of omnidirectional/directional and a better model of real directional antennas.
- L. Bao and J.J.Garcia-Luna-Aceves. Transmission scheduling in ad hoc networks with directional antennas. In ACM MobiCom'02, September 2002. Google Scholar
Digital Library
- J. J. Carr. Directional or Omnidirectional Antenna? Http://www.dxing.com/tnotes/tnote01.pdf.Google Scholar
- R. R. Choudhury, X. Yang, R. Ramanathan, and N. Vaidya. Using directional antennas for medium access control in ad hoc networks. In ACM MobiCom'02, September 2002. Google ScholarDigital Library
- M. Gastpar and M. Vetterli. On the capacity of wireless networks: The relay case. In IEEE INFOCOM'02, June 2002.Google ScholarCross Ref
- M. Grossglauser and D. Tse. Mobility increases the capacity of ad hoc wireless networks. In IEEE INFOCOM'01, April 2001.Google ScholarCross Ref
- P. Gupta and P. R. Kumar. The capacity of wireless networks. IEEE Transactions on Information Theory, IT-46(2):388--404, March 2000. Google ScholarDigital Library
- Y. Ko, V. Shankarkumar, and N. H. Vaidya. Medium access control protocols using directional antennas in ad hoc networks. In IEEE INFOCOM'2000, March 2000.Google Scholar
- J. D. Kraus and R. J. Marhefka. Antennas: for All Applications, 3rd Ed. McGraw-Hill, New York, 2002.Google Scholar
- J. Li, C. Blake, D. D. Couto, H. Lee, and R. Morris. Capacity of ad hoc wireless networks. In ACM MobiCom'01, July 2001. Google ScholarDigital Library
- B. Liu, Z. Liu, and D. Towsley. On the capacity of hybrid wireless networks. In IEEE INFOCOM'03, March 2003.Google ScholarCross Ref
- A. Nasipuri, S. Ye, and R. E. Hiromoto. A mac protocol for mobile ad hoc networks using directional antennas. In Proceedings of the IEEE Wireless Communications and Networking Conference (WCNC 2000), September 2000.Google ScholarCross Ref
- R. Ramanathan. On the performance of ad hoc networks using beamforming antennas. In ACM MobiHoc'01, October 2001. Google ScholarDigital Library
- T. S. Rappaport. Wireless Communications: Principles and Practice. Prentice Hall, Upper Saddle River, New Jersey, 1996. Google ScholarDigital Library
Index Terms
- On the capacity improvement of ad hoc wireless networks using directional antennas
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