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Impact of Power Control on Performance of IEEE 802.11 Wireless Networks
November 2007 (vol. 6 no. 11)
pp. 1245-1258
Optimizing spectral reuse is a major issue in large-scale IEEE 802.11 wireless networks. Power control is an effective means for doing so. Much previous work simply assumes that each transmitter should use the minimum transmit power needed to reach its receiver, and that this would maximize the network capacity by increasing spectral reuse. It turns out that this is not necessarily the case, primarily because of hidden nodes. This paper shows that in a network with power control, avoiding hidden nodes can achieve higher overall network capacity compared with the minimum-transmit-power approach. It is not always best to use the minimum transmit powers even from the network capacity viewpoint. Specifically, we propose and investigate two distributed adaptive power control algorithms that minimize mutual interferences among links while avoiding hidden nodes. Different power control schemes have different numbers of exposed nodes and hidden nodes, which in turn result in different network capacities and fairness. Although there is usually a fundamental tradeoff between network capacity and fairness, we show that, interestingly, this is not always the case. In addition, our power control algorithms can operate at desirable network- capacity-fairness tradeoff points, and can boost the capacity of ordinary non-power-controlled 802.11 networks by two times while eliminating hidden nodes.

[1] W.H. Ho and S.C. Liew, “Achieving Scalable Capacity in Wireless Networks with Adaptive Power Control,” Proc. Fifth Int'l IEEE Workshop Wireless Local Networks (WLN '05), Nov. 2005.
[2] V. Kawadia and P.R. Kumar, “Principles and Protocols for Power Control in Ad Hoc Networks,” IEEE J. Selected Areas in Comm., vol. 23, no. 5, pp. 76-88, Jan. 2005.
[3] S. Agarwal, S.V. Krishnamurthy, R.H. Katz, and S.K. Dao, “Distributed Power Control in Ad-Hoc Wireless Networks,” Proc. Personal Indoor Mobile Radio Conf., Oct. 2001.
[4] J.P. Monks, V. Bharghavan, and W.-M. Hwu, “A Power Controlled Multiple Access Protocol for Wireless Packet Networks,” Proc. IEEE INFOCOM, 2001.
[5] L.B. Jiang and S.C. Liew, “Hidden-Node Removal and Its Application in Cellular WiFi Networks,” Proc. IEEE Vehicular Technology Conf., Sept. 2005.
[6] P.C. Ng and S.C. Liew, “Throughput Analysis of IEEE 802.11 Multi-Hop Ad Hoc Networks,” Proc. First IEEE Int'l Conf. Mobile Ad-Hoc and Sensor Systems (MASS '04), Oct. 2004.
[7] E. Jung and N. Vaidya, “A Power Control MAC Protocol for AdHoc Networks,” Proc. ACM MobiCom, 2002.
[8] “The Network Simulator—ns2,” http://www.isi.edu/nsnamns, 2007.
[9] P.C. Ng, S.C. Liew, and L. Jiang, “Achieving Scalable Performance in Large-Scale IEEE 802.11 Wireless Networks,” Proc. IEEE Wireless Comm. and Networking Conf., Mar. 2005.
[10] W.H. Ho, “Adaptive Power Control in Wireless Networks for Scalable and Fair Capacity Distributions,” master's thesis, Chinese Univ. of Hong Kong, May 2006.
[11] R. Jain, D.M. Chiu, and W. Hawe, “A Quantitative Measure of Fairness and Discrimination for Resource Allocation in Shared Computer Systems,” Technical Report TR-301, DEC Research Report, Sept. 1984.
[12] I. Milchtaich, “Network Topology and the Efficiency of Equilibrium,” working paper, Dept. of Economics, Bar-Ilan Univ., Israel, June 2001.
[13] A. Sheth and R. Han, “Adaptive Power Control and Selective Radio Activation for Low-Power Infrastructure-Mode 802.11 LANs,” Proc. Int'l Conf. Distributed Computing Systems Workshops (ICDCSW '03), May 2003.
[14] P. Gupta and P.R. Kumar, “The Capacity of Wireless Networks,” IEEE Trans. Information Theory, vol. 46, no. 2, pp. 388-404, Mar. 2000.
[15] A. Agarwal and P.R. Kumar, “Improved Capacity Bounds for Wireless Networks,” Wireless Comm. and Mobile Computing, vol. 4, pp. 251-261, 2004.
[16] A. Agarwal and P.R. Kumar, “Capacity Bounds for Ad-Hoc and Hybrid Wireless Networks,” Proc. ACM SIGCOMM Computer Comm. Rev., special issue on science of networking design, vol.34, no. 3, pp. 71-81, July 2004.

Index Terms:
Wireless Networks, WLAN, Power Control, 802.11, Network Capacity, Scalability, CSMA/CA, Ad-hoc Networks, Hidden Nodes, Exposed Nodes
Citation:
Ivan Wang-Hei Ho, Soung Chang Liew, "Impact of Power Control on Performance of IEEE 802.11 Wireless Networks," IEEE Transactions on Mobile Computing, vol. 6, no. 11, pp. 1245-1258, Nov. 2007, doi:10.1109/TMC.2007.1045
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