Nicholas B. Chang
ABSTRACT
In this study we consider optimal opportunistic spectrum access (OSA) policies for a transmitter in a multichannel wireless system, where a channel can be in one of multiple states. Each channel state is associated with either a probability of transmission success or a transmission rate. In such systems, the transmitter typically has partial information concerning the channel states, but can deduce more by probing individual channels, e.g. by sending control packets in the channels, at the expense of certain resources, e.g., energy and time. The main goal of this work is to derive optimal strategies for determining which channels to probe (in what sequence) and which channel to use for transmission. We consider two problems within this context,allthe constant data time (CDT) and the constant access time (CAT) problems. For both problems, we derive key structural properties of the corresponding optimal strategy. In particular, we show that it has a threshold structure and can be described by an index policy. We further show that the optimal CDT strategy can only take on one of three structural forms. Using these results we present a two-step lookahead CDT (CAT) strategy. This strategy is shown to be optimal for a number of cases of practical interest. We examine its performance under a class of practical channel models via numerical studies.
- Y. Chen, Q. Zhao, and A. Swami. Joint design and separation principle for opportunistic spectrum access. Proc. of IEEE Asilomar Conference on Signals, Systems, and Computers, November 2006.Google Scholar
Cross Ref
- S. Guha, K. Munagala, and S. Sarkar. Approximation schemes for information acquisition and exploitation in multichannel wireless networks. Proc. of 44th Annual Allerton Conference on Communication, Control and Computing, September 2006. Monticello, IL.Google Scholar
- S. Guha, K. Munagala, and S. Sarkar. Jointly optimal transmission and probing strategies for multichannel wireless systems. Proc. of Conference on Information Sciences and Systems, March 2006. Princeton, NJ.Google ScholarCross Ref
- S. Guha, K. Munagala, and S. Sarkar. Optimizing transmission rate in wireless channels using adaptive probes. Poster paper in ACM Sigmetrics/Performance Conference, June 2006. Saint-Malo, France. Google ScholarDigital Library
- J. Heiskala and J. Terry. OFDM wireless LANs: A theoretical and practical guide. SAMS, 2001. Google ScholarDigital Library
- G. Holland, N. Vaidya, and P. Bahl. A rate-adaptive mac protocol for multi-hop wireless networks. Proc. of MOBICOM, 2001. Rome, Italy. Google ScholarDigital Library
- Z. Ji, Y. Yang, J. Zhou, M. Takai, and R. Bagrodia. Exploiting medium access diversity in rate adaptive wireless lans. Proc. of MOBICOM, September 2004. Philadelphia, PA. Google ScholarDigital Library
- V. Kanodia, A. Sabharwal, and E. Knightly. MOAR: A multi-channel opportunistic auto-rate media access protocol for ad hoc networks. Proc. of Broadnets, October 2004. Google ScholarDigital Library
- J. Kennedy and M. Sullivan. Direction finding and "smart antennas" using software radio architectures. IEEE Communications Magazine, pages 62--68, May 1995. Google ScholarDigital Library
- R. Knopp and P. Humblet. Information capacity and power control in a single cell multiuser environment. Proc. of IEEE ICC, 1995. Seattle, WA.Google ScholarCross Ref
- P. Kumar and P. Karaiya. Stochastic Systems: Estimation, Identification, and Adaptive Control. Prentice-Hall, Inc, 1986. Englewood Cliffs, NJ. Google ScholarDigital Library
- X. Liu, E. Chong, and N. Shroff. Transmission scheduling for efficient wireless network utilization. Proc. of IEEE INFOCOM, 2001. Anchorage, AK.Google Scholar
- X. Quin and R. Berry. Exploiting multiuser diversity for medium access control in wireless networks. Proc. of IEEE INFOCOM, 2003. San Francisco, CA.Google ScholarCross Ref
- A. Sabharwal, A. Khoshnevis, and E. Knightly. Opportunistic spectral usage: Bounds and a multi-band CSMA/CA protocol. IEEE/ACM Transactions on Networking, pages 533--545, June 2007. Google ScholarDigital Library
Index Terms
- Optimal channel probing and transmission scheduling for opportunistic spectrum access
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