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Throughput Modeling of Single Hop CSMA Networks with Non-Negligible Propagation Delay.
- Source :
-
IEEE Transactions on Communications . Jul2013, Vol. 61 Issue 7, p2911-2923. 13p. - Publication Year :
- 2013
-
Abstract
- We analyze the performance of the CSMA protocol under propagation delays that are comparable with packet transmission times. We propose a semi-Markov model for the 2-node CSMA channel. For the 2-node case, the capacity reduces to 40% of the zero-delay capacity when the one-way propagation delay is 10% of the packet transmission time. We then extend this model and obtain the optimum symmetric probing rate that achieves the maximum network throughput as a function of the average propagation delay, \bard, and the number of nodes sharing the channel, N. The proposed model predicts that the total capacity decreases with \bard^-1 as N goes to infinity when all nodes probe the channel at the optimum rate. The optimum probing rate for each node decreases with 1/N and the total optimum probing rate decreases faster than \bard^-1 as N goes to infinity. We investigate how the short-term unfairness problem in CSMA worsens as the propagation delay increases and propose a back-off mechanism to mitigate this issue. The theoretical results presented in this paper can be used as a benchmark for the performance improvements provided by algorithms that have already been developed. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00906778
- Volume :
- 61
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- IEEE Transactions on Communications
- Publication Type :
- Academic Journal
- Accession number :
- 89454618
- Full Text :
- https://doi.org/10.1109/TCOMM.2013.050813.130004