It has been shown that IEEE 802.11 DCF medium access control (MAC) protocol may not be suitable for multihop wireless networks due to its relatively low throughput and severely unfairness problems. A token-passing MAC protocol, named Ripple, has been proposed to enhance the throughput of DCF by utilizing spatial reuse. However, two perfect assumptions of ‘fixed-length data packet’ and ‘identical interference range and transmission range’ in Ripple make it less practical in the real world. In this work, the poor performance results of Ripple in operation without these two assumptions are firstly investigated. Then, an Enhanced Ripple (E-Ripple) MAC protocol aiming to remove the two restrictions is proposed. An analytical model is further presented to estimate the performance of E-Ripple. The computer simulations verify the accuracy of the analysis and illustrate the proposed protocol’s performance. The numerical results indicate that E-Ripple performs well in such a non-perfect environment.

It has been shown that IEEE 802.11 DCF medium access control (MAC) protocol may not be suitable for multihop wireless networks due to its relatively low throughput and severely unfairness problems. A token-passing MAC protocol, named Ripple, has been proposed to enhance the throughput of DCF by utilizing spatial reuse. However, two perfect assumptions of ‘fixed-length data packet’ and ‘identical interference range and transmission range’ in Ripple make it less practical in the real world. In this work, the poor performance results of Ripple in operation without these two assumptions are firstly investigated. Then, an Enhanced Ripple (E-Ripple) MAC protocol aiming to remove the two restrictions is proposed. An analytical model is further presented to estimate the performance of E-Ripple. The computer simulations verify the accuracy of the analysis and illustrate the proposed protocol’s performance. The numerical results indicate that E-Ripple performs well in such a non-perfect environment.

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