Impact of Different Thresholds on SSB Algorithm

Abstract

Slow Start Backoff (SSB) Algorithm is a simple, efficient, distributed, and well performed medium access control (MAC) layer protocol designed for wireless adhoc networks to share the medium. SSB is able to alleviate intensive collisions in congested environments and SSB can also minimize the average channel access delay in light load environments. Compare with the traditional binary exponential backoff (BEB) algorithm, SSB provides better performance over a wider range of network condition. In this paper, impact of different threshold values on the performance of SSB algorithm is evaluated, and then we use this result to find out a proper value of threshold that increases the performance of SSB algorithm based on the channel status. Moreover, we provide a simple and accurate analytical model to analysis the system throughput of SSB algorithm in this paper. Simulations are also conducted to evaluate the performance of SSB algorithm. The results confirm that the performance of SSB algorithm can be greatly improved by an appropriate value of threshold. Besides, the results also show the SSB algorithm outperforms the traditional BEB algorithm and other backoff algorithms in both high load and light load environments.