• Dr.R.MANIKANDAN
• R.Premkumar

Abstract: Ad hoc networks have been proposed for emergency communication wherein the required infrastructure is unavailable. .Even in infrastructure based wireless networks, when the number of contending nodes is high, more number of frame collisions occur which leads to drastic reduction in network performance.However, a major concern in Ad hoc networks is collisions .Furthermore, the packet transmission procedure of the DCF protocol is modified to avoid channel capture effect and this is represented with a Markov chain model. In SCW algorithm, each station (STA) actively tracks the transmission cases of the network and when the channel state is changed, the contention window (CW) of each station which participates in the competition is synchronized by resetting the CW, which makes each station get the medium access grant with the same probability in next channel contention. The experimental results show that with the increase of the number of the stations, the fairness index of the SCW algorithm is nearly equal to 1 and always keeps stable, and when the number of stations is large (nearly 36 STAs), the throughput and delay of the network are respectively increased and reduced by nearly 11% and 6% than the conventional BEB algorithm. The proposed algorithm can effectively improve the performance of throughput and delay, and it has an excellent fairness of network. Therefore, it is especially suitable the wireless networks with the dense stations.higher throughput, and high fairness. Index Terms—IEEE 802.11, Channel Contention, Backoff Algorithm, Fairness, Contention Window, distributed coordination function, Collision Avoidance

IEEE 802.11, Channel Contention, Backoff Algorithm, Fairness, Contention Window, distributed coordination function, Collision Avoidance

"Performance of Collision Alleviating DCF Protocol with Synchronized Contention Windows Algorithm for Wireless Ad hoc Networks ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 6, page no.536-540, June-2019, Available :http://www.jetir.org/papers/JETIR1906086.pdf

"Performance of Collision Alleviating DCF Protocol with Synchronized Contention Windows Algorithm for Wireless Ad hoc Networks ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 6, page no. pp536-540, June-2019, Available at : http://www.jetir.org/papers/JETIR1906086.pdf