In this paper, we propose an improvement of Transmission Control Protocol (TCP) protocol performance in MANET by exploiting the backoff algorithm of Medium Access Control (MAC) protocol. This improvement is IB-MAC (Improvement of Backoff algorithm of MAC protocol), it propose a new backoff algorithm based on a dynamic adaptation of its maximal limit according to the number of nodes and their mobility. The evaluation of our IB-MAC solution and the study of its incidences on TCP performance are done with AODV as like routing protocol, TCP New Reno as like transport protocol and varied network conditions such as load and mobility. The results are satisfactory and show that our algorithm can outperform not only MAC standard, but also similar techniques that have been proposed in the literature like MAC-LDA and MAC-WCCP.
