We are dealing with two different problem scenarios in two different layers. In MAC layer a problem known as Contention Window Cheating's existence has been discovered recently. In this paper, we propose a cross layer solution for the contention window cheating problem. Our solution is implemented based on congestion details provided by the Transport layer to the MAC layer. Currently in the Transport layer, during the congestion scenario, packet loss causes the current window size to be set to half its original value. Due to this the bandwidth is not effectively utilized. As a solution we provide "TCP-BHL", which is based on fuzzy state machine which provides an adaptive congestion window management technique. We also consider delays like processing delay, serialization delay and propagation delay. © 2010 IEEE.