This book includes a synthesis of some of our previsions research works. It presents firstly a study of interactions between two routing protocols (AODV, DSR) and two transport protocol versions (TCP New Reno, Vegas). After this study, we conduct some simulations to analyze the behavior of these protocols with different node mobility and network load values. The performance results of each protocol are examined to identify our own scenarios in order to evaluate our proposed solution for better interactions between these protocols. This solution is called CL-TCP (Cross Layer TCP). It is an adaptation of the TCP congestion control mechanism with some parameters provided by the routing layer (mobility nodes and the size of routing length). After the evaluation of CL-TCP, the results showed that it significantly improves the interactions between TCP Vegas and AODV protocols.