Mobile ad-hoc networks (MANET) enable the communication of mobile wireless nodes without any pre-defined infrastructure. Therefore, they are predestined for future mobile applications. To use existing applications and to inter-operate with the world wide internet, ad-hoc networks have to use TCP/IP, which were not designed for mobile ad-hoc networks and yield poor performance when deployed in this kind of networks. The poor performance of TCP in ad-hoc networks has several reasons, especially the communication medium with high bit error rates (BER) and TCP?s optimization on fixed networks.

In this paper, we present an enhancement, the restricted congestion window enlargement (TCP/RCWE), and show its ability to handle TCP?s problems in mobile ad-hoc networks. We also illustrate the performance gain of TCP by the enhancement.