Abstract: Mobile Ad-hoc networks (MANET) and peer-to-peer (P2P) systems share a common underlying paradigm:self-organization. However, the two fields were researched independently all the time. In recent years, with the success of P2P over Internet and rapid development of wireless technology, P2P systems began to be applied to MANET. Because of the limited resource and dynamic topology structure, the performance of applying P2P directly over MANET is poor. A lot of cross layer approaches were proposed to improve the performance. In this paper, after analyzing the similarity and difference between P2P and MANET, some existing cross layer approaches were compared in their characteristics and classifications. Finally, the important features that good approaches possess and the future research strategies and trends were summarized.

Key words: P2P,Mobile ad-hoc network,Routing,Cross-layer