Challenges and Protocols for P2P applications in Multi-hop Wireless Networks

P2P (Peer-to-Peer) systems are mainly designed for fixed wired networks and attracted researchers due to increase in the Internet based applications. Wireless multi-hop networks such as mobile ad-hoc networks (MANETs) and wireless mesh networks (WMNs) share many key characteristics with P2P networks like dynamic overlay, self-organization and decentralization. These networks have high degree of dynamicity due to churn (join and leave) of the nodes in the network. P2P networks suffer from challenges like malicious file spreading, free riding, whitewashing, poor resource search scalability, lack of a robust trust model, etc. The join and leave of the nodes at their will and it makes management of topology management and resource searching more challenging. The wireless multi-hop networks have their own challenges like limited bandwidth, limited backup power, security, overlay maintenance, mobility management, etc. When P2P protocols are implemented for wireless multi-hop networks, more challenges are added. But good thing is the deployment DHT (Distributed Hash Table) based protocols without any changes at network layer of wireless multi-hop networks. The DHT is a resource searching and retrieval mechanism in P2P networks. We have presented a comprehensive survey over the challenges and protocols for wireless multi-hop networks for P2P applications in this paper.