A peer-to-peer file sharing system for wireless ad-hoc networks

Abstract

In recent years, we have witnessed an increasing popularity of peer-to-peer (P2P) networks. Especially, file sharing applications aroused considerable interest of the Internet users and currently there exist several peer-to-peer file sharing systems that are functional on the Internet. In the mean time, recent developments in mobile devices and wireless communication technologies enabled personal digital assistants (PDA) to form ad-hoc networks in an easy and automated way. However, file sharing in wireless ad-hoc networks imposes many challenges that make conventional peer-to-peer systems operating on wire-line networks (i.e. Internet) inapplicable for this case. Information and workload distribution as well as routing are major problems for members of a wireless ad-hoc network, which are only aware of peers that are within their communication range. In this thesis, we propose a system that solves peer-to-peer file-sharing problem for wireless ad-hoc networks. Our system works according to principles of peer-to-peer systems, without requiring a central server, and distributes information regarding the location of shared files among members of the network. By means of constructing a distributed hash table (DHT) and forming a tree shaped overlay network based on the topology of the network itself, the system is able to answer location queries, and also discover and maintain routing information that is used to transfer files from a source-peer to another peer.