Background

Ad-hoc Networks are built by the cooperation of the participants. While exisiting architectures assume that nodes would behave properly and cooperate, such assumption is not realistic when applied to community-based networks. In such network, each node is its own authority, and has its own utility.

In a decentralized architecture like ad-hoc networks, policing nodes to behave properly and share resources is an inherently difficult task. Since there are no commonly trusted nodes, there would be no one who can be trusted to perform such job. Without an authoritative source, nodes might rely on rumours, but they are highly unprecise and susceptible to false accusations. This project proposes a virtual economy system, in which nodes that use shared resources has to compensate the provider through a virtual currency system. Nodes that are selfish, and never cooperate would run out of funds, and wouldn't be able to use shared resources any longer.

The aims of the resource charging system are:

• To provide an incentive to cooperate and share resources: the more a node shares, the more resources it can use.
• To balance the network load fairly: popular resources can charge higher prices, which would direct some of the clients to other cheaper providers.
• To prevent resource abuse: request flood and lavish use of resources become 'expensive' in a network which charge resource usage.

This project proposes a design of a resource charging system, which is fully decentralized and extensible. While the idea of charging resource usage in ad-hoc networks is not new, to the extent of our knowledge, no existing systems provide a decentralized approach. They either rely on the existance of trusted nodes, or the use of trusted hardware. Additionally, the charging systems are only usable for charging packet forwarding. This is very limiting, since the nature of ad-hoc networks open up a lot of possibilities in cooperation.