A download time first self-adaptive incentive protocol in BitTorrent

The goal of current incentive mechanism for BitTorent is to guarantee the node's fairness between upload bandwidth and download bandwidth. However, the file download time is more preferable than such fairness for the users in real file sharing environments. Therefore, a new self-adaptive incentive protocol denoted as AIPS to minimize the file download time is provided in this paper for BitTorrent. This paper firstly analyzes the influence of incentive mechanism on file sharing, the file transfer structures under incentive mechanisms based on Markov model. The conditions to minimize the file download time are inferred further based on the transfer structures and then a game with file download time as its utility is defined in this paper. The AIPS is the strategy adopted by nodes under the Nash equilibrium for that game. Simulations show that the AIPS can improve the efficiency for file sharing.