Multi-swarm collaboration for improved content availability in BitTorrent-like systems

In spite of its success, BitTorrent is facing a content unavailability problem where peers can not finish their content download due to an absence of seeders. Although some approaches have been proposed to improve the content availability, the prior conditions such as a downloaded content and a set of related contents to be bundled limit their application scopes. Our main contribution is a multi-swarm collaboration to improve the content availability of the BitTorrent-like systems without the content-related limitations. The multi-swarm collaboration enables the collaborating swarms cache some chunks that are likely to be unavailable in near future of each other when the seeders are online and share the cached chunks when the content unavailability happens. Our approach enables any swarms that have appropriate amount of resources to collaborate with each other for the improved content availability. Through simulations, we show that the multi-swarm collaboration improves the peer performance as well as the content availability.