Storage Tradeoffs in a Collaborative Backup Service for Mobile Devices

Mobile devices are increasingly relied on but are used in contexts that put them at risk of physical dam- age, loss or theft. We consider a fault-tolerance ap- proach that exploits spontaneous interactions to imple- ment a collaborative backup service. We define the con- straints implied by the mobile environment,analyze how they translate into the storage layer of such a backup system and examine various design options. The paper concludes with a presentation of our prototype imple- mentation of the storage layer, an evaluation of the im- pact of several compression methods,and directions for future work.