DeltaCast: Efficient File Reconciliation in Wireless Broadcast Systems

Third International Conference on Mobile Systems, Applications, and Services

Julian Chesterfield ; Pablo Rodriguez

Others  :  http://www.usenix.org/publications/library/proceedings/mobisys05/tech/full_papers/chesterfield/chesterfield.pdf
PID  :  8872

来源: CEUR

【 摘 要 】

Recently, there has been an increasing interest in wire- less broadcast systems as a means to enable scalable con- tent delivery to large numbers of mobile users. However, gracefully providing efficient reconciliation of different versions of a file over such broadcast channels still re- mains a challenge. Such systems often lack a feedback channel and consequently updates cannot be easily tai- lored to a specific user. Moreover, given the potentially large number of possible versions of a file, it is impracti- cal to send a tailored update for each particular user. In this paper we consider the problem of efficiently updating files in such wireless broadcast channels. To this extent, we present DeltaCast, a system that combines hierarchical hashes and erasure codes to minimise the amount of battery power and the amount of time needed to synchronise each mobile device. Based on our exper- imental results, we show that DeltaCast is able to effi- ciently identify the missing portions of a file and quickly updated each client.