17-09-2009, 10:01 PM
MINING FILE DOWNLOADING TIME IN STOCHASTIC PEER TO PEER NETWORKS
Abstract: On-demand routing protocols use route caches to make routing decisions. Due to mobility, cached routes easily become stale. To address the cache staleness issue, prior work in DSR used heuristics with ad hoc parameters to predict the lifetime of a page link or a route. However, heuristics cannot accurately estimate timeouts because topology changes are unpredictable. In this paper, we propose proactively disseminating the broken page link information to the nodes that have that page link in their caches. We define a new cache structure called a cache table and present a distributed cache update algorithm. Each node maintains in its cache table the information necessary for cache updates. When a page link failure is detected, the algorithm notifies all reachable nodes that have cached the page link in a distributed manner. The algorithm does not use any ad hoc parameters, thus making route caches fully adaptive to topology changes. We show that the algorithm outperforms DSR with path caches and with Link-Max Life, an adaptive timeout mechanism for page link caches. We conclude that proactive cache updating is key to the adaptation of on-demand routing protocols to mobility.
