Information Technology Reference
In-Depth Information
Chapter 12
Peer-Based Collaborative
Caching and Prefetching in
Mobile Broadcast
Wei Wu
Singapore-MIT Alliance, and School of Computing, National University of Singapore, Singapore
Kian-Lee Tan
Singapore-MIT Alliance, and School of Computing, National University of Singapore, Singapore
abStract
Caching and prefetching are two effective ways for mobile peers to improve access latency in mobile
environments. With short-range communication such as IEEE 802.11 and Bluetooth, a mobile peer
can communicate with neighboring peers and share cached or prefetched data objects. This kind of
cooperation improves data availability and access latency. In this chapter the authors review several
cooperative caching and prefetching schemes in a mobile environment that supports broadcasting. They
present two schemes in detail: CPIX (Cooperative PIX) and ACP (Announcement-based Cooperative
Prefetching). CPIX is suitable for mobile peers that have limited power and access the broadcast channel
in a demand-driven fashion. ACP is designed for mobile peers that have sufficient power and prefetch
from the broadcast channel. They both consider the data availability in local cache, neighbors' cache,
and on the broadcast channel. Moreover, these schemes are simple enough so that they do not incur
much information exchange among peers and each peer can make autonomous caching and prefetch-
ing decisions.
introduction
broadcast, a server broadcasts data objects on a
wireless channel and (a large number of) mobile
peers get their required data objects by tuning
into the broadcast channel and retrieving the data
objects when they appear. Data broadcast differs
Mobile broadcast is a scalable data dissemination
model for mobile computing (Acharya & Alonso,
1995; Imielinski, 1997; Tan, 2000). In mobile
Search WWH ::
Custom Search