DIMACS TR: 95-11
Airdisks and AirRAID: Modeling and scheduling periodic wireless da
ta broadcast
Authors: Ravi Jain, John Werth
ABSTRACT
We introduce a simple model, called the airdisk, for modeling the
access of data transmitted periodically over wireless media as being
analogous to the access of data from a standard magnetic disk. We
consider several issues related to airdisks, such as their mean
rotational latency under certain assumptions. The problem of
scheduling the order in which data items are broadcast is analogous to
that of determining how data should be laid out on the disk. Two
problems of laying out data so as to minimize read time, given
information about which data items are of most interest to the
clients, are defined; both are shown to be NP-complete. We discuss
ways in which the information about which items are of interest to
clients can be obtained. Finally we consider how to increase the performance
and storage capacity of airdisks, using the magnetic disk analogy as a guide.
We suggest using multiple-track airdisks or borrowing the idea of Redundant
Arrays of Inexpensive Disks (RAID) which is used for magnetic disks; for the
wireless data broadcast environment we call the latter approach airRAID.
Paper available at:
ftp://dimacs.rutgers.edu/pub/dimacs/TechnicalReports/TechReports/1995/95-11.ps.gz
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