BENEFIT-BASED DATA CACHING IN AD HOC NETWORKS-MOBILE COMPUTING

[amitha]

This article is presented by:Dr.Yatindra Nath Singh
Mobile Computing Networks

What is mobile computer?
A computer which you can take with you all around.
You can do all the things which can be done with a
desktop computer.
You should be able to use same software, which you use
on a desktop computer.

Mobile computer - How?
One possibility is to have a standalone computer capable of
storing large amount of software and data files,
processing power to support the required applications.
Modern day laptop computer are something like this.

Whenever you are static, connect to internet through an
access point and you can do the file transfer, telnet, web
browsing etc..
While on the move, connectivity is desired for using
software which require cooperation of at least two
machines.

Option for connectivity
An easy option
Use cellular mobile phone network to connect to some
Internet Service Provider and hence to internet.
What you need - cellular phone/ corresponding modem.
Not a good option for campus wide mobile network.
dependent on the mobile telephone network operator
cheaper wireless LAN options available
Other extreme of mobile computer
Mobile computing device
acts as a terminal
have wireless connectivity to the network
Whatever command or application you run is executed
on a remote server.
Mobile computing device acts as remote terminal.
Advantages/ disadvantages of this extreme
Very small, compact and light weight mobile computer
Less power consumption and large battery life - this may
not be true, if radio communication requires more power
than to power up all necessary devices for a standalone
computer on average basis.

For more information about this article,please follow the link:
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BENEFIT-BASED DATA CACHING IN AD HOC NETWORKS-MOBILE COMPUTING

Data caching can significantly improve the efficiency of information access in a wireless ad hoc network by reducing the access latency and bandwidth usage. However, designing efficient distributed caching algorithms is non-trivial when network nodes have limited memory. In this article, we consider the cache placement problem of minimizing total data access cost in ad hoc networks with multiple data items and nodes with limited memory capacity. The above optimization problem is known to be NP-hard. Defining benefit as the reduction in total access cost, we present a polynomial-time centralized approximation algorithm that provably delivers a solution whose benefit is at least one-fourth (one-half for uniform-size data items) of the optimal benefit. The approximation algorithm is amenable to localized distributed implementation, which is shown via simulations to perform close to the approximation algorithm. Our distributed algorithm naturally extends to networks with mobile nodes. We simulate our distributed algorithm using a network simulator (ns2), and demonstrate that it significantly outperforms another existing caching technique (by Yin and Cao [30]) in all important performance metrics. The performance differential is particularly large in more challenging scenarios, such as higher access frequency and smaller memory.
Technology to use:JAVA

[ashish rawat]

How to get the source code of benefit based data caching