A mobile ad-hoc or on the fly network is the collection of mobile nodes that communicate over a wireless medium and do not require any pre installed communication infrastructure. Communication in such a network can be performed if nodes are agreed to exchange packets.

Effective support of multicast or group communication is essential for most ad-hoc network applications. There are many applications where group communication is a crucial task. Group communication, both one-to-many or many-to-many, has become increasingly important in mobile ad-hoc networks. In mobile ad-hoc network group communications, issues differ from those in wired networks because of the variable and unpredictable nature of the wireless medium, where the signal strength and propagation varies with the time and the environment. Moreover, node mobility causes continuously changing topology in which routes break unpredictably and new routes form dynamically.

In mobile ad-hoc network, an efficient group communication model can ease effective communication among various groups in the network. At present, multicasting routing in mobile ad-hoc networks is gained by adopting one of two approaches: flooding and tree-based routing. Flooding offers the lowest control overheads with very high data traffic, while tree-based routing reduces data traffic in the network but requires many control data exchanges. Studies show less efficient performance of these techniques on mobile ad-hoc network.

Group communication technologies have proven their importance in different fields of our daily life, such as education, entertainment, and other industries. Providing efficient group communication is one of the main issues in mobile ad-hoc networks. Moreover, the highly dynamic nature and frequent topology changes make this issue even more challenging. While these networks are rapidly gaining popularity, there is a strong need to develop efficient strategies to support group communication in mobile ad-hoc networks.

Dr. Humayun Bakht completed his Ph.D at the School of Computing and Mathematics in Liverpool at John Moores University. Prior to his current course of studies, he has successfully completed his MSc Software Engineering and BSc Electronics Engineering from University of Liverpool UK and Sir Syed University of Engineering and Technology in Karachi, Pakistan. Humayun's research interest is mobile ad-hoc networks, in particular, the development of a new routing algorithm for this type of networking. He can be reached at humayunbakht@yahoo.co.uk and you can visit his Web site at http://www.geocities.com/humayunbakht/.