The concept of ad-hoc networking opens a broad spectrum of potential applications. The first, and the most important scenario, is the ability to establish a network in places where it's not possible otherwise: i.e., in a disaster relief setting, or in a situation where the entire communication structure has been destroyed.

One thing we should be clear about is, there's no doubt two machines in an ad-hoc network could be networked, but with a completely different art of network formation. No router, no administrator, no access server, etc. What does it mean? It means we can't use the existing strategies for network control as efficiently as we do in a fixed wireless network. New technology requires new techniques. This is one of the major issues that appears to be an obstacle in deploying an ad-hoc network as a leading technology in the future wireless generation.

Routing, security, limited bandwidth, and low power are some of the important challenges to the technology. As far as low power is concerned, it's more of a hardware issue. However, it does effect the other operations of the ad-hoc network. When each participating host has to be a router, packets are forwarded to all other nodes in the network. For wireless 1 to send packets to wireless 4, it has to take routing services from wireless 2. But what if wireless 2 refuses or is unable to do so. That's a problem.

If we were to ask someone their basic motive in establishing a network, a typical answer might be "to ease communication" among various parties. So, for the time being we'll limit our discussion to the routing mechanism in a mobile ad-hoc network.

As no router is available, each node has to rely on the others to route packets from one host to another. Possible problems could be that a node is not awake, or low on power. What if the node is busy fulfilling the other requests? What if there are already too many packets involved? What if the network is large? What if the node has changed location? Many more questions arise when we talk about routing mechanisms in mobile ad-hoc networks.

A number of solutions have already been proposed for routing in a mobile ad-hoc network. Some focus on maintaining a continuous network view, and some on establishing routes only when required. Both techniques have resolved problems up to a point, but they don't provide the complete solution to the problem.

As for the first solution, maintaining network status all the time reduces the battery life of the participating nodes, and chances are the network won't last long. And with the second, too many query packets not only could lead us toward a bottleneck, but would also consume a good amount of available bandwidth.

One of the possible solutions to the various problems in a mobile ad-hoc network is to recognize one problem as a central issue, and the rest of the problems as inter-related to the central problem. Based on the basic motivation of establishing a communication network, I personally regard routing as one of the core issues. If we take this approach, I'm quite sure we could come up not only with the solution to one problem, but with the solution to many other problems as well. This solution will hopefully lead us toward a structured form of a non-structured network.

David Gewirtz is the author of How To Save Jobs and Where Have All The Emails Gone? For more than 20 years, he has analyzed current, historical, and emerging issues relating to technology, competitiveness, and policy. David is the Editor-in-Chief of the ZATZ magazines, is the Cyberterrorism Advisor for the International Association for Counterterrorism and Security Professionals, and is a member of the instructional faculty at the University of California, Berkeley extension. He can be reached at david@zatz.com and you can follow him at http://www.twitter.com/DavidGewirtz.