Mobile nodes in mobile ad-hoc networks play an important role in establishing communication between various devices in the network. These mobile nodes are free to move and organize themselves in an arbitrary fashion. Each user is free to roam about while in communication with others. The path between each pair of the mobile devices may have multiple links, and the radio between them can be heterogeneous. This organization allows an association of various links to be a part of the same network.

In situations where networks are constructed and destructed in an ad-hoc manner, mobile ad-hoc networking is an excellent choice. The idea of mobile ad-hoc, or packet radio networks, first emerged in the early 1970s when they were first implemented to conduct a feasible report about the performance of radio devices in providing communication in a battle field environment.

However, with the development of notebooks, etc. the idea of commercial ad-hoc networks was developed. In this article, I'll present a brief overview of the critical features of mobile ad-hoc networks. This article should be helpful to readers who have already gained a fair understanding of these networks through some of my previous articles.

Mobile ad-hoc networks are highly dynamic. Node mobility introduces certain scalability problems in mobile ad-hoc network protocols. When network topology changes frequently, control messages have to be sent between nodes so that new routes are found and propagated throughout the network.

In such environments, it's reasonable to expect that when topology changes happen there might be a short period where a lot of control messages will propagate across the network to distribute the new destination paths. Therefore, the protocol designer should make provision for highly dynamic and fast adapting algorithms that minimize control messages, and attempt to utilize long-lived routes to the maximum extent.

Minimising control messages is also essential, because of the additional load they place in the bandwidth-constrained wireless links. There's at least an order of magnitude difference between wired and wireless data rates, with the former having a standardised 100 megabits/sec in a local Ethernet, and the latter having a nominal bit rate of 10Mbit/sec in the best case. The techniques used to reduce control messages must strike a balance between the minimum amount of messages and flooding the network each time the topology changes by keeping network state information in each node.