Adaptive Intelligent Ad-Hoc Networks
The Wireless network has seen an exponential growth due to its ability to free its user from the expenses and hassles in setting up their infrastructure. Such growth is more spectacular in the emerging economies where there was minimal or no presence of wired communication infrastructure in the past. Reputable market research firms have identified that the wireless network users will grow by a factor of 8 by 2007 (Gartner, Inc., March 26, 2003), while wireless product shipments grew by 73% in 2002 (Dataquest Inc., September 19, 2002). Even a small fraction, such as 1%, of the broadband network market is a significant figure for a viable medium sized business. Despite many new advances in technology, consumers are dependent on the infrastructures of large companies to satisfy their need. The performance of centralized and large-scale networks could be significantly curtailed at a time of congestion, or completely lost due to natural or unnatural disasters. There are numerous applications of a communication network whose operation does not depend on such large-scale infrastructure and does not require any network administrator to configure the system at the end-user premises.
However, not much breakthrough has been made in this area and the ad-hoc networking industry is in its infancy. Self-organizing wireless networks can extend the power of computing technology to dynamic and harsh environments. To achieve this, network protocols need to extract relevant information from the environment (i.e., sense the environment), and make intelligent decisions about how best to support the requirements of an individual user or application. This is done while maximizing overall system utilization. This significantly extends current network technology, which was designed for more predictable and stable environments. Applications such as remote community communications, battle management, emergency responses and tough terrain communications in oil-field exploration need to take advantage of self-organizing networks.
What is Ad-Hoc?
In the last decade, developments in wireless data communication, such as GSM, GPRS, WLAN and mobile devices, including PDAs and mobile phones, were combined into a trend—mobile communication. The movement of mobile nodes in the network could be random or predictable, static or fast moving. They may move as individual or as a group.
Ad-hoc networks are formed by users or devices wishing to communicate without the necessity or existence of any centralized administration or infrastructure. Total Mobility is one of the most common reasons to apply ad-hoc topologies.
Wireless Ad-Hoc Networks:
Wireless Ad-Hoc networks are mobile by virtue of their characteristic. Each node in a wireless ad-hoc network has a wireless access interface, e.g. Bluetooth, WLAN, UWB, etc., and is free to enter or leave the network at any time. Ad-hoc networks can function as standalone networks meeting direct communication requirements of their users, or as an addition to existing infrastructure based networks to extend or enhance their coverage. This kind of communication becomes a valuable solution, especially in situations of missing or incomplete network. Regardless of application and technology, the following are the main features of ad-hoc networks:
Dynamic network topology: Due to node mobility and wireless radio propagation, network topology is constantly changing. This requires specific designed network protocol functions for topology construction and maintenance
Distributed nature: As there is no permanent central administrator or authority, all networking functions have to be distributed across participating nodes
Multi-hop communications: Due to limited range of wireless interfaces, usually it is not possible to setup direct communication links between all nodes. The nodes must run routing algorithms to establish routes in the network and to forward packets destined for other nodes; as well as route packets with real-time constraint in some cases (e.g. voice transmission)
Limited bandwidth: Wireless technologies that are envisaged to be suitable for ad-hoc networks provide.