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WIRELESS INFRASTRUCTURE
The history of mobile ad-hoc networks
By Humayun Bakht
A mobile ad-hoc network is a collection of mobile nodes forming an ad-hoc network without the assistance of any centralized structures. These networks introduced a new art of network establishment and can be well suited for an environment where either the infrastructure is lost or where deploy an infrastructure is not very cost effective.
There are quite a number of uses for mobile ad-hoc networks. For example, the military can track an enemy tank as it moves through the geographic area covered by the network. Your local community can use an ad-hoc network to detect your car moving though an intersection, checking the speed and direction of the car. In an environmental network, you can find out the temperature, atmospheric pressure, amount of sunlight, and the relative humidity at a number of locations.
The whole life-cycle of ad-hoc networks could be categorized into the first, second, and the third generation ad-hoc networks systems. Present ad-hoc networks systems are considered the third generation.
The first generation goes back to 1972. At the time, they were called PRNET (Packet Radio Networks). In conjunction with ALOHA (Areal Locations of Hazardous Atmospheres) and CSMA (Carrier Sense Medium Access), approaches for medium access control and a kind of distance-vector routing PRNET were used on a trial basis to provide different networking capabilities in a combat environment.
The second generation of ad-hoc networks emerged in 1980s,when the ad-hoc network systems were further enhanced and implemented as a part of the SURAN (Survivable Adaptive Radio Networks) program. This provided a packet-switched network to the mobile battlefield in an environment without infrastructure. This program proved to be beneficial in improving the radios' performance by making them smaller, cheaper, and resilient to electronic attacks.
In the 1990s, the concept of commercial ad-hoc networks arrived with notebook computers and other viable communications equipment. At the same time, the idea of a collection of mobile nodes was proposed at several research conferences.
The IEEE 802.11 subcommittee had adopted the term "ad-hoc networks" and the research community had started to look into the possibility of deploying ad-hoc networks in other areas of application.
Meanwhile, work was going on to advance the previously built ad-hoc networks. GloMo (Global Mobile Information Systems) and the NTDR (Near-term Digital Radio) are some of the results of these efforts. GloMo was designed to provide an office environment with Ethernet-type multimedia connectivity anywhere and anytime in handheld devices.
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