Wireless ad hoc networks
Irish researchers are using collaborative learning techniques to develop a routing protocol for mobile ad hoc networks (MANETs). In these networks, which can integrate any kind of WiFi-enabled computing devices such as laptops, smart mobile phones and handheld devices, the "mobile nodes collectively learn and self-organize to exploit any fixed or temporary network infrastructure in the environment." Such networks are currently being tested in the center of Dublin before being deployed in other large cities.
Here is the introduction of this article published in a spcial issue of ERCIM News about "Emergent Computing."
In the SAMPLE project, we are investigating decentralized collaborative learning techniques to develop a routing protocol for Mobile Ad Hoc Networks, where routing agents collectively learn to exploit stable routing paths in the network environment. This approach to routing lends itself to large-scale ubiquitous computing scenarios, in which large numbers of ubiquitous mobile devices are intermixed with static infrastructure networks.
How does this work?
The SAMPLE project is concerned with developing a MANET routing protocol for WiFi-enabled computing devices such as laptops, smart mobile phones and handheld devices. In MANET routing protocols, computing devices, also called nodes, act as both consumers and providers of the routing services in the network. In particular, we have been investigating how nodes can collectively determine the stability and quality of network links in the system. This ability is particularly beneficial in the presence of a wireless infrastructure, as nodes learn to route over the higher-performance stable paths in the infrastructure to access popular services such as e-mail and the Web.
Below is a small diagram showing the components of a wireless node and the installation of these nodes in the WAND testbed (Credit: WAND project).
This routing protocol, SAMPLE, has already being tested successfully in simulators and is moving now to the real world.
We are now moving to the deployment phase of the project, in which the protocol will be tested on a real-world testbed. The Wireless Area Network for Dublin (WAND), which we have deployed in the centre of Dublin city, is a testbed infrastructure covering a 1.5km route from Trinity College to Christchurch Cathedral. It allows experimentation on both protocols and applications for MANETs in a metropolitan area. An initial implementation of the protocol has been developed for Linux and experiments will establish its performance in a real-world wireless network.
Below is a map of the WAND testbed in the center of Dublin (Credit: WAND project).
For more information about these self-organizing networks, you can read these two highly technical papers, "Using Feedback in Collaborative Reinforcement Learning to Adaptively Optimize MANET Routing" (PDF format, 13 pages, 571 KB) and "Emergent Consensus in Decentralised Systems using Collaborative Reinforcement Learning" (PDF format, 18 pages, 176 KB).
Sources: Jim Dowling and Stefan Weber, ERCIM News No. 64, January 2006; and various web sites
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