A self-healing and self-adaptive wireless network infrastructure - the stuff of network administrators' dreams - is expected to become a reality in June this year, following pilots, begun last year, of wireless meshed network technology conducted by Nortel Networks and MIT.

The wireless meshed network architecture has auto-discovery and self-healing algorithms to simplify deployment and reduce outages by optimising radio link communications and minimising interference, the company claims. It creates a Community Access Network (CAN), which is a cluster of wireless access points that form a mesh, expanding the WLAN hotspot.

"The administration work increases exponentially when the access points increase from two or three to 200 or 300 access points," said Philip Goldie, Alteon product manager for Nortel Networks Asia Pacific.

The self-organising nature of the architecture removes the need for radio frequency engineering or commissioning, so it can be installed anywhere where there's power - significantly increasing WLAN coverage. Previously, a detailed radio frequency design had to be produced so access points did not interfere with another.

"The wireless meshed network is a self-healing network," said Goldie. "When an access point fails, the network can dynamically raise the strength of surrounding access points to provide coverage for the missing area."

This is achieved by using a different radio frequency between adjacent access points which transmits status, as well as data between access points. The self-healing, self-discovery functions allow the system to dynamically re-provision itself, Nortel says. Meshes also make it easier to identify illegal or unauthorised access points.

Meshes are particularly good for deployments in open areas or where no LAN infrastructure exists, such as warehouse and university campus environments. They replace the wired backhaul or transit link with a wireless link, eliminating the need to install additional LAN cabling and other infrastructure to extend WLAN service beyond the reach of the existing LAN.

"In the usual setup, every wireless access point will need to be connected to a wired network," said Goldie. "For the meshed network, it is possible to have the whole network access supported through a single wire feed, with all the access points meshed into a network."

A meshed network ought to provide consistent quality of service. For example, if signal strength were affected by other appliances such as microwave ovens, the network should detect it and counter it by increasing the transmit power of the access points. According to Goldie, each access point currently needs an AC power outlet but future versions could use solar power.

Nortel's Optivity Network Management System (ONMS) provides centralised facilities for monitoring and managing the network operations.

The trial projects were started late last year and are due to end soon. According to Goldie, more trials will be set up by educational centres and carriers entering the market.