Nortel Networks Corporation

Kris Ng

David G Steer

Koon Hoo Teo

Adrian Smith

Hamid Syed Mahmood

Fayaz Kadri

Yusupha Touray

Tricci So

Donald Wade

System and method for seamless roaming over scalable wide area Wireless LAN networks (WAWLAN) with clientless mobile subscribers. A preferred embodiment comprises a wireless gateway (WG) coupled to one or more access points in a wireless network to form a wireless cluster (WC), a network access gateway (NAG) coupled to a wired network, and a switch coupled to the WG and the NAG. Each wireless cluster is a Wireless LAN Network (WLAN) with homogenous or heterogeneous network architecture. The WG detects mobile nodes in a wireless cluster and tracks mobile node location in the wireless cluster. The NAG is an anchor point for mobile nodes in the WAWLAN and maintains a fixed source of information about each mobile node regardless of their mobility. The switch provides connectivity between the NAG and the WG. Seamless roaming across Wireless LAN network boundary by mobile subscribers without requiring special mobility enabling client software.

Clientless mobile subscribers with seamless roaming over scalable wide area wireless networks

A wireless network has nodes, which can be accessed by wireless terminals via wireless access links, coupled via wireless transit links using multiple directional antenna beams. The nodes are self-organizing and self-adapting as nodes are added and as other changes occur. A new node uses beam scanning to listen for signals from any existing nodes and responds accordingly to join a network. Established nodes each recurrently transmit a welcome message on unused beams, to be received by a new node. Failure of transit links, e.g. due to interference on a channel frequency, is detected with automatic restoration using another frequency. Beam scanning can be enhanced using alternate overlapping beams and diversity techniques.

Distributed multi-beam wireless system

Growing community of inventors

Kanata, Canada

Kris Ng