A broadband wireless access network based on mesh-connected free-space optical links

Abstract

Driven by the twin forces of industry-wide deregulation and the explosive demand for Internet access and bandwidth-intensive multimedia services, broadband local access has emerged as one of the key issues in modern telecommunications. We describe a broadband local access network consisting of small, densely spaced packet-switching nodes interconnected by focused free-space optical links in a multihop mesh arrangement. Each switch serves a client, which may be an office building (containing, for example, conventional PBXs and LANs), a picocellular base station, or both. It is the responsibility of our local access network to economically and reliably extend broadband local access service (perhaps OC-3 or OC-12 for building LANs and PBXs; perhaps several tens of megabits per second to base stations) from an infrastructure end office or fiber ring add/drop multiplexer without requiring the installation of new buried optical cabling. Computed is the capacity of the multihop mesh, defined to be the maximum number of virtual connections which can be delivered to the infrastructure access point such that, independent of the traffic distribution among clients, all quality of service guarantees are maintained.