APPARATUS AND METHOD FOR AUTOMATICALLY RECONFIGURING FREE SPACE LOCAL AREA NETWORK SYSTEMS

摘要

Communication devices such as computers are connected to nodes (102, 104, 106) equipped with free-space optical receivers and transmitters (108, 110, 112, 114). Nodes are linked optically by line-of-sight paths to neighboring nodes. The topology of the links can be a ring (100) or a string (200) or a star (300). Optical signals are passed from a node to a neighboring node. A link is robust when it is viable in both directions. The advantage of a robust link is that if the optical link between two adjacent nodes becomes impaired, the data communication path at the node that is upstream to the impairment can be reversed and the signals directed in the opposite direction from node to node until they are received by the node that is downstream from the impairment. In this way the network either remains functional or else forms into two functional sub-networks, depending on the original configuration.