Importance

Loading Importance Indicators...

Abstract

A local area network permits wireless transfer of digitized data among data processing machines in the interior of a building. The network includes a base station which may commonly be associated with shared network resources such as a host computer, print servers and file servers and a plurality of local stations each associated with a data processing machine such as a dumb terminal dependent on the host computer. The base station polls each local station to initiate a transmission of data to the base station. All data including request for data is transmitted as temporally spaced-apart packets spread spectrum modulated according to a pseudo-random noise code common to all stations and encoded onto an RF carrier which is common to all stations. The transmitted data packets include a synchronization code which permits proper spread spectrum decoding without loss of relevant data. The base station uses one of three spaced-apart antennas for transmission of data to each of the local stations and records for each local station the antenna last used for data transfer. If an insufficient number of successful transmissions occur between successive transmission errors, the base station selects a different antenna for further transmissions and effectively updates its recorded information regarding the antenna used. Accordingly, with RF obstructions such as persons passing between the base station and a local station, the base station hunts for an alternative transmission path to maintain communications with the local station.

Loading the Abstract Image...

First Claim