Abstract: Cells in a radio telephone scheme are covered by beam-spots generated by multi-beam antenna system. Forward communication channels follow mobile units as they move between beam-spots. Additionally, each cell is divided into zones based on the mobile traffic patterns within the cell. Typically, there will be a high density zone covered by many, small area beam-spots, a medium density zone covered by two or three medium sized beam-spots, and a low density zone covered by one large beam-spot. As the mobile traffic patterns change throughout the day, multi-beam antenna dynamically reconfigures the zone and beam-spot layout for each cell, thereby keeping a nearly optimal zone and beam-spot configuration despite varying mobile traffic patterns.

Abstract: A peripheral controller for a PBX system accepts PCM data from a plurality of channels. The channels may be processed in time and space switches of more than one network loop. A channel-merge device merges the PCM data into a combined PCM data stream for connection to a time switch. The time switch is controlled by a connection memory to direct data on specific channels to specific terminals.

Abstract: A drive circuit for terminators in a SCSI (Small Computer Standard Interface) system comprises a bipolar transistor operating in saturated condition to keep the voltage drop to less than 200 millivolts. A second transistor serves to detect when, due to overcurrent conditions, the first transistor goes out off saturation and turns it off. Also provided is means for ensuring that the first transistor turns on before the second transistor on power-up.