Patent ID: 7142521

Claim:
A wireless packet data communications system, comprising: a control station, and a plurality of widely dispersed, remote terminals having an active mode during which they are capable of at least one of transmitting and receiving data packets and a sleep mode during which they are inactive, said control station and each of said remote terminals being capable of engaging in packet data communication over a TDM forward link from said control station to said terminals and a multiple access return link from said terminals to said control station, each said remote terminal having an address and being assigned specific times on the forward link during which it may be addressed by said control station, and each said terminal including a timer operable in said sleep mode to cause said terminal to periodically enter the active mode during its assigned time and listen for incoming data packets from said control station addressed to said terminal, and a means for interpreting packets received over the forward link, and said control station including a storage device for storing information pertaining to the times assigned to the various remote terminals, means for transmitting data packets addressed to specific terminals at their assigned times on the forward link, and means for receiving data packets from the terminals in times on the return link.