Method and system for data link expansion or contraction using spread

Abstract

A simple and flexible over-air protocol for use with a mobile telephone system, having hand-held telephones in a micro cell or other type of cellular communication system. A method in which user stations communicate with one or more base stations to place and receive telephone calls, in which the user stations are provided a secure voice or data link and have the ability to handoff calls between base stations while such calls are in progress. Each base station has a set of 'air channels' to which it transmits in sequence. The air channels supported by each base station are called that base station's 'polling loop'. A user station receives general polling information on an unoccupied air channel, transmits responsive information to the base station, and awaits acknowledgment from the base station. Each base station may therefore simultaneously maintain communication with as many user stations as there are air channels in its polling loop. The ability of a user station to communicate on any unoccupied air channel makes the protocol air-channel agile, while the stability of user station and base station clocks may define air channels, gaps, and minor frames. In a preferred embodiment, a user station may communicate at an increased data rate by acquiring and communicating in multiple time slots that are either contiguous or non-contiguous within a time frame, or may communicate at a reduced data rate by communicating in alternating time frames or every N time frames.