Method and apparatus using alternate frames for handover in TDMA mobile communications system

A mobile telephone comprising:

• a single radio;
• circuitry that monitors signal quality with various base stations;
• and
• circuitry that, when the mobile telephone is in communication with a first base station, wherein the frame has a plurality of timeslots for the base station to use to communicate with various of a plurality of mobile telephones in a cell covered by the base station and the frame comprises an uplink and downlink communication, causes the mobile telephone to request communication with a second base station based on the measured signal quality of the respective base stations, wherein the circuitry causes the communication to occur with both the first base station and the second base station on a series of alternate frames before communication is dropped with the first base station.

A base station comprising:

• a radio capable of communication with mobile telephones, the radio using frames, a frame comprising a plurality of times lots;
• and
• circuitry that establishes communication with a mobile telephone when the mobile telephone is in communication with another base station, wherein
• the circuitry sends to the mobile telephone the same frames from the network that the another base station sends to the mobile telephone
• the circuitry receives alternate frames from the mobile telephone, which sends frames alternately to the base station and the another base station before communication is dropped from either the base station or the another base station.

A mobile communications system comprising:

• a plurality of base stations;
• a plurality of mobile telephones, each mobile telephone communicating with at least a base station from the plurality of base stations using frames;
• circuitry that, when a mobile telephone has established communication with a first base station, if resources are available in a second base station, causes communication to be established with the second base station, the circuitry causing communication to occur with both the first and second base stations on a series of alternate frames before communication is dropped with the first base station, wherein a frame comprises two half frames and each half frame includes no more than six timeslots, wherein the circuitry attempts to establish communication with the second base station if signal quality of communication with the first base station is below a particular level and the circuitry drops communication with a base station if signal quality of communication with the base station is below a particular level;
• circuitry in the mobile telephone that monitors signal quality with various base stations;
• and circuitry in the mobile telephone that selects the second base station based on the measured signal quality of the various base stations.