Method and system for effecting handoff in a cellular communication system
AssigneeHughes Aircraft Compnay
InventorsCharles A. Barnett, Stanley E. Kay, Lou King, Ashok D. Mehta
Life of this patent
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Abstract
A method and system for handing off an on-going communication from a serving cell to a neighboring cell of a cellular communication system having scanning receivers associated with each base transceiver station. A dynamic threshold is calculated for effecting the handoff in accordance with various operating conditions. The current mobile minimum attentuation level, (MT) the minimum permissible attenuation level of a serving (MS) cell and a neighboring cell (MN), together with the RF signal strength of the mobile unit at the neighboring cell (RSSI-NBR) and the serving cell (RSSI-SRV) are used in calculating a dynamic threshold (RSSI-THP).
Claims22
A method of handing off an on-going communication of a mobile unit from a serving cell to a neighboring cell of a cellular communication system, comprising:
- handing off the communication to a neighboring cell at times when the scanning receiver signal strength of the mobile unit at the neighboring cell is greater than a determined cell selection threshold for the neighboring cell;
- and
- determining the cell selection threshold using the current attenuation level of the mobile unit, a minimum permissible attenuation level permitted by the serving cell, and a minimum permissible attenuation level permitted by the neighboring cell.
A system for effecting handoff of a mobile telephone communication from a serving cell to a neighboring cell of a cellular communication system having a plurality of mobile switching centers coupled to a telephone network, a plurality of base station controllers coupled to each mobile switching center, and a plurality of base transceiver stations, each defining an individual cell, and a plurality of scanning receivers for each base transceiver station for scanning neighboring cells, the system comprising:
- means for handing off the communication to a neighboring cell at times when the scanning receiver signal strength of the mobile unit at the neighboring cell is greater than a cell selection threshold for the neighboring cell;
- and
- means for determining the cell selection threshold in accordance with a current attenuation level of the mobile unit, as compared to a minimum attenuation level permitted by the serving cell and a minimum attenuation level permitted by the neighboring cell.
Dependencies are inferred from the claim text.