EP0717580A2
Expired / Lapsed
EP
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Handover method based upon channel quality measurements
Assignee: AT&T Inc
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Filing: 1995-12-01
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Granted: —
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Expires: 2015-12-01
Abstract
Abstract A method is disclosed for executing handovers in a cellular network, based upon channel quality measurements. For AMPS service, the method involves the monitoring of a supervisory audio tone (SAT) signal which is superimposed on the voice signal that is transmitted between base stations and mobile terminals traveling within a cellular network, and handovers are executed in dependence upon noise power measurements associated therewith. For TDMA service, the method involves the monitoring of a raw data signal associated with digital transmissions, and handovers are executed in dependence upon noise power measurements associated therewith.
Inventors
- 👤 Robert Chuenlin Wang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 18:16
CPC Classifications
H; H04; H04W; H04W36/00; H04W36/08; H04W36/083; H04W36/24; H04W36/30; H04W36/302; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
82 words
A method for handing over an ongoing radio transmission of a mobile terminal traveling within a cellular network, said network having a plurality of adjoining cells each having a base station, and a multiplicity of channels, comprising the step of: handing over the ongoing radio transmission of a mobile terminal traveling in one of said plurality of cells to an idle channel in an adjacent cell in dependence upon a baseband noise power level measured by a base station in that cell.
Claim 2
Dependent Claim
56 words
A method according to Claim 1, wherein said step of handing over an ongoing radio transmission of a mobile terminal involves a measurement of the baseband noise power of a supervisory audio tone (SAT) signal superimposed on a voice signal received by a baseband signal processing unit associated with each base station in the cellular network.
Claim 3
Dependent Claim
41 words
A method according to Claim 2, wherein said step of handing over an ongoing radio transmission of a mobile terminal includes the step of selecting an idle channel having the highest baseband SAT noise power level in a selected target cell.
Claim 4
Dependent Claim
44 words
A method according to Claim 1, wherein said step of handing over an ongoing radio transmission of a mobile terminal involves a measurement of a raw data noise power associated with a digital voice/data signal generated in a time divisional multiple access (TDMA) system.
Claim 5
Dependent Claim
41 words
A method according to Claim 4,. wherein said step of handing over an ongoing radio transmission of a mobile terminal includes the step of selecting an idle channel having the highest raw data noise power level in a selected target cell.
Claim 6
Independent Claim
200 words
A method of allocating channels to mobile terminals traveling within a cellular network having a plurality of adjoining cells, each of said cells having therein a base station and a multiplicity of channels for call allocation, each base station having a signal processing unit for generating and monitoring a baseband voice/data signal having a supervisory audio tone (SAT) superimposed thereon, said method comprising the steps of: a) calculating the SAT signal power to SAT noise power ratio for an ongoing radio transmission between a mobile terminal and a base station; b) determining whether the ratio between the SAT signal power and the SAT noise power is below a predetermined threshold value; c) commanding each base station adjacent to the base station in communication with the mobile terminal to determine the SAT signal power to SAT noise power ratio for the mobile terminal; d) selecting the adjacent cell having the highest determined SAT signal power to SAT noise power ratio as a target cell for receiving the ongoing radio transmission; e) selecting an idle channel within the target cell having the highest SAT noise power; and f) handing-over the ongoing radio transmission to the selected idle channel within the target cell.
Claim 7
Independent Claim
206 words
A method of allocating channels to mobile terminals travelling within a cellular network having a plurality of adjoining cells, each of said cells having therein a base station and a multiplicity of channels for call allocation, each mobile terminal configured to transmit a digital voice/data signal in accordance with a time division multiple access system, the method comprising the steps of: a) calculating the raw data signal power to raw data noise power ratio for an ongoing digital transmission between a mobile terminal and a base station during a synchronization word interval; b) determining whether the raw data signal power to raw data noise power ratio is below a predetermined threshold value; c) commanding each base station adjacent to the base station in communication with the mobile terminal to determine the raw data signal power to raw data noise power ratio for the mobile terminal; d) selecting an adjacent cell having the highest determined raw data signal power to raw data noise power ratio as a target cell for receiving the ongoing radio transmission; e) selecting an idle channel within the target cell having the highest raw data noise power; and f) handing-over the ongoing radio transmission to the selected idle channel within the target cell.
References Cited (Backward Citations)
US5001742A
Cited
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