US6434389B1
Expired / Lapsed
US
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Method for selecting cell in cellular network
Assignee: Nokia Technologies Oy
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Filing: 2000-03-03
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Granted: 2002-08-13
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Expires: 2020-03-03
Abstract
Abstract The present invention relates to prioritizing special cells in cell selection in a cellular radio network. In a cellular radio network one or more cells provide a subscriber with special services or tariffs not offered to all subscribers. These cells are called subscriber's special cells. The mobile station measures an average reception level and calculates by means of them cell selection parameters on the basis of which the best cell is selected. In accordance with the invention, when the mobile station detects that the cell is one of cells of a special cell list stored in a memory, it checks first if the cell fulfils a minimum requirement of cell selection on the basis of the measured signal level. If the minimum requirement is fulfilled, the mobile station manipulates the calculation of the cell selection parameter of a special cell to the effect that the selection probability of a special cell is improved with respect to a normal cell. In a preferred embodiment of the invention, the manipulation of the calculation comprises a step of adding a predetermined margin to the measured signal level of a special cell before the cell selection parameter is calculated. This will minimize the possibility that the mobile station would accidentally be camped on a normal cell when it is within the area of a special cell.
Inventors
- 👤 Harri Meskanen
- 👤 Petri Jolma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:38
CPC Classifications
H; H04; H04W; H04W48/00; H04W48/20
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
164 words
A method for selecting a cell of a cellular radio network in a mobile station, which method comprises the steps of measuring signal levels of a serving cell and adjacent cells in a mobile station in the idle mode, calculating a cell selection parameter for each measured cell by means of the measured signal levels, and selecting the best cell to be the serving cell on the basis of the cell selection parameters, characterized in that the method further comprises the steps of comparing the cells to be measured with a special cell list stored in the memory of the mobile station, checking if each cell identified as a special cell fulfils the pre-determined minimum requirement of cell selection on the basis of the measured signal level, and manipulating the calculation of a cell selection parameter of a special cell that fulfils the minimum requirement to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 2
Independent Claim
164 words
A method for selecting a cell of a cellular radio network in a mobile station, which method comprises the steps of measuring signal levels of a serving cell and adjacent cells in a mobile station in the idle mode, calculating a cell selection parameter for each measured cell by means of the measured signal levels, and selecting the best cell to be the serving cell on the basis of the cell selection parameters, characterized in that the method further comprises the steps of comparing the cells to be measured with a special cell list stored in the memory of the mobile station, checking if each cell identified as a special cell fulfils the pre-determined minimum requirement of cell selection on the basis of the measured signal level, and manipulating the calculation of a cell selection parameter of a special cell that fulfils the minimum requirement to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 3
Dependent Claim
64 words
A method according to claim 1 , characterized in that the step of manipulating the calculation of the cell selection parameter comprises a step of adding a pre-determined margin to the measured signal level of a special cell before the cell selection parameter is calculated to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 4
Dependent Claim
57 words
A method according to claim 1 , characterized in that the step of manipulating the calculation of the cell selection parameter comprises a step of adding a pre-determined margin to the cell selection parameter of the special cell to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 5
Dependent Claim
32 words
A method according to claim 1 , characterized in that the method comprises the step of broadcasting the pre-determined margin to the mobile stations from the base station of the serving cell.
Claim 6
Dependent Claim
55 words
A method according to claim 1 , characterized in that the method comprises the step of broadcasting to the mobile station from the base station of the cell a first parameter reporting the lowest signal level the mobile station is to receive from the measured cell to fulfil the minimum requirement for a normal cell.
Claim 7
Dependent Claim
89 words
A method according to claim 1 , characterized in that the calculation of the minimum requirement for a normal or special cell comprises the steps of calculating a parameter C 1 =(A−Max(B, 0 )) where A=the received level average-RXLEV_ACCESS_MIN B=MS_TXPWR_MAX_CCH-P RXLEV_ACCESS_MIN=the minimum received level at the mobile station required for accessing the system MS_TXPWR_MAX_CCCH=the maximum transmission power level the mobile station can use for accessing the system unless otherwise commanded, P=the maximum output power of the mobile station, considering the minimum requirement to be fulfilled if C 1 >0.
Claim 8
Dependent Claim
64 words
A method according to claim 1 , characterized in that the method comprises the step of broadcasting to the mobile station from the base station of the cell a second parameter reporting the lowest signal level the mobile station is to receive from the measured cell to fulfil the minimum requirement for a special cell, the second parameter being higher than the first parameter.
Claim 9
Dependent Claim
122 words
A method according to claim 7 , characterized in that the calculation of the minimum requirement comprises the steps of calculating a parameter C 1 =(A−Max(B, 0 )) where A=the received level average−RXLEV_ACCESS_MIN when the cell is a normal cell, A=the received level average−LSA_RXLEV_ACCESS_MIN when the cell is a special cell, B=MS_TXPWR_MAX_CCH−P RXLEV_ACCESS_MIN=the minimum received level at the mobile station required for accessing the system in a normal cell, LSA_RXLEV_ACCESS_MIN=the minimum received level at the mobile station required for accessing the system in a special cell, MS_TXPWR_MAX_CCCH=the maximum transmission power level the mobile station can use for accessing the system unless otherwise commanded, P=the maximum output power of the mobile station, considering the minimum requirement to be fulfilled if C 1 >0.
Claim 10
Dependent Claim
97 words
A method according to claim 6 , characterized by calculating for a normal cell a cell selection parameter C 2 =C 1 −CELL_RESELECT_OFFSET where CELL_RESELECT_OFFSET=the cell selection offset in the cell, calculating for a special cell a cell selection parameter C 2 =[(A+LSA_CAMPING_MARGIN)-Max(B, 0 )]−CELL_RESELECT_OFFSET where LSA_CAMPING_MARGIN is the margin added to the received signal level before the cell selection parameter is calculated to the effect that the selection probability of a special cell is improved with respect to a normal cell, selecting a cell with the highest value of the cell selection parameter C 2 .
Claim 11
Dependent Claim
26 words
A method according to claim 1 , characterized in that the cell selection parameter is a cell re-selection criterion C 2 in accordance with GSM recommendations.
Claim 12
Dependent Claim
44 words
A method according to claim 1 characterized by a step of preventing the manipulation of the calculation of the cell selection parameter for prioritizing special cells after the mobile station is switched on until the mobile station the first time camps on some cell.
Claim 13
Dependent Claim
151 words
A cellular radio system comprising mobile stations and base stations, the mobile stations being arranged to measure in the idle mode the received signal levels of cells and to select as the serving base station the cell which is the best on the basis of a cell selection parameter calculated by means of the measured signal levels, characterized in that the mobile station comprises means for storing a special cell list, means for comparing the cells to be measured with the special cell list, a means which checks if a cell identified as a special cell fulfils the pre-determined minimum requirement of cell selection on the basis of the measured signal level, and means for manipulating the calculation of the cell selection parameter of a special cell that fulfils this minimum requirement to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 14
Dependent Claim
151 words
A cellular radio system comprising mobile stations and base stations, the mobile stations being arranged to measure in the idle mode the received signal levels of cells and to select as the serving base station the cell which is the best on the basis of a cell selection parameter calculated by means of the measured signal levels, characterized in that the mobile station comprises means for storing a special cell list, means for comparing the cells to be measured with the special cell list, a means which checks if a cell identified as a special cell fulfils the pre-determined minimum requirement of cell selection on the basis of the measured signal level, and means for manipulating the calculation of the cell selection parameter of a special cell that fulfils this minimum requirement to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 15
Dependent Claim
57 words
A system according to claim 12 , characterized in that the means for manipulating the calculation of the cell selection parameter comprise a means that adds a pre-determined margin to the measured signal level of a special cell to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 16
Dependent Claim
63 words
A system according to claim 12 , characterized in that the means for manipulating the calculation of the cell selection parameter comprise a means that adds a pre-determined margin to the measured cell selection parameter of a special cell, calculated in the normal manner, to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 17
Dependent Claim
23 words
A system according to claim 13 , characterized in that the broadcasting of the base station of the cell comprises the pre-determined margin.
Claim 18
Dependent Claim
47 words
A system according to claim 13 , characterized in that the broadcasting of the base station of the cell comprises a first parameter indicating the lowest signal level the mobile station is to receive from the measured cell to fulfil the minimum requirement for a normal cell.
Claim 19
Dependent Claim
56 words
A system according to claim 16 , characterized in that the broadcasting of the base station of the cell comprises a second parameter indicating the lowest signal level the mobile station is to receive from the measured cell to fulfil the minimum requirement for a special cell, the second parameter being higher than the first parameter.
Claim 20
Dependent Claim
46 words
A system according to claim 12 , characterized in that the mobile communication system is GSM or DCS or the like, and that the minimum requirement is a path loss criterion parameter C 1 and the cell selection parameter is a re-selection, criterion C 2 .
Claim 21
Dependent Claim
26 words
A system according to claim 12 , characterized in that the special cells are cells specified to belong to the local location area of the subscriber.
Claim 22
Dependent Claim
48 words
A system according to claim 12 , characterized in that the means for manipulating the calculation of the cell selection parameter for prioritizing special cells is arranged to be disabled after the mobile station is switched on until the mobile station the first time camps on some cell.
Claim 23
Dependent Claim
143 words
A mobile station which is arranged to measure in the idle mode the received signal levels of cells and to select as the serving base station the cell which is the best on the basis of a cell selection parameter calculated by means of the measured signal levels, characterized in that the mobile station comprises means for storing a subscriber-specific special cell list, means for comparing the cells to be measured with the special cell list, a means which checks if a cell identified as a special cell fulfils the pre-determined minimum requirement of cell selection on the basis of the measured signal level, and means for manipulating the calculation of the cell selection parameter of a special cell that fulfils the minimum requirement to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 24
Dependent Claim
143 words
A mobile station which is arranged to measure in the idle mode the received signal levels of cells and to select as the serving base station the cell which is the best on the basis of a cell selection parameter calculated by means of the measured signal levels, characterized in that the mobile station comprises means for storing a subscriber-specific special cell list, means for comparing the cells to be measured with the special cell list, a means which checks if a cell identified as a special cell fulfils the pre-determined minimum requirement of cell selection on the basis of the measured signal level, and means for manipulating the calculation of the cell selection parameter of a special cell that fulfils the minimum requirement to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 25
Dependent Claim
55 words
A mobile station according to claim 21 , characterized in that the mobile station comprises means for incrementing the measured signal level or the normally calculated value of the cell selection parameter by a pre-determined margin to the effect that the selection probability of a special cell is improved with respect to a normal cell.
Claim 26
Dependent Claim
38 words
A mobile station according to claim 21 , characterized in that the mobile station is arranged to receive the predetermined margin and possibly the minimum requirement of cell selection in the broadcasting of the currently serving base station.
Claim 27
Dependent Claim
52 words
A mobile station according claim 21 , characterized in that the mobile station is a mobile station of a GSM or DCS or corresponding mobile communication system, and that the minimum requirement is a path loss criterion parameter C 1 and the cell selection parameter is a re-selection parameter C 2 .
Claim 28
Dependent Claim
51 words
A mobile station according to claim 21 , characterized by means with which the means for manipulating the calculation of the cell selection parameter for prioritizing special cells is arranged to be disabled after the mobile station is switched on until the mobile station the first time camps on some cell.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-08-12 | 2006-02-11 | 2006-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-08-12 | 2010-02-11 | 2010-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-08-12 | 2014-02-11 | 2014-08-13 | $7700.00 | Window Closed / Lapsed |