US6542742B2
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US
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Cell selection in mobile radio systems
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1999-03-31
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Granted: 2003-04-01
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Expires: 2019-03-31
Abstract
Abstract The present invention relates generally to the problem of cell selection, for e.g. cell handover, in mobile telecommunication systems, and more particularly to the problem of selecting the optimum cell among cells with differing capabilities due to different air interface modes. Known algorithms for cell selection and handover are extended by applying additional criteria that take into account the capabilities, due to different modulation and coding schemes, of the mobile station and the base stations that are possible candidates. The quality of service (“QoS”) is predicted for the different cell candidates based on a combination of signal strength or C/I, different cell capabilities, multislot capability, etc. Then the cell is selected for which the predicted QoS is maximum. In another embodiment the invention is extended by taking into account further criteria which are suitable from a system point of view, e.g. to avoid a significant increase of average outage probability or interference level. The present invention increases the use of base stations supporting high data rates. The result is an increase in overall system throughput.
Inventors
- 👤 Peter Schramm
- 👤 Frank Müller
- 👤 Håkan Gunnar Olofsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:28
CPC Classifications
H; H04; H04W; H04W36/00; H04W36/24; H04W36/30; H04W36/304; H04W36/26; H04W72/00; H04W72/50; H04W72/54
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
160 words
A method for cell selection in a cellular mobile communications system having a plurality of cells with different air interface schemes, each of said cells comprising at least one Base Station, wherein a Mobile Station communicates with said mobile communications system through an air interface link to one of said at least one Base Station, the method comprising the steps of: determining communications capabilities of said Base Stations and of said Mobile Station based on a corresponding air interface scheme; determining possible links between said Mobile Station and said Base Stations based on the communication capabilities; estimating the quality of each of said possible links between said Mobile Station and said Base Stations; estimating a Quality of Service value for each of said possible links between said Mobile Station and said Base Stations based on at least the measured link quality and the communication capabilities; and selecting the cell with the Base Station having the highest estimated Quality of Service.
Claim 2
Independent Claim
160 words
A method for cell selection in a cellular mobile communications system having a plurality of cells with different air interface schemes, each of said cells comprising at least one Base Station, wherein a Mobile Station communicates with said mobile communications system through an air interface link to one of said at least one Base Station, the method comprising the steps of: determining communications capabilities of said Base Stations and of said Mobile Station based on a corresponding air interface scheme; determining possible links between said Mobile Station and said Base Stations based on the communication capabilities; estimating the quality of each of said possible links between said Mobile Station and said Base Stations; estimating a Quality of Service value for each of said possible links between said Mobile Station and said Base Stations based on at least the measured link quality and the communication capabilities; and selecting the cell with the Base Station having the highest estimated Quality of Service.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein, each air interface scheme based on a different coding and modulation scheme.
Claim 4
Dependent Claim
32 words
The method of claim 1 wherein, said communications capabilities of said plurality of Base Stations and of said Mobile Station are measured in terms of the capabilities of said air interface schemes.
Claim 5
Dependent Claim
36 words
The method of claim 1 wherein, said capabilities of said plurality of Base Stations and of said Mobile Station are measured in terms of the multislot availability on the links to said plurality of Base Stations.
Claim 6
Dependent Claim
36 words
The method of claim 1 wherein, said capabilities of said plurality of Base Stations and of said Mobile Station are measured in terms of the multicarrier availability on the links to said plurality of Base Stations.
Claim 7
Dependent Claim
21 words
The method of claim 1 wherein, said highest Quality of Service is equivalent to the highest data throughput on said link.
Claim 8
Dependent Claim
27 words
The method of claim 1 wherein, said highest Quality of Service is equivalent to a combination of the lowest Bit Error Rate and a sufficient data rate.
Claim 9
Dependent Claim
27 words
The method of claim 1 wherein, said highest Quality of Service is equivalent to a combination of the sufficient Bit Error Rate and the highest data rate.
Claim 10
Dependent Claim
18 words
The method of claim 1 wherein, said highest Quality of Service is equivalent to the highest speech quality.
Claim 11
Dependent Claim
16 words
The method of claim 1 further comprising the step of: testing for a given system criterion.
Claim 12
Dependent Claim
19 words
The method of claim 10 wherein, said system criterion is the test if load is below a given threshold.
Claim 13
Dependent Claim
25 words
The method of claim 10 wherein, said system criterion is a test to determine if the increase in interference level is below a given threshold.
Claim 14
Dependent Claim
33 words
The method of claim 10 wherein, said system criterion is the test if system criterion indicator based on a combination of load, interference level, and desired data rate is below a given threshold.
Claim 15
Dependent Claim
39 words
The method of claim 1 wherein, said Mobile Station is currently accessing said mobile system from a first Base Station and said cell selection is performed for implementing a handover for said Mobile Station to a second Base Station.
Claim 16
Dependent Claim
33 words
The method of claim 1 wherein, said Mobile Station is preparing to access said mobile system and said cell selection is performed for selecting the best cell through which to access said system.
Claim 17
Dependent Claim
19 words
The method of claim 1 wherein, said cell selection is performed while said Mobile Station is in idle mode.
Claim 18
Dependent Claim
24 words
The method of claim 1 wherein, said Mobile Station and said plurality of Base Stations all support an equal number of air interface schemes.
Claim 19
Dependent Claim
46 words
The method of claim 1 wherein, said Mobile Station and at least one of said plurality of Base Stations supports an equal number of air interface schemes, and at least one of the plurality of Base Station supports fewer air interface schemes than said Mobile Station.
Claim 20
Dependent Claim
46 words
The method of claim 1 wherein, said Mobile Station and at least one of said plurality of Base Stations supports an equal number of air interface schemes, and at least one of the plurality of Base Station supports more air interface schemes than said Mobile Station.
Claim 21
Dependent Claim
36 words
The method of claim 1 wherein, said Mobile Station, at least one of said plurality of Base Stations and a second of said plurality of Base Stations each support a different number of air interface schemes.
Claim 22
Independent Claim
164 words
A system for cell selection in a cellular mobile communications system having a plurality of cells with different air interface schemes, each of said cells comprises at least one Base Station, wherein a Mobile Station for communicating with said mobile system though an air interface link to one of said at least one Base Stations, comprising: means for determining communication capabilities of said Base Stations and of said Mobile Station based on a corresponding air interface scheme; means for determining possible links between said Mobile Station and said Base Stations based on the communication capabilities; means for estimating the quality of each of said possible links between said Mobile Station and said Base Stations; means for estimating a Quality of Service value for each of possible links between said Mobile Station and said Base Stations based on at least the measured link quality and the communication capabilities; and means for selecting the cell with the Base Station having the highest estimated Quality of Service.
Claim 23
Independent Claim
164 words
A system for cell selection in a cellular mobile communications system having a plurality of cells with different air interface schemes, each of said cells comprises at least one Base Station, wherein a Mobile Station for communicating with said mobile system though an air interface link to one of said at least one Base Stations, comprising: means for determining communication capabilities of said Base Stations and of said Mobile Station based on a corresponding air interface scheme; means for determining possible links between said Mobile Station and said Base Stations based on the communication capabilities; means for estimating the quality of each of said possible links between said Mobile Station and said Base Stations; means for estimating a Quality of Service value for each of possible links between said Mobile Station and said Base Stations based on at least the measured link quality and the communication capabilities; and means for selecting the cell with the Base Station having the highest estimated Quality of Service.
Claim 24
Dependent Claim
18 words
The system for cell selection of claim 21 further comprising: means for testing for a given system criterion.
Claim 25
Dependent Claim
158 words
A radiocommunication system comprising: a mobile station; a first base station; a second base station; and a control unit connected to said first and second base stations, wherein communication capabilities of said first and second base stations and of said mobile station are determined based on a corresponding air interface scheme, wherein possible links between the mobile station and the first and second base stations are determined based on the communication capabilities, wherein the quality of each of the possible links between the mobile station and the first and second base stations are estimated, wherein a Quality of Service value for each of the possible links between the mobile station and the first and second base stations is estimated based on at least the measured link quality and the communication capabilities, and wherein a cell in the radiocommunication system associated with either the first or the second base stations is selected based upon the estimated Quality of Service.
Claim 26
Dependent Claim
158 words
A radiocommunication system comprising: a mobile station; a first base station; a second base station; and a control unit connected to said first and second base stations, wherein communication capabilities of said first and second base stations and of said mobile station are determined based on a corresponding air interface scheme, wherein possible links between the mobile station and the first and second base stations are determined based on the communication capabilities, wherein the quality of each of the possible links between the mobile station and the first and second base stations are estimated, wherein a Quality of Service value for each of the possible links between the mobile station and the first and second base stations is estimated based on at least the measured link quality and the communication capabilities, and wherein a cell in the radiocommunication system associated with either the first or the second base stations is selected based upon the estimated Quality of Service.
Claim 27
Dependent Claim
16 words
The radiocommunication system of claim 23 , wherein the control unit is a base station controller.
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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) | 2006-03-31 | 2006-09-30 | 2007-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2010-03-31 | 2010-09-30 | 2011-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2014-03-31 | 2014-09-30 | 2015-04-01 | $7700.00 | Window Closed / Lapsed |