Multiband mobile telephone system

• US 5,960,354 A
• Filed: 01/14/1997
• Issued: 09/28/1999
• Est. Priority Date: 05/16/1995
• Status: Expired due to Term

• Current Assignee: Conversant Wireless Licensing S.à.r.l. (f/k/a Core Wireless Licensing S.a.r.l.) (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management)), 2011 Intellectual Property Asset Trust (Nokia Corporation)
• Original Assignee: Nokia Telecommunications Oy (Nokia Corporation)
• Inventors: Einola, Heikki
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/776,279
• Time in Patent Office: 987 Days
• Field of Search: 455/422, 455/436, 455/437, 455/443, 455/444, 455/450, 455/451, 455/452, 455/454, 455/455, 455/67.1, 455/62, 455/63, 370/329, 370/331, 370/332
• US Class Current: 455/454
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/0066 of control information between different types of networks in order to establish a new radio link in the target network
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/0088 Scheduling hand-off measurements
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A cellular mobile telephone system is provided. The system operates on frequency bands each of which comprises a respective total number of sub-bands. Each sub-band has a different respective frequency. The system includes a network of base stations, and mobile stations. The mobile stations comprise a given mobile station communicating with the network on a sub-band within a current operational frequency band comprising one of the operational frequency bands. The network transmits to the given mobile station certain information regarding designated sub-bands for which the given mobile station is to perform measurements. The certain information comprises a minimum number of alternate sub-bands of an alternate operational frequency band other than the current operational frequency band. The given mobile station receives from the network the certain information and transmits to the network a measurement report comprising measurement results for a number of alternate sub-bands equal to at least the minimum number but less than the total number of alternate sub-bands.

Claims

1. A cellular mobile telephone system comprising:

operational frequency bands, each of said operational frequency bands comprising a respective total number of sub-bands, each of said sub-bands having a different respective frequency;

a network of base stations; and

mobile stations comprising a given mobile station communicating with said network on a sub-band within a current operational frequency band comprising one of said operational frequency bands;

said network transmitting to said given mobile station certain information regarding designated sub-bands for which said given mobile station is to perform measurements, said designated sub-bands including current sub-bands within said current operational frequency band and alternate sub-bands within an alternate operational frequency band different from said current operational frequency band, said certain information comprising number data comprising a minimum number of said alternate sub-bands; and

said given mobile station receiving from said network said certain information and transmitting to said network a measurement report comprising measurement results for a reported number of sub-bands including a number of said alternate sub-bands equal to at least said minimum number but less than said total number of said alternate sub-bands.

2. The system according to claim 1, wherein said certain information comprises a precise number of said alternate sub-bands, and wherein said given mobile station transmits to said network a measurement report comprising measurement results for a number of said alternate sub-bands equal to said precise number.

3. The system according to claim 1, wherein said measurement report comprises measurement results for alternate sub-bands with the highest audibility and measurement results for current sub-bands with the highest audibility.

4. The system according to claim 3, wherein said measurement report comprises measurement results for a limited number of sub-bands comprising said current sub-bands and said alternate sub-bands, and wherein said limited number is allocated to said current sub-bands and to said alternate sub-bands so that if the reported number of said current sub-bands is reduced, the reported number of said alternate sub-bands is increased.

5. The system according to claim 1, wherein said minimum number of said alternate sub-bands may be changed.

6. The system according to claim 5, wherein during a communication between said given mobile station and said network, said network transmits a message changing said number data.

7. The system according to claim 6, wherein said certain information comprises a message comprising said number data, said message being transmitted on a dedicated control channel to said mobile station.

8. The system according to claim 1, wherein said certain information comprises a common message including said number data and a list of frequencies corresponding to said current sub-bands and said alternate sub-bands.

9. The system according to claim 1, wherein said certain information comprises one message including a list of frequencies corresponding to said current sub-bands and said alternate sub-bands and a separate message including said numbered data.

10. The system according to claim 9, wherein said operational frequency bands comprise a GSM and a DCS frequency band.

11. The system according to claim 10, wherein said network transmits to said given mobile station system information messages comprising said number data.

12. The system according to claim 1, wherein said system comprises a time division multiple access (TDMA) mobile telephone system.

13. A cellular mobile communications system comprising:

at least two operating frequency bands;

base stations;

mobile stations capable of operating on each one of said at least two frequency bands;

a serving one of said base stations being arranged to transmit at least certain information to a given mobile station communicating on a frequency of a current frequency band of said at least two frequency bands, said certain information comprising designated frequencies that said mobile station will measure within said at least two frequency bands, and a minimum number of frequencies to be reported from an alternate frequency band other than said current frequency band;

said given mobile station being arranged to measure said designated frequencies and to report measurement results for a predetermined number of the measured frequencies in a measurement report transmitted to said serving base station, said predetermined number being less than all of said measured frequencies, and said measurement report including measurement results for at least said minimum number of frequencies from said alternate frequency band.

14. The system according to claim 13, wherein said measurement report always comprises measurements for precisely said minimum number of frequencies from said alternate frequency band.

15. The system according to claim 14, wherein said base station is arranged to transmit said minimum number on a dedicated control channel associated with an on-going call of said given mobile station.

16. A cellular mobile communications system comprising:

a first operating frequency band having first frequencies;

a second operating frequency band having second frequencies;

base stations;

mobile stations capable of operating on each one of said first and second frequency bands;

a serving one of said base stations being arranged to transmit at least certain information to a given mobile station communicating on one of said first frequencies, said certain information comprising a list of designated frequencies that said given mobile station will measure within said first and second frequency bands, and a minimum number N_MIN of said second frequencies to be reported from said second frequency band;

said given mobile station being arranged to measure said designated frequencies and to report measurement results for a predetermined number N₁ of said designated frequencies in a measurement report transmitted to said serving base station, said predetermined number N₁ being smaller than a number N₂ of said designated frequencies, and said measurement report including measurement results for at least said minimum number N_MIN of said second frequencies and measurement results for not more than N₁ -N_MIN of said first frequencies.

17. The system according to claim 16, wherein said measurement report always includes a value representing said minimum number N_MIN of said second frequencies.

18. The system according to claim 16, wherein said measurement report comprises said minimum number N_MIN of said second frequencies having a highest measured signal strength in said second frequency band and measured results for N₁ -N_MIN of said first frequencies having a highest measured signal strength in said first frequency band.

19. The system according to claim 16, wherein said minimum number is adjustable.

20. The system according to claim 16, wherein said base station is arranged to transmit said minimum number in a message in common with said list of frequencies.

21. The system according to claim 16, wherein said base station transmits said minimum number and said list of frequencies in different respective messages.

22. The system according to claim 16, wherein said serving base station is arranged to change said minimum number during an on-going call by transmitting new minimum number information.

23. The system according to claim 16, wherein said base station transmits said minimum number in one system information message.