Base station control equipment, mobile station equipment, and radio communication system

• US 20030008656A1
• Filed: 05/24/2002
• Published: 01/09/2003
• Est. Priority Date: 11/24/1999
• Status: Active Grant

• Current Assignee: SGI, Inc.
• Original Assignee: Fujitsu Limited
• Inventors: Yamashita, Atsushi, Tetsuka, Akiko
• Granted Patent: US 6,987,972 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/20 for optimising the interference level
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

The invention relates to a radio communication system, a base station control equipment and a mobile station equipment which constitute the radio communication system. An object of the present invention to maintain high channel capacity while adapting to geographical distribution of a mobile station which can perform soft hand-off. The base station control equipment comprises a transmission-quality measuring section for measuring the transmission qualities of reception waves arriving from mobile stations. In the process of channel control, the base station control equipment is given the allowable maximum number N of radio channels through which a BTS transmits in parallel, as a tolerable limit of interference with wireless zones formed by a local station and/or other stations. It allots, in descending order of the transmission qualities, N or less radio channels to the mobile stations which are transmitting ends of reception waves having measured transmission qualities.

Claims

1. A base station control equipment, comprising:

a channel controlling section being cooperative with a plurality of BTSs individually forming a plurality of wireless zones, for performing channel control of a call occurring in a single or a plurality of mobile stations which is located in any of the wireless zones;

a radio interfacing section for transmitting/receiving a speech signal and/or control information relating to the channel control via a radio channel which is allotted to the single or each of the plurality of mobile stations via any of the plurality of BTSs, under the channel control performed by said channel controlling section; and

a transmission-quality measuring section for measuring, under the channel control performed by said channel controlling section, transmission qualities of reception waves individually reaching all or a part of the plurality of BTSs from any of the single or the plurality of mobile stations, which is a possible subject of soft hand-off, and wherein,

said channel controlling section being given a maximum number N of radio channels through which the plurality of BTSs transmits in parallel, for allotting, in descending order of the measured transmission qualities, N or less radio channels to the mobile stations via one of the BTSs as radio channels to be used for the soft hand-off, the mobile stations being transmitting ends of the reception waves with their transmission qualities measured by said transmission-quality measuring section.

2. The base station control equipment according to claim 1, wherein

said channel controlling section allots, via a BTS, a radio channel preferentially to one of the single or plurality of mobile stations whose transmission quality has been measured by said transmission-quality measuring section, the radio channel being used for transmission of the speech signal, the BTS having received a reception wave having the highest measured transmission quality.

3. The base station control equipment according to claim 1, wherein:

said channel controlling section identifies one of the single or the plurality of mobile stations which has notified, based on a procedure of the channel control, a state in which the soft hand-off is feasible; and

said transmission-quality measuring section measures a transmission quality of only a reception wave arriving from the identified mobile station.

4. The base station control equipment according to claim 1, wherein

said channel controlling section is given from an exterior an allowable limit of interference to a wireless zone formed under control of a local station and/or other stations to apply a value suitable for the limit as the maximum number N of the radio channels.

5. The base station control equipment according to claim 1, wherein

said channel controlling section applies a number given from an exterior as the maximum number N of the radio channels.

6. A mobile station equipment, comprising:

a radio interfacing section forming a radio transmission path between the mobile station equipment and a single or a plurality of BTSs which forms wireless zones, for transmitting/receiving transmission information via the radio transmission path;

a channel controlling section being cooperative with the single or the plurality of BTSs via said radio interfacing section and the radio transmission path, for performing channel control of the wireless zones; and

a transmission-quality measuring section for measuring a transmission quality of a downlink of a wireless zone which is formed by all or a part of the single or the plurality of BTSs, and which is identified in a process of the channel control by said channel controlling section, and wherein

being given an allowable maximum number n of radio channels which are used in parallel for soft hand-off of a local station, and when identifying a state in which the local station is feasible of the soft hand-off, said channel controlling section notifies the state to one of the single or the plurality of BTSs which forms n or less individual wireless zones specified according to the measured transmission qualities in descending order of the qualities.

9. The mobile station equipment according to claim 6, wherein

said transmission-quality measuring section measures a level of a downlink of a wireless zone to convert the measured level to the transmission quality of the downlink, the wireless zone being formed by all or a part of the single or plurality of BTSs, and being identified by said channel controlling section in a process of the channel control.

10. The mobile station equipment according to claim 6, wherein

said transmission-quality measuring section determines a phase of a reception wave received via a downlink of a wireless zone to convert the phase to the transmission quality of the downlink, the wireless zone being formed by all or a part of the single or the plurality of BTSs, and being identified by said channel controlling section in a process of the channel control.

13. The mobile station equipment according to claim 6, wherein

said channel controlling section obtains or calculates, based on a procedure of the channel control, the allowable maximum number n of the radio channels which are used for the soft hand-off of the local station.

15. The mobile station equipment according to claim 6, wherein

said channel controlling section obtains or is given in advance, based on a procedure of the channel control, information indicating a form of service to be provided for the local station, and sets the allowable maximum number n of the radio channels to be used for the soft hand-off of the local station at a value suitable for the information.

7. A mobile station equipment, comprising:

a radio interfacing section forming a radio transmission path between the mobile station equipment and a single or a plurality of BTSs which forms wireless zones, for transmitting/receiving transmission information via the radio transmission path;

a channel controlling section being cooperative with the single or the plurality of BTSs via said radio interfacing section and the radio transmission path, for performing channel control of the wireless zones; and

a position measuring section for measuring a position of a local station, and wherein

being given an allowable maximum number n of radio channels which are used in parallel for soft hand-off of the local station and base-station positions which indicate individual positions of all or a part of the BTSs, and when identifying a state in which the local station is feasible of the soft hand-off, said channel controlling section notifies the state to a BTS forming n or less wireless zones which are specified according to relative distances in ascending order of the relative distances between the measured position of the local station and its corresponding base-station positions.

8. The mobile station equipment according to claim 7, wherein

said position measuring section measures levels of downlinks of the plurality of wireless zones to convert the measured levels to the position of the local station, the wireless zones being formed by all or a part of the single or plurality of BTSs, and being identified by said channel controlling section in a process of the channel control.

11. The mobile station equipment according to claim 7, wherein

said position measuring section determines phases of reception waves received via downlinks of a plurality of wireless zones to convert the phases to the position of the local station, the wireless zone being formed by all or a part of the single or the plurality of BTSs, and being identified by said channel controlling section in a process of the channel control.

12. The mobile station equipment according to claim 7, wherein

said channel controlling section obtains positional information of all or a part of the BTSs to apply the positional information as the base-station position, the positional information being notified from the BTSs based on a procedure of the channel control.

14. The mobile station equipment according to claim 7, wherein

said channel controlling section obtains or calculates, based on a procedure of the channel control, the allowable maximum number n of the radio channels which are used for the soft hand-off of the local station.

16. The mobile station equipment according to claim 7, wherein

said channel controlling section obtains or is given in advance, based on a procedure of the channel control, information indicating a form of service to be provided for the local station, and sets the allowable maximum number n of the radio channels to be used for the soft hand-off of the local station at a value suitable for the information.

17. A radio communication system, comprising:

a single or a plurality of mobile station equipments which can be located in any of a plurality of wireless zones;

a plurality of BTSs individually forming the plurality of wireless zones; and

a base station controller being cooperative with said plurality of BTSs, for performing channel control of a call occurring in said single or plurality of mobile station equipments, the channel control including soft hand-off, and wherein

said single or plurality of mobile station equipments each includes;

a transmission-quality obtaining section for measuring transmission qualities of downlinks of all or a part of the plurality of wireless zones; and

a notifying section being given an allowable maximum number n of radio channels to be used in parallel for the soft hand-off of a local station, and when identifying a state in which the local station is feasible of the soft hand-off, for notifying the state to one of the plurality of BTSs forming n or less wireless zones which are specified according to the measured transmission qualities in descending order of the qualities; and

said base station controller includes;

a transmission-quality measuring section for measuring transmission qualities of reception waves arriving in the notified state from said single or plurality of mobile station equipments; and

a channel allotting section being given a maximum number N of radio channels through which the plurality of BTSs can transmit in parallel, for allotting N or less radio channels to mobile stations in descending order of the measured transmission qualities via a BTS as radio channels to be used for the soft hand-off, the mobile stations being transmitting ends of the reception waves with their transmission qualities measured.

18. A radio communication system, comprising:

a single or a plurality of mobile station equipments which can be located in any of a plurality of wireless zones;

a plurality of BTSs individually forming the plurality of wireless zones; and

a base station controller being cooperative with said plurality of BTSs, for performing channel control of a call occurring in said single or plurality of mobile station equipments, the channel control including soft hand-off, and wherein

said single or plurality of mobile station equipments each includes;

a position measuring section for measuring a position of a local station; and

a notifying section being given an allowable maximum number n of radio channels used in parallel for the soft hand-off of the local station and base-station positions indicating positions of all or a part of said single or plurality of BTSs, and when identifying a state in which the local station is feasible of the soft hand-off, for notifying the state to the BTSs individually forming n or less wireless zones which are specified according to relative distances in ascending order of the relative distances between the measured position of the local station and the corresponding base-station positions; and

said base station controller includes;

a transmission-quality measuring section for measuring transmission qualities of reception waves arriving in the notified state from said single or plurality of mobile station equipments; and

a channel allotting section being given a maximum number N of radio channels through which the plurality of BTSs can transmit in parallel, for allotting N or less radio channels to mobile stations in descending order of the measured transmission qualities via a BTS as radio channels to be used for the soft hand-off, the mobile stations being transmitting ends of the reception waves with their transmission qualities measured.