RADIO COMMUNICATION SYSTEM AND METHOD, RADIO TERMINAL, RADIO STATION, AND OPERATION ADMINISTRATION AND MAINTENANCE SERVER APPARATUS

• US 20130170362A1
• Filed: 09/20/2011
• Published: 07/04/2013
• Est. Priority Date: 10/01/2010
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Futaki, Hisashi, Morita, Motoki
• Granted Patent: US 9,294,950 B2
• Time in Patent Office: Days
• US Class Current: 370/241.1
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 84/045 using private Base Stations, e.g. femto Base Stations, home Node B

Abstract

A system includes: first and second radio stations (eNB1,2) of a similar type and/or a third radio station (HeNB) of a different type, a radio terminal (UE) served by the eNB1; and an operation administration and maintenance server (OAM/SON server), wherein the eNB1 instructs the UE to measure interference from at least one of the second or third radio stations, the eNB1 and/or OAM/SON server receives a report of a measurement result by the UE, determines whether or not a change is to be made to the radio network configuration of the relevant radio station that is at least one of the first to third radio stations, and/or executes a change of the radio network configuration.

Claims

1. A radio communication system wherein the system comprises:

a first radio station;

a second radio station of a similar type to the first radio station and/or a third radio station of a different type from the first radio station;

a radio terminal served by the first radio station; and

an operation administration and maintenance server that exchanges configuration information with at least one of the first to third radio stations,

wherein the first radio station instructs the radio terminal to measure received quality of a downlink signal from at least one of the second or the third radio station,

the radio terminal performs the measurement in accordance with the instruction,

at least one of the first radio station and the operation administration and maintenance server comprises

a unit that receives a report of a measurement result by the radio terminal, identifies, from the report, a type of the radio station, and performs at least one of determining whether or not a change is to be made to a radio network configuration of at least one radio station of the first to third radio stations, and changing the radio network configuration.

2. The radio communication system according to claim 1, wherein a change in the radio network configuration by at least one of the first radio station and the operation administration and maintenance server is intended for optimization of at least one of coverage and inter-cell interference.

3. The radio communication system according to claim 1, wherein based on one or more measurement reports by the radio terminal, in a case where

an interference or a received quality of an interference signal from the second radio station is less than or equal to a predetermined first preset level, and

an interference or a received quality of an interference signal from the third radio station is greater than or equal to a predetermined second preset level,

at least one of the first radio station and the operation administration and maintenance server makes no change to the radio network configuration.

4. The radio communication system according to claim 1, wherein based on one or more measurement reports by the radio terminal, in a case where

an interference or a received quality of an interference signal from the second radio station is less than or equal to a predetermined first preset level, and

an interference or a received quality of an interference signal from the third radio station is greater than or equal to a predetermined second preset level,

at least one of the first radio station and the operation administration and maintenance server executes optimization of inter-cell interference between the first radio station and the third radio station with priority over optimization of coverage of at least one of the first radio station and the second radio station.

5. The radio communication system according to claim 3, wherein a preset offset is provided between the first preset level and the second preset level.

6. The radio communication system according to claim 1, wherein based on one or more measurement reports by the radio terminal, in a case where

reports stating that an interference or a received quality of an interference signal from the second radio station is greater than or equal to a predetermined third preset level, are less than a predetermined first preset threshold in number, and

reports stating that an interference or a received quality of an interference signal from the third radio station is greater than or equal to a predetermined fourth preset level, are greater than or equal to a predetermined second preset threshold in number,

at least one of the first radio station and the operation administration and maintenance server makes no change to the radio network configuration.

7. The radio communication system according to claim 1, wherein based on one or more measurement reports by the radio terminal, in a case where

reports stating that an interference or a received quality of an interference signal from the second radio station is greater than or equal to a predetermined third preset level, are less than a predetermined first preset threshold in number, and

reports stating that an interference or a received quality of an interference signal from the third radio station is greater than or equal to a predetermined fourth preset level, are greater than or equal to a predetermined second preset threshold in number,

at least one of the first radio station and the operation administration and maintenance server executes optimization of inter-cell interference between the first radio station and the third radio station with priority over optimization of coverage of at least one of the first radio station and the second radio station.

8. The radio communication system according to claim 6, wherein a preset offset is provided between the third preset level and the fourth preset level.

9. The radio communication system according to claim 2, wherein the first and second radio stations are macro cell base stations,

the third radio station is a femto cell base station,

the radio terminal, responsive to a measurement instruction from the first radio station, measures received quality of a downlink signal of a serving macro cell and a neighboring cell, and reports a measurement result to the first radio station,

the first radio station transmits the report received from the radio terminal to the operation administration and maintenance server,

the operation administration and maintenance server aggregates contents of measurement reports transmitted via the first radio station from the radio terminal, per type of a neighboring cell that is a target of the measurement,

based on the contents of measurement reports aggregated per type of a neighboring cell, in a case where

among the reports stating that a received quality of a neighboring cell is greater than or equal to a predetermined preset value, the number of the neighboring cells, each being a macro cell, is greater than or equal to a predetermined preset number,

the operation administration and maintenance server determines that optimization of the macro cell is necessary, and

in a case where

among the reports stating that a received quality of a neighboring cell is greater than or equal to the preset value, the number of the neighboring cells, each being a femto cell, is greater than or equal to the preset number,

the operation administration and maintenance server determines that optimization of the femto cell is necessary,

the operation administration and maintenance server instructing at least one relevant radio station among the first to third radio stations to adjust the radio network configuration in order to optimize at least one of coverage and inter-cell interference.

10. The radio communication system according to claim 2, wherein the first and second radio stations are macro cell base stations,

the third radio station is a femto cell base station,

the radio terminal, on receipt of an measurement instruction over a radio from the first radio station, measures received quality of a serving macro cell and a neighboring cell, and reports a measurement result to the first radio station,

the first radio station aggregates contents of measurement reports transmitted from the radio terminal, per type of a neighboring cell that is a target of the measurement, and then reports to the operation administration and maintenance server,

based on the contents of measurement reports aggregated per type of a neighboring cell, in a case where

among the reports stating that a received quality of a neighboring cell is greater than or equal to a predetermined preset value, the number of the neighboring cells, each being a macro cell, is greater than or equal to a predetermined preset number,

the operation administration and maintenance server determines that optimization of the macro cell is necessary, and

in a case where

among the reports stating that a received quality of a neighboring cell is greater than or equal to the preset value, the number of the neighboring cells, each being a femto cell, is greater than or equal to the preset number,

the operation administration and maintenance server determines that optimization of the femto cell is necessary,

the operation administration and maintenance server instructing at least one relevant radio station among the first to third radio stations to adjust the radio network configuration in order to optimize at least one of coverage and inter-cell interference.

11. The radio communication system according to claim 6, wherein based on one or more measurement reports by the radio terminal, in a case where;

among the reports stating that a received quality of the neighboring cell is greater than or equal to the preset value, the number of the neighboring cells, each being a macro cell, is greater than or equal to the preset number,

at least one of the first radio station and the operation administration and maintenance server executes coverage optimization by increase or decrease of coverage, while in a case where;

the number of the neighboring cells, each being a femto cell, is greater than or equal to the preset number,

at least one of the first radio station and the operation administration and maintenance server executes avoidance of interference from the femto cell.

12. The radio communication system according to claim 1, wherein the first and second radio stations are macro cell base stations,

the third radio station is a femto cell base station,

the radio terminal receives over a radio an instruction of measurement from the first radio station, measures received quality of a serving macro cell and a neighboring cell, and reports a measurement result to the first radio station,

the first radio station aggregates contents of measurement reports transmitted from the radio terminal per type of a neighboring cell that is a target of the measurement, and in a case where a decision is made that optimization by the first radio station is necessary, executes optimization and then reports to the operation administration and maintenance server,

based on the contents of measurement reports aggregated per type of a neighboring cell, in a case where

among the reports stating that a received quality of a neighboring cell is greater than or equal to a predetermined preset value, the number of the neighboring cells, each being a macro cell, is greater than or equal to a predetermined preset number, the operation administration and maintenance server determines that optimization of the macro cell is necessary, and executes optimization, and

in a case where

among the reports stating that a received quality of a neighboring cell is greater than or equal to the preset value, the number of the neighboring cells, each being a femto cell, is greater than or equal to a predetermined preset number, the operation administration and maintenance server determines that optimization of the femto cell is necessary,

the operation administration and maintenance server instructing the corresponding second radio station or the corresponding third radio station to adjust the radio network configuration in order to perform optimization.

13. The radio communication system according to claim 1, wherein the first and second radio stations are macro cell base stations,

the third radio station is a femto cell base station,

based on one or more measurement reports by the radio terminal, in a case where

the number of reports stating that a received quality (RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality)) of a downlink reference signal from a base station of a femto cell which is a neighboring cell of a cell of the first radio station is greater than or equal to a predetermined preset value, is greater than or equal to a predetermined preset number, and

the number of reports stating that a received quality (RSRP, RSRQ) of a downlink reference signal from a base station of a macro cell which is a neighboring cell of a cell of the first radio station is greater than or equal to a predetermined preset value, is less than the preset number,

coverage increase or decrease, or interference avoidance between macro cells is not performed, and

in a case where

the number of reports stating that a received quality (RSRP, RSRQ) of a downlink reference signal from a base station of the neighboring macro cell is greater than or equal to a predetermined preset value, is greater than or equal to the preset number,

optimization for coverage increase or decrease of macro cell, or interference avoidance are performed.

14. The radio communication system according to claim 1, wherein the radio terminal performs measurement and recording in an idle mode, and after detecting a coverage hole in an idle mode, establishes a radio link with the first radio station, goes to an active mode, and reports a measurement result to the first radio station.

15. The radio communication system according to claim 1, wherein the first and second radio stations are macro cell base stations,

the third radio station is a femto cell base station,

even if the number of reports received by the first radio station, wherein the reports stating that femto cell interference is dominant, is greater than or equal to a predetermined preset number, the first radio station makes no change to a radio network configuration for macro cell coverage optimization, and

in a case where the number of reports received by the first radio station, wherein the reports stating that neighboring macro cell interference is dominant, is greater than or equal to a predetermined preset number, the first radio station changes a radio network configuration of a base station of the neighboring macro cell and performs coverage optimization.

16. A radio communication method comprising:

instructing a radio terminal from a first radio station, to measure interference received from at least one radio station that is at least one of a second radio station of a similar type to the first radio station, and a third radio station of a different type from the first radio station;

the radio terminal performing measurement in accordance with the instruction; and

receiving, by at least one of the first radio station and an operation administration and maintenance server, a report of a measurement result by the radio terminal, identifying a type of the radio station from the report, and performing at least one of determining whether or not to change a radio network configuration of at least one radio station of the first to third radio stations, and changing the radio network configuration.

17. The radio communication method according to claim 16, wherein a change of a radio network configuration by at least one of the first radio station and the operation administration and maintenance server, is intended for optimization of at least one of coverage and inter-cell interference.

18. The radio communication method according to claim 16, wherein based on one or more measurement reports by the radio terminal, in a case where an interference or a received quality of an interference signal from the second radio station is less than or equal to a predetermined first preset level, and

an interference or a received quality of an interference signal from the third radio station is greater than or equal to than a predetermined second preset level,

at least one of the first radio station and the operation administration and maintenance server making no change to the radio network configuration, or, at least one of the first radio station and the operation administration and maintenance server performing optimization of inter-cell interference between the first radio station and the third radio station with priority over optimization of coverage of at least one of the first radio station and the second radio station.

19. The radio communication method according to claim 16, comprising:

the operation administration and maintenance server aggregating contents of measurement reports transmitted via the first radio station from the radio terminal, per type of a neighboring cell that is a target of the measurement,

based on the contents of measurement reports aggregated per type of a neighboring cell, in a case among the reports stating that a received quality of a neighboring cell is greater than or equal to a predetermined preset value, the number of the neighboring cells, each being a macro cell, is greater than or equal to a predetermined preset number, the operation administration and maintenance server determining that optimization of the macro cell is necessary,

in a case where among the reports stating that a received quality of a neighboring cell is greater than or equal to the preset value, the number of the neighboring cells, each being a femto cell, is greater than or equal to the preset number, the operation administration and maintenance server determining that optimization of the femto cell is necessary, and

the operation administration and maintenance server instructing at least one relevant radio station among the first to third radio stations, to adjust the radio network configuration in order to optimize at least one of coverage and inter-cell interference.

20. A radio station connected by radio to a radio terminal, where the radio station comprises

a unit that instructs the radio terminal to measure interference received from at least one radio station that is at least one of a second radio station of a similar type to the radio station and a third radio station of a different type from the radio station;

and

a unit that receives a report of a measurement result from the radio terminal, identifies a type of the radio station from the report, and executes at least one of determining whether or not to change a radio network configuration of at least one of the radio station and the second and third radio stations, and changing the radio network configuration.

21. The radio station according to claim 20, wherein based on one or more measurement reports by the radio terminal, in a case where an interference or a received quality of an interference signal from the second radio station is less than or equal to a predetermined first preset level, and

a received quality of at least one of an interference signal and interference from the third radio station is greater than or equal to than a predetermined second preset level,

the radio station makes no change to the radio network configuration, or, performs optimization of inter-cell interference between the first radio station and the third radio station with priority over optimization of coverage of at least one of the first radio station and the second radio station.

22. An operation administration and maintenance server apparatus, wherein the server apparatus comprises

a unit that receives a report of a measurement result by a radio terminal via a first radio station that instructs the radio terminal to measure interference received from at least one radio station that is at least one of a second radio station of a similar type to the first radio station and a third radio station of a different type from the first radio station, identifies a type of the radio station from the report, and

a unit that performs at least one of determining whether or not to change a radio network configuration of at least one radio station of the first radio station through third radio station, and changing the radio network configuration.

23. The operation administration and maintenance server apparatus according claim 22, wherein based on one or more measurement reports by the radio terminal, in a case where an interference or a received quality of an interference signal from the second radio station is less than or equal to a predetermined first preset level, and

an interference or a received quality of an interference signal from the third radio station is greater than or equal to than a predetermined second preset level,

the operation administration and maintenance server apparatus makes no change to the radio network configuration, or, executes optimization of inter-cell interference between the first radio station and the third radio station with priority over optimization of coverage of the first radio station and/or the second radio station.

24. The operation administration and maintenance server apparatus according claim 22, wherein based on one or more measurement reports by the radio terminal, in a case where

among the reports stating that a received quality of the neighboring cell is greater than or equal to a predetermined preset value, the number of the neighboring cells, each being a macro cell, is greater than or equal to a predetermined preset number, the operation administration and maintenance server determines that optimization of the macro cell is necessary, and

in a case where

among the reports stating that received quality of the neighboring cell is greater than or equal to the preset value, the number of the neighboring cells, each being a femto cell, is greater than or equal to the preset number, the operation administration and maintenance server determines that optimization of the femto cell is necessary,

the operation administration and maintenance server determines giving an instruction to at least one relevant radio station among the first to third radio stations, to adjust the radio network configuration in order to optimize at least one of coverage and inter-cell interference.