JP2014017535A - Radio communication system and its radio resource determination method, radio base station, communication management device and its control method, and control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately determine radio resources by accurately measuring a building penetration loss.SOLUTION: A radio communication system comprises: a first radio station which comprises first measuring means for measuring a first reception level of a radio wave transmitted by a transmission source and transmission means for transmitting a radio signal, and its antenna is placed indoor; and a second radio station which comprises second measuring means for measuring a second reception level of the radio wave transmitted by the transmission source, and its antenna is placed outdoor. The radio communication system is characterized by determining a radio parameter used by the transmission means to transmit a radio signal on the basis of the first reception level and the second reception level.

Description

  The present invention relates to a radio resource setting technique in consideration of an intrusion loss of a radio signal due to a building wall or the like.

  In a radio communication system in which a macro cell controlled by a macro base station includes a plurality of femto cells, the downlink transmission power of the femto base station affects the macro mobile station of the macro cell. Therefore, the device which prevents the interference to the communication of the macro mobile station by the downlink transmission power of the femto base station is made. For example, Patent Document 1 discloses a process in which each femto base station controls the downlink transmission power of the femto base station in consideration of the reception level of a reference signal transmitted from the macro base station.

  Also, when the femtocell is in a building and the femto base station is indoors, even if the downlink transmission power of the femto base station is increased by the amount of building intrusion loss due to the wall of the building, interference with the macro mobile station can be prevented. it can. For this reason, in Patent Document 2, it is assumed that a GPS (Global Positioning System) radio wave is received by a femto base station, and the difference from the estimated outdoor GPS radio wave reception level is a building entry loss. And the technique which further adds this building penetration loss to the downlink transmission power of the said femto base station in patent document 1 is disclosed.

British Publication No. 2428937 International Publication No. 2009/054205

  However, in Patent Document 2, since the estimated standard level is used for the outdoor GPS radio wave reception level, it may be different from the actual building entry loss. For example, if the estimated outdoor GPS radio wave reception level is smaller than the actual level, the building entry loss is smaller than the actual level. Therefore, although the downlink transmission power of the femto base station is further increased, the communication quality in the femto cell is deteriorated by being suppressed to a low level. On the other hand, if the estimated outdoor GPS radio wave reception level is greater than the actual level, the building entry loss is greater than the actual level. For this reason, since the downlink transmission power of the femto base station becomes too high, interference with the macro mobile station is increased. In particular, the latter case becomes a problem.

  The objective of this invention is providing the technique which solves the above-mentioned subject.

In order to achieve the above object, a system according to the present invention provides:
A first wireless station that includes a first measurement unit that measures a first reception level of a radio wave transmitted from a transmission source, and a transmission unit that transmits a radio signal; and an antenna disposed indoors;
A second wireless station comprising a second measuring means for measuring a second reception level of the radio wave transmitted from the transmission source, the antenna being disposed outdoors;
With
Based on the first reception level and the second reception level, the transmission unit determines a radio parameter to be used for transmission of a radio signal.

In order to achieve the above object, the method according to the present invention comprises:
A first wireless station with an antenna indoors;
A radio resource determination method in a radio communication system including a second radio station having an antenna outdoors,
A first measurement step of measuring a first reception level of a radio wave transmitted from a transmission source in the first wireless station;
A second measurement step of measuring a second reception level of the radio wave transmitted from the transmission source in the second wireless station;
A determination step of determining a radio parameter used for transmission of a radio signal by the transmission means of the first radio station based on the first reception level and the second reception level;
It is characterized by including.

In order to achieve the above object, an apparatus according to the present invention provides:
A wireless base station with an antenna indoors,
Measuring means for measuring a first reception level of radio waves transmitted from a transmission source;
Receiving means for receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining means for determining a radio parameter used by the radio base station to transmit a radio signal based on the first reception level and the second reception level;
It is characterized by providing.

In order to achieve the above object, an apparatus according to the present invention provides:
A wireless base station with an antenna indoors,
First receiving means for receiving a first reception level of a radio wave transmitted from a transmission source, measured by a radio mobile station communicating with the radio base station;
Second receiving means for receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining means for determining a radio parameter used by the radio base station to transmit a radio signal based on the first reception level and the second reception level;
It is characterized by providing.

In order to achieve the above object, a method for controlling an apparatus according to the present invention includes:
A control method for a radio base station provided with an antenna indoors,
A measurement step of measuring a first reception level of radio waves transmitted from a transmission source;
A reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
It is characterized by including.

In order to achieve the above object, a method for controlling an apparatus according to the present invention includes:
A control method for a radio base station provided with an antenna indoors,
A first reception step of receiving a first reception level of a radio wave transmitted from a transmission source measured by a radio mobile station communicating with the radio base station;
A second reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
It is characterized by providing.

In order to achieve the above object, a program according to the present invention provides:
A control program for a radio base station with an antenna indoors,
A measurement step of measuring a first reception level of radio waves transmitted from a transmission source;
A reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
A control program that causes a computer to execute.

In order to achieve the above object, a program according to the present invention provides:
A control program for a radio base station with an antenna indoors,
A first reception step of receiving a first reception level of a radio wave transmitted from a transmission source measured by a wireless mobile station located indoors;
A second reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
A control program that causes a computer to execute.

In order to achieve the above object, an apparatus according to the present invention provides:
A communication management device for managing communication in a wireless communication system including a first wireless station having an antenna indoors and a second wireless station having an antenna outdoors,
First acquisition means for acquiring a first reception level of a radio wave transmitted from a transmission source measured by the first wireless station;
Second acquisition means for acquiring a second reception level of a radio wave transmitted from the transmission source, measured by the second wireless station;
Determining means for determining a radio parameter used by the first radio station for transmission of a radio signal based on the first reception level and the second reception level;
It is provided with.

In order to achieve the above object, a method for controlling an apparatus according to the present invention includes:
A control method for a communication management apparatus for managing communication in a wireless communication system including a first wireless station having an antenna indoors and a second wireless station having an antenna outdoors,
A first acquisition step of acquiring a first reception level of a radio wave transmitted from a transmission source measured by the first wireless station;
A second acquisition step of acquiring a second reception level of the radio wave transmitted from the transmission source, measured by the second radio station;
A determining step of determining a radio parameter used by the first radio station for transmitting a radio signal based on the first reception level and the second reception level;
It is characterized by including.

In order to achieve the above object, a program according to the present invention provides:
A control program for a communication management device for managing communication in a wireless communication system including a first wireless station having an antenna indoors and a second wireless station having an antenna outdoors,
A first acquisition step of acquiring a first reception level of a radio wave transmitted from a transmission source measured by the first wireless station;
A second acquisition step of acquiring a second reception level of the radio wave transmitted from the transmission source, measured by the second radio station;
A determining step of determining a radio parameter used by the first radio station for transmitting a radio signal based on the first reception level and the second reception level;
Is executed by a computer.

  ADVANTAGE OF THE INVENTION According to this invention, a radio | wireless resource can be determined appropriately by the accurate measurement of a building penetration loss.

It is a block diagram which shows the structure of the radio | wireless communications system as 1st Embodiment of this invention. It is a figure which shows the structure of the radio | wireless communications system as 2nd Embodiment of this invention. It is a block diagram which shows the structure of the femto base station and macro base station which concern on 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the macro base station which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the femto base station which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the radio | wireless communications system as 3rd Embodiment of this invention. It is a block diagram which shows the structure of the femto base station, macro base station, and macro mobile station which concern on 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the macro mobile station which concerns on 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the macro base station which concerns on 3rd Embodiment of this invention. It is a figure which shows the structure of the radio | wireless communications system as 4th Embodiment of this invention. It is a block diagram which shows the structure of the femto base station which concerns on 4th Embodiment of this invention, a macro base station, and a macro mobile station. It is a flowchart which shows the operation | movement procedure of the macro mobile station which concerns on 4th Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the macro base station which concerns on 4th Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the femto base station which concerns on 4th Embodiment of this invention. It is a figure which shows the structure of the radio | wireless communications system as 5th Embodiment of this invention. It is a block diagram which shows the structure of the femto base station of FIG. 11, a femto mobile station, a macro mobile station, and a management server. It is a flowchart which shows the operation | movement procedure of the macro mobile station which concerns on 5th Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the management server which concerns on 5th Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the femto mobile station which concerns on 5th Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of the femto base station which concerns on 5th Embodiment of this invention.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the components described in the following embodiments are merely examples, and are not intended to limit the technical scope of the present invention only to them.

[First Embodiment]
A wireless communication system as a first embodiment of the present invention will be described with reference to FIG. 1 includes a first radio station 110 located indoors, a second radio station 120 located outdoors, and a determination unit 140. The first radio station 110 includes a first measurement unit 111 and a transmission unit 112. The second radio station 120 includes a second measurement unit 121.

  The first measurement unit 111 measures the first reception level 113 of the signal 131 transmitted from the transmission source 130 and sends it to the determination unit 140. The second measurement unit 121 measures the second reception level 122 of the signal 131 transmitted from the transmission source 130 and sends it to the determination unit 140. The determination unit 140 determines a radio parameter 141 used by the transmission unit 112 of the first radio station 110 based on the first reception level 113 and the second reception level 122.

  With this configuration, it is possible to set an appropriate radio resource by accurately measuring the building entry loss.

[Second Embodiment]
A radio communication system according to the second embodiment of the present invention will be described below. In this embodiment, a GPS satellite is used as a signal source, a signal from the GPS satellite is received by a femto base station and a macro base station, and the reception levels are compared, thereby measuring the building intrusion loss. To do.

<Configuration of Radio Communication System of Second Embodiment>
FIG. 2 is a diagram illustrating a configuration of a wireless communication system 200 according to the second embodiment.

  In the wireless communication system 200 of FIG. 2, a macro base station 220, which is a radio base station having an antenna installed outdoors, controls connection with the macro mobile station 230, which is a radio mobile station in the macro cell 250, by a radio signal 220a. To do. The macro base station 220 receives the GPS radio wave 270a from the GPS satellite 270 and measures the reception level. On the other hand, the femto base station 210, which is a radio base station with an antenna installed indoors, controls connection with the femto mobile station 240, which is a radio mobile station in the femto cell 260, by a radio signal 210a. Further, the femto base station 210 receives the GPS radio wave 270a from the GPS satellite 270 via the wall or roof of the building 280 and measures the reception level. The macro base station 220 sends the measured reception level of the GPS radio wave 270a to the femto base station 210 as transmission data 220b. In the femto base station 210, the difference between the reception level of the GPS radio wave 270a of the femto base station 210 is subtracted from the reception level of the GPS radio wave 270a of the macro base station 220, and the difference is regarded as a building entry loss.

  The femto base station 210 sets the downlink transmission power (to the femto mobile station 240) of the femto base station 210 as high as the building intrusion loss by using the measured accurate building intrusion loss. By setting the downlink transmission power, the transmission power of the radio signal 210a is increased and the communication quality in the femto cell 260 is sufficiently maintained while preventing the interference 210b to the macro mobile station 230 due to the transmission power of the femto base station 210. It becomes possible to do.

<Configuration of Femto Base Station 210 and Macro Base Station 220 of Second Embodiment>
FIG. 3 is a block diagram showing configurations of the femto base station 210 and the macro base station 220 in FIG.

  In FIG. 3, the femto base station 210 receives a GPS radio wave 270 a from a GPS satellite 270 at a GPS radio wave receiver 311 and the macro base station 220 at a GPS radio wave receiver 321. The measurement execution unit 312 of the femto base station 210 measures the reception level of the GPS radio wave 270a received indoors by the femto base station 210. The measurement execution unit 322 of the macro base station 220 measures the reception level of the GPS radio wave 270a received by the macro base station 220 outdoors. The measurement result notification unit 323 of the macro base station 220 transmits the reception level of the GPS radio wave 270a as the measurement result by the measurement execution unit 322 to the femto base station 210 as the transmission data 220b. The femto base station 210 receives the transmission data 220b including the reception level of the GPS radio wave 270a transmitted from the macro base station 220 by the measurement result acquisition unit 313.

  The intrusion loss calculation unit 314 of the femto base station 210 subtracts the reception level of the GPS radio wave 270a measured indoors by the femto base station 210 itself from the reception level of the GPS radio wave 270a measured outdoors transmitted from the macro base station 220. . Then, this difference is calculated as an actual accurate building entry loss. The accurate building entry loss is sent to the wireless parameter update unit 315. The radio parameter update unit 315 updates the radio parameter, in this example, in particular, the downlink transmission power of the femto base station 210 using an accurate building intrusion loss. The transmission unit 316 communicates with the femto mobile station 240 using the radio signal 210a having the downlink transmission power. Since the femto base station 210 communicates with the femto mobile station 240 using the radio signal 210a based on the updated radio parameters, the communication quality in the femtocell 260 is sufficiently maintained while preventing interference with the macro mobile station 230. it can.

<Operation of Femto Base Station 210 and Macro Base Station 220 of Second Embodiment>
FIG. 4 is a flowchart showing an operation procedure of the femto base station 210 and the macro base station 220 shown in FIG.

  In step S421, the macro base station 220 measures the reception level of the GPS radio wave 270a outdoors. In step S422, the data is transmitted to the femto base station 210 as transmission data 220b. In step S411, the femto base station 210 measures the reception level of the indoor GPS radio wave 270a. In step S412, the reception level of the outdoor GPS radio wave 270a is obtained from the macro base station 220, and in step S413, the femto base station 210 receives the reception level of the femto base station 210 based on the difference in the reception level of the indoor and outdoor GPS radio wave 270a. Set the downlink transmission power.

[Third Embodiment]
A radio communication system according to the third embodiment of the present invention will be described below. In the second embodiment described above, signals from GPS satellites are received by the femto base station and the macro base station, and their reception levels are compared. On the other hand, in this embodiment, a signal from a GPS satellite as a transmission source is received by the femto base station and the macro mobile station, and the reception level is compared to measure the building intrusion loss. .
Thereby, even if the macro base station is installed in a place where GPS radio waves cannot be received, there is an effect that the building intrusion loss can be measured. Furthermore, since outdoor GPS radio waves can be received near the target femtocell, the building intrusion loss around the femto base station can be calculated more appropriately.

<Configuration of Radio Communication System of Third Embodiment>
FIG. 5 is a diagram illustrating a configuration of a wireless communication system 500 according to the third embodiment.

  In the wireless communication system of FIG. 5, the macro base station 220 controls the connection with the macro mobile station 230 in the macro cell 250 by a radio signal 220 a. Then, the macro base station 220 sends a request signal 220 c to measure the reception level of the GPS radio wave 270 a and send it to the macro base station 220, particularly to the macro mobile station 230 in the vicinity of the femtocell 260 that is outdoors. The macro mobile station 230 that has received the request signal 220c receives the GPS radio wave 270a from the GPS satellite 270, measures the reception level, and returns the outdoor reception level of the GPS radio wave 270a to the macro base station 220 as the transmission data 230a. To do.

  On the other hand, the indoor femto base station 210 controls the connection with the femto mobile station 240 in the femtocell 260 by the radio signal 210a and transmits the GPS radio wave 270a from the GPS satellite 270 via the wall or roof of the building 280. And measure the reception level. The macro base station 220 sends the reception level of the GPS radio wave 270a received from the macro mobile station 230 to the femto base station 210 as transmission data 220b. The femto base station 210 subtracts the reception level of the GPS radio wave 270a of the femto base station 210 from the reception level of the GPS radio wave 270a of the macro mobile station 230, and the difference is regarded as a building entry loss.

  The femto base station 210 sets the downlink transmission power (to the femto mobile station 240) of the femto base station 210 as high as the building intrusion loss by using the measured accurate building intrusion loss. In this way, communication quality within the femtocell 260 is guaranteed while preventing interference 210b to the macro mobile station 230 due to the transmission power of the femto base station 210. In the present embodiment, the reception level of the GPS radio wave 270a is measured by the macro mobile station 230 in the vicinity of the femtocell 260 in particular. As a result, even if the normally fixed macro base station 220 does not have the reception function of the GPS radio wave 270a, the actual and more accurate measurement of the building entry loss can be performed.

<Configuration of Femto Base Station 210, Macro Base Station 220, and Macro Mobile Station 230 of Third Embodiment>
FIG. 6 is a block diagram illustrating configurations of the femto base station 210, the macro base station 220, and the macro mobile station 230 in FIG.

  In FIG. 6, an outdoor macro mobile station 230 receives a GPS radio wave 270 a from a GPS satellite 270 by a GPS radio wave receiving unit 631. Then, the macro mobile station 230 uses the measurement execution unit 632 to measure the reception level of the GPS radio wave 270a received outdoors. The measurement result request unit 621 of the macro base station 220 transmits a request signal 220 c for requesting a report of the measurement result to the macro mobile station 230. In response to the request signal 220c, the macro mobile station 230 returns the reception level of the GPS radio wave 270a from the measurement report unit 633 as the transmission data 230a. When receiving the reception level of the GPS radio wave 270a, the measurement result notification unit 622 of the macro base station 220 transmits the reception level to the femto base station 210 as transmission data 220b.

  On the other hand, the indoor femto base station 210 receives the GPS radio wave 270a from the GPS satellite 270 by the GPS radio wave receiving unit 611 as in the second embodiment. The measurement execution unit 612 of the femto base station 210 measures the reception level of the GPS radio wave 270a received indoors by the femto base station 210. The femto base station 210 receives the transmission data 220b including the reception level of the GPS radio wave 270a transmitted from the macro base station 220 by the measurement result acquisition unit 613.

  The subsequent configuration of updating the radio parameters of the femto base station 210 is the same as that of the second embodiment. The intrusion loss calculation unit 614 calculates the building intrusion loss based on the transmission data 220b including the reception level of the GPS radio wave 270a transmitted from the macro base station 220. Then, the radio parameter update unit 615 updates the radio parameter (in particular, the downlink transmission power of the femto base station 210 in this example) using an accurate building entry loss. The transmission unit 616 communicates with the femto mobile station 240 using the radio signal 210a having the downlink transmission power. Since the femto base station 210 communicates with the femto mobile station 240 using the radio signal 210a based on the updated radio parameters, the communication quality in the femtocell 260 is sufficiently maintained while preventing interference with the macro mobile station 230. can do.

<Operations of Femto Base Station 210, Macro Base Station 220, and Macro Mobile Station 230 of Third Embodiment>
FIG. 7 is a flowchart showing an operation procedure of the femto base station 210, the macro base station 220, and the macro mobile station 230 of FIG.

  In step S731, the macro mobile station 230 measures the reception level of GPS radio waves outdoors. In step S721, the macro base station 220 requests the macro mobile station 230 to report the reception level of the GPS radio wave 270a by sending a request signal 220c, and waits for the report in step S722. When the macro mobile station 230 receives the request signal 220c in step S732, the macro mobile station 230 proceeds to step S733 and reports the reception level of the GPS radio wave 270a as a measurement result to the macro base station 220 as transmission data 230a. Receiving the report, the macro base station 220 proceeds from step S722 to S723 and further notifies the reception level of the received GPS radio wave 270a to the femto base station 210 as transmission data 220b.

  In step S411, the femto base station 210 measures the reception level of the indoor GPS radio wave 270a. In step S412, the reception level of the GPS radio wave 270a measured outdoors by the macro mobile station 230 is acquired from the macro base station 220. In step S413, the downlink transmission power of the femto base station 210 is set based on the building entry loss, which is the difference in the reception level of the indoor and outdoor GPS radio waves 270a.

[Fourth Embodiment]
A radio communication system according to the fourth embodiment of the present invention will be described below. In the second and third embodiments described above, the reception levels are compared using signals from GPS satellites. In contrast, in the present embodiment, a macro base station is used as a signal transmission source, a reference signal from the macro base station is received by the femto base station and the macro mobile station, and their reception levels are compared. To measure the building entry loss.
Thereby, there is an effect that the building intrusion loss can be measured even when both the macro base station and the macro mobile station cannot receive GPS radio waves. Furthermore, there is an effect that it is possible to cope with a case where the femto base station does not have a GPS radio wave reception function.

<Configuration of Radio Communication System of Fourth Embodiment>
FIG. 8 is a diagram illustrating a configuration of a wireless communication system according to the fourth embodiment.

  In the wireless communication system of FIG. 8, the macro base station 220 transmits a reference signal 220 d to the macro mobile station 230 in the macro cell 250. Then, the macro base station 220 sends a request signal 220 c to measure the reception level of the reference signal 220 d and send it to the macro base station 220, particularly to the macro mobile station 230 in the vicinity of the femtocell 260 located outdoors. The macro mobile station 230 that has received the request signal 220 c measures the reception level of the reference signal 220 d received from the macro base station 220, and returns the reception level of the reference signal 220 d outdoors in the transmission data 230 a to the macro base station 220. .

  On the other hand, the indoor femto base station 210 controls the connection with the femto mobile station 240 in the femtocell 260 by the radio signal 210a. Further, the femto base station 210 receives the reference signal 220d from the macro base station 220 through the wall or roof of the building 280 and measures the reception level. The macro base station 220 sends the reception level of the reference signal 220d received from the macro mobile station 230 to the femto base station 210 using transmission data 220b. In the femto base station 210, the difference between the reception level of the reference signal 220d of the femto base station 210 is subtracted from the reception level of the reference signal 220d of the macro mobile station 230, and the difference is regarded as a building entry loss.

  The femto base station 210 sets the downlink transmission power (to the femto mobile station 240) of the femto base station 210 as high as the building intrusion loss by using the measured accurate building intrusion loss. In this way, communication quality within the femtocell 260 is guaranteed while preventing interference 210b to the macro mobile station 230 due to the transmission power of the femto base station 210. In the present embodiment, the actual intrusion loss can be measured more accurately by measuring the reception level of the reference signal 220d of the macro base station 220 broadcast in common in the macro cell 250 instead of the GPS radio wave 270a. .

<Configuration of Femto Base Station 210, Macro Base Station 220, and Macro Mobile Station 230 of Fourth Embodiment>
FIG. 9 is a block diagram illustrating configurations of the femto base station 210, the macro base station 220, and the macro mobile station 230 in FIG.

  In FIG. 9, an outdoor macro mobile station 230 receives a reference signal 220 d from a radio wave transmission unit 921 of the macro base station 220 by a macro base station radio wave reception unit 931. Then, the macro mobile station 230 uses the measurement execution unit 932 to measure the reception level of the reference signal 220d received outdoors. The macro base station 220 transmits a request signal 220c for requesting a report of the measurement result from the measurement result request unit 922 to the macro mobile station 230. In response to the request signal 220c, the macro mobile station 230 returns the reception level of the reference signal 220d as the transmission data 230a from the measurement report unit 933. Upon receiving the reception level of the reference signal 220d, the measurement result notification unit 923 of the macro base station 220 transmits the reception level to the femto base station 210 as transmission data 220b.

  On the other hand, the indoor femto base station 210 receives the reference signal 220 d from the radio wave transmission unit 921 of the macro base station 220 by the macro base station radio wave reception unit 911. The measurement execution unit 912 of the femto base station 210 measures the reception level of the reference signal 220d received indoors by the femto base station 210. The femto base station 210 receives the transmission data 220b including the reception level of the reference signal 220d transmitted from the macro base station 220 by the measurement result acquisition unit 913.

  The intrusion loss calculation unit 914 of the femto base station 210 subtracts the reception level of the reference signal 220d measured indoors by the femto base station 210 itself from the reception level of the reference signal 220d measured outdoors from the macro base station 220. . Then, this difference is calculated as an actual accurate building entry loss. The accurate building intrusion loss is sent to the radio parameter updating unit 915, and the radio parameters (in particular, the downlink transmission power of the femto base station 210 in this example) are updated using the accurate building intrusion loss. In this embodiment, the radio parameters are updated using the exact building penetration loss calculated by measuring the reference signal 220d from the macro base station 220. Since the transmitter 916 of the femto base station 210 communicates with the femto mobile station 240 using the radio signal 210a based on the updated radio parameter, communication within the femtocell 260 is prevented while preventing interference with the macro mobile station 230. Sufficient quality can be maintained.

<Operations of Femto Base Station 210, Macro Base Station 220, and Macro Mobile Station 230 of Fourth Embodiment>
FIG. 10 is a flowchart showing operation procedures of the femto base station 210, the macro base station 220, and the macro mobile station 230 in FIG.

  In step S1031, the macro mobile station 230 determines a predetermined measurement condition (for example, when the distance from the femto base station 210 is equal to or smaller than a predetermined threshold), and proceeds to step S1032 if the measurement condition is satisfied. As for the distance between the macro mobile station 230 and the femto base station 210 being equal to or less than a predetermined threshold, the interference from the femto base station has received a certain level of interference or a signal specific to the femto base station has been detected. It can be determined from. Further, SINR (Signal to Interference and Noise Ratio) is deteriorated due to strong interference from a nearby femto base station, or the distance between the macro mobile station 230 and the femto base station 210 is less than a predetermined threshold based on GPS position information. The determination may be made based on the fact that In step S1032, the reception level of the reference signal 220d of the macro base station 220 outdoors is measured. In step S1021, the macro base station 220 requests the macro mobile station 230 to report the reception level of the reference signal 220d by sending a request signal 220c, and waits for the report in step S1022. When the macro mobile station 230 receives the request signal 220c in step S1033, the macro mobile station 230 proceeds to step S1034 and reports the reception level of the reference signal 220d as a measurement result to the macro base station 220 as transmission data 230a. The macro base station 220 that has received the report proceeds to step S1023 and further notifies the femto base station 210 of the reception level of the received reference signal 220d as transmission data 220b.

  In step S1011, the femto base station 210 measures the reception level of the reference signal 220d indoors. In step S1012, the reception level of the outdoor reference signal 220d is acquired from the macro base station 220. Next, in step S1013, the downlink transmission power of the femto base station 210 is set based on the building entry loss, which is the difference in the reception level of the indoor / outdoor reference signal 220d.

[Fifth Embodiment]
A radio communication system according to the fifth embodiment of the present invention will be described below. In the second to fourth embodiments described above, the reception level of the signal from the transmission source is compared in the femto base station. In contrast, in the present embodiment, the management server outside the femto base station obtains the reception level of the common radio wave indoors and outdoors, obtains the building intrusion loss from the difference, and determines the downlink transmission power of the femto base station To do.
In the second to fourth embodiments, the femto base station 210 measures the indoor signal reception level. However, in the fifth embodiment, the femto mobile station 240 instead of the femto base station 210 performs indoor signal reception. Measure the reception level.
As a result, the processing load at the femto base station can be reduced.

<Configuration of Wireless Communication System of Fifth Embodiment>
FIG. 11 is a diagram illustrating a configuration of a wireless communication system 1100 according to the fifth embodiment.

  In the wireless communication system 1100 of FIG. 11, the macro base station 220 controls the connection with the macro mobile station 230 in the macro cell 250 by the radio signal 220a. The macro mobile station 230 located outdoors measures the outdoor reception level of the GPS radio wave 270a from the GPS satellite 270 serving as a transmission source, particularly when in the vicinity of the femtocell 260. In response to the measurement result transmission request 1101a from the management server 1101, the outdoor reception level of the GPS radio wave 270a is transmitted to the management server 1101 as transmission data 230b. On the other hand, the indoor femto base station 210 controls the connection with the femto mobile station 240 in the femtocell 260 by the radio signal 210a. Also, the femto mobile station 240 indoors receives the GPS radio wave 270a via the wall or roof of the building 280 and measures the indoor reception level. In response to the measurement result transmission request 1101b from the management server 1101, the indoor reception level of the GPS radio wave 270a is transmitted to the management server 1101 as transmission data 240a.

  The management server 1101 collects the outdoor reception level of the GPS radio wave 270a measured by the macro mobile station 230 located outdoors and the indoor reception level of the GPS radio wave 270a measured by the femto mobile station 240 located indoors. The management server 1101 extracts the outdoor reception level and the indoor reception level of the GPS radio wave 270a corresponding to one femtocell 260 from the collected reception levels. Then, the building intrusion loss due to the wall or roof of the building 280 defining the femtocell 260 is obtained from the difference. Then, the radio parameters of the femto base station 210 that controls the femtocell 260, particularly the downlink transmission power, are determined using the accurate building intrusion loss obtained from the measured values, and transmitted to the femto base station 210 as transmission data 1101c. . Each femto base station 210 communicates with the femto mobile station 240 using a radio signal 210a of downlink transmission power determined according to each accurate building penetration loss.

  In addition, in FIG. 11, the reception level of the measured GPS radio wave 270a is reported to the management server 1101 in response to transmission requests 1101a and 1101b from the management server 1101. However, it may be reported at any time or at a predetermined timing.

  In this embodiment, instead of having each femto base station 210 take the reception level and calculate the downlink transmission power, which is a radio parameter, of each femto base station 210, the management server 1101 collects the reception levels collectively. Then, the downlink transmission power is calculated. Therefore, it is possible to reduce the load on the femto base station 210 and effectively use resources for communication control with the femto mobile station 240.

  In this embodiment, the management server 1101 calculates the downlink transmission power of the femto base station 210 and notifies the femto base station 210 as a radio parameter. However, the indoor / outdoor reception level for each femtocell 260 may be collected and the indoor / outdoor reception level itself may be reported as a radio parameter in response to a request from the femto base station 210. Or the structure which notifies the value of a building penetration loss as a radio | wireless parameter may be sufficient.

<Configuration of Femto Base Station 210, Femto Mobile Station 240, Macro Mobile Station 230, and Management Server 1101 of Fifth Embodiment>
FIG. 12 is a block diagram showing configurations of the femto base station 210, the femto mobile station 240, the macro mobile station 230, and the management server 1101 in FIG. In FIG. 12, for the sake of simplification, a configuration in which the reception level from the macro mobile station 230 is acquired via the macro base station 220, or the management server 1101 requests the reception level and reports it as a response. The configuration when doing so is omitted.

  In FIG. 12, an outdoor macro mobile station 230 receives a GPS radio wave 270 a by a GPS radio wave receiving unit 1231. Then, the macro mobile station 230 uses the measurement execution unit 1232 to measure the reception level of the GPS radio wave 270a received outdoors. The macro mobile station 230 transmits the outdoor reception level of the GPS radio wave 270a from the measurement report unit 1233 as the transmission data 230b to the management server 1101. On the other hand, the GPS radio wave receiving unit 1241 of the indoor femto mobile station 240 receives the GPS radio wave 270a. Then, the measurement execution unit 1242 of the femto mobile station 240 measures the reception level of the GPS radio wave 270a received indoors. The femto mobile station 240 transmits the indoor reception level of the GPS radio wave 270a from the measurement result notification unit 1243 to the management server 1101 as the transmission data 240a.

  The measurement result acquisition / collection unit 1201 of the management server 1101 acquires the reception level of the outdoor GPS radio wave 270a sent from the macro mobile station 230 and the reception level of the indoor GPS radio wave 270a sent from the femto mobile station 240. And collect. The intrusion loss calculation unit 1202 calculates the difference between the outdoor reception level and the indoor reception level as a building intrusion loss. Radio parameter calculation section 1203 calculates downlink transmission power, which is a radio parameter of femto base station 210, using an accurate building intrusion loss obtained from the measured value. The radio parameter notification unit 1204 notifies the calculated downlink transmission power of the femto base station 210 to the femto base station 210 as transmission data 1101c.

  The femto base station 210 acquires the downlink transmission power that is the radio parameter notified from the management server 1101 by the radio parameter acquisition unit 1211, and the transmission unit 1215 communicates with the femto mobile station 240 using the radio signal 210 a of the downlink transmission power. .

<Operations of Femto Base Station 210, Femto Mobile Station 240, Macro Mobile Station 230, and Management Server 1101 of Fifth Embodiment>
FIG. 13 is a flowchart showing operation procedures of the femto base station 210, the femto mobile station 240, the macro mobile station 230, and the management server 1101 in FIG. Note that the flowchart of FIG. 13 also omits detailed procedures such as exchange with the macro base station 220 and requesting the measurement result of the management server 1101 in order to avoid complexity.

  In step S1331, the macro mobile station 230 determines a predetermined measurement condition (for example, approach to the femtocell 260). If the measurement condition is satisfied, the macro mobile station 230 proceeds to step S1332. In step S1332, the reception level of the GPS radio wave 270a from the outdoor GPS satellite 270 is measured. In step S 1333, the reception level of the GPS radio wave 270 a as a measurement result is reported to the management server 1101 as transmission data 230 b. On the other hand, the femto mobile station 240 determines a predetermined measurement condition (for example, a request from the management server 1101 or the femto base station 210) in step S1341, and proceeds to step S1342 if the measurement condition is satisfied. In step S1342, the reception level of the indoor GPS radio wave 270a is measured. In step S1343, the reception level of the GPS radio wave 270a as a measurement result is reported to the management server 1101 as transmission data 240a.

  When receiving the reception level of the GPS radio wave 270a from the macro mobile station 230 or the femto mobile station 240, the management server 1101 proceeds from step S1381 to S1382, and collects the reception level of the GPS radio wave 270a. The reception level of the GPS radio wave 270a is managed according to the femto mobile station 240 and the neighboring macro mobile station 230 corresponding to each femtocell 260. In step S1383, the reception levels of the outdoor / indoor GPS radio wave 270a corresponding to the femtocell 260 for which building intrusion loss is to be calculated are extracted in pairs. In step S1384, the building intrusion loss is obtained from the difference for each pair, and the downlink transmission power that is the radio parameter of the femto base station 210 is calculated using the accurate building intrusion loss obtained from the measured value. In step S1385, the calculated transmission power is notified to the femto base station 210 as transmission data 1101c.

  In step S1311, the femto base station 210 waits for reception of radio parameter transmission power. If there is reception, the femto base station 210 sets downlink transmission power for communication with the femto mobile station 240 in step S1312.

  In the above embodiment, the calculation method of the transmission power of the femto base station 210 has not been described in detail. However, according to Patent Document 2, for example, the transmission power of the femto base station 210 can be calculated as follows. is there. The difference between the outdoor reception level and the indoor reception level is a building intrusion loss. To further improve accuracy, for example, correction of the difference between GPS radio waves and femto base station radio waves or correction of geographical differences is performed. . Then, the received power of the reference signal 220d from the macro base station 220 is added to the transmission power offset and the building intrusion loss to obtain the transmission power (however, the maximum and minimum values of the transmission power predicted or calculated in advance) Between).

[Other Embodiments]
In the second, third and fifth embodiments, the GPS radio wave transmitted from the GPS satellite is used as a common radio wave for measuring the reception level indoors and outdoors. In the fourth embodiment, the reference signal transmitted from the macro base station is used. However, the present invention is not limited to the above-mentioned radio waves, and broadcast radio waves within a predetermined frequency band that are continuously broadcast without being ubiquitous, such as radio waves for digital television, radio waves for FM (Frequency modulation) radio, etc. can be used. is there. In that case, the broadcasting station becomes the signal source. Further, although GPS is used as a positioning satellite, there is no particular limitation as long as it is a more general GNSS (Global Navigation Satellite Systems). For example, positioning satellites such as GALILEO, GLONASS (GLObal NAvigation Satellite System), and quasi-zenith satellites can be used. In the first to fifth embodiments, the example in which the downlink transmission power of the femto base station is set has been described. However, the uplink transmission power of the femto mobile station may be set. For example, in a femto base station that transmits radio waves having directivity, the radio parameter may set directivity. Furthermore, the present invention can also be applied to a configuration in which other radio parameters related to transmission of the femto base station are controlled based on the structural characteristics of the femto cell affecting radio waves.

  Further, in the second to fourth embodiments, the reception level notification from the macro base station 220 to the femto base station 210 has been described as being performed by data communication via wireless, but it is dedicated or via wire via a network. It may be done. The wireless communication system to which the present embodiment is applied is not particularly limited. For example, LTE (Long Term Evolution), W-CDMA (Wideband Code Division Multiple Access), WLAN (Wireless Local Area Network), IEEE (Institute of Electrical). and Electronics Engineers) Various wireless communication methods including the specifications defined in 802.16m are applicable.

  As mentioned above, although embodiment of this invention was explained in full detail, the system or apparatus which combined the separate characteristic contained in each embodiment how was included in the category of this invention.

  Further, the present invention may be applied to a system composed of a plurality of devices, or may be applied to a single device. Furthermore, the present invention is also applicable to a case where a control program that implements the functions of the embodiments is supplied directly to a system or apparatus or executed remotely. Therefore, in order to realize the functions of the present invention on a computer, a control program installed in the computer, a storage medium storing the control program, and a WWW (World Wide Web) server for downloading the control program are also included in the present invention. Included in the category.

Claims (21)

A first wireless station that includes a first measurement unit that measures a first reception level of a radio wave transmitted from a transmission source, and a transmission unit that transmits a radio signal; and an antenna disposed indoors;
A second wireless station comprising a second measuring means for measuring a second reception level of the radio wave transmitted from the transmission source, the antenna being disposed outdoors;
With
A radio communication system, characterized in that, based on the first reception level and the second reception level, a radio parameter used by the transmission means for transmitting a radio signal is determined.   The wireless communication system according to claim 1, wherein the transmission source is a GPS satellite, and the radio wave transmitted from the transmission source is a GPS radio wave from the GPS satellite.   The first radio station is a first base station or a first mobile station that communicates with a first base station, and the second radio station is a second base station or communicates with a second base station. The wireless communication system according to claim 1, wherein the wireless communication system is a second mobile station to perform.   The wireless communication system according to claim 3, wherein the first base station is a femto base station that controls a femto cell, and the second base station is a macro base station that controls a macro cell.   The wireless communication system according to claim 3 or 4, wherein the transmission source is the second base station, and the radio wave transmitted from the transmission source is a reference signal from the second base station.   The second mobile station measures the second reception level of the radio wave by the second measuring means on condition that the distance from the first base station is equal to or less than a predetermined value. The wireless communication system according to any one of 3 to 5.   The transmission power loss due to a building surrounding the first radio station is determined based on a difference between the first reception level and the second reception level. The wireless communication system described.   Based on the difference between the first reception level and the second reception level, a transmission power loss due to a building surrounding the first wireless station is obtained, and the transmission power of the first wireless station is determined based on the loss. The wireless communication system according to claim 1, wherein the wireless communication system is a wireless communication system.   The first reception level measured by the first radio station and the second reception level measured by the second radio station are collected, and the collected first reception level and second reception level are used as the first radio level. 9. The wireless communication system according to claim 1, further comprising communication management means for reporting to a station.   The said communication management means determines the radio | wireless parameter which the said transmission means uses for transmission of a radio signal based on the said 1st reception level and the said 2nd reception level. Wireless communication system. A first wireless station with an antenna indoors;
A radio resource determination method in a radio communication system including a second radio station having an antenna outdoors,
A first measurement step of measuring a first reception level of a radio wave transmitted from a transmission source in the first wireless station;
A second measurement step of measuring a second reception level of the radio wave transmitted from the transmission source in the second wireless station;
A determination step of determining a radio parameter used for transmission of a radio signal by the transmission means of the first radio station based on the first reception level and the second reception level;
A radio resource determination method comprising: A wireless base station with an antenna indoors,
Measuring means for measuring a first reception level of radio waves transmitted from a transmission source;
Receiving means for receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining means for determining a radio parameter used by the radio base station to transmit a radio signal based on the first reception level and the second reception level;
A radio base station comprising: A wireless base station with an antenna indoors,
First receiving means for receiving a first reception level of a radio wave transmitted from a transmission source, measured by a radio mobile station communicating with the radio base station;
Second receiving means for receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining means for determining a radio parameter used by the radio base station to transmit a radio signal based on the first reception level and the second reception level;
A radio base station comprising:   The radio base station according to claim 12 or 13, wherein the radio base station controls a femto cell. A control method for a radio base station provided with an antenna indoors,
A measurement step of measuring a first reception level of radio waves transmitted from a transmission source;
A reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
A control method for a radio base station, comprising: A control method for a radio base station provided with an antenna indoors,
A first reception step of receiving a first reception level of a radio wave transmitted from a transmission source measured by a radio mobile station communicating with the radio base station;
A second reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
A control method for a radio base station, comprising: A control program for a radio base station with an antenna indoors,
A measurement step of measuring a first reception level of radio waves transmitted from a transmission source;
A reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
A control program that causes a computer to execute. A control program for a radio base station with an antenna indoors,
A first reception step of receiving a first reception level of a radio wave transmitted from a transmission source measured by a wireless mobile station located indoors;
A second reception step of receiving a second reception level of radio waves transmitted from the transmission source measured by a radio station having an antenna outdoors;
Determining a radio parameter used by the radio base station for radio signal transmission based on the first reception level and the second reception level;
A control program that causes a computer to execute. A communication management device for managing communication in a wireless communication system including a first wireless station having an antenna indoors and a second wireless station having an antenna outdoors,
First acquisition means for acquiring a first reception level of a radio wave transmitted from a transmission source measured by the first wireless station;
Second acquisition means for acquiring a second reception level of a radio wave transmitted from the transmission source, measured by the second wireless station;
Determining means for determining a radio parameter used by the first radio station for transmission of a radio signal based on the first reception level and the second reception level;
A communication management device comprising: A control method for a communication management apparatus for managing communication in a wireless communication system including a first wireless station having an antenna indoors and a second wireless station having an antenna outdoors,
A first acquisition step of acquiring a first reception level of a radio wave transmitted from a transmission source measured by the first wireless station;
A second acquisition step of acquiring a second reception level of the radio wave transmitted from the transmission source, measured by the second radio station;
A determining step of determining a radio parameter used by the first radio station for transmitting a radio signal based on the first reception level and the second reception level;
A control method for a communication management apparatus, comprising: A control program for a communication management device for managing communication in a wireless communication system including a first wireless station having an antenna indoors and a second wireless station having an antenna outdoors,
A first acquisition step of acquiring a first reception level of a radio wave transmitted from a transmission source measured by the first wireless station;
A second acquisition step of acquiring a second reception level of the radio wave transmitted from the transmission source, measured by the second radio station;
A determining step of determining a radio parameter used by the first radio station for transmitting a radio signal based on the first reception level and the second reception level;
A control program for a communication management apparatus, which causes a computer to execute.

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