JP2011199563A - Sending power controller, sending power control system, sending power control method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique of varying a service area, in response to the situation of an adjoining base station.SOLUTION: The technique includes a monitoring means for monitoring at least one of a communication situation and an operation situation of the base station, and a control means for raising a sending power of a base station adjacent to the base station, when it becomes clear that there is a base station in which the number of failures or calls in a base station is at least equal to or more than a threshold, as a result of system monitoring.

Description

  The present invention relates to a transmission power control apparatus, a transmission power control system, a transmission power control method, and a program.

  In a mobile communication system, the communication quality may deteriorate due to the weakness of radio waves around cell boundaries, or the strength of radio waves fluctuates due to shielding or reflection of radio waves by buildings or the like. In order to avoid this, base stations have been added or transmission power has been increased, but there are areas that cannot be handled. Femtocell base stations are installed in such areas to cover the communication area.

  However, since new interference occurs due to the installation of the femtocell base station, there is a technique for controlling the transmission power of the femto base station (for example, Patent Document 1).

  The technique of Patent Literature 1 derives a transmission power control amount that reduces the possibility of interference with adjacent macrocell base stations, and uses the derived transmission power control amount as the maximum transmission power amount of the femtocell. Yes.

JP 2009-225039 A

  As described above, the technique disclosed in Patent Document 1 sets the transmission power amount at which the possibility of interference with an adjacent macro cell base station to be low as a maximum. For this reason, even if the adjacent macro cell base station fails or the call concentrates and exceeds the allowable number of calls, the transmission power cannot be increased beyond the possibility of causing interference to the macro cell base station. As a result, the service area of the adjacent base station cannot be covered, and an area where the service cannot be received occurs.

  Therefore, the problem to be solved by the present invention is to provide a technique for solving the above-mentioned problems, and to provide a technique capable of changing a service area according to the situation of an adjacent base station. is there.

  The present invention for solving the above-mentioned problems is a transmission power control apparatus, comprising: monitoring means for monitoring at least one of a communication status and an operation status of a base station; When it is found that there is a base station whose number is at least a threshold value or more, there is a control means for increasing the transmission power of the base station adjacent to the base station.

  The present invention for solving the above-mentioned problems is a transmission power control system, comprising: monitoring means for monitoring at least one of a communication status and an operating status of a base station; When it is found that there is a base station whose number is at least a threshold value or more, there is a control means for increasing the transmission power of the base station adjacent to the base station.

  The present invention for solving the above problems is a transmission power control method, comprising: a monitoring step for monitoring at least one of a communication status and an operation status of a base station; A control step of increasing the transmission power of a base station adjacent to the base station when it is found that there is a base station whose number is at least a threshold value or more.

  The present invention for solving the above-described problem is a program for a transmission power control apparatus, wherein the program monitors the transmission power control apparatus for at least one of a communication status and an operation status of a base station; As a result of the monitoring, if it is found that there is a base station in which the number of failures or calls in the base station is at least a threshold value, a control process for increasing the transmission power of the base station adjacent to the base station is executed. It is characterized by.

  According to the present invention, the femto base station can change the cell size according to the situation of the adjacent femto base station.

FIG. 1 is a schematic diagram showing an example of a wireless communication system according to the present invention. FIG. 2 is a block diagram illustrating an example of a base station. FIG. 3 is a diagram for explaining a cell transition state. FIG. 4 is a diagram for explaining a cell transition state. FIG. 5 is a diagram illustrating an example of a wireless communication system according to the present invention. FIG. 6 is a flow for explaining the operation of the present invention. FIG. 7 is a flow for explaining the operation of the present invention.

  In order to explain the features of the present invention, it will be specifically described below with reference to the drawings.

  FIG. 1 is a diagram showing an example of a wireless communication system according to the present invention. Although FIG. 1 shows a configuration in which four femto base stations A to D are installed in the operator, the number is not limited to this number.

  FIG. 2 is a block diagram of the femto base station 11.

  The femto base station 11 includes a wireless transmission unit 12, a wireless reception unit 13, a control unit 14, a storage unit 15, a LAN interface unit 16, a HELLO packet communication module 17, and a display unit 18.

  The wireless transmission unit 12 and the wireless reception unit 13 are interfaces for wireless communication with a mobile phone.

  The control unit 14 controls various communications with the mobile phone and the communication carrier network. Then, the transmission power of the neighboring base stations is measured based on the cell search result in the mobile station received by the wireless reception unit 13. The femto base station with the highest transmission power among the measured transmission powers of the neighboring base stations is determined as the adjacent femto base station, and the base station is stored in the neighbor list of the storage unit 15 as the adjacent base station. In addition, the control unit 14 stores the operation status and communication status of the adjacent femto base station monitored by the HELLO packet communication module 17 in association with the corresponding adjacent base station in the neighbor list 15. Further, a failure of the base station is detected based on the operation status output from the HELLO packet communication module 17. Further, based on the communication status output from the HELLO packet communication module 17, it is determined whether the number of calls is equal to or greater than the maximum allowable number, that is, whether the number of calls is at least equal to or greater than a threshold value.

  The storage unit 15 stores information on neighboring femto base stations as a neighbor list.

  The LAN interface unit 16 is a broadband line interface.

  The HELLO packet communication module 17 transmits and receives HELLO packets via the LAN interface unit 16 and periodically monitors the operation status and communication status of adjacent femto base stations and neighboring base stations.

  The display unit 18 displays the status of the adjacent femto base station.

  The operation of varying the power in the present invention will be described.

  When detecting the failure of the adjacent femto base station from the operation status of the adjacent femto base station, the control unit 14 autonomously varies the transmission power of the wireless transmission unit 12 and varies the service area. A specific operation will be described with reference to FIGS. FIG. 3 shows that a mobile phone 35 is located in a business operator, and a femto base station A31, a femto base station B32, a femto base station C33, and a femto base station D34 are installed in the business operator, and each femto base station is a gateway device. 1 is connected to the communication carrier network via a broadband line. Further, the adjacent femto base station of the femto base station A is the femto base station B, the adjacent femto base station of the femto base station B is the femto base stations A and C, and the adjacent femto base station of the femto base station C is the femto base station. Base stations B and D, and a femto base station C adjacent to the femto base station D is a femto base station C.

  It is assumed that the mobile phone 35 is located in the area of the femto base station B32 (step 61). In such a state, it is assumed that the femto base station B32 has failed (step 62).

  The control unit 14 of the femto base station A31, the femto base station C33, and the femto base station D34 detects a failure of the femto base station B32 based on the operating state of the HELLO packet (step 63). Then, the femto base station A31, the femto base station C33, and the femto base station D34 confirm from the neighbor list whether the femto base station B32 is an adjacent femto base station (step 64). The control unit 14 may be configured to monitor the neighbor list and detect whether the operation status of the adjacent base station indicates “failure”.

  Since the femto base station A31 and the femto base station C33 are adjacent femto base stations to the femto base station B32, the transmission power of the wireless transmission unit is increased (step 66). As a result, the service area of the femto base station A31 and the femto base station C33 is expanded (step 67).

  Thereby, even if the area of the femto base station B32 runs out, the mobile phone 35 can enter the area of the femto base station A31 or the femto base station C32 (step 68). The service area of the femto base station A31 and the femto base station C32 at this time is an area indicated by a dotted line in FIG.

  Since the femto base station D34 is not an adjacent femto base station of the femto base station B32, the output of the wireless transmission unit remains as it is (step 65).

  In the above description, the configuration is described in which the transmission output is controlled when the base station fails. However, the configuration may be such that the transmission output is controlled when the allowable number of calls is exceeded. In that case, when the control unit 14 detects that the adjacent femto base station is communicating with the maximum allowable number from the communication status of the adjacent femto base station in the neighbor list, the control unit 14 autonomously varies the output of the wireless transmission unit 12, Change the service area. A specific operation will be described with reference to FIGS. In FIG. 4, mobile phones a to e are located in the business, and femto base station A 41, femto base station B 42, and femto base station C 43 are installed in the business, and each femto base station is connected to the gateway device. 1 shows a configuration in which a network is connected to a telecommunications carrier network via a broadband line. Further, the adjacent femto base station of the femto base station A is the femto base station B, the adjacent femto base station of the femto base station B is the femto base stations A and C, and the adjacent femto base station of the femto base station C is the femto base station. Base station B.

  The mobile phone e48 is located in the femto base station C43 (step 71). At this time, it is assumed that the maximum allowable number of mobile phones (mobile phone a44 to mobile phone d47) starts communication within the service area of the femto base station C43 (step 72).

  The femto base station A41 and the femto base station B42 detect from the communication state of the HELLO packet that the femto base station C43 is communicating with the maximum allowable number of mobile phones (step 73). Then, the femto base station A41 and the femto base station B42 confirm from the neighbor list whether the femto base station C43 is an adjacent femto base station (step 74). The control unit 14 may be configured to monitor the neighbor list and detect whether the communication status of the adjacent base station indicates “exceeding the allowable number of calls”.

  Since the femto base station B42 is an adjacent femto base station of the femto base station C43, the transmission power of the wireless transmission unit is increased (step 75).

  As a result, the service area of the femto base station B42 is expanded to cover a part of the area of the femto base station C43 (step 76). As a result, the mobile phone e48 can be located in the area of the femto base station B42 and can communicate (step 77). The service area of the femto base station B42 at this time is the area indicated by the dotted line in FIG.

  Next, the operation of displaying the status of the adjacent base station on the display unit 18 will be described.

  Since the femto base station A41 is not an adjacent femto base station of the femto base station C43, the output of the wireless transmission unit remains as it is (step 78).

  In FIG. 1, when the control unit 14 detects a failure of the adjacent femto base station from the operation status of the adjacent femto base station, the control unit 14 displays on the display unit 18 that the adjacent femto base station has failed. A specific operation will be described with reference to FIG. FIG. 5 shows that the femto base station A52 is installed on the first floor and the femto base station B51 is installed on the second floor.

  When the femto base station B51 fails and the femto base station A52 detects the failure of the femto base station B51 by the above-described method, the failure of the femto base station 51 is displayed on the display unit of the femto base station A52. Thereby, even if the user is on the first floor, the failure of the femto base station B51 on the second floor can be detected, and the maintainability is improved.

  Note that the base station of the present invention described above can be configured by hardware as is apparent from the above description, but can also be realized by a computer program.

  Functions and operations similar to those of the above-described embodiments are realized by a processor that operates with a program stored in a program memory. Note that only a part of the functions of the above-described embodiment can be realized by a computer program.

  Although the present invention has been described with reference to the embodiments and examples, the present invention is not necessarily limited to the above-described embodiments and examples, and various modifications can be made within the scope of the technical idea. I can do it.

  In the above-described embodiment, each base station monitors an adjacent femto base station and increases the transmission power according to the monitoring result. However, all the base stations are monitored and monitored. A configuration may be provided in which a control device that performs control to increase the transmission power of the corresponding base station according to the result is provided.

  In the above description, the base station failure has been described based on the operation status output from the HELLO packet communication module 17 using the configuration for determining whether the allowable number of calls has been exceeded based on the communication status. If it is possible to determine whether the base station has failed or the allowable number of calls has been exceeded, the determination may be made by referring to at least one of the operation status and the communication status.

  Moreover, although demonstrated using the femto base station, this invention is applicable also to the base station of a macrocell with a cell size larger than a femtocell.

The effect of the present invention will be described.
According to the present invention, since the femto base station monitors the operation of the adjacent femto base station and varies the service area, even if a certain base station fails, the service area of the femto base station in which the adjacent base station has failed can be covered. .

  In addition, since the femto base station monitors the operation of the adjacent femto base station and varies the service area, the adjacent femto base station can cover the service area even when a certain base station communicates with the maximum allowable number.

  Furthermore, since the femto base station monitors and displays the operation of the adjacent femto base station, even if a base station installed on a different floor fails, the administrator can recognize the failure early.

11 Femto base station 12 Wireless transmission unit 13 Wireless reception unit 14 Control unit 15 Storage unit 16 LAN interface unit 17 HELLO packet communication module 18 Display unit

Claims (7)

Monitoring means for monitoring at least one of communication status and operation status of the base station;
As a result of the monitoring, if it is found that there is a base station in which the number of failures or calls in the base station is at least a threshold value or more, there is a control means for increasing the transmission power of the base station adjacent to the base station. A transmission power control device.   The transmission power control apparatus according to claim 1, further comprising search means for searching for an adjacent base station of each base station based on received power between each base station notified from a mobile station. Monitoring means for monitoring at least one of communication status and operation status of the base station;
As a result of the monitoring, if it is found that there is a base station in which the number of failures or calls in the base station is at least a threshold value or more, there is a control means for increasing the transmission power of the base station adjacent to the base station. A characteristic transmission power control system.   The transmission power control system according to claim 3, further comprising search means for searching for an adjacent base station of each base station based on reception power between each base station notified from a mobile station. A monitoring step of monitoring at least one of a communication status and an operation status of the base station;
A control step of increasing the transmission power of a base station adjacent to the base station when it is determined that there is a base station in which the number of failures or calls in the base station is at least a threshold value or more as a result of the monitoring. A characteristic transmission power control method.   6. The transmission power control method according to claim 5, further comprising a search step of searching for an adjacent base station of each base station based on received power between each base station notified from a mobile station. A program for a transmission power control device, the program being stored in the transmission power control device,
A monitoring process for monitoring at least one of the communication status and operation status of the base station;
As a result of the monitoring, if it is found that there is a base station in which the number of failures or calls in the base station is at least a threshold value, a control process for increasing the transmission power of the base station adjacent to the base station is executed. A program characterized by

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