JP2006197264A - Radio base station system and communication control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable telephone base station system and a communication control method capable of corresponding also to traffic variation. <P>SOLUTION: A micro base station 4 stores relation between time and transmission outputs as a table T based on time and traffic data collected by a mobile exchange 1 and a radio communication control device 32 refers to the table T and a timer 31 and controls the level of a carrier signal in a transmission radio wave corresponding to the time to increase/decrease the number of terminals 6 allowing the micro base station 4 to be stored in and cope with traffic variation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile phone radio base station and a communication control method thereof.

  The mobile phone base station is installed by adjusting the cover area and the number of stations according to the output of the base station and the traffic volume with the terminal so that access from a mobile phone terminal (hereinafter simply referred to as a terminal) can be accommodated. Is done. As the number of terminals increases, a large number of small output base stations (hereinafter referred to as micro base stations) are provided in a small cover area (micro-cell), and traffic is being absorbed in a downtown area.

  In order to prevent such a micro cell from being used, in order to prevent an increase in the facilities of each micro base station, an optical fiber cable is used to transmit light from a base station having a large cover area (hereinafter referred to as a macro base station) to the micro base station. An optical fiber radio (hereinafter referred to as ROF: Radio Over Fiber) that transmits a high-frequency signal whose intensity is modulated and transmits radio waves from a micro base station to a terminal has been adopted (for example, Patent Document 1). ).

However, even if these ROF micro base stations are adopted, the traffic fluctuates dynamically throughout the day. Therefore, if the number of micro base stations is increased and installed to match the maximum traffic, except when traffic is concentrated, There are problems such as waste caused by unused micro base stations and a heavy computer load for communication management such as frequent handovers between the micro base stations.
JP 2004-229180 A (page 12, FIG. 1)

  Even when a ROF micro base station is adopted as a mobile phone base station, there is a problem that an unused micro base station generates excess traffic except when traffic is concentrated, and handover between micro base stations must be made frequent. There was a problem that the computer load of communication management became large.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a mobile phone radio base station system and a communication control method that can cope with traffic fluctuations.

  In order to achieve the above object, a radio base station system of the present invention includes a macro base station and a micro base station that is connected to the macro base station and communicates with a mobile phone terminal in a smaller cover area than the macro base station. The macro base station converts a radio wave carrier signal transmitted from the transmitter of the micro base station to the mobile phone terminal into an optical transmission signal, and the optical base station transmits the optical transmission signal via an optical fiber cable. In the radio base station system of a mobile phone that transmits to the E.O, an E / O converter that converts the carrier signal into the optical transmission signal and outputs the optical transmission signal to the optical fiber cable, and corresponds to the time based on time variation data of traffic. A table in which an adjustment value of the signal level of the carrier signal to be transmitted is set, a timer, and a carry input to the E / O converter. A first level control means for adjusting a signal level of a signal; and a wireless communication control section for outputting control information for adjusting the signal level with reference to the table and the timer to the level control means and the micro base station; A macro base station comprising: a transmission means for transmitting the control information output from the radio communication control unit of the macro base station to the micro base station; and receiving the optical transmission signal from the optical fiber cable. An O / E converter that reconverts and outputs an electric carrier signal again, and receives the control information via the transmission means, and the reconverted carrier that is input from the O / E converter A second level control means for adjusting a signal level of the signal according to the received control information and outputting the signal to a transmitter; and Characterized by comprising the micro base station and a transmitter for transmitting from the antenna.

  Further, the communication control method of the radio base station system of the present invention comprises a macro base station and a micro base station that is connected to the macro base station and communicates with a mobile phone terminal in a cover area smaller than the macro base station, The macro base station converts a carrier signal of a radio wave transmitted from the transmitter of the micro base station to the mobile phone terminal into an optical transmission signal, and transmits the optical transmission signal to the micro base station via an optical fiber cable. In the communication control method of the mobile phone radio base station system, the radio base station system includes a radio communication control unit, an E / O converter connected to the optical fiber cable, a first level control means, A table in which an adjustment value of the signal level of the carrier signal to be transmitted is set corresponding to time based on data of time variation of traffic, a timer, A micro base station comprising a macro base station, an O / E converter connected to the optical fiber cable, a second level control means, and a transmitter; and control information from the macro base station to the micro base station. The wireless communication control unit of the macro base station refers to the signal level of the carrier signal input to the E / O converter with reference to the table and the timer. Is output to the first level control means and the transmission means, and the first level control means outputs the carrier signal, the signal level of which is adjusted by the input control information, to the E / The E / O converter of the macro base station converts the inputted carrier signal into the optical transmission signal and outputs it to the optical fiber cable. The O / E converter of the micro base station reconverts the optical transmission signal input from the optical fiber cable into a carrier signal of an electrical signal, and outputs it to the second level control means, The second level control means of the micro base station that has received the output control information from the transmission means has received the signal level of the carrier signal input from the O / E converter. The transmitter, which is adjusted according to information and is output to the transmitter, and the carrier signal whose signal level is adjusted, is input, and the input carrier signal is transmitted as a radio wave from an antenna. To do.

  According to the present invention, by adjusting the output of the radio wave transmitted by the ROF radio base station (micro base station) included in the macro base station according to the time variation data of traffic, the ROF radio base station The mobile phone base station system and communication control method for adjusting the number of mobile phone terminals that can be accommodated.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of a radio base station system according to Embodiment 1 of the present invention.
1, a radio base station system includes a mobile switch 1, a network 2, a macro base station 3 connected to the mobile switch 1, at least one micro base station 4a connected to the macro base station 3, and a macro base station. 3 and a micro base station 4a are provided with an optical fiber cable 5 and a transmission unit 51. The macro base station 3 and the micro base station 4a perform wireless communication with a mobile phone terminal (hereinafter abbreviated as a terminal) 6.

  The mobile switch 1 performs call processing and connection processing between the terminal 6 and a communication terminal that is a communication partner of the terminal 6 via the network 2, as well as call connection processing control signals and signals such as voice and data. , Traffic information and the like are transmitted to the macro base station 3.

  The macro base station is a mobile phone base station having a cover area of several kilometers, and is connected to the micro base station 4 in order to eliminate a dead zone or the like.

  The micro base station 4 is a radio base station with a small cover area installed in the cover area of the macro base station 3. Then, an optical transmission signal in which the carrier signal of the radio wave transmitted between the micro base station 4 and the terminal 6 from the macro base station 3 via the optical fiber cable 5 is converted into an optical signal is transmitted and converted again into a radio wave. (The ROF wireless base station itself may similarly transmit an optical reception signal obtained by converting the received radio wave to the macro base station 3, but here only the transmitting side is handled. .)

  The transmission unit 51 transmits a control signal for outputting the carrier signal between the macro base station 3 and the micro base station 4 and may be included in the optical fiber cable 5 as an order wire.

  The macro base station 3 includes a table T, a timer 31, a wireless communication control device 32, a transceiver 33, and an input / output unit 34.

  The table T is a table in which the mobile switch 1 has previously acquired traffic information corresponding to time, and is stored in an internal memory (not shown). The timer 31 is a clock that generates time information based on timing information supplied from the mobile switch 1 or is synchronized with the timing information. Alternatively, the radio communication control device 32 performs radio communication control for communicating various signals input / output to / from the mobile exchange 1 with the terminal 6 via the transmitter / receiver 32 or the micro base station 4.

  That is, in the macro base station 3, the radio communication control device 32 inputs / outputs a voice signal, a connection control signal, and the like to / from the mobile switch 1, and generates a carrier signal. Then, the generated carrier signal is transmitted to / from the terminal 6a via the transmitter / receiver 33 connected to the wireless communication control device 32, or is connected to the input / output unit 34 and the micro base station 4, for example. 6b... (Hereinafter simply referred to as “terminal 6” unless otherwise distinguished) to perform wireless communication.

  The radio communication control device 32 outputs a carrier signal of a radio wave transmitted from the micro base station 4 to the input / output unit 34 and generates a control signal for adjusting the signal level of the carrier signal according to the table T to generate an input / output unit. 34.

  The input / output unit 34 is prepared corresponding to each micro base station 4 accommodated in the macro base station 3, and each input / output unit 34 receives signal radio waves transmitted from the wireless communication control device 32 to the terminal 6 and The carrier signal is converted into an optical signal. The optical signal is transmitted to the micro base station 4 via the optical fiber cable 5 and is reconverted into a carrier signal of an electric signal by the micro base station 4. Then, call connection management and telephone communication are performed between the micro base station 4 and the terminal 6 that transmits and receives radio waves in the same manner as call connection management and telephone communication between the transceiver 32 and the terminal 6.

  In other words, the radio communication control device 32 controls the radio communication with the terminal 6 by regarding the micro base station 4 as one of the transceivers 32 of its own station. A plurality of the micro base stations 4 may be installed, for example, like the micro base stations 4a, 4b... (Hereinafter, in the case of explaining common items for the plurality of micro base stations 4a, 4b,. Only the station 4a is omitted for explanation.)

FIG. 2 is a diagram for explaining the concept of the coverage area of the radio base station system.
In FIG. 2, the macro base station 3 has a wide cover area Mx having a radius of a maximum of several kilometers. Usually, the cover area Mx is a range in which communication is possible using radio waves transmitted and received by the transceiver 32.

  The micro base stations 4a, 4b,... Have smaller cover areas Mia, Mib (hereinafter simply referred to as Mi) in order to eliminate the dead zone where radio waves do not reach in the cover area Mx or to increase the number of terminals 6 accommodated. For example, it is installed in a downtown area in front of a station or in a building. The wireless communication control device 32 controls the range of the cover area Mi of the micro base station 4 so as to become wider or narrower according to the traffic in the cover area Mx. The mobile switch 1 and the radio communication control device 32 perform a handover process so that communication continues even if the terminal 6 moves between these cover areas Mx and Mi.

  For example, in a PDC (Personal Digital Cellular) mobile phone base station, the macro base station 3 and the micro base stations 4a and 4b are set to have different frequencies, and a CDMA (Code Division Multiple Access) mobile phone base station. Then, the encoding codes of the macro base station 3 and the micro base stations 4a and 4b are set differently. As a result, handover is performed in the same manner as when the terminal 6 moves across the macro base station 3, and radio communication continues.

FIG. 3 is a block diagram showing a functional configuration of the input / output unit 34 of the macro base station 3 and the micro base station 4.
Hereinafter, the configuration and operation outline of the macro base station 3 and the micro base station 4 will be described with reference to FIGS. 1 and 3.

  3A, the input / output unit 34 of the macro base station 3 includes an amplifier 341 that amplifies the carrier signal input from the radio communication control device 32, a controller 343 that adjusts the level of the carrier signal with the amplifier 341, and a carrier. An E / O (electric / optical converter) 342 that converts a signal from an electric signal to an optical signal (hereinafter referred to as an optical transmission signal), and an O / that receives an optical signal from the micro base station 4 via an optical fiber 5. E (optical / electrical converter) 344 is provided.

  The optical transmission signal is a high-frequency signal obtained by modulating the carrier of the frequency of the radio wave transmitted by the macro base station 3 for communicating with the terminal 6. The controller 343 outputs a control signal for adjusting the level of the carrier signal input from the wireless communication control device 32 to the amplifier 341. According to the level of the carrier signal, the output of the radio wave transmitted by the micro base station 4 is increased and decreased, and the range of the cover area Mxi is changed.

  The control signal of the carrier signal level is transmitted to the micro base station 4 via the transmission unit 51. The transmission unit 51 is selected and applied from several means. For example, as shown in FIG. 3B, an order wire into the optical fiber cable 5 or an order wire by optical fiber transmission combining the dotted lines E / O 342 and O / E 41 in FIG. 3C is used. There may be. Further, although not shown, the transmission unit 51 may be a communication network such as a dedicated line.

  Further, the input / output unit 34 receives the radio signal transmitted from the terminal 6 by the micro base station 4 and is converted into an optical signal by the O / E 344 via the optical fiber cable 5. The electric signal is reconverted to 32 and output. However, as described above, the processing of the signal received by the micro base station 4 from the terminal 6 is not directly related to the present invention, and thus the description thereof is omitted below.

  The micro base station 4 receives the optical transmission signal transmitted from the E / O 342 of the input / output unit 34 of the macro base station 3 through the optical fiber cable 5, and the O / E 41 and the O / E 41 reconvert to an electric signal. The control signal from the controller 343 of the input / output unit 34 of the macro base station 3 is received via the attenuator 42, the transmitter 43, the antenna 45, and the transmission unit 51 that attenuates the signal level of the carrier signal. Is provided with a controller 44 for controlling the amount of attenuation. The micro base station 4 also includes a receiver 46 that receives radio waves from the terminal 6, a hybrid H, and an E / O 47 that converts the received signal into an optical signal.

  In general, mobile phone traffic fluctuates with time. Here, the case where the micro base station 4a is installed in the station square in the cover area of the macro base station 3 installed in the city center and the micro base station 4b is installed in a shopping street a little away from the station is taken up wirelessly. The operation of the base station system will be described.

  For example, the macro base station 3 determines that the number of terminals 6 existing in the cover area Mx increases from 7:30 am to 9 pm before and after that and is considered to be substantially constant until about 8 pm thereafter. Take control. The coverage area Mx of the macro base station 3 is wide, but if there is only the transmitter / receiver 33, there is a dead zone in the station square and there is a place where the mobile phone cannot communicate, so the micro base station 4a is installed as a dead zone countermeasure. ing.

  However, during the morning and evening commuting hours, commuting and attending students concentrate around the station square and calls from the station square increase. In the embodiment of the present invention, the radio communication control device 32 increases the transmission output of the micro base station 4a and widens the cover area Mia to cope with the traffic increase (the number of the call terminals 6) at the time of congestion. The number of terminals 6 that can be accessed via the station 4a (hereinafter referred to as the accommodation number) is increased.

  On the other hand, the micro base station 4b similarly provided as a dead zone countermeasure is located in a shopping street, so there are few people accessing it in the morning, and the output is lowered to set the cover area Mib small. On the other hand, people gather at the shopping street at lunch time, evening work, or going home, so the output is increased to expand the cover area Mib. If the traffic of the micro base station 4a is not large at the time of lunch or evening, the radio wave transmission output is lowered so as to reduce the cover area Mia of the micro base station 4a.

  Conventionally, the micro base station 4 has been installed around the station or the like as a countermeasure for the dead zone. However, since the transmission output is constant, the cover area is constant, and when the number of terminals 6 increases, the micro base station 4 The number of terminals that can be accommodated is also limited because the received power per terminal 6 from the terminal decreases. Therefore, conventionally, when traffic is concentrated in the morning and evening, in the area where the traffic is concentrated in the vicinity of the station even though there is a sufficient number of terminals accommodated in the mobile switch 1 within the coverage area of the macro base station 3. There was a problem going inside.

  In the embodiment of the present invention, the output can be changed to widen the cover area, and the transmission output can be increased. Therefore, the number of terminals 6 that can be accommodated by the micro base station 4 in a place where traffic is concentrated can be increased or decreased. The occurrence of inside can be prevented.

  In order to examine the traffic change, each micro base station 4a, 4b is activated or deactivated in advance and the traffic of each station is monitored by the mobile switch 1. Then, based on the monitoring result, traffic data obtained by statistically obtaining the traffic amount of each micro base station 4a, 4B in units of time is acquired, and the data is initially set in the wireless communication control device 32 as a table T.

  This table T is provided in a storage device (not shown) of the wireless communication control unit 34 in order to adjust the transmission output corresponding to the time so that it can cope with traffic (the number of call terminals) that changes with time. The wireless communication control device 32 compares the built-in timer 321 with the table T and outputs a control signal for controlling the transmission signal output (transmission radio wave output) to the controller 343 of the input / output unit 34.

Hereinafter, the procedure of the output control process will be described using the micro base station 4a installed in the station square as an example.
Now, it is assumed that the micro base station 4a can be set so that the terminal 6 can accommodate up to “5” as the minimum condition and the number of accommodation can be increased up to “20” that is four times the minimum as the maximum condition. That is, it is assumed that the transmission output of the micro base station 4a can be increased up to four times (6 dB increase) compared to the transmission output of xdBm in the minimum condition.

FIG. 4 is a table T in which the average number of terminals (traffic data) accessing the micro base stations 4a and 4b every hour and the transmission output for each hour are set.
In FIG. 4, the micro base station 4a has a low output until 7 am, and the output is minimum xdBm because the traffic is low and not more than 5 units. In the micro base station 4a installed in the station square, 5 to 8 units access from 8 o'clock to 14 o'clock when the number of passengers increases. Meanwhile, the wireless communication control device 32 sends a control signal for collating the timer 321 and the table T and raising the output by 3 dB to the controller 343 of the input / output unit 34 and the micro base station 4a via the input / output unit 34. A control signal is transmitted to the controller 44. The table T describes gains or attenuations set in the controller 343 of the input / output unit 34 and the controller 44 of the micro base station 4a.

  Here, since the gain of the amplifier 342 is set to increase by “+3 dB”, the controller 343 receives the control signal for increasing the 3 dB gain from the radio communication control device 32 and increases the signal level 3 dB of the carrier signal.

  The controller 343 transmits a control signal to the controller 44 of the micro base station 4 via the optical fiber cable. However, the controller 44 has no control to change the attenuation amount (“0”). The attenuation of the device 42 remains the same. Since the signal level of the carrier signal input to the transmitter 43 is set to a value 3 dB higher than before the adjustment, the output of the radio wave transmitted from the antenna 45 is set to 3 dB higher. As a result, when the output of the transmitter 43 is doubled, the area of the cover area is doubled, and the number of terminals 6 that can be accommodated is increased from “5” to “10”.

  The control signal for increasing the transmission output by 3 dB may be a method of transmitting a control signal for decreasing the attenuation amount by “−3 dB” to the controller 44 of the micro base station 4 a instead of increasing the gain by “+3 dB”. The gain increase and the attenuation reduction may be performed at the same time (for example, “+1.5 dB” and “−1.5 dB”).

  Further, in the table T of FIG. 4, the micro base station 4b is adjusted so that the transmission output is increased by “+6 dB” so that a maximum of 20 stations can be accommodated from 11:00 am to 14:00. The wireless communication control device 32 refers to the table T and transmits a control signal to the input / output unit 34 and the micro base station so as to increase the gain by “+3 dB” and increase the attenuation by “−3 dB” in order to increase the transmission output by 6 dB. To do.

  In the above description, the input / output unit 34 of the macro base station 3 includes the amplifier 341 and the micro base station 4 includes the attenuator 42. However, if the macro base station 4 has a level adjustment function capable of adjusting the level of the carrier signal, the macro base station 3 Either the station 3 or the micro base station 4 may be provided with an amplifier or an attenuator, or may be provided with a gain adjusting means combining the attenuator and the amplifier. The method for setting the gain adjustment can be easily inferred and will not be described.

  The second embodiment is the same as the first embodiment except for the following description. However, a timer and tables t1 and t2 are provided in the input / output unit 34 of the macro base station 3 and the controller 44 of the micro base station 4, and gain control is performed. And the attenuation is adjusted.

FIG. 5 is a block diagram illustrating functional configurations of the input / output unit 34 of the macro base station 3 and the micro base station 4 according to the second embodiment.
The procedure for adjusting the transmission output of the micro base station in the second embodiment will be described below with reference to FIG.
In FIG. 5, the input / output unit 34 of the macro base station 3 and the controllers 343 and 44 of the micro base station 4 are provided with tables t1 and t2 for level adjustment and timers 3431 and 441 for synchronization, respectively. Perform output control.

  As a timer synchronization method, for example, the timers t1 and t2 are GPS receivers, and time information output from the GPS receivers may be used, or a radio clock may be used.

  The input / output unit 34 of the macro base station 3 and the controllers 343 and 44 of the micro base station 4 are provided with tables t1 and t2, respectively, in which level adjustment values that become transmission outputs corresponding to the table T of FIG. 4 are set. . Then, the control unit 3432 of the input / output unit 34 of the macro base station 3 and the control unit 442 of each of the micro base stations 4a and 4b collate the tables t1 and t2 corresponding to the respective timers and adjust the gain or attenuation amount. To do.

  As described above, the radio base station system according to the present invention increases or decreases the number of terminals that can be accommodated by adjusting the output of the micro base station, which is the ROF radio base station, according to the traffic data corresponding to the time. Communication corresponding to fluctuations is possible.

1 is a configuration diagram of a radio base station system according to Embodiment 1 of the present invention. The figure explaining the concept of the cover area of the wireless base station system which concerns on Example 1 of this invention. The block diagram which shows the input-output part of a macro base station, and the function structure of a micro base station. The figure of the table which memorized the traffic corresponding to the time of a micro base station, and the output. The block diagram which shows the function structure of the input / output part of a macro base station in Example 2, and a micro base station.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mobile switch 2 Network 21 Switched telephone network 22 Data network 3 Macro base station 32 Communication control apparatus 33 Transmitter / receiver 34 Input / output unit 341 Amplifier 4a 4b Micro base station 41, 344 O / E (optical / electrical converter)
42 Attenuator 43 Transmitter 44, 343 Controller 45 Antenna 46 Receiver 47, 342 E / O (electrical / optical converter)
5 Optical fiber cable 51 Transmission unit 6 (mobile phone) terminal Mx, Mia, Mib Cover area

Claims (4)

A macro base station, and a micro base station that is connected to the macro base station and communicates with a mobile phone terminal in a coverage area smaller than the macro base station, wherein the macro base station includes a transmitter of the micro base station. In a radio base station system of a mobile phone that converts a carrier signal of a radio wave to be transmitted to a mobile phone terminal into an optical transmission signal and transmits the optical transmission signal to the micro base station via an optical fiber cable.
An E / O converter for converting the carrier signal into the optical transmission signal and outputting the optical transmission signal to the optical fiber cable; and a signal level of the carrier signal to be transmitted corresponding to a time based on time variation data of traffic A table with adjustment values, a timer,
First level control means for adjusting a signal level of a carrier signal input to the E / O converter, control information for adjusting the signal level with reference to the table and a timer, the level control means and the level control means A macro base station comprising a wireless communication control unit for outputting to a micro base station;
Transmission means for transmitting the control information output from the radio communication control unit of the macro base station to the micro base station;
An O / E converter that receives the optical transmission signal from the optical fiber cable, converts the signal again into an electric carrier signal, and outputs the carrier signal; receives the control information via the transmission means; Second level control means for adjusting a signal level of the reconverted carrier signal input from a converter according to the received control information and outputting the adjusted signal to a transmitter; and And a micro base station comprising a transmitter for transmitting from an antenna. A macro base station, and a micro base station that is connected to the macro base station and communicates with a mobile phone terminal in a coverage area smaller than the macro base station, wherein the macro base station includes a transmitter of the micro base station. In a radio base station system of a mobile phone that converts a carrier signal of a radio wave to be transmitted to a mobile phone terminal into an optical transmission signal and transmits the optical transmission signal to the micro base station via an optical fiber cable.
An E / O converter that converts the carrier signal into the optical transmission signal and outputs the optical transmission signal to the optical fiber cable, and adjustment of the signal level of the carrier signal to be transmitted corresponding to the time based on data of time variation of traffic A signal level of the carrier signal input to the E / O converter with reference to the first table and the first timer, the first table having a value set therein and a first timer; A macro base station comprising first level control means for adjusting
An O / E converter that receives the optical transmission signal from the optical fiber cable, converts the signal again into a carrier signal of an electric signal, and outputs the carrier signal;
A second table in which an adjustment value of a signal level of the transmitted carrier signal is set corresponding to time based on time variation data of the traffic, and a second timer synchronized with the first timer, Second level control means for adjusting a signal level of the carrier signal input from the O / E converter with reference to the second table and the second timer and outputting the signal to a transmitter; A radio base station system comprising: a micro base station including a transmitter that transmits the input carrier signal as a radio wave from an antenna. A macro base station, and a micro base station that is connected to the macro base station and communicates with a mobile phone terminal in a coverage area smaller than the macro base station, wherein the macro base station includes a transmitter of the micro base station. In a communication control method for a radio base station system of a mobile phone that converts a carrier signal of a radio wave to be transmitted to a mobile phone terminal into an optical transmission signal and transmits the optical transmission signal to the micro base station via an optical fiber cable.
The radio base station system is:
A wireless communication control unit, an E / O converter connected to the optical fiber cable, a first level control unit, and the carrier signal to be transmitted corresponding to the time based on traffic time variation data. A macro base station comprising a table in which adjustment values of signal levels are set, and a timer;
A micro base station comprising an O / E converter connected to the optical fiber cable, a second level control means, and a transmitter;
Transmission means for transmitting control information from the macro base station to the micro base station,
The wireless communication control unit of the macro base station outputs control information for adjusting the signal level of the carrier signal input to the output E / O converter with reference to the table and the timer. Output to the level control means and the transmission means,
The first level control means outputs the carrier signal, the signal level of which is adjusted according to the input control information, to the E / O converter,
The E / O converter of the macro base station converts the inputted carrier signal into the optical transmission signal and outputs it to the optical fiber cable,
The O / E converter of the micro base station reconverts the optical transmission signal input from the optical fiber cable into a carrier signal of an electrical signal and outputs it to the second level control means,
The second level control means of the micro base station that has received the output control information from the transmission means has received the signal level of the carrier signal input from the O / E converter. Adjust to information and output to the transmitter,
The communication control method of a radio base station system, wherein the transmitter, to which the carrier signal whose signal level has been adjusted, is input, transmits the input carrier signal as a radio wave from an antenna. A macro base station, and a micro base station that is connected to the macro base station and communicates with a mobile phone terminal in a coverage area smaller than the macro base station, wherein the macro base station includes a transmitter of the micro base station. In a communication control method for a radio base station system of a mobile phone that converts a carrier signal of a radio wave to be transmitted to a mobile phone terminal into an optical transmission signal and transmits the optical transmission signal to the micro base station via an optical fiber cable.
The radio base station system is:
An E / O converter connected to the optical fiber cable, a first level control means, and an adjustment value of the signal level of the carrier signal transmitted corresponding to the time based on traffic time fluctuation data A macro base station comprising a set first table and a first timer;
An O / E converter connected to the optical fiber cable, a second level control means, and an adjustment value of the signal level of the carrier signal transmitted corresponding to the time based on the time variation data of the traffic A micro base station comprising: a second table in which is set; a second timer synchronized with the first timer; and a transmitter;
The first level control means of the macro base station adjusts the signal level of the carrier signal input to the output E / O converter with reference to the first table and the first timer. Output to the E / O converter,
The E / O converter converts the carrier signal input with the level adjusted into the optical transmission signal and outputs the optical transmission signal to the optical fiber cable.
The O / E converter of the micro base station reconverts the optical transmission signal input from the optical fiber cable into a carrier signal of an electrical signal and outputs it to the second level control means,
The second level control means of the micro base station adjusts the signal level of the carrier signal input from the O / E converter by referring to the second table and the second timer. And output to the transmitter,
The transmission control method for a radio base station system, wherein the transmitter to which the carrier signal having the adjusted level is inputted transmits the inputted carrier signal as a radio wave from an antenna.

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