JP2001320348A - Mobile communication base station network and base station switching method in said network - Google Patents

Abstract

(57) [Problem] To provide an efficient mobile communication base station network and a base station switching method in the network by reducing processing in a control station even when switching of a base station occurs due to movement of a mobile terminal. To do. A radio base station (BS) includes a variable light source for transmitting an optical signal of a predetermined wavelength, and a WDM coupler for multiplexing the optical signal from the variable light source for wavelength multiplex transmission.
5, the control station 40 includes a plurality of optical receivers 43 for receiving the wavelengths of the wavelength-multiplexed optical signals, and an optical receiver for wavelength-multiplexed optical signals from a plurality of BSs. A WDM coupler 45 is provided. B
When the mobile terminal MS1 that has communicated with S3 moves and changes the base station with which it communicates to BS4, BS4 transmits the same optical signal wavelength λ as the optical signal wavelength λ _MS1 transmitted by BS3.
_It is transmitted to the supervising station by _MS1 .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system in which a radio base station arranged in a plurality of cells and a supervision station supervising the radio base station are connected by wavelength division multiplex transmission or subcarrier optical transmission through optical fibers. The present invention relates to a base station switching method in a base station network and a mobile communication base station network.

[0002]

2. Description of the Related Art FIG. 14 is a block diagram showing a configuration example of a conventional base station network for mobile communication.

The control station 10 and radio base stations (BS1 to BS1)
7. The number of BSs is not limited to seven. Hereinafter, "B
S ". ) Are connected in a loop by an optical fiber 30, and optical signals are transmitted and received by wavelength multiplex transmission.

In this configuration, when optical transmission is performed from the control station 10 to each BS, a reception wavelength is assigned to each BS, and an optical transmitter 16 that transmits the optical wavelength for each BS is assigned to the control station 10. The optical signals are combined and transmitted by the WDM coupler 17 for wavelength multiplex transmission.

[0005] In each of the BS 1 to BS 7, the optical signal of the wavelength addressed to itself is demultiplexed by the respective WDM coupler 25 and received by the optical receiver 23. Optical receiver 2
The number of mobile terminals (MS1, MS2, MS is not limited to 2) from an access system wireless (wireless communication between BS and mobile terminal) transceiver 22 via an antenna 21. ").

A wireless signal from the MS is received by an access wireless transceiver 22 via an antenna 21, converted into an optical signal by an optical transmitter 24, and multiplexed by a WDM coupler 25 for wavelength multiplex transmission.

Note that the BS access system radio transceiver 22
A mobile communication radio signal demodulator for demodulating a radio signal received from the MS and converting it to a digital signal; and a mobile communication radio signal demodulator for converting a digital signal output from the optical receiver 23 to a mobile communication radio frequency signal. A wireless signal modulator.

The control station 10 converts the optical signal from each BS into a WD
The light is demultiplexed for each wavelength by the M coupler 17 and received by the optical receiver 15.

For example, when the MS 1 is communicating with the BS 3, the MS 1 transmits the signal to the BS ₃ at the wavelength λ _BS 3,
3 to the supervising station 10 at the wavelength λ _{BS3 ′} .

At this time, when the MS moves and starts communicating with the BS4, the control station 10 switches from the wavelength λBS3 for the _BS3 to the optical transmitter of the wavelength λBS4 for the _{BS4 by} the selection switch 14. , The wavelength λ _BS4 from the central office 10
Is transmitted to BS4. At the same time, the BS 4 transmits the signal to the control station 10 at the wavelength λ _{BS4 ′} . As a result, the signal to the control station 10 changes from the wavelength λ _{BS3 ′} to λ _{BS4 ′} , and the control station 10 switches to the optical receiver that receives the signal of the wavelength λ _{BS4 ′} by the selection switch 13 and receives the signal. This allows the MS and the control station to continue communication.

FIG. 15 is a diagram showing an example of a WDM coupler in a conventional control station.

[0012] In WDM coupler 17 _1, the signal is inputted from the optical transmitters of each wavelength, it is transmitted are multiplexed to a wavelength multiplexing to each BS.

Therefore, the transmitting BS changes from BS3 to BS4.
When it switched to transmits to switch the optical transmitter from the wavelength lambda _{B S3} to lambda _BS4.

[0014] On the other hand, in the WDM coupler 17 _2, optical signals of _{'lambda B SN from'} wavelength lambda _BS1 from each BS is
The light is demultiplexed to each terminal by each wavelength and received by the optical receiver.

[0015] Therefore, the receiving BS is changed from BS3 to BS.
4, the output terminal is switched to the wavelength λ _{BS3 ′.}
To λ _{BS4 ′} , the optical receiver is switched by the selection switch to receive.

[0016]

However, if the base station is frequently switched due to the movement of the mobile terminal, the process of selecting and combining the selection switches and the like of the optical transceivers in the control station becomes excessively large. There was a problem that the processing capacity became too large.

The present invention has been made in view of the above problems, and reduces the processing at the control station even if the base station is switched due to the movement of the mobile terminal. An object of the present invention is to provide a method for switching a base station in the network.

[0018]

In order to solve the above problems, the present invention employs means for solving the problems having the following features.

According to a first aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by wavelength division multiplexing through optical fibers. In the wireless base station,
A wavelength tunable transmitter (for example, the wavelength tunable light source 54 in FIG. 1) for transmitting an optical signal of a predetermined wavelength, and a WDM coupler for multiplexing an optical signal from the wavelength tunable transmitter for wavelength multiplex transmission. A plurality of optical receivers for receiving the wavelengths of the wavelength-multiplexed transmitted optical signals, and an optical signal wavelength-multiplexed transmitted from the plurality of wireless base stations to the optical receivers for each wavelength. When the mobile terminal that communicates with the radio base station includes a WDM coupler that performs demultiplexing and changes the radio base station with which the mobile terminal communicates, the radio base station to which the mobile terminal has moved is connected to the wavelength tunable transmitter. And transmitting the same optical signal wavelength as the optical signal wavelength transmitted by the wireless base station before moving to the control station. Thereby, even if the mobile terminal moves and changes the base station, the supervising station can receive a signal from the base station related to the mobile terminal at the wavelength before the movement.

According to a second aspect of the present invention, in the mobile communication base station network according to the first aspect, the WDM coupler provided in the wireless base station converts an optical signal of a plurality of wavelengths transmitted by wavelength division multiplexing. , The radio base station includes an optical receiver that receives an optical signal demultiplexed by the WDM coupler, and the control station transmits an optical signal for wavelength multiplex transmission. It comprises a plurality of tunable optical transmitters for transmitting (for example, the tunable light source 64 in FIG. 2), and a WDM coupler provided in the control station performs wavelength multiplex transmission of optical signals from the plurality of tunable optical transmitters. When the mobile terminal that communicates with the wireless base station moves and changes the wireless base station that communicates, the supervising station controls the wavelength of the tunable transmitter, and the mobile terminal The wireless base station to which you have moved Change to only the light wavelength, and transmits to the destination of moving of the radio base station.

Thus, even if the mobile terminal moves and changes the base station, the control station controls the signal to the base station related to the mobile terminal by controlling the wavelength of the tunable transmitter of the control station. ,
This can be dealt with by changing to an optical wavelength for the wireless base station to which the mobile terminal has moved.

According to a third aspect of the present invention, in the mobile communication base station network according to the first aspect, the WDM coupler provided in the radio base station is a variable WDM coupler, and the wavelength division multiplexed transmission is performed. The wavelength to be demultiplexed from the optical signals of a plurality of wavelengths is made variable, and the radio base station makes the variable W
An optical receiver for receiving an optical signal demultiplexed by a DM coupler, wherein when a mobile terminal communicating with the radio base station moves and changes a radio base station to communicate with, the control station is configured to be a mobile terminal. Even if the wireless base station with which the communication is changed, the wavelength of the optical signal to be transmitted to the wireless base station is transmitted without being changed, and the wireless base station to which the optical base station has moved is controlled by the variable WDM coupler to receive light from the central station. It is characterized in that a signal wavelength is demultiplexed and received.

Thus, even if the mobile terminal moves and changes the base station, the control station can transmit a signal to the base station related to the mobile terminal at the wavelength before the movement.

According to a fourth aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by optical fiber to wavelength division multiplexing transmission. In the wireless base station,
A mobile communication radio signal demodulator that demodulates and converts a radio signal received from the mobile terminal into a digital signal; and a digital signal for the control station converted by the mobile communication radio signal demodulator is wavelength-multiplexed and transmitted. An optical transmitter that converts the optical signal into an optical signal, an optical receiver that receives an optical signal in which the digital signal from the central office is wavelength-division multiplexed and converts the optical signal into a digital signal, and a digital signal that is converted by the optical receiver. And a mobile communication radio signal modulator for converting a signal into a mobile communication radio frequency signal,
An optical receiver for converting a digital signal received from the radio base station into a wavelength-multiplexed optical signal into a digital signal, and a digital signal intended for the radio base station into a wavelength-multiplexed digital signal optical signal An optical transmitter is provided.

According to a fifth aspect of the present invention, there is provided a mobile communication base station in which a radio base station arranged in a plurality of cells and a supervising station supervising the radio base station are connected by subcarrier optical transmission via optical fibers. In the network, the radio base station is a mobile communication radio signal demodulator that demodulates and converts a mobile communication radio signal received from the mobile terminal into a digital signal, and the radio communication base station is converted by the mobile communication radio signal demodulator. An entrance radio signal modulator for converting a digital signal into an entrance radio signal; and an optical transmitter for converting the entrance radio signal converted by the entrance radio signal modulator into an optical signal for subcarrier optical transmission. An optical receiver for converting an entrance radio signal transmitted by a subcarrier optical signal into an electric signal; A wireless signal demodulator for entrance which converts the radio signal for sensing into a digital signal, and a radio signal modulator for mobile communication which converts the digital signal converted by the radio signal demodulator for entrance into a radio frequency signal for mobile communication. Comprising, the control station, an optical receiver that converts an optical signal transmitted by subcarrier optical transmission with a wireless signal for entrance transmitted by the wireless base station into an electrical signal,
An entrance wireless signal demodulator that converts an entrance wireless signal converted into an electric signal into a digital signal,
An entrance radio signal modulator for converting a digital signal for a radio base station into an entrance radio signal, and an entrance radio signal converted by the entrance radio signal modulator into an optical signal for subcarrier optical transmission And an optical transmitter.

According to a sixth aspect of the present invention, there is provided a mobile communication base station in which a radio base station arranged in a plurality of cells and a supervising station supervising the radio base station are connected by subcarrier optical transmission via optical fibers. In the network, the radio base station includes: an optical transmitter that converts a radio signal received from the mobile terminal into an optical signal for subcarrier optical transmission; and a mobile communication radio frequency signal received from the control station is a subcarrier. An optical receiver for converting an optical signal transmitted optically into an electric signal, wherein the control station converts the optical signal transmitted from the radio base station to a radio frequency signal for mobile communication by subcarrier optical transmission. An optical receiver for converting to an electrical signal,
A mobile communication radio signal demodulator for converting a mobile communication radio frequency signal converted into an electric signal into a digital signal, and a mobile communication radio signal demodulation for converting a digital signal for a radio base station into a mobile communication radio frequency signal. And an optical transmitter for converting the mobile communication radio frequency signal converted by the mobile communication radio signal demodulator into an optical signal transmitted by subcarrier optical transmission.

Thus, subcarrier optical transmission can be performed using a radio frequency signal for mobile communication instead of the radio signal for entrance according to the fifth aspect of the present invention.

According to a seventh aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by subcarrier optical transmission via optical fibers. In the above, the radio base station is a mobile communication radio signal demodulator for demodulating a mobile communication radio signal received from the mobile terminal and converting it to a digital signal, and a digital signal converted by the mobile communication radio signal demodulator. A variable frequency entrance radio signal modulator for converting a signal into an entrance radio signal, and an optical reception for converting the subcarrier optically transmitted entrance radio signal transmitted from the control station or another radio base station into an electric signal And a coupler for multiplexing the output of the optical receiver and the output of the radio signal modulator for the frequency-variable entrance. An optical receiver for converting an optical signal in which an entrance wireless signal is transmitted as a subcarrier optical signal into an electric signal, a frequency selective coupler for demultiplexing the output of the optical receiver for each frequency, and the frequency selective coupler And an entrance radio signal demodulator for converting each entrance radio signal demultiplexed into a digital signal, wherein the mobile terminal communicating with the radio base station moves and changes the radio base station to communicate with. In this case, the radio base station to which the mobile terminal has moved controls the carrier frequency of the frequency-variable entrance radio signal modulator, and uses the same entrance radio signal frequency as the entrance radio signal frequency transmitted by the radio base station before moving. The signal is transmitted to the control station at a radio signal frequency.

Thus, even if the mobile terminal moves and changes the base station, the control station can receive the signal from the base station related to the mobile terminal at the entrance radio signal frequency before the movement. it can.

According to an eighth aspect of the present invention, in the mobile communication base station network according to the seventh aspect, the wireless base station converts an entrance wireless signal transmitted by subcarrier optical transmission into an electric signal. A receiver, a frequency-selective coupler for demultiplexing a predetermined frequency signal from an output of the optical receiver, and an entrance radio-signal demodulator for converting an entrance radio signal demultiplexed by the frequency-selective coupler into a digital signal And a mobile communication radio signal modulator for converting the digital signal converted by the entrance radio signal demodulator to a mobile communication radio frequency signal, wherein the control station converts the digital signal for the radio base station. A frequency-variable entrance radio signal modulator for converting to an entrance radio signal; A coupler for multiplexing the output of the transmitter, and an optical transmitter for converting the entrance radio signal converted by the entrance radio signal modulator into an optical signal for subcarrier optical transmission, the radio base station When the mobile terminal that communicates with the mobile terminal moves and changes the wireless base station with which it communicates, the supervising station converts the digital signal for the wireless base station into an entrance wireless signal. It is characterized in that the carrier frequency is controlled and changed to an entrance radio frequency for the radio base station to which the mobile terminal has moved.

Thus, even if the mobile terminal moves and changes the base station, the control station changes the radio frequency for entrance to the base station related to the mobile terminal by modulating the radio signal for variable frequency entrance of the control station. This can be dealt with by controlling the carrier frequency of the device and changing it to the entrance radio frequency for the radio base station to which the mobile terminal has moved.

According to a ninth aspect of the present invention, in the mobile communication base station network according to the seventh aspect, the radio base station converts a plurality of sub-optically transmitted entrance radio signals into electric signals. An optical receiver for conversion, a variable frequency selective coupler for demultiplexing only a predetermined frequency, and a mobile communication radio signal for converting an electric signal demultiplexed by the variable frequency selective coupler to a mobile communication radio frequency signal A plurality of entrance radio signal modulators for converting a digital signal for a radio base station into an entrance radio signal, and an electric signal from the plurality of entrance radio signal modulators. And a light transmitter for converting an output of the coupler into an optical signal for subcarrier optical transmission, and communicating with the radio base station. When the mobile terminal moves and changes the radio base station with which it communicates, the supervising station changes the carrier frequency of the frequency-variable entrance radio signal modulator even if the radio base station with which the mobile terminal communicates changes. The mobile base station, to which the mobile terminal has moved without transmitting, changes the demultiplexing frequency of the variable frequency selective coupler to an entrance wireless signal frequency for the wireless base station before moving. .

Thus, even if the mobile terminal moves and changes the base station, the control station can transmit a signal to the base station related to the mobile terminal at the entrance radio signal frequency before the movement. it can.

The invention described in claim 10 is the first invention.
In the mobile communication base station network according to any one of claims 1 to 9, a radio base station arranged in a plurality of cells,
A mobile communication base station network to which a control station for controlling the base station is connected by an optical fiber is characterized by being formed in a loop.

The invention described in claim 11 is the first invention.
In the mobile communication base station network according to any one of claims 1 to 9, a radio base station arranged in a plurality of cells,
A mobile communication base station network to which a control station for controlling the base station is connected by an optical fiber is configured in a mesh shape.

The invention described in claim 12 is the first invention.
In the mobile communication base station network according to any one of claims 1 to 9, a radio base station arranged in a plurality of cells,
The mobile communication base station network to which the control station for controlling the base station is connected by an optical fiber is a cluster type base station network.

The invention described in claim 13 is the first invention.
3. The mobile communication base station network according to 2, further comprising a higher-level control station that controls the cluster control station, wherein a mobile terminal that communicates with the wireless base station moves and changes a cluster that communicates with the mobile terminal. The cluster supervisory station transmits a signal from the mobile terminal to the cluster supervisory station after the movement through the higher-level supervisory station at the same wavelength as the wavelength of the optical signal transmitted by the base station before the movement. The base station of the cluster transmits the signal from the mobile terminal to the cluster control station after the movement at the same wavelength as the wavelength of the optical signal transmitted by the base station before the movement.

The invention described in claim 14 is the first invention.
3. The mobile communication base station network according to 2, further comprising a higher-level control station that controls the cluster control station, wherein a mobile terminal that communicates with the wireless base station moves and changes a cluster that communicates with the mobile terminal. The cluster control station transmits, via the higher control station and the moved cluster control station, the signal to the mobile terminal to the moved cluster base station and the same wavelength as the wavelength of the optical signal transmitted to the pre-movement base station. Transmit at a wavelength, and the cluster control station after the movement transmits a signal to the mobile terminal to the cluster base station after the movement at the same wavelength as the wavelength of the optical signal transmitted to the base station before the movement. It is characterized by the following.

The invention described in claim 15 is the first invention.
15. The mobile communication base station network according to 3 or 14, wherein the higher-level control station has an optical wavelength conversion unit, and the higher-level control station transmits light to the base station before the movement in the cluster after the movement. If you are using the signal wavelength,
The wavelength converting means converts the wavelength of the optical signal not used by the moved cluster into a wavelength of the optical signal, and transmits the converted signal to the cluster control station of the moved cluster.

According to a sixteenth aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station for supervising the radio base stations are connected by optical fiber to respective wavelength division multiplexing transmissions. In the base station switching method, the transmission wavelength that the radio base station transmits to the control station is set at the start of communication with a mobile terminal, and the transmission wavelength is fixed while the mobile terminal is communicating, The mobile terminal transmits information of the mobile terminal from a new radio base station to a control station by a transmission wavelength set for the mobile terminal, even if a radio base station with which the mobile terminal moves and communicates changes. And

According to a seventeenth aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by wavelength division multiplexing transmission via optical fibers. In the base station switching method according to the above, the control station has a wavelength variable transmitter,
The transmission wavelength that the control station transmits to the radio base station is set for each radio base station, and when the mobile terminal changes the radio base station that moves and communicates, the control station transmits the wavelength variable transmitter. And transmitting the information to the mobile terminal to the changed radio base station using the transmission wavelength set in the changed radio base station.

The invention according to claim 18 is a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station that supervises the radio base stations are respectively connected by optical fiber to wavelength division multiplexing transmission. In the base station switching method in, the transmission wavelength transmitted by the control station to the radio base station is set for each radio base station, the mobile terminal,
When changing the radio base station that moves and communicates, the control station transmits the information of the mobile terminal to the radio base station after the movement by using the transmission wavelength set in the radio base station before the movement. Features.

According to a nineteenth aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by subcarrier optical transmission via optical fibers. In the base station switching method in the, the wireless signal for the entrance that the wireless base station performs subcarrier optical transmission to the supervising station, is set at the start of communication with the mobile terminal, the wireless signal for the entrance,
While the mobile terminal is communicating, the mobile terminal is fixed, and even if the wireless base station with which the mobile terminal moves and communicates changes, the entrance frequency set in the mobile terminal is changed from the new wireless base station to the control station. The information of the mobile terminal is transmitted by subcarrier optical transmission by a signal.

According to a twentieth aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station for supervising the base stations are connected by subcarrier optical transmission via optical fibers. In the base station switching method in, the radio signal for entrance that the control station transmits to the radio base station is set for each radio base station, and when the mobile terminal changes the radio base station that moves and communicates, The supervising station transmits the information to the mobile terminal to the changed radio base station by subcarrier light using an entrance radio signal set in the changed radio base station.

According to a twenty-first aspect of the present invention, there is provided a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by subcarrier optical transmission via optical fibers. In the base station switching method in, the radio signal for entrance that the control station transmits to the radio base station is set for each radio base station, and when the mobile terminal changes the radio base station that moves and communicates, The information of the mobile terminal is transmitted by subcarrier light from the new radio base station to the supervising station using an entrance frequency signal set in the radio base station before the movement.

[0046]

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

FIG. 1 is a diagram showing a first embodiment.

The control station 40 and the radio base station (BS) are connected in a loop by an optical fiber, and optical signals are transmitted and received by wavelength multiplex transmission.

In the control station 40, a wavelength tunable light source 44 is provided as an optical transmitter for transmitting each optical wavelength.
The optical signals are multiplexed by the coupler 45 for wavelength multiplex transmission and transmitted to the BS.

In each of the radio base stations BS1 to BS7,
Each WDM coupler 55 demultiplexes the optical signal of the wavelength addressed to itself, and the optical signal is received by the optical receiver 53.
A signal from the optical receiver 53 is transmitted to an antenna 51 by an access system wireless (wireless communication between the BS and the mobile terminal) transceiver 52.
Wirelessly transmitted to the mobile terminal (MS) via A radio signal from a mobile terminal is received by an access-system radio transceiver 52 via an antenna 51, converted into an optical signal of an arbitrary wavelength by a wavelength variable light source 54, and multiplexed by a WDM coupler 55 for wavelength multiplex transmission. You.

In the control station 40, the optical signal from each BS is
Demultiplexed for each wavelength by the WDM coupler 45,
The light is received by the optical receiver 43.

Here, when MS1 is communicating with BS3, BS3 is transmitting information from MS1 to the supervising station at wavelength _λMS1 . At this time, when the MS 1 starts communication with the BS 4 by moving, the BS 4 sets the wavelength of the tunable light source 54 to λ _MS1 and transmits it to the control station 40, so that the control station 40 performs a switching operation. It is possible to continue receiving the signal of the wavelength λ _MS1 without performing.

Thus, the switching of the base station from BS3 to BS4 of MS1 is realized.

FIG. 2 is a diagram showing an example of the WDM coupler 45 in the control station 40.

[0055] In the WDM coupler 45 ₂ is the wavelength lambda _MS1 to [lambda] light signals _MSN from each BS is demultiplexed to the terminals by the respective wavelengths, it is received by the optical receiver 43, respectively.

In the first embodiment, even if the base station is switched due to the movement of the MS, the wavelength of the MS from the BS does not change, so that the optical signal is split from the same output terminal. The same optical receiver 43
, And the switching operation becomes unnecessary.

FIG. 3 is a diagram showing a second embodiment.

The control station 60 and the radio base station (BS) are connected in a loop by an optical fiber 30, and optical signals are transmitted and received by wavelength multiplex transmission.

The control station 60 is provided with a wavelength variable light source 64 capable of changing the wavelength of the light to be transmitted. The WDM coupler 65 multiplexes the respective optical signals for wavelength-division multiplex transmission and transmits them to the BS.

In each of the BS 1 to BS 7, the optical signal of the wavelength addressed to itself is demultiplexed by the respective WDM coupler 75 and received by the optical receiver 73. Optical receiver 7
The signal from 3 is wirelessly transmitted to the mobile terminal (MS) via the antenna 71 by the access wireless transceiver 72.
A radio signal from a mobile terminal is received by an access-type radio transceiver 72 via an antenna 71 and a tunable light source 74.
Is converted into an optical signal of an arbitrary wavelength, and multiplexed by the WDM coupler 75 for wavelength multiplex transmission.

In the control station 60, the optical signal from each BS is
The light is demultiplexed for each wavelength by the WDM coupler 65 and received by the optical receiver 63.

Here, when the MS 1 is communicating with the BS 3, the communication information is transmitted from the control station 60 to the _{BS 3} at the wavelength λ _{BS 3} .
It is transmitted to S3. Next, when the MS moves to start communication with the BS 4, the control station 60 changes the wavelength of the variable wavelength light source from λ _{BS 3} to λ _{BS 4} and transmits, thereby realizing the switching of the BS. I do.

As a result, the control station 80 can switch the BS only by controlling the wavelength of the wavelength variable light source which is the transmitter.

FIG. 4 is a diagram showing an example of a WDM coupler in a BS. In WDM coupler 75 _1, of the light signals of wavelengths lambda _BS1 to [lambda] _BSN from the control station 60 or another BS, the optical signal lambda _BSM wavelength of the self BS addressed demultiplexed, the other signal passes. The signal from the tunable light source of BS is
The WDM coupler 75 _2, are combined to wavelength multiplexing transmission.

Therefore, when the MS 1 switches to communication with BS 3 to BS 4, the control station changes the wavelength of the tunable light source for transmitting the communication information from λ _{BS 3} to λ _{BS 4.}
, And the transmission is changed.

FIG. 5 is a diagram showing a third embodiment.

The control station 80 and the radio base station (BS) are connected in a loop by the optical fiber 30, and optical signals are transmitted and received by wavelength multiplex transmission.

In the control station 80, an optical transmitter 84 for transmitting each optical wavelength is provided, and each optical signal is multiplexed by a WDM coupler 85 for wavelength-division multiplexing transmission.
Transmitted to S.

A transmission light source of the optical transmitter 84 is prepared for each MS. For example, when MS1 initially starts communicating with BS3, the wavelength of the transmission light source of MS1 is λ
Set to _BS3 .

In each of the BS 1 to BS 7, an optical signal of an arbitrary wavelength is demultiplexed by the respective variable WDM coupler 95 and received by the optical receiver 93. Optical receiver 9
The signal from 3 is transmitted by the access wireless transceiver 92.
It is wirelessly transmitted to a mobile terminal (MS) via an antenna 91.

The radio signal from the mobile terminal is transmitted to the antenna 91
Is received by the access system wireless transceiver 92 via
The light is converted into an optical signal of a predetermined wavelength by the wavelength
The signals are multiplexed by the DM coupler 95 for wavelength multiplex transmission. The variable wavelength light source 94 is a light source that can arbitrarily control the output wavelength of the light source.

In the control station 80, the optical signal from each BS is W
The light is demultiplexed for each wavelength by the DM coupler 85 and received by the optical receiver 83.

Here, when the MS 1 is communicating with the BS 3, the communication information is transmitted from the control station to the _{BS 3} at the wavelength λ _BS3 . Then, as the MS moves, B
Even when communication with S4 is started, the control station 80 does not change the transmission wavelength for the base station. That is, even if the mobile terminal changes the base station, the wavelength λ _{BS 3} of the optical signal of the base station before the movement is performed.
Is transmitted to BS4 without change.

On the other hand, the BS 4 _converts the signal transmitted from the control station 80 for the MS 1 transmitted at the wavelength λ _{BS 3} into a variable WD signal.
The signal is demultiplexed by the M coupler 85 and received by the optical receiver 93.
Wireless transmission to S1.

As a result, the control station 80 does not perform the operation of switching the optical transmitter or controlling the wavelength, and the MS 1
Communication can be continued, and the BS switching is realized.

FIG. 6 is a diagram showing an example of the WDM coupler 95 in the BS.

[0077] In WDM coupler 95 _1, of the light signals of wavelengths λ _BS1 ~λ _{BS N} from the control station 80 or another BS,
The optical signal λ _BSM of a predetermined wavelength is split, and the other signals pass. The signal from the tunable light source 94 of the BS is WDM
By the coupler 95 _2, they are combined to wavelength multiplexing transmission.

Accordingly, when the MS 1 switches from the BS 3 to the communication with the BS 4, the optical signal from the control station 80 is transmitted to the BS 4 by controlling the demultiplexing wavelength of the variable WDM coupler to λ _{BS 3} at the BS 4. Switching of BS is realized.

FIG. 7 is a diagram showing a fourth embodiment.

The control station 100 and the radio base station (BS) are connected in a loop by an optical fiber 30.

In the control station 100, the MUX / DEM
The signal separated by the UX 102 is converted into an entrance wireless signal by the variable frequency entrance MOD 104, frequency-multiplexed by the frequency selective coupler 105, and transmitted to the BS by subcarrier optical transmission by the E / O 106.

In each of the BS1 to BS7, the signal is converted into a frequency-multiplexed radio signal by the respective O / E 115, and a signal of a predetermined entrance radio frequency is demultiplexed by the frequency selective coupler 114, and the frequency variable entrance DEM113 ₁ (the frequency variable entrance MODEM113 is composed of variable-frequency entrance MOD113 ₂ for modulating the frequency variable entrance DEM113 ₁ for demodulating.) is demodulated from. Digital signal demodulated by the variable-frequency entrance DEM113 ₁ is the access-system wireless transceiver 112, is converted into a radio frequency signal for the mobile terminal is wirelessly transmitted to the mobile terminal (MS) via the antenna 111.

The radio signal from the mobile terminal is transmitted to the antenna 11
1 and received by the access wireless transceiver 112 and converted into a digital signal. The digital signal is then converted into entrance radio signal (frequency _{f MS1)} by variable-frequency entrance MOD113 _2. The output signal is multiplexed by the frequency-selective coupler 114 and transmitted to the control station or another BS by subcarrier optical transmission by the E / O 116.

In the control station 100, the optical signal from each BS is converted into a radio signal which is frequency-multiplexed by the O / E 107, demultiplexed for each frequency by the frequency selective coupler 105, and each output is output at the frequency. The signal is demodulated by the variable entrance DEM 103 to be a digital signal.

When the MS 1 is communicating with the BS 3, the BS 3 modulates information from the _{MS 1 with} a frequency-variable entrance radio signal of the frequency f _MS1 and transmits the modulated signal to the control station 100 by subcarrier optical transmission. are doing.

At this time, when the MS 1 moves, the BS
4 and when started communication, BS4, the frequency variable entrance MOD113 ₂ of carrier (i.e., the entrance radio frequency) by controlling the modulates the information from MS1 at the entrance radio frequency of the frequency _{f MS1,} The signal is transmitted to the control station 100 by subcarrier optical transmission.
In the control station 100, the same entrance radio frequency f
By receiving the signal of _MS1 , it becomes possible to receive the signal of MS1.

Thus, switching of the base station from BS3 to BS4 of MS1 is realized.

FIG. 8 is a diagram showing a fifth embodiment.

The control station 120 and the radio base station (BS) are connected in a loop by the optical fiber 30.

In the control station 120, the MUX / DEM
The signal separated by the UX 122 is converted into a radio signal for entrance by the frequency variable entrance MOD 124.
(Frequency f _{BS1 to} f _BSN ), frequency multiplexed by the frequency selective coupler 125, and transmitted to each BS by subcarrier optical transmission by the E / O 126.

In each of BS 1 to BS 7, the signal is converted into a frequency-multiplexed radio signal by each O / E 135, and the signal of the frequency addressed to the own BS is demultiplexed by frequency selective coupler 134, and frequency variable entrance DE
M133 ₁ (Frequency variable entrance MODEM
133 is a frequency variable entrance DEM1 for demodulation.
33 ₁ and the frequency variable entrance MOD13 for modulating
It is constituted by 3 _2. ). The digital signal demodulated by the variable entrance DEM 133 ₁ is transmitted to the antenna 1 by the access system radio transceiver 132.
The data is wirelessly transmitted to the mobile terminal (MS) via the communication terminal 31. A radio signal from the mobile terminal is received by an access-type radio transceiver 132 via an antenna 131 and converted into a digital signal. Then, the digital signal is modulated into a radio signal for entrance by variable-frequency entrance MOD133 _2. The output signal is frequency-multiplexed by the frequency selective coupler 134 and transmitted to the control station 120 or another BS by subcarrier optical transmission by the E / O 136.

At the control station 120, the optical signal from each BS is
The signal is converted into a frequency-multiplexed radio signal by the O / E 127, and is demultiplexed for each frequency by the frequency selective coupler 125.
23 demodulates the digital signal.

Here, when the MS 1 is communicating with the BS 3, the control station 120 modulates the information into an entrance radio signal of the frequency f _BS 3 and transmits it to the BS 3 by subcarrier optical transmission.

At this time, the MS 1 moves and the BS
4 and when started communication, the control station 120 controls the carrier frequency variable entrance MOD124 (i.e., entrance radio frequency), the entrance radio frequency f _BS3, to convert the entrance radio frequency f _BS4 Then, it transmits to BS4 by subcarrier optical transmission. Thus, the control station 120 can change the destination of the signal from the BS 3 to the BS 4 by controlling the carrier of the frequency variable entrance MOD 124, thereby realizing the switching of the BS.

FIG. 9 is a diagram showing a sixth embodiment.

The control station 140 and the radio base station (BS) are connected in a loop by the optical fiber 30.

In the control station 140, the MUX / DEM
The signal separated by the UX 142 is
The lance MOD 144 allows the entrance radio signal (round
Wave number f _BS1~ F_BSN) And frequency-selective
Frequency is multiplexed by the E / O 146
It is transmitted to each BS by carrier optical transmission.

In each of the BS1 to BS7, the signal is converted into a radio signal multiplexed by the respective O / E 155, and a signal of a predetermined frequency is demultiplexed by the variable frequency selection type coupler 154.
153 ₁ (Frequency variable entrance MODEM1
53 is a frequency variable entrance DEM15 for demodulation
3 ₁ and the frequency variable entrance MOD153 for modulating
₂ . ). The digital signal demodulated by the variable entrance DEM 153 ₁ is transmitted to the mobile terminal (M) via an antenna 151 by an access system radio (wireless communication between the BS and the mobile terminal) 152.
Wirelessly transmitted to S).

The radio signal from the mobile terminal is transmitted to the antenna 15
1 and received by the access system wireless transceiver 152 and converted into a digital signal. The digital signal is converted into a radio signal for entrance by variable-frequency entrance MOD153 _2. The output signal is multiplexed by the variable frequency selection type coupler 154, and E / O1
The signal is transmitted to the control station 140 or another BS by subcarrier optical transmission by 56.

[0100] The control station 140 determines that the optical signal from each BS is
The signal is converted into a frequency-multiplexed radio signal by the O / E 147, demultiplexed for each frequency by the frequency selective coupler 145, and each output is demodulated to a digital signal by the frequency variable entrance DEM 143.

Here, when the MS 1 is communicating with the BS 3, the control station 140 modulates the information at the entrance frequency of the frequency f _BS 3 and transmits the information to the BS 3 by subcarrier optical transmission.

At this time, when the MS 1 moves, the BS
4 starts communication, but the supervising station 140 determines that the frequency f _BS3
And transmitted to the BS 4 by subcarrier optical transmission.

On the other hand, BS4 controls the demultiplexing frequency of the variable frequency selective coupler 154 to be _fBS3 .
The radio signal for entrance at the frequency _fBS3 from the control station 140 is received.

As a result, it is possible to change the signal transmission destination from BS3 to BS4 without performing the frequency switching operation, and the switching of the BS is realized.

FIG. 10 is a diagram showing a seventh embodiment.

The control station and the plurality of BSs are connected in a mesh form to realize the network configuration shown in FIGS.

FIG. 11 is a diagram showing an eighth embodiment.

A plurality of BSs are clustered, and cluster control stations 161 to 163 are arranged in each cluster.
The cluster control stations 161 to 163 control the BSs in the cluster.

Further, the control station 160 that controls the cluster control stations 161 to 163 is connected to the backbone network 31.
Connect with

FIGS. 12 and 13 show the ninth embodiment and the tenth embodiment.

FIG. 12 shows an embodiment in which the mobile terminal (MS) roams from cluster 1 to cluster 2.
Shows the control of the uplink, and FIG. 13 shows the control of the downlink.

In FIG. 12, MS 1 is connected to BS 6 of cluster 1.
While communicating with the BS 6, the BS 6 is transmitting information from the MS 1 to the cluster control station 1 at the wavelength λ _MS1 .

At this time, it is assumed that MS1 moves and changes the cluster, and starts communication with BS2 of cluster 2. In this embodiment, in this case, the cluster control station 1 of the cluster 1 transmits the signal from the MS 1 to the BS 6 before the movement.
At the same wavelength λ _MS1 as the wavelength transmitted by
To the cluster control station 160 for the cluster control station 2.

In the control station 160, in the cluster 2, the wavelength λ
_{If the MS1} is not used, the signal of the MS1 put on the wavelength _λMS1 from the cluster control station 1 is used as it is.
The signal is relayed without wavelength conversion and transmitted to the cluster control station 2.

On the other hand, if the wavelength λ _MS1 is used in the cluster 2, the control station 160 transmits the wavelength λ _MS1 from the cluster control station 1 to the wavelength λ _MS1 not used in the cluster 2.
_The wavelength is converted to the _{MS 1 ′} and transmitted to the cluster control station 2.

The BS of the cluster 2 to which the MS 1 has moved
2 transmits the signal from MS1 to the BS of cluster 1 before movement.
6 transmits to the cluster control station 2 at the same wavelength λ _{M S1} as the wavelength transmitted to the cluster control station 1. If the wavelength λ _MS1 is used in the cluster 2, the cluster 2
Of the wavelength λ _MS not used in the cluster 2
_{At 1 '} , it transmits to the cluster control station 2.

As a result, the mobile terminal can switch between the cluster and the radio base station. This also gives
Seamless inter-cluster handover can be realized.

In FIG. 13, MS 1 is connected to BS 6 of cluster 1.
When communicating with the BS 6, the BS 6 is receiving information from the cluster control station 1 at the wavelength λ _MS1 .

At this time, it is assumed that the MS 1 moves, changes the cluster, and starts communication with the BS 2 of the cluster 2. In this embodiment, in this case, the cluster control station 1 of the cluster 1 transmits the signal for the MS 1 to the BS 6 before the movement.
The same wavelength λ _MS1 as the wavelength transmitted to
To the supervising station 160 for the BS2.

In the control station 160, in the cluster 2, the wavelength λ
_{If the MS1} is not used, the signal of the MS1 put on the wavelength _λMS1 from the cluster control station 1 is used as it is.
The signal is transmitted to the cluster control station 2 as a relay without wavelength conversion.

On the other hand, if the wavelength λ _MS1 is used in the cluster 2, the control station 160 transmits the wavelength λ _MS1 from the cluster control station 1 to the wavelength λ _MS1 not used in the cluster 2.
_The wavelength is converted to the _{MS 1 ′} and transmitted to the cluster control station 2.

The cluster control station 2 converts the signal for _MS1 to the BS2 of the movement destination by using the wavelength _λMS1 or the wavelength _{λMS1 '.}
Send to The BS 2 converts the frequency to an access system radio (wireless communication between the BS and the mobile terminal) and transmits the radio to the MS 1.

As a result, the mobile terminal can switch between the cluster and the radio base station. This also gives
Seamless inter-cluster handover can be realized.

Although there are places where the WDM couplers are described separately for multiplexing and demultiplexing (for example, FIG. 2 and FIG. 4), they focus on the multiplexing function and the demultiplexing function. Thus, one WDM coupler having both functions may be used.

[0125] Instead of connecting a plurality of radio base stations and their supervising stations by subcarrier optical transmission using entrance radio signals, it is also possible to connect them using subcarrier optical transmission using mobile communication radio signals. It is possible.

[0126]

As described above, according to the present invention,
In a mobile communication base station network in which a plurality of wireless base stations supervise the wireless base station are connected by wavelength division multiplexing, a wavelength is allocated to communication between the wireless base station and the mobile terminal, and the mobile terminal moves. Thus, when switching of the base station occurs, by controlling the wavelength of the optical signal for transmitting information in the base station or the control station, the control operation is not required in the control station and the control can be simplified.

Further, in combination with subcarrier optical transmission,
The same effect can be obtained by controlling the frequency of the subcarrier.

Further, by applying the present invention to a mesh type network and a cluster type network, a highly scalable mobile communication base station network can be realized.

Further, the mobile terminal can roam between clusters.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a WDM coupler in a control station according to the first embodiment.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram illustrating an example of a WDM coupler in a BS according to a second embodiment.

FIG. 5 is a diagram showing a third embodiment of the present invention.

FIG. 6 is a diagram illustrating an example of a WDM coupler in a BS according to a third embodiment.

FIG. 7 is a diagram showing a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a fifth embodiment of the present invention.

FIG. 9 is a diagram showing a sixth embodiment of the present invention.

FIG. 10 is a diagram showing a seventh embodiment of the present invention.

FIG. 11 is a diagram showing an eighth embodiment of the present invention.

FIG. 12 is a diagram showing a ninth embodiment of the present invention.

FIG. 13 is a diagram showing a tenth embodiment of the present invention.

FIG. 14 is a diagram illustrating an example of a conventional mobile communication base station network.

FIG. 15 is a diagram showing an example of a WDM coupler in a control station in a conventional example.

[Explanation of symbols]

10, 40, 60, 80, 100, 120, 140
Administration Bureau 11, 41, 61, 81, 101, 121, 141
Control unit 12, 42, 62, 82, 102, 122, 142
MUX / DEMUX 13, 14 selection switch 15, 23, 43, 53, 63, 73, 83, 93
Optical receiver 16, 24, 84 Optical transmitter 17, 25, 45, 55, 65, 75, 85 WDM
Couplers 21, 51, 71, 91, 111, 131, 151
Antennas 22, 52, 72, 92, 112, 132, 152
Access wireless transmitter / receiver 30 Optical fiber 31 Backbone network 44, 54, 64, 74, 94 Variable wavelength light source 95 Variable WDM coupler 103, 123, 143 Variable frequency entrance D
EM 104, 124, 144 Frequency variable entrance M
OD 105, 114, 125, 134, 145 Frequency-selective coupler 107, 115, 127, 135, 147, 155
O / E 106, 116, 126, 136, 146, 156
E / O 113, 133, 153 Variable frequency entrance M
ODEM 154 Variable frequency selection coupler 160 Control station that controls the cluster control station 161 Cluster control station

Continuation of front page (72) Inventor Yasushi Yamao 2-1-1, Nagatacho, Chiyoda-ku, Tokyo NTT Mobile Communication Network Co., Ltd. F-term (reference) 5K002 AA01 AA03 BA05 DA02 DA11 FA01 5K067 AA42 BB04 DD57 EE02 EE10 EE16 EE32 EE37

Claims (21)

[Claims] 1. A radio base station arranged in a plurality of cells,
In a mobile communication base station network in which a control station for controlling the base station is connected by wavelength multiplexing transmission through an optical fiber, the radio base station includes: a wavelength-variable transmitter that transmits an optical signal having a predetermined wavelength; A WDM coupler for multiplexing an optical signal from the variable transmitter for wavelength multiplex transmission, the control station includes a plurality of optical receivers for receiving wavelengths of the wavelength multiplexed optical signal, and a plurality of the optical receivers. A wireless base station that includes a WDM coupler that demultiplexes an optical signal wavelength-division multiplexed from a wireless base station to each of the optical receivers at each wavelength, wherein a mobile terminal that communicates with the wireless base station moves and communicates When the mobile terminal has moved, the radio base station to which the mobile terminal has moved controls the wavelength of the tunable transmitter, and controls the wavelength with the same optical signal wavelength as the optical signal wavelength transmitted by the radio base station before the movement. Send to station A base station network for mobile communication. 2. The mobile communication base station network according to claim 1, wherein the WDM coupler provided in the radio base station demultiplexes only a specific wavelength from an optical signal of a plurality of wavelengths transmitted by wavelength division multiplexing. The radio base station includes an optical receiver that receives an optical signal demultiplexed by the WDM coupler, and the control station transmits a plurality of wavelength-variable optical transmission signals for transmitting an optical signal for wavelength-division multiplexing transmission. A WDM coupler provided in the control station is multiplexed for wavelength multiplex transmission of optical signals from the plurality of wavelength-variable optical transmitters, and a mobile terminal communicating with the wireless base station moves. When the radio base station to communicate with is changed, the control station controls the wavelength of the variable wavelength transmitter, changes the wavelength to the optical wavelength for the radio base station to which the mobile terminal has moved, and Specially for transmitting to a wireless base station. Base station network for mobile communication to. 3. The mobile communication base station network according to claim 1, wherein the WDM coupler provided in the radio base station is a variable WDM coupler, and is separated from optical signals of a plurality of wavelengths transmitted by wavelength division multiplexing. The radio base station includes an optical receiver that receives an optical signal demultiplexed by the variable WDM coupler, and a mobile terminal that communicates with the radio base station moves and communicates. When the radio base station is changed, the controlling station transmits the wavelength of the optical signal transmitted to the radio base station without changing even if the radio base station with which the mobile terminal communicates is changed, and The base station network for mobile communication, wherein the base station receives the wavelength of the optical signal from the control station after being demultiplexed by the variable WDM coupler. 4. The mobile communication base station network according to claim 1, wherein said radio base station demodulates a radio signal received from said mobile terminal and converts it into a digital signal. A radio signal demodulator; an optical transmitter for converting the digital signal for the control station converted by the mobile communication radio signal demodulator into an optical signal transmitted by wavelength multiplexing; and a digital signal from the control station having a wavelength An optical receiver that receives the multiplexed optical signal and converts it into a digital signal, and a mobile communication radio signal modulator that converts the digital signal converted by the optical receiver into a mobile communication radio frequency signal. An optical receiver for converting an optical signal in which a digital signal received from the wireless base station is wavelength-division multiplexed into a digital signal; Base station network for mobile communication, wherein the digital signal of the ground station for to and a light transmitter which converts the optical signal of the wavelength multiplexing transmission digital signal. 5. The mobile communication base station network according to claim 1, wherein the radio base station demodulates a mobile communication radio signal received from the mobile terminal and converts the demodulated radio signal into a digital signal. A mobile communication radio signal demodulator, an entrance radio signal modulator for converting the digital signal converted by the mobile communication radio signal demodulator into an entrance radio signal, and a digital signal converted by the entrance radio signal modulator. An optical transmitter that converts an entrance wireless signal into an optical signal for subcarrier optical transmission, an optical receiver that converts an entrance wireless signal transmitted by the subcarrier optical into an electric signal, and an entrance that is converted into an electric signal A wireless signal demodulator for an entrance for converting a wireless signal for use into a digital signal; A mobile communication radio signal modulator for converting the digital signal converted by the transmitter into a mobile communication radio frequency signal, wherein the control station transmits a subcarrier light with an entrance radio signal transmitted by the radio base station. An optical receiver that converts a transmitted optical signal into an electric signal, an entrance radio signal demodulator that converts an entrance radio signal converted into an electric signal into a digital signal, and an entrance digital signal for a radio base station. An entrance wireless signal modulator for converting into a wireless signal, and an optical transmitter for converting the entrance wireless signal converted by the entrance wireless signal modulator into an optical signal for subcarrier optical transmission. Characteristic base station network for mobile communication. 6. The mobile communication base station network according to claim 1, wherein the radio base station converts a radio signal received from the mobile terminal into an optical signal for subcarrier optical transmission. An optical transmitter, and an optical receiver that converts an optical signal, in which a mobile communication radio frequency signal received from the control station is transmitted as a subcarrier optical signal, into an electric signal, the control station includes the radio base station. An optical receiver that converts an optical signal transmitted by a subcarrier from a mobile communication radio frequency signal received from a station into an electric signal, and a mobile device that converts the mobile communication radio frequency signal converted into an electric signal into a digital signal. A communication radio signal demodulator, a mobile communication radio signal demodulator for converting a digital signal for a radio base station into a mobile communication radio frequency signal, and the mobile communication radio signal demodulation Base station network for mobile communication, characterized by comprising an optical transmitter for converting the converted radio frequency signals for mobile communication and the transmitted optical signal subcarrier light by. 7. A radio base station arranged in a plurality of cells,
In a mobile communication base station network in which a control station for controlling the mobile communication base station is connected by an optical fiber through subcarrier optical transmission, the radio base station demodulates a mobile communication radio signal received from the mobile terminal and generates a digital signal. A wireless signal demodulator for mobile communication, which converts the digital signal converted by the wireless signal demodulator for mobile communication into a wireless signal for entrance, and a radio signal modulator for variable frequency entrance, An optical receiver for converting an entrance wireless signal transmitted from a base station and transmitted by a subcarrier optical signal into an electric signal; and combining an output of the optical receiver and an output of the frequency variable entrance wireless signal modulator. And a coupler, wherein the control station converts the optical signal in which the entrance radio signal is transmitted by subcarrier optical transmission into an electric signal. An optical receiver, a frequency selective coupler for demultiplexing the output of the optical receiver for each frequency, and an entrance for converting each of the entrance radio signals demultiplexed by the frequency selective coupler into a digital signal. A radio signal demodulator for mobile communication, wherein a mobile terminal communicating with the radio base station moves and changes a radio base station to communicate with, and the radio base station to which the mobile terminal has moved is provided with the frequency variable entrance. Control the carrier frequency of the wireless signal modulator for the entrance, the same wireless signal frequency for the entrance as the wireless signal for the entrance transmitted by the wireless base station before moving,
A base station network for mobile communication, wherein the network is transmitted to the control station. 8. The base station network for mobile communication according to claim 7, wherein the radio base station converts an entrance radio signal transmitted by subcarrier optical transmission into an electric signal, and the optical receiver. A frequency selective coupler for demultiplexing a predetermined frequency signal from the output of the antenna, an entrance radio signal demodulator for converting an entrance radio signal demultiplexed by the frequency selective coupler into a digital signal, and an entrance radio signal demodulation A radio signal modulator for mobile communication that converts the digital signal converted by the device into a radio frequency signal for mobile communication, wherein the control station converts the digital signal for the radio base station into a radio signal for entrance. Radio signal modulator for variable frequency entrance, coupler for multiplexing output of said radio signal modulator for variable frequency entrance An optical transmitter that converts the entrance wireless signal converted by the entrance wireless signal modulator into an optical signal for subcarrier optical transmission, wherein a mobile terminal communicating with the wireless base station moves. When the wireless base station for communication is changed, the control station controls the carrier frequency of the frequency variable entrance wireless signal modulator that converts a digital signal for the wireless base station into an entrance wireless signal, and the mobile terminal A base station network for mobile communication, wherein the network is changed to an entrance radio frequency for a moved radio base station. 9. The mobile communication base station network according to claim 7, wherein the wireless base station converts an optical signal for a plurality of frequencies of entrance-transmitted subcarrier optical signals into an electric signal, and a predetermined signal. A variable frequency selection type coupler for demultiplexing only the frequency of, and a mobile communication radio signal modulator for converting an electric signal demultiplexed by the variable frequency selection type coupler to a mobile communication radio frequency signal, The control station includes a plurality of entrance radio signal modulators for converting a digital signal for a radio base station into an entrance radio signal, a coupler for multiplexing electric signals from the plurality of entrance radio signal modulators, and the coupler And an optical transmitter for converting the output of the wireless base station into an optical signal for subcarrier optical transmission. When the radio base station to be transmitted is changed, the control station transmits the radio signal without changing the carrier frequency of the frequency-variable entrance radio signal modulator even if the radio base station with which the mobile terminal communicates is changed. A mobile communication base station network, wherein the wireless base station to which the mobile station has moved changes the branching frequency of the variable frequency selective coupler to an entrance wireless signal frequency for the wireless base station before the movement. 10. The mobile communication base station network according to claim 1, wherein a radio base station arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by an optical fiber. A mobile communication base station network, wherein the mobile communication base station network is configured in a loop. 11. The mobile communication base station network according to claim 1, wherein a radio base station arranged in a plurality of cells and a supervision station supervising the radio base stations are connected by an optical fiber. The mobile communication base station network is configured in a mesh shape. 12. The mobile communication base station network according to claim 1, wherein a radio base station arranged in a plurality of cells and a supervision station supervising the radio base stations are connected by an optical fiber. The mobile communication base station network is a cluster base station network. 13. The mobile communication base station network according to claim 12, further comprising a higher-level control station that controls the cluster control station, wherein a mobile terminal that communicates with the radio base station moves and communicates with a cluster. In the case of a change, the cluster supervisory station before the move, via the higher-level supervisory station, the signal from the mobile terminal to the cluster supervisory station after the move, the same wavelength as the optical signal transmitted by the base station before the move Transmit at the wavelength, the base station of the moved cluster transmits the signal from the mobile terminal to the moved cluster control station at the same wavelength as the wavelength of the optical signal transmitted by the base station before the movement. A base station network for mobile communication, characterized in that: 14. The mobile communication base station network according to claim 12, further comprising a higher-level control station that controls the cluster control station, wherein a mobile terminal that communicates with the radio base station moves and communicates with a cluster. In the case of a change, the cluster supervisory station before the movement transmits a signal to the mobile terminal to the cluster base station after the movement and to the base station before the movement via the higher-level management station and the cluster management station after the movement. Transmitted at the same wavelength as the wavelength of the transmitted optical signal, and the cluster control station after the movement transmits the signal to the mobile terminal to the cluster base station after the movement and the optical signal transmitted to the base station before the movement. A base station network for mobile communication, wherein transmission is performed at the same wavelength as the wavelength. 15. The mobile communication base station network according to claim 13, wherein the higher-level control station has an optical wavelength conversion unit, and the higher-level control station is a base before movement in a cluster after movement. When the wavelength of the optical signal transmitted to the station is used, the wavelength converting means converts the wavelength of the optical signal not used in the moved cluster to the wavelength of the optical signal which is not used in the moved cluster, and the cluster managing station of the moved cluster. A base station network for mobile communication characterized by transmitting to a base station. 16. A base station switching method in a mobile communication base station network in which a radio base station arranged in a plurality of cells and a supervising station supervising the base station are connected by wavelength multiplex transmission through optical fibers, respectively. The transmission wavelength that the radio base station transmits to the control station is set at the start of communication with the mobile terminal, the transmission wavelength is fixed while the mobile terminal is communicating, and the mobile terminal moves. A base station switching method comprising transmitting information of a mobile terminal from a new wireless base station to a supervising station at a transmission wavelength set for the mobile terminal, even if a wireless base station with which communication is performed changes. 17. A base station switching method in a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are respectively connected by optical fiber to wavelength division multiplexing transmission. The control station has a variable wavelength transmitter, a transmission wavelength transmitted by the control station to the radio base station is set for each radio base station, and the mobile terminal changes a radio base station with which the mobile terminal moves and communicates. In that case, the supervising station controls the wavelength of the tunable transmitter, and by the transmission wavelength set in the changed radio base station,
And transmitting information to the mobile terminal to the changed radio base station. 18. A base station switching method in a mobile communication base station network in which a radio base station arranged in a plurality of cells and a supervising station supervising the radio base stations are respectively connected by wavelength division multiplex transmission through optical fibers, The transmission wavelength transmitted by the control station to the radio base station is set for each radio base station, and when the mobile terminal changes the radio base station to move and communicate with, the control station transmits the radio base station after the movement. A base station switching method, wherein information on the mobile terminal is transmitted to a station according to a transmission wavelength set in a wireless base station before moving. 19. A base station switching method in a mobile communication base station network in which a radio base station arranged in a plurality of cells and a supervising station supervising the base station are connected by an optical fiber through subcarrier optical transmission, The radio signal for the entrance that the radio base station performs subcarrier optical transmission to the control station is set at the start of communication with the mobile terminal, and the radio signal for the entrance is fixed while the mobile terminal is communicating, Even if the mobile terminal moves and changes the radio base station with which the mobile terminal moves, from the new radio base station to the supervising station, the information of the mobile terminal is transmitted by subcarrier optical transmission according to the entrance frequency signal set in the mobile terminal. A method for switching a base station, the method comprising: 20. A base station switching method in a mobile communication base station network in which a radio base station arranged in a plurality of cells and a supervising station supervising the base station are connected by subcarrier optical transmission through an optical fiber, The radio signal for entrance transmitted by the supervising station to the radio base station is set for each radio base station, and when the mobile terminal changes the radio base station with which the mobile station moves and communicates, the supervising station sets the changed radio signal. A base station switching method, comprising transmitting subcarrier optical transmission of information to the mobile terminal to a changed radio base station by an entrance radio signal set in the base station. 21. A base station switching method in a mobile communication base station network in which radio base stations arranged in a plurality of cells and a supervising station supervising the radio base stations are connected by subcarrier optical transmission via optical fibers, The entrance radio signal transmitted by the supervising station to the radio base station is set for each radio base station, and when the mobile terminal changes the radio base station to move and communicate with, the new radio base station to the supervision station Is, by the entrance frequency signal set in the wireless base station before moving,
A base station switching method, wherein information of the mobile terminal is transmitted by subcarrier optical transmission.