JP2002204477A - Mobile communication system and its base station and mobile communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication system that allows specific mobile communication terminals to make wireless communication even when call transmission is restricted, and enhance the capability of coping with emergency. SOLUTION: When the call transmission is restricted, a mobile communication terminal MSi uses a control channel with a 2nd frequency band separately prepared for a conventional standby control channel to transmit idle channel use reservation information to a base station BS1. When the base station BS1 receives the reservation information, the base station checks whether or not the mobile communication terminal sending the reservation information is a specific terminal qualified to use the idle channel, and then the base station registers the result to a reservation terminal list. On the occurrence of an idle channel that is available to assignment, the base station uses the control channel with the 2nd frequency band to transmit the permission information of the use of the idle channel to the mobile terminal MSi, and the mobile communication terminal MSi receiving the permission information makes transmission.

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 such as a cellular mobile telephone system, and more particularly to a mobile communication system having a function of restricting a call when communication traffic of a radio communication channel in a base station exceeds a predetermined amount. The present invention relates to a communication system, a base station thereof, and a mobile communication terminal.

[0002]

2. Description of the Related Art In a cellular mobile communication system, when communication traffic at a specific base station increases due to a disaster, accident, event, or the like, a call becomes congested or communication quality deteriorates, so that communication cannot be performed. For example, CDMA (Code Division Multiple A)
In a system adopting the ccess) scheme, when the number of channels that can be simultaneously transmitted and received by the base station increases, the interference power level for each wireless communication channel in that frequency band increases, and communication quality cannot be maintained.

[0003] In general, in a cellular mobile communication system, before the communication quality can no longer be maintained, a call is restricted to each mobile communication terminal existing in the wireless communication area. When the transmission restriction is performed, information indicating that the transmission restriction is being performed is transmitted from the base station to the mobile communication terminal and displayed, and the transmission from the mobile station is rejected by the base station.

[0004]

However, in this type of system, all mobile communication terminals are controlled to make outgoing calls under the same conditions, so that, for example, an emergency contact such as a key person, medical care, security or fire fighting, etc. However, there is a problem for those who are engaged in the task of performing wireless communication, even if they want to make important communications.

It has also been proposed to provide a mobile communication terminal with a distinction between a general station and a priority station so that the level of transmission restriction is made different for these stations. However, even in such a system, when a high-level transmission restriction is implemented for all mobile communication terminals including the priority station, even the priority station is transmitted until the transmission restriction is released. It becomes almost impossible.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to enable a specific mobile communication terminal to perform wireless communication even when transmission restriction is being implemented. An object of the present invention is to provide a mobile communication system excellent in emergency response capability, a base station thereof, and a mobile communication terminal.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a base station forming a wireless communication area and a plurality of wireless communication channels selectively used between the base station. A mobile communication system comprising: a plurality of mobile communication terminals that perform communication; and a mobile communication system that has a function of restricting transmission to the mobile communication terminal when communication traffic of the base station exceeds a predetermined value. A specific mobile communication terminal registered in advance among the mobile communication terminals includes a reservation information transmitting unit and a specific wireless communication unit. When receiving a notification from the base station that the transmission restriction is being implemented, the base station transmits reservation information for reserving the use of an empty channel using a control channel prepared separately from the wireless communication channel. In addition to the transmission to the station, when the use permission notification of the vacant channel arrives from the base station for the transmission of the reservation information, the radio communication is performed using the specified vacant radio communication channel. On the other hand, the base station is provided with use permission control means, and when the reservation information arrives from the mobile communication terminal during transmission restriction, gives permission to use the free mobile communication terminal to the source mobile communication terminal. It is like that.

That is, the present invention generally relates to a base station,
Focusing on the fact that a certain number of vacant channels for incoming calls are reserved even during outgoing call restriction, reservation information for reserving the use of vacant channels via a control channel from a specific mobile communication terminal registered in advance is provided. The transmission is performed, and the base station permits the use of the vacant channel, thereby enabling the specific mobile communication terminal to perform wireless communication.

Therefore, according to the present invention, even when the communication traffic of the base station is remarkably increased and the outgoing call is regulated, for example, important persons or jobs requiring emergency communication such as medical care, security or firefighting. With respect to a specific mobile communication terminal used by a person involved, wireless communication can be performed by following a procedure for reserving an unused channel and permitting it. That is, a system with high emergency response capability can be provided.

Further, according to the present invention, when reservation information arrives from a mobile communication terminal during transmission restriction at the base station, the transmission source mobile communication terminal is stored in an idle channel use waiting list. It is characterized in that a vacant wireless communication channel is monitored, and when a vacant wireless communication channel is found, this wireless channel is sequentially allocated to the mobile communication terminals stored in the use waiting list.

In this way, even when reservation information from a plurality of specific mobile communication terminals is congested, it is possible to receive all of the reservation information and allocate an empty channel to each reservation sequentially.

Further, in the present invention, the base station includes a specific terminal registration list storing information for identifying a specific mobile communication terminal, and an authentication unit. Then, when the reservation information arrives during the transmission restriction, it is confirmed whether or not the mobile communication terminal of the transmission source is a specific mobile communication terminal registered in advance based on the specific terminal registration list. Also features.

In this way, even if an unspecified number of mobile communication terminals transmit the reservation information, it is possible to exclude the reservation information and to make only the specific mobile communication terminal use the idle channel. .

[0014]

FIG. 1 is a schematic configuration diagram of a CDMA mobile communication system which is a first embodiment of a mobile communication system according to the present invention.

In the service area of the system, a plurality of base stations BS1, BS2,... Are distributed and arranged, and these base stations BS1, BS2,. . Each base station BS1, B
The wireless communication areas formed by S2,... Respectively include normal cells TE1, TE2,.
Control cells CE1, CE2,... Using a second frequency band different from the first frequency band.
The first frequency band includes a channel called a paging channel, and is used for performing standby control and the like. On the other hand, the second frequency band is used for transmitting the reservation information for use of the vacant channel according to the present invention and the permission notification information thereof.

The mobile communication terminals MS1 to MSn are connected to the nearest base station via a wireless communication channel in a wireless communication area formed by the base stations BS1, BS2,. Not connected to a public network via a mobile communication exchange.

A wireless communication channel is identified by a spreading code. For example, a PN code (Pseudo noise c
ode) and an orthogonal code (Orthogonal Code). The reason for using orthogonal codes is to increase the orthogonality between channels and further suppress interference. Examples of orthogonal codes include Walsh sequence and Or.
There is a thogonal Gold sequence.

The mobile communication terminals MS1 to MS
n is configured as follows. FIG. 2 is a block diagram showing the functional configuration.

A radio frequency signal transmitted from a base station is received by an antenna 1 and then received by an antenna duplexer 2 (DUP).
Is input to the receiving circuit (RX) 3 via the. Receiving circuit 3
In the above, the radio frequency signal is converted to a frequency synthesizer (SY
N) The signal is mixed with the reception local oscillation signal output from 4 and frequency-converted to an intermediate frequency signal. Note that the frequency of the reception local oscillation signal generated from the frequency synthesizer 4 is specified by a control signal SYC from the control unit 12.

The received intermediate frequency signal is subjected to a quadrature demodulation process in a CDMA signal processing unit 6, and then subjected to a despreading process by a spreading code (PN code) assigned to a reception channel, and is processed according to a data rate. Is converted into demodulated data in a predetermined format. The converted demodulated data is input to the voice code processing unit 7, and data indicating the data rate among the received data is input to the control unit 12 as the reception data rate.

The voice code processing section 7 subjects the demodulated data output from the CDMA signal processing section 6 to decompression processing in accordance with the reception data rate notified from the control section 12, and then uses Viterbi decoding or the like. The decoding process and the error correction decoding process are performed to reproduce the baseband received digital data.

The PCM code processing section 8 performs different signal processing according to the type of digital voice signal communication (voice communication, data communication) output from the control section 12. That is,
At the time of voice communication, the received digital data output from the voice code processor 7 is PCM decoded and an analog reception signal is output. This analog reception signal is amplified by the reception amplifier 9 and then output from the speaker 10 as loudspeaker. At the time of data communication, the reception digital data output from the voice code processor 7 is output to the controller 12. Control unit 1
2 stores the received digital data in the storage unit 13. If necessary, the received digital data can be transferred from an external interface to a portable information terminal (PD) (not shown).
A: Output to a personal computer such as a Personal Digital Assistance) or a notebook personal computer.

On the other hand, the input voice of the speaker at the time of voice communication is input as an analog transmission signal through the microphone 11, amplified to an appropriate level by the transmission amplifier 18, and then processed by the PCM code processor 8. An encoding process is performed, and the encoded data is supplied to the audio encoding unit 7 as transmission data. Data output from a personal computer (not shown) is input to the control unit 12 via an external interface, and is output from the control unit 12 to the voice code processing unit 7 via the PCM code processing unit 8.

At the time of voice communication, the voice code processing unit 7
The energy amount of the input voice is detected from the transmission voice data output from the CM code processing unit 8, and the data rate is determined based on the detection result. Then, the transmission data is compressed into a burst signal having a format corresponding to the data rate, and further subjected to error correction coding processing.
Output to the A signal processing unit 6. At the time of data communication, the transmission data output from the PCM code processing section 8 is compressed into a burst signal having a format corresponding to a preset data rate, and further subjected to error correction coding processing to perform CDMA signal processing. Output to the unit 6. In addition, both the data rate at the time of voice communication and the data rate at the time of data communication are notified to the control unit 12 as the transmission data rate.

The CDMA signal processing unit 6 performs a spreading process on the burst signal compressed by the voice code processing unit 7 using a PN code assigned to a transmission channel. A quadrature modulation process is performed on the spread-coded transmission signal, and the quadrature modulation signal is transmitted to a transmission circuit (TX)
Output to 5

The transmitting circuit 5 combines the quadrature modulated signal with a transmitting local oscillation signal generated from the frequency synthesizer 4 and converts it into a radio frequency signal. Then, the transmission circuit 5
Based on the transmission data rate notified by the control unit 12, high-frequency amplification of only the effective portion of the radio frequency signal,
Output as a transmission radio frequency signal. The transmission radio frequency signal output from the transmission circuit 5 is supplied to the antenna 1 via the antenna duplexer 2, and is burst-transmitted from the antenna 1 to a base station (not shown).

The input unit 14 is provided with a key group such as a dial key, a transmission key, a power key, an end key, a volume control key, a mode designation key, and the like. L for displaying the operating state of the
There are provided a CD display and an LED lamp for indicating the discharge state of the battery 16 (requesting charging of the battery 16).

Reference numeral 17 denotes a power supply circuit, and the battery 1
6, a predetermined operating power supply voltage Vcc is generated and supplied to each circuit section.

The control unit 12 has, for example, a microcomputer as a main control unit, and establishes a communication link with a base station in response to outgoing / incoming calls to perform a voice communication or data communication. In addition to a control function of recording / reproducing the voice of the other party using the storage unit 13, a reservation information transmission control function 12a and a specific transmission control function 12b are provided as new functions according to the present invention.

The reservation information transmission control function 12a generates reservation information when a user inputs a reservation instruction for an empty channel in a state where transmission restriction has been notified from the base station.
The reservation information includes a message for reserving use of an empty channel and identification information of the terminal itself. And
A control channel using a second frequency band different from the paging channel is acquired, and the reservation information is transmitted to the base station using the control channel.

The specific transmission control function 12b waits for the arrival of transmission permission information from the base station in the second frequency band as it is after the transmission of the reservation information, and transmits the transmission using a control channel for transmission restriction control in the second frequency band. When the permission information is received, the control channel of the first frequency band forming the normal cells TE1, TE2,... Is captured and a transmission request is transmitted. The reservation number notified by the transmission permission information is inserted into the transmission request.

On the other hand, the base stations BS1, BS2,... Are configured as follows. FIG. 3 is a block diagram showing the functional configuration. That is, the base stations BS1, BS2,... Include a radio interface unit 22 having an antenna 21, a baseband signal processing unit 23, a network interface unit 24,
It comprises a control unit 25 and a storage unit 26.

The radio interface unit 22 transmits and receives communication information and control information to and from the mobile communication terminals MS1 to MSn via a radio communication channel and a control channel. The baseband signal processing unit 23 performs signal processing such as encoding / decoding processing and error correction encoding / decoding processing for wirelessly transmitting and receiving communication information and control information. The network interface unit 24 transmits communication information and control information to the communication line 27.
For transferring data to and from a mobile communication exchange (not shown) via the network.

The specific terminal list storage unit 2 is stored in the storage unit 26.
6a and a reserved terminal list storage unit 26b. The specific terminal list storage unit 26a stores the terminal number of a specific mobile communication terminal that has a qualification to use an empty channel under call restriction. Reserved terminal list storage unit 26
“b” is used to store reservation information received from a specific mobile communication terminal during transmission restriction.

By the way, the control unit 25 includes, in addition to the existing control function as a base station, a transmission restriction control means 25a and a reservation registration control function 25 as control functions according to the present invention.
b and an empty channel allocation control function 25c.

The transmission restriction control function 25a monitors the communication traffic of the own station, and when the communication traffic exceeds a preset value, sets the operation mode of the own station to the transmission restriction operation mode. A message to the effect that transmission restriction is being implemented is notified to each mobile communication terminal existing in the normal cell to be formed.

When reservation information arrives from the mobile communication terminal in the call restriction operation mode, the reservation registration control function 25b determines whether or not the transmission source mobile communication terminal is a specific mobile communication terminal having a qualification for using an available channel. Is determined based on the information stored in the specific terminal list storage unit 26a. Only when the mobile communication terminal is a specific mobile communication terminal, the received reservation information is stored in the reservation terminal list storage unit 26.
b.

The free channel allocation control function 25c
The state of the vacant channel is monitored while the reservation information is stored in the reserved terminal list storage unit 26b. Each time
The vacant wireless communication channels are sequentially allocated to the mobile communication terminals whose reservation information is stored in the reservation terminal list storage unit 26b. Then, the use permission information of the free channel is transmitted to the mobile communication terminal to which the free channel is allocated. In the use permission information, the assigned wireless channel number and reservation number are inserted together with the permission message.

Next, the operation of the mobile communication system configured as described above when transmission restriction is performed will be described. 4 to 8 are flowcharts showing control procedures and control contents in the base stations BS1, BS2,... And the mobile communication terminals MS1 to MSn.

The base stations BS1, BS2,... Monitor the communication traffic of the wireless communication channel in a normal control state. In this state, for example, the base station BS shown in FIG.
Assume that communication traffic rapidly increases due to a disaster, accident, event, or the like in 1 and the value exceeds a preset threshold. Then, the control unit 25 of the base station BS1
Sets the operation mode of its own station to the operation mode with transmission restriction in step 4b of FIG. 4, and proceeds to step 4c to add a control channel using the second frequency band to the control channel used here. . That is, the cell to be used is set to both the normal cell TE1 and the cell CE1 for transmission restriction control. Then, transmission regulation notification information is transmitted to each of the mobile communication terminals MS1, MS2,... Existing in the normal cell TE1 by using the control channel.

After the transition to the transmission restriction operation mode, the control unit 25 of the base station BS1 continuously monitors the communication traffic in step 4a. When detecting that the communication traffic has dropped below the threshold value, FIG.
In step 4b, the operation mode of the own station is returned from the transmission restriction operation mode to the normal control state. Then, the process proceeds to step 4d, where the cell CE for transmission restriction control is transmitted.
Then, the mobile station returns to the state in which only the normal cell TE1 is used, and notifies the mobile communication terminals existing in the cell of the release of the transmission restriction.

On the other hand, the mobile communication terminals MS1 to MSn monitor the outgoing / incoming call and the incoming call notification in the standby state. In this state, when communication traffic suddenly increases in the base station BS1 and transmission restriction notification information arrives, the mobile communication terminal detects this transmission restriction notification in step 5a and shifts to the transmission restriction operation mode as shown in FIG.

When the mode shifts to the transmission restriction operation mode, the control unit 12 of each of the mobile communication terminals MS1 to MSn monitors an input of a reservation request for use of a vacant channel by the user in step 5b. In this state, for example, it is assumed that the user inputs a reservation request for use of a vacant channel at the mobile communication terminal MSi. Then, the control unit 12 of the mobile communication terminal MSi
In step 5c, a control channel for reservation permission control of a vacant channel using the second frequency band is searched, and it is confirmed in step 5d that the control channel has been captured.
In step 5e, reservation information for reserving the use of an empty channel using this control channel is transmitted.
The reservation message includes the reservation message and the terminal identification number of the terminal itself.

In response to the transmission of the reservation information, when a registration completion notification of the reservation information arrives from the base station BS1, the control unit 12 shifts from step 5f to step 5g and sends a message to the effect that the reservation has been made. It is displayed on the display unit 15. On the other hand, when a reservation refusal notice is received from the base station BS1, a message to that effect is displayed on the display unit 15 in step 5h.

The base station BS1 monitors the arrival of the use reservation information of the vacant channel from the mobile communication terminal during the transmission restriction. In this state, when the reservation information arrives from the mobile communication terminal MSi, the reservation information is received in step 6a shown in FIG. 6, and thereafter, the reservation registration control is executed.

That is, the control unit 25 first executes step 6b
It is determined based on the list stored in the specific terminal list storage unit 26a whether or not the mobile communication terminal MSi that has transmitted the reservation information is a specific mobile communication terminal having a free channel use qualification. If the result of this determination is that the mobile communication terminal MSi of the reservation request source is a specific mobile communication terminal having a qualification to use a free channel, then step 6d
In step 6e, the reservation information received from the mobile communication terminal MSi is stored at the end of the list in step 6e.

On the other hand, the mobile communication terminal MSi as the transmission source of the reservation information is a terminal that does not have the qualification to use the free channel, or even if the reservation information is not registered, the reservation terminal list storage unit 2
If there is no free space in the mobile communication terminal MSi, the control unit 25 of the mobile communication terminal MSi proceeds to step 6f, where information for notifying that the reservation cannot be accepted is transmitted to the mobile communication terminal MS of the request source.
Send to i.

When the reservation information is registered, the base station BS1
Executes the allocation control of the empty channel. That is, as shown in FIG. 7, the control unit 25 first monitors the status of the idle channel in step 7a. For example, whether there is a channel that can be diverted to outgoing calls among available channels prepared for incoming calls and whether the mobile communication terminals MS1, MS2,.
Monitors whether the communication has ended and an empty channel has occurred among the wireless communication channels in use.

When a free channel is found by this monitoring, the reservation terminal list storage section 26b
, And reads out the reservation information with the oldest registration timing, that is, the reservation information with the highest registration order, and creates free channel use permission information based on this reservation information. In this use permission information, the assigned wireless channel number and reservation number are inserted together with the permission message. In step 7c, the control unit 25 uses the control channel of the second frequency band to send the use permission information to the mobile communication terminal (for example, MS
Send to i).

On the other hand, as described above, the mobile communication terminal MSi having received the registration completion notification of the reservation information from the base station BS1.
In the control unit 12, as shown in FIG.
Monitor the arrival of use permission information from the base station BS1.
When the use permission information of the vacant channel arrives from the base station BS1 in this state, the control unit 12 controls the standby control channel from the control channel of the second frequency band to the first frequency band used for normal standby in step 8b. Switch to the control channel. That is, the cell to be used is switched from the cell CE1 for transmission restriction control to the normal cell TE1.

Subsequently, the controller 12 generates a transmission signal in step 8c, and transmits the transmission signal to the base station BS1 using the control channel of the normal cell. At this time, the reservation number notified from the base station BS1 by the use permission information is inserted into the transmission signal. The base station BS1 confirms the mobile communication terminal based on this reservation number, and thereafter executes a radio link establishment control with the mobile communication terminal MSi. Thus, a wireless link is established between the mobile communication terminal MSi and the base station BS1, and thereafter the mobile communication terminal MSi can perform wireless communication with a desired communication partner.

As described above, in this embodiment, the control channel of the second frequency band set separately from the normal standby control channel from the mobile communication terminal MSi to the base station in a state where the transmission restriction is performed. Is used to transmit the reservation information of the vacant channel. When the reservation information is received at the base station BS1, it is determined whether or not the mobile communication terminal of the transmission source is a specific terminal having the qualification for using the vacant channel. After confirmation, register in the reserved terminal list. Then, when a vacant channel that can be allocated occurs, the use permission information of the vacant channel is transmitted to the mobile communication terminal MSi using the control channel of the second frequency band, and the mobile station receives the permission information and moves to the mobile communication terminal MSi. The communication terminal MSi transmits.

Therefore, even when the communication traffic of the base station is significantly increased and transmission restrictions are being enforced, it is used by, for example, important persons or persons engaged in work requiring emergency communication such as medical care, security or fire fighting. With respect to a specific mobile communication terminal, it becomes possible to perform wireless communication by following a procedure for reserving a free channel and permitting it.

Further, the base station registers reservation information arriving from a specific mobile communication terminal in a reservation terminal list, and allocates an idle channel based on this list. Even when the reservation information arrives from the terminal, the reservation information can be completely received and an empty channel can be sequentially allocated to each reservation. That is, smooth channel allocation can be performed without causing confusion in the reservation process.

Further, since it is confirmed based on the specific terminal list whether or not the mobile communication terminal MSi of the transmission source is a specific mobile communication terminal having a qualification to use an available channel, an unspecified number of mobile communication terminals are determined. Even if the terminal transmits the reservation information, the reservation information can be excluded and only a specific mobile communication terminal can use an available channel.

Further, a notification message indicating whether the reservation information can be accepted is notified from the base station to the requesting mobile communication terminal and displayed. Therefore, the user of the mobile communication terminal can clearly know the result of accepting the reservation.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, when outgoing call restriction is performed, an empty channel left for incoming call is assigned to a specific mobile communication terminal for outgoing call. However, a vacant channel for outgoing calls of a specific mobile communication terminal may be left separately from the vacant channel for incoming calls. In this case, if the threshold value for implementing the transmission restriction at the base station is set slightly lower than the normal value, the transmission restriction may be performed before the communication traffic exceeds the conventional threshold value. Good. In this way, an outgoing free channel can be allocated to a specific mobile communication terminal without affecting incoming calls.

Further, for a plurality of specific mobile communication terminals,
A priority level is set according to the importance of the job or position (status) of the user, and when reservation information arrives from a plurality of mobile communication terminals, an empty channel is set according to the priority level of the terminal user of the request source. Assignment may be performed.

Further, in the above-described embodiment, the CDMA mobile communication system has been described as an example. However, if the system has a function of performing transmission restriction, the TDMA system or the FD
The present invention may be applied to a mobile communication system employing the MA system. Also, for transmission of the reservation information and its permission information, it is possible to use a vacant area in the information transmitted by the control channel used during normal standby.

In addition, the type and configuration of the mobile communication system,
The types and configurations of mobile communication terminals and base stations, and the procedures and contents of reservation information transmission control, reservation registration control, and vacant channel allocation control can be variously modified without departing from the scope of the present invention.

[0061]

As described above in detail, according to the present invention, reservation information for reserving the use of an empty channel is transmitted from a specific mobile communication terminal registered in advance via a control channel. Permits the use of the idle channel to enable the wireless communication of the specific mobile communication terminal. Therefore, according to the present invention, even when the outgoing call is restricted, the specific mobile communication terminal Makes it possible to provide a mobile communication system having excellent emergency response capability and its base station and mobile communication terminal.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a CDMA mobile communication system which is a first embodiment of a mobile communication system according to the present invention.

FIG. 2 is a block diagram showing a functional configuration of a mobile communication terminal of the system shown in FIG.

FIG. 3 is a block diagram showing a functional configuration of a base station of the system shown in FIG. 1;

FIG. 4 is a flowchart showing the procedure and contents of the call barring control by the base station shown in FIG. 3;

FIG. 5 is a flowchart showing a procedure and contents of reservation information transmission control by the mobile communication terminal shown in FIG. 2;

FIG. 6 is a flowchart showing a procedure and contents of reservation registration control by the base station shown in FIG. 3;

FIG. 7 is a flowchart showing a procedure and contents of an idle channel allocation control by the base station shown in FIG. 3;

FIG. 8 is a flowchart showing a procedure and contents of specific transmission control by the mobile communication terminal shown in FIG. 2;

[Explanation of symbols]

 BS1, BS2, ... Base station TE1, TE2, ... Normal cell CE1, CE2, ... Control cell MS1 to MSn Mobile communication terminal 1: Mobile communication terminal antenna 2: Antenna duplexer (DUP) (RX) 4 frequency synthesizer (SYN) 5 transmission circuit (TX) 6 CDMA signal processing unit 7 voice code processing unit 8 PCM code processing unit 9 reception amplifier 10 speaker 11 microphone 12 mobile communication terminal 12a ... Reservation information transmission control function 12b ... Specific transmission control means 13 ... Storage unit 14 ... Input unit 15 ... Display unit 16 ... Battery 17 ... Power supply circuit 18 ... Transmission amplifier 21 ... Base station antenna 22 ... Wireless interface 23: baseband signal processing unit 24: network interface unit 25: base station control unit 25a: transmission restriction control function 25 ... reservation registration control function 25c ... storage unit 26a of the idle channel allocation control function 26 ... base station ... specific terminal list storage unit 26b ... Book terminal list storage unit

Claims (7)

[Claims] 1. A base station, comprising: a base station forming a wireless communication area; and a plurality of mobile communication terminals for performing wireless communication with the base station by selectively using a plurality of wireless communication channels. In a mobile communication system having a function of restricting transmission to a mobile communication terminal when the communication traffic exceeds a predetermined value, the specific mobile communication terminal registered in advance among the plurality of mobile communication terminals includes: When receiving a notification from the base station that transmission restriction is being implemented, the base station transmits reservation information for reserving use of an empty channel to the base station using a control channel prepared separately from the wireless communication channel. A reservation information transmitting unit that performs wireless communication by using a specified free wireless communication channel when a use permission notification of a free channel arrives from the base station for the transmission of the reservation information. The base station, when the reservation information arrives from the mobile communication terminal during transmission restriction, permits the transmission source mobile communication terminal to use an available wireless communication channel. A mobile communication system, comprising: a use permission control unit for giving. 2. The storage means for storing, when the reservation information arrives from the mobile communication terminal during transmission restriction, the mobile communication terminal of the transmission source in an idle channel use waiting list. Management means for managing an idle wireless communication channel; means for allocating a wireless communication channel determined to be idle by the management means to mobile communication terminals stored in the waiting list; and the wireless communication channel. 2. The mobile communication system according to claim 1, further comprising: means for transmitting use permission information for notifying the use of the wireless communication channel to the mobile communication terminal to which the wireless communication channel is assigned. 3. The use permission control means includes: a specific terminal registration list storing information for identifying a specific mobile communication terminal; and, when reservation information arrives during transmission restriction enforcement, moving of the transmission source. 3. The authentication device according to claim 1, further comprising an authentication unit configured to check whether the communication terminal is a specific mobile communication terminal registered in advance based on the specific terminal registration list. Mobile communication system. 4. A base station of a mobile communication system having a function of restricting transmission to a mobile communication terminal when communication traffic of a radio communication channel exceeds a predetermined value. Monitoring means for monitoring the arrival of reservation information for reserving the use of an empty channel from the mobile communication terminal in a control channel prepared separately from the wireless communication channel; and that the reservation information has arrived from the mobile communication terminal. Base station comprising: a use permission control unit that, when detected by the monitoring unit, gives permission to use the free wireless communication channel to the mobile communication terminal of the transmission source. 5. The storage means for storing, when the reservation information arrives from the mobile communication terminal during transmission restriction, the mobile communication terminal of the transmission source in an idle channel use waiting list. Management means for managing an idle wireless communication channel; means for allocating a wireless communication channel determined to be idle by the management means to mobile communication terminals stored in the waiting list; and the wireless communication channel. 5. The base station according to claim 4, further comprising: means for transmitting use permission information for notifying the mobile communication terminal to which the use of the wireless communication channel is permitted to use. 6. The use permission control means includes: a specific terminal registration list storing information for identifying a specific mobile communication terminal; and, when reservation information arrives during transmission restriction enforcement, movement of the transmission source. 6. The authentication device according to claim 4, further comprising an authentication unit configured to check whether the communication terminal is a specific mobile communication terminal registered in advance based on the specific terminal registration list. Base station. 7. A wireless communication using a wireless communication channel with a base station having a function of restricting transmission to a mobile communication terminal when communication traffic of the wireless communication channel exceeds a predetermined value. In the mobile communication terminal performing, when receiving a notification from the base station that the transmission restriction is being implemented, to reserve the use of an empty channel using a control channel prepared separately from the wireless communication channel Reservation information transmitting means for transmitting the reservation information to the base station, and wirelessly using the specified free radio communication channel when the use permission notification of the free channel arrives from the base station for the transmission of the reservation information. A mobile communication terminal comprising: a specific wireless communication unit for performing communication.