JPH0738938A - Base station state notice device in mobile communication system - Google Patents

Abstract

PURPOSE:To allow the user to obtain allocation of a radio channel from a base station without any dialing operation in the mobile station of the mobile communication system. CONSTITUTION:In the mobile communication system in which base stations CS1-3 connecting to an exchange PBX through wired lines K1-3 receive a radio channel allocation request from mobile stations (cordless telephone sets) PS1-4, return radio channel information in use when the allocation is available and return a reject signal when no allocation is available, each of the base stations CS1-3 always send intermittently state information representing whether or not a radio channel of a telephone set of a concerned station and a wired line to the PBX are idle, and each of the telephone sets PS1-4 receives the state information from a base station registered to be a communication opposite party at present and lights an LED on its front panel when the base station is not idle. As a result, the user of each telephone set makes dialing after confirming it that the base station is idle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile station requesting a base station connected to a predetermined communication network to allocate a radio channel for communication to the base station. A mobile communication used for a mobile communication system that transmits a request signal and for notifying a user who uses a mobile station whether or not a base station is in a state where a communication radio channel can be allocated in advance. The present invention relates to a base station status notification device.

[0002]

2. Description of the Related Art Due to the recent development of communication technology and the increasing demand for communication tools that support speedy acquisition of information and space movement, mobile communication systems such as car phones and mobile phones have been put to practical use. . In such a mobile communication system, each mobile station such as a telephone is connected to a communication network by performing wireless communication with a base station connected to a predetermined communication network such as a telephone switching network. However, since the base station communicates with a plurality of mobile stations, each mobile station allocates a communication radio channel used for communication in advance by the base station before starting communication with the base station. You need to get it.

Therefore, conventionally, in this type of mobile communication system, when a user performs a transmission operation at a mobile station,
The mobile station transmits to the base station a request signal requesting allocation of a communication radio channel via a preset predetermined control radio channel, and the base station receives the request signal from the mobile station. Then, first, a communication wireless channel can be assigned to the mobile station depending on availability of wireless resources (wireless lines such as carrier frequencies and slots) and wired resources (wired lines connecting a communication network and a base station). If it can be assigned, it sends information about the wireless communication channel (carrier frequency, communication protocol, etc.) to the mobile station, and conversely, if it cannot be assigned, a rejection signal indicating that fact. Was to be sent.

Therefore, conventionally, in a mobile communication system of this kind, when a mobile station is denied the allocation of a communication radio channel by a base station, the mobile station notifies the user who uses the mobile station. Then, it was notified that the call could not be made, and it returned to the standby state for incoming calls.

[0005]

However, in the above-mentioned conventional mobile communication system, it would be better if the allocation of the communication radio channel could be obtained from the base station by one transmission operation. When a station is located in a place with a lot of traffic, such as a station or an office, it is often impossible to obtain an allocation from the base station at one time, so the user of the mobile station must repeat the call operation many times. There was a problem.

The present invention has been made in view of such a problem, and in a mobile communication system, a base station can change a communication wireless channel from a base station without requiring the user of the mobile station to repeatedly make a transmission operation. An object of the present invention is to provide a base station status notification device in a mobile communication system that enables allocation to be obtained.

[0007]

That is, according to the present invention made to achieve the above object, a mobile station wirelessly communicates with a base station connected to a predetermined communication network, as shown in FIG. Before, the base station transmits a request signal requesting allocation of a communication radio channel to the base station via a predetermined control radio channel, and the base station receives the request signal and transmits the request signal. If the communication wireless channel can be allocated to the mobile station, the information about the communication wireless channel is transmitted to the mobile station, and if the communication wireless channel cannot be allocated, the mobile station is transmitted to the mobile station. In a mobile communication system that transmits a refusal signal indicating that, in order to notify a user who uses the mobile station whether or not the base station is in a state where a radio channel for communication can be assigned in advance. Mobile communication A base station status notification device in the system, wherein the base station is configured to constantly determine whether or not the base station is in a state in which a communication radio channel can be allocated to the mobile station, and the determination means. And a status signal transmitting means for transmitting a status signal representing the determination result of the means, and when the status signal is received by the mobile station, the base station that has transmitted the status signal based on the status signal causes the communication radio to A base station status notification device in a mobile communication system is characterized in that a notification means is provided to notify a user of the mobile station whether or not a channel can be assigned.

[0008]

In the base station state notifying device in the mobile communication system of the present invention configured as described above, the base station connected to the predetermined communication network is provided with a judging means,
The status signal transmitting means is provided, and the judging means constantly judges whether or not the base station is in a state in which the radio station for communication can be assigned to the mobile station. A status signal indicating the determination result of the means is transmitted. Then, when the notification means provided in the mobile station receives the status signal from the base station, based on the status signal,
The base station that has transmitted the status signal informs the user of the mobile station whether or not the communication radio channel is currently available for allocation.

Therefore, according to the base station status notifying apparatus in the mobile communication system of the present invention, the user of the mobile station is
It becomes possible to constantly recognize whether or not the mobile station used by the user is in a state where it can receive the allocation of the communication wireless channel from the base station, and the base station can allocate the communication wireless channel. You will be able to make outgoing calls after confirming that it is ready. In other words, the user of the mobile station only needs to perform one call operation to obtain the communication radio channel allocation without being rejected by the base station.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 2 is a block diagram showing the configuration of a mobile communication system of an embodiment to which the present invention is applied.

As shown in FIG. 2, the mobile communication system according to the present embodiment is arranged in a premises such as a business office and is connected to a public telephone line. A well-known private branch exchange P for connection with
BX (hereinafter simply referred to as PBX) and a plurality of (three in FIG. 2) base stations CS1 to CS3 connected to the PBX by wires K1 to K3, respectively, and arranged at predetermined locations in the premises.
And a plurality of (four in FIG. 2) cordless telephones as mobile stations, which are connected to the public telephone line and are mutually connected by performing wireless communication between the base stations CS1 to CS3. , Simply called a telephone) PS1-P
And S4.

In FIG. 2, LEDs are light emitting diodes (hereinafter simply referred to as LEDs) provided on the front panel of each of the telephones PS1 to PS4, and C1 is a base station CS1 to CS3 and telephones as described later. PS1 to PS
4 is a control carrier commonly used by each communication device mainly for the purpose of controlling incoming / outgoing calls to achieve communication for actual communication with C4, and C2 is individually assigned to each communication device. It represents a communication carrier that is allocated and used for communication for an actual call. Also, E1
E3 represents the wireless zone of each of the base stations CS1 to CS3.

The mobile communication system of this embodiment is
Time Division Multiplex Acces (TDMA) in which frequencies are time-division multiplexed and a time slot is assigned to each telephone.
s) method, and TDD (Time Division Duty) that uses the same frequency in time division for downlink communication (communication from the base station to the telephone) and uplink communication (communication from the telephone to the base station).
piex) method, 4-channel multiplexing multi-carrier TDMA that can multiplex and use up to 4 lines per frequency.
A so-called PHP (Personal Handy P
Hone) is a digital cordless phone system called.

Next, as shown in FIG. 3, each of the telephones PS1 to PS4 includes a CPU 2, a ROM 4, a RAM 6, an operation key 8 including a power switch, a transmission switch, a dial button, and a communication logic circuit group for processing communication data. Composed of a gate array 10, a drive circuit 11 for driving an LED provided on the front panel of the telephone, a bus line 12 connecting these parts, and an analog audio signal from a microphone 14 converted into a digital signal to form a gate array 10. Audio processing circuit 18 which outputs the digital audio signal from the gate array 10 to an analog signal and outputs the analog signal to the speaker 16 and the communication data from the gate array 10 at a radio frequency of 1.9 GHz band by π / 4. Shift QPSK
(Quadrature Phase Shift Keying) As a well-known cordless telephone equipped with a wireless unit 22 including a modulation / demodulation circuit that modulates and transmits from the antenna 20, demodulates a received signal from the antenna 20 and outputs the demodulated signal to the gate array 10. It is configured.

Here, the gate array 10 is based on the communication timing instructed by the CPU 2, control data for outgoing / incoming call control generated by the CPU 2, and a call converted into a digital signal by the microphone 14 and the voice processing circuit 18. The voice data is converted into communication data for TDMA transmission and output to the wireless unit 22, and the call voice data is extracted from the received signal demodulated by the wireless unit 22 and output to the voice processing circuit 18, and the received signal is received. To base stations CS1-C
The control data for outgoing / incoming call control transmitted in S3 is taken out and output to the CPU 2. Then, the CPU 2, based on the command input from the operation key 8 and the control data for controlling the incoming and outgoing calls from the base stations CS1 to CS3, as described later, when the power switch of the operation key 8 is turned on, the telephone set concerned. Is registered in one of the base stations to recognize each other's communication partners, and a call operation (a call operation) is performed by pressing the call button and dial button of the operation key 8. When the telephone is connected to a base station, a communication wireless channel used for a call with the base station (hereinafter, simply referred to as a wireless channel in the [Example]) is determined. Base station CS1
It is possible to perform various incoming / outgoing call control processing for connecting to the CS3 and whether or not the telephone is currently in a state of being able to receive a wireless channel assignment from the base station of the communication partner.
LE specific to the present invention for notifying the user by D
D drive processing is executed.

On the other hand, as shown in FIG. 3, each of the base stations CS1 to CS3 has a CPU 32, a ROM 34, a RAM 36, a gate array 38 including a communication logic circuit group for processing communication data, and an interface circuit (I / F) with the PBX. ) 4
0, the bus line 42 connecting these units, and the communication data generated by the gate array 38 to the telephones PS1 to PS1.
A known transmitting / receiving station including a radio section 46 including a modulation / demodulation circuit that modulates and transmits from the antenna 44 exactly as in the case of PS4 and demodulates a reception signal from the antenna 44 and outputs the demodulated signal to the gate array 38. Is configured as.

Then, the base station CS configured as described above
In 1 to CS3, the gate array 38 includes the CPU 32
Based on the communication timing instructed from, the control data for controlling incoming and outgoing calls generated by the CPU 32 and the communication data from the public telephone line or the extension telephone line input from the PBX via the I / F 40 are transmitted for TDMA transmission. And outputs to the wireless unit 46, the received signal demodulated by the wireless unit 46 is output to the PBX via the I / F 40, and at the same time, the incoming / outgoing signals transmitted from the telephones PS1 to PS4 are transmitted from the received signal. Retrieve control data for call control and C
Output to PU32. Then, the CPU 32 causes the telephone P to
Based on the control data for outgoing / incoming call control from S1 to PS4, the line usage state at that time, and the incoming call request (call request) data input from the PBX via the I / F 38, and the like, between the telephones PS1 to PS4. In addition to executing various incoming / outgoing call control processing for connecting each of the telephones PS1 to PS4 to the PBX, such as processing for location registration and link establishment performed in step 1, and processing for calling the telephones PS1 to PS4, which will be described later. As described above, the state notification processing peculiar to the present invention for notifying the telephones PS1 to PS3 of the current line use state in the base station is executed.

Here, the telephone set PS configured as described above
An outline of communication performed between the base stations 1 to PS4 and the base stations CS1 to CS3 will be described with reference to FIG. As shown in the uppermost row of FIG. 4, in the 4-channel TDMA / TDD system transmission used in the mobile communication system of the present embodiment, one frame on one frequency (hereinafter referred to as TDMA frame) is 5 ms. , Each TDMA frame is divided into eight slots every 625 μs. And the first four slots among them are the first to fourth slots for downlink communication from the base station to the telephone,
The four slots in the latter half are respectively assigned as the first to fourth slots for upstream communication from the telephone set to the base station, and each telephone set PS1 to PS4 receives its own signal 2.5 ms after receiving the signal from the base station. It is designed to send.
That is, for example, when the base station transmits to the telephone in the second slot for downlink communication, the telephone sends back in the second slot for uplink communication, so that the telephone and the base station have the same frequency. Communication is performed using slots for uplink communication and downlink communication having the same number. still,
The code length of each slot is 240 bits and the transmission rate is 3
It is 84 kbps.

Next, the base stations CS1 to CS3 and the telephone PS
An outline of outgoing / incoming call control (location registration, link establishment, telephone call, etc.) performed to realize communication for an actual call with 1 to PS4 will be described. First, as a premise, each of the base stations CS1 to CS3 is usually the second station of FIG.
As shown from the fourth stage to the fourth stage, the TD at a common predetermined frequency (control carrier indicated by C1 in FIG. 1)
By the control radio channel LCCH consisting of a predetermined slot group of the MA frame, at different timings, always,
Control data for outgoing / incoming call control is transmitted intermittently. This control radio channel LCCH has a so-called superframe structure. In this embodiment, as shown in FIG. 4, one frame is formed by four first slots for every n TDMA frames (hereinafter referred to as LCCH superframe). Frame).

As shown in FIG. 4, the breakdown of each slot constituting the LCCH superframe is as follows: information about the frame structure such as the interval between slots in the frame, the sending order, and information about the base station. Dedicated for downlink communication for notifying each telephone PS1 to PS4
CH1, BCCH2, BCCH3 dedicated to downlink communication for transmitting the base station status information as a status signal for notifying the respective telephones PS1 to PS3 of the current line use status in the base station, and any of the phones PS1 to PS1. PCH1 and PCH2 dedicated to downlink communication for simultaneously notifying the telephone number of the telephone when the PS4 is called
And each of the telephone sets PS1 to PS4 responds to uplink communication for transmitting a link establishment request as a request signal requesting allocation of a radio channel used for a call to the base station, and the link establishment request. SCHs used for downlink communication for the base stations CS1 to CS3 to respond, respectively. The PCH1, PCH2 and SCH are shown in FIG.
As shown in, the order of PCH1, SCH, PCH2 is B
CCH1, BCCH2, and BCCH3 are transmitted as heads, respectively, and each of the telephones PS1 to PS
When S4 receives both BCCH1 and BCCH2,
All the information necessary for communication with the base station that sent it is now available.

Here, in the mobile communication system of this embodiment, the power switches of the telephones PS1 to PS4 are turned on.
When it is answered N, it will be registered in PBX,
As a result, the PBX can recognize in which base station each telephone PS1 to PS4 exists in the wireless zone, and the PBX can promptly call the telephone through the corresponding base station. The position registration is performed between the telephone and the base station when the power switch of the telephone is turned on.

This location registration is generally executed in the following procedure. First, as described above, each of the base stations CS1 to CS
When the user turns on the power switch of the telephone in the state where the control data is always transmitted from No. 3, the telephone firstly has the BCCH1 and BCC in all the LCCH superframes transmitted from each of the base stations CS1 to CS3.
H2 and are received. Then, the LCCH is synchronized with the LCCH superframe of the base station having the highest reception level among them, and 2.5 ms after receiving the next LCCH (that is, the SCH transmission timing for uplink communication), the LCCH
A link establishment request is transmitted to the base station transmitting the super frame. The link establishment request is made up of data relating to the type of channel to be used, the type of communication protocol, and the like.

On the other hand, the base station which has received the link establishment request has the wireless channel free state, the wired free state with the PBX, and the type of channel or protocol requested by the telephone set of the base station. It is determined whether or not they match with each other, and whether or not a wireless channel can be assigned to the telephone. When it is determined that the wireless channel can be assigned, information about the wireless channel such as the carrier number and slot number of the frequency (communication carrier) used for the actual call is returned at the next SCH transmission timing.

Then, the telephone recognizes that the wireless channel allocation permission has been obtained, and transmits a burst signal to the base station at the frequency and slot corresponding to the designated carrier number and slot number, and The base station also transmits burst signals at the same frequency and slot accordingly, thereby performing burst synchronization between them. After that, both parties checked each other's phone number and a predetermined ID code,
Further, by setting various functions, the mutual communication partners are recognized and the location registration is completed.

Here, each of the telephones PS1 to PS4 is
In addition to the above-mentioned location registration, when the own telephone number is included in the data transmitted on the PCH1 and PCH2 of the LCCH superframe, that is, when the call is received from the base station, or the user When the call button and dial button of the operation key 8 are pressed to perform a call operation (a call operation), a link establishment request is transmitted to the base station whose position is registered at that time. And
The base station that has received the link establishment request determines whether or not a wireless channel can be allocated, just as in the case of location registration. When it is determined that a wireless channel can be allocated, the base station uses it for communication. Returns information about wireless channels. That is, each telephone PS1 to P
When S4 transmits a link establishment request to the base station and receives the information about the radio channel returned from the base station, the radio channel to be used for the call is determined (link establishment) and burst synchronization or the like is performed. You can get ready for the call.

When the base station that receives the link establishment request from the telephone determines that the radio channel cannot be assigned, the base station sends the SC of the LCCH superframe.
At the transmission timing of H, data indicating the reason why allocation is impossible, such as no wireless channel available, no wired side available, communication protocol mismatch, and base station unusable, is transmitted as a link allocation rejection.

Therefore, normally, in this type of mobile communication system, when the base station rejects the link allocation even though the user of the telephone set performs the call origination operation, the user is required to use the radio channel. The calling operation is repeated until the allocation is obtained. However, here, in the mobile communication system of the present embodiment, each base station C described below is used.
State notification processing in S1 to CS3 and each telephone PS
1 to PS4, the LED driving process allows the telephone to immediately receive a wireless channel assignment from the base station in which the telephone is currently registered before the user of the telephone makes a call operation, and a telephone call can be started. It is possible to confirm whether or not

That is, first, the status notification processing performed in each of the base stations CS1 to CS3 is always executed at predetermined time intervals, and is executed as shown in FIG. As shown in FIG. 5, when the state notification process is started, first, in step (hereinafter,
In S) 110, it is determined whether or not the number of wireless channels currently used with each telephone is equal to or more than a preset number M of channels that can be simultaneously used, and the current use is performed. When it is determined that the number of wireless channels being used is not more than the number M of channels that can be used simultaneously, the process proceeds to S120. Then, in S120, it is determined whether or not the number of wireless channels currently in use is equal to or more than the number of wires Y provided between the PBX and the number of currently used wireless channels. When it is determined that is not equal to or more than the number of wired lines Y, the process proceeds to S130.

Then, in S130, the wireless channel of the base station and the wired line to the PBX are currently vacant,
The "free" indicating that the wireless channel can be assigned to the telephone is set in the base station status information, and then the process ends. On the other hand, if it is determined in S110 that the number of wireless channels currently used is equal to or more than the number M of channels that can be used simultaneously, or in S120, the number of wireless channels currently used is the number of wired lines. If it is determined that the value is Y or more, the process proceeds to S140, and in S140, there is currently no available wireless channel of the base station or the wired line with the PBX, and the wireless channel is allocated to the telephone. "Busy" indicating that it is not possible is set in the base station status information, and then the process ends.

The base station status information for which "vacant" or "busy" is set in this way is the above-mentioned LCCH.
It is transmitted to each of the telephone sets PS1 to PS4 at the transmission timing of BCCH3 of the superframe. Therefore, as shown in FIG. 4, this base station status information is always transmitted at intervals of once every three LCCH superframes.

That is, in this state notification process, S11
The process of 0 and S120 executes a process as a determining unit that determines whether or not the base station is in a state where a wireless channel can be assigned to the mobile station, and the process of S130 and S140 causes the base As a status signal transmitting means for transmitting a status signal indicating whether or not the station is in a state where radio channels can be allocated to the mobile station, that is, base station status information in which "vacant" or "busy" is set. The process of is being executed.

Next, the LED drive processing performed by each of the telephones PS1 to PS4 is performed by the B of the LCCH superframe transmitted from the base station in which the telephone is currently registered.
It is executed every time CCH3 is received, and is executed as shown in FIG. As shown in FIG. 6, when the LED drive processing is started, first, in S210, the base station status information transmitted from the base station whose current position is registered is "vacant" or "free".
When it is determined which of "busy" is set and "free" is set in the base station status information,
In subsequent S220, the drive circuit 11 turns off the LED, and the process ends.

On the other hand, in S210, the base station status information is set to "
When it is determined that "busy" is set, S23
After moving to 0, the drive circuit 11 turns on the LED,
The process ends. That is, in this LED drive processing, the processing of S220 and S230 is executed as the notification means for driving the LED based on the content represented by the base station state information.

The base stations CS1 to CS3 and the telephones PS1 to execute the status notification process and the LED drive process.
In the mobile communication system of the present embodiment including PS4, for example, as shown in FIG. 2, the telephone set PS3 is currently registered in the base station CS1 and the base station CS1 is connected to the other telephone sets PS1, PS2. When it is in communication with PS4 and the wireless channel cannot be further allocated, the LED provided on the front panel of the telephone PS3 is turned on. Then, the user of the telephone PS3 receives the LE
By illuminating D, you can recognize that your phone is not currently assigned a wireless channel, and if you make a call after the LED goes off, you only need to make one call to make a wireless channel from the base station. Will be obtained.

As described above, according to the mobile communication system of this embodiment, even if the user of each of the telephone sets PS1 to PS4 operates the operation key 8 to make a call again many times, the user can make a call once. You can start a call just by operating. In the above embodiment, each of the telephones PS1 to PS4 is provided with an LED, and the LED is used to notify the user whether or not the base station whose current location is registered can receive the wireless channel assignment. It was something that was done,
For example, when the telephones PS1 to PS4 have an LCD for displaying various messages, the LCD may notify that the base station is busy.

Further, for example, the telephones PS1 to PS4 are
In addition to having such an LCD, the LCCH described above is also displayed every time the user operates a predetermined selection button.
If the base station that can receive the superframe, that is, the number of communicable base stations is sequentially displayed on the LCD and the user has a selection function that allows the user to arbitrarily select the base station whose location is to be registered, use it. It becomes possible for a person to actively search for a vacant base station and promptly perform a calling operation.

On the other hand, in the mobile communication system of the above embodiment, the base stations CS1 to CS3 are connected to the PBX via the wires K1 to K3.
A predetermined control station may be interposed between S3 and PBX, and each base station CS1 to CS3 may be connected to the control station by radio to connect to the PBX. Then, in this case, in S120 of the status notification process performed by each of the base stations CS1 to CS3, the number of wireless channels currently used with each of the telephones is between the base station and the control station. It may be configured to determine whether or not the number is equal to or more than the number of available wireless channels.

In the above embodiment, the case where the present invention is applied to a digital cordless telephone system which is being put to practical use has been described. Of course, the present invention is not limited to the communication channel between the mobile station and the base station. The present invention can also be applied to mobile communication systems that have already been put into practical use, such as analog cordless telephones and car telephones, which use different frequencies for each and every uplink / downlink communication.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of the present invention.

FIG. 2 is a block diagram showing a configuration of a mobile communication system according to an embodiment.

FIG. 3 is a block diagram showing configurations of a telephone and a base station in the mobile communication system according to the embodiment.

FIG. 4 is an explanatory diagram illustrating an outline of communication in the mobile communication system according to the embodiment.

FIG. 5 is a flowchart showing a state notification process performed by each base station.

FIG. 6 is a flowchart showing an LED driving process performed by each telephone.

[Explanation of symbols]

PS1, PS2, PS3, PS4 ... Telephone PB
X ... Private branch exchange CS1, CS2, CS3 ... Base station LE
D ... Light emitting diode 2, 32 ... CPU 4, 34 ... ROM 6,
36 ... RAM 11 ... Driving circuit 20, 44 ... Antenna 2
2,46 ... Radio section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location 7304-5K H04B 7/26 109 T 7304-5K 110 Z (72) Inventor Koji Oda Kariya city, Aichi prefecture 1-chome, Showa-cho, Nihon Denso Co., Ltd. (72) Inventor Katsumasa Matsui 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd.

Claims (1)

[Claims] 1. Before a mobile station wirelessly communicates with a base station connected to a predetermined communication network, a request signal for requesting allocation of a communication radio channel to the base station is sent to the predetermined control radio. If the base station receives the request signal and can allocate a communication radio channel to the mobile station that has transmitted the request signal, the base station transmits the communication radio to the mobile station. In a mobile communication system that transmits information about a channel and transmits a refusal signal to that effect to the mobile station when a communication radio channel cannot be assigned, to a user who uses the mobile station. A base station state notification device in a mobile communication system for notifying whether or not the base station is in a state capable of allocating a communication radio channel in advance, wherein the base station is configured to move to the base station. Station On the other hand, the mobile station is provided with a judging means for constantly judging whether or not a communication wireless channel can be assigned, and a status signal transmitting means for transmitting a status signal indicating the judgment result of the judging means. In addition, when the status signal is received, a notification for notifying the user of the mobile station whether or not the base station that has transmitted the status signal based on the status signal is in a state where the wireless channel for communication can be assigned A base station status notification device in a mobile communication system, comprising: