JP2000253460A - Method for connecting emergency call, radio base station and mobile terminal in mobile object communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to connect an emergency call even when there is no free calling slot on a radio line in a mobile object communication system. SOLUTION: It is supposed that an emergency call is originated from a mobile terminal 10d when all calling slots S1 to S3 on a radio line are being used by mobile terminals 101a to 101c. When the emergency call is sent from the terminals 101d to a radio base station 102 in the state, the station 102 allocates a slot S4 being used as a controlling slot to a calling slot for the emergency call of the terminal 101d. Thereby even when an emergency call is originated to a police station/firehouse, the emergency call can be connected. Even when handover to another radio base station is executed due to an unstable radio state during the calling of the terminal 101d by the emergency call, the radio base station receiving the handover can specify the controlling slot as a calling slot for the emergency call.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency call connection method, a radio base station and a mobile terminal in a mobile communication system, and more particularly to an emergency call connection even when a communication slot on a radio line is in full use. TECHNICAL FIELD The present invention relates to an emergency call connection method, a radio base station, and a mobile terminal in a mobile communication system that enables a mobile communication system.

[0002]

2. Description of the Related Art As a conventional technique relating to a method of connecting an emergency call in a mobile communication system, the following techniques are known. That is, JP-A-6-24525
No. 6 discloses that when an emergency call is issued when there is no available radio line, a specific general call is selected from the general calls in communication, and the selected general call is transmitted to an adjacent radio base station. A technology has been proposed to move to a new connection. Also, JP-A-9-20
Japanese Patent Laid-Open No. 0119 proposes a technique in which an emergency call channel is reserved at a fixed rate with respect to a communication channel so that connection of an emergency call is guaranteed with a higher probability. Further, Japanese Patent Application Laid-Open No. 5-75536 proposes a technology that enables an emergency call from a mobile terminal to be restricted when a restriction process is performed due to network congestion.

[0003]

A mobile communication system according to the prior art requests a radio base station to allocate a communication channel on a radio line using a control channel when a mobile terminal originates a call, and receives the request. The radio base station determines whether there is an available communication channel and, if there is an available communication channel, allocates the available communication channel to the calling terminal. In the above description, when there is no available communication channel, the radio base station notifies the mobile terminal that the communication channel cannot be allocated, and the call is not connected.

[0004] In general, the number of mobile terminals that can be accommodated by one radio base station is limited, and in a place where there is a lot of traffic, a situation occurs in which there is no available communication channel. Therefore, the mobile communication system according to the related art has a problem that, in such a case, even if an emergency call such as a report to a police station or a fire department occurs, the emergency call cannot be connected. I was

The above-mentioned Japanese Patent Application Laid-Open No. 6-245256,
The prior art described in Japanese Patent Application Laid-Open No. 9-200119 is a method for solving the problem that an emergency call cannot be connected when there is no available channel. The prior art described is
This is a method of transferring a general call during a call to a connection with an adjacent wireless base station. If there is no free communication channel in the adjacent wireless base station, or the wireless condition between adjacent wireless base stations is poor, connection cannot be established. In such a case, a problem occurs that a general call during a call is disconnected. Also, JP-A-9-20
The prior art disclosed in Japanese Patent No. 0119 is a method of previously reserved a communication channel for an emergency call, and thus has a problem that the number of communication channels for a general call is reduced even when there is no emergency call. are doing. Also, Japanese Patent Laid-Open No. 5-7
The prior art described in Japanese Patent No. 5536 is a proposal for connection of an emergency call during regulation processing at the time of network congestion, and has a problem that connection of an emergency call when there is no available communication channel is not considered. ing.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an emergency call connection method in a mobile communication system capable of connecting an emergency call even when there is no free communication channel on a radio line, It is to provide a base station and a mobile terminal.

[0007] That is, an object of the present invention is to use a control slot when an emergency call is issued from a mobile terminal or an emergency call is handed over while a call slot on a radio line is in full use. An object of the present invention is to provide an emergency call connection method, a radio base station, and a mobile terminal in a mobile communication system capable of connecting an emergency call.

Another object of the present invention is to provide an emergency call originating from a mobile terminal or a handover of an emergency call when all of the communication slots on the radio line are in use. An emergency call connection method in a mobile communication system for notifying the suspension of control signal transmission and reception in a control slot when connecting the emergency call,
It is another object of the present invention to provide a mobile terminal capable of displaying a message indicating that control signal transmission / reception is temporarily stopped.

Further, a third object of the present invention is to allocate a control slot to an emergency call, and then, when a general call using the communication slot is terminated, switch the emergency call to the communication slot. It is an object of the present invention to provide an emergency call connection method and a radio base station in a mobile communication system.

[0010]

According to the present invention, the object is to provide a mobile terminal, a plurality of radio base stations accommodating the plurality of mobile terminals via a radio line, and a wired line for the radio base station. In an emergency call connection method in a mobile communication system having an exchange accommodated through a network and a network to which the exchange is connected, the mobile terminal performs a handover during an emergency call or during an emergency call. When performing, the emergency call origination notification message is notified to the wireless base station or the handover destination wireless base station via the wireless line, and the wireless base station that has received the notification notifies the wireless base station that there is no free space in the communication slot. This is achieved by, for example, allocating a control slot as a communication slot for the emergency call, and notifying the mobile terminal of the allocated slot via the wireless line.

[0011] The object of the present invention is to provide a control channel temporary stop message indicating that control signal transmission / reception by the control slot is temporarily stopped when the radio base station assigns the control slot as a call slot for an emergency call. By transmitting to the mobile terminal located in the own wireless zone via the wireless line, the general call using the call slot is terminated while the emergency call is using the control slot. This is achieved by switching the emergency call to a call slot.

According to the present invention, the object is to provide a mobile terminal, a plurality of radio base stations accommodating the plurality of mobile terminals via a radio line, and a radio base station accommodating the radio base station via a wire line. Base station used for a mobile communication system having an exchange to be connected and a network to which the exchange is connected, the radio base station stores a control microcomputer for controlling the operation of each unit of the radio base station, and stores various information. A wireless controller, a wireless controller that controls a wireless line, a line controller that controls a wired line, and a wired interface unit that is a connection unit with the wired line. When the call origination notification message or the emergency call notification message is received, if there is no available slot, the control slot is assigned as the emergency call slot. It is achieved by notifying the abutting slot to the mobile terminal via the wireless channel.

[0013] The object of the present invention is to provide a control channel temporary stop message indicating that control signal transmission / reception by the control slot is temporarily stopped when the radio base station assigns the control slot as a call slot for an emergency call. Is transmitted to the mobile terminal located within the own wireless zone via the wireless line, and during an emergency call using the control slot, a general call using the communication slot can be performed. Upon completion, this is achieved by transmitting a slot switching instruction message to the mobile terminal that has issued the emergency call, and executing a communication slot switching process for switching the emergency call to a communication slot.

Further, according to the present invention, the object is to provide a mobile terminal, a plurality of radio base stations accommodating the plurality of mobile terminals via a radio line, and a radio base station accommodating the radio base station via a wire line. Mobile terminal for use in a mobile communication system having an exchange to be connected and a network to which the exchange is connected, the mobile terminal comprising: a control microcomputer for controlling the operation of each unit of the mobile terminal; and a radio control for controlling a radio line. Unit, a radio wave quality monitoring unit for monitoring the state of the wireless line, a memory for storing various information, a keyboard for inputting a telephone number, a display for displaying various information, a microphone for inputting voice, and a voice for inputting voice. A speaker for outputting, and a voice processing unit for processing voice input from the microphone and voice output to the speaker, and when an emergency call is made, indicates that the call is an emergency call This is achieved by transmitting an emergency call notification message to the radio base station via the radio line, and transmitting an emergency call notification message to the handover destination radio base station when performing handover during an emergency call. You.

[0015] Further, the object is that the mobile terminal, when receiving a control channel suspension message from a radio base station, displays the content of the notification, and, after receiving the control channel suspension message, displays broadcast information reported by the radio base station. Upon receipt, this is accomplished by clearing the display of the contents of the control channel suspend message.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an emergency call connection method, a radio base station and a mobile terminal in a mobile communication system according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining an example of using slots on a radio line in a mobile communication system to which the present invention is applied.
FIG. 2 is a block diagram showing a configuration of a mobile communication system to which the present invention is applied, FIG. 3 is a diagram for explaining a slot configuration on a radio channel in a mobile communication system to which the present invention is applied,
FIG. 4 is a sequence diagram between a mobile terminal and a radio base station in a mobile communication system to which the present invention is applied. FIG. 13 is a diagram showing a sequence between a mobile terminal and a radio base station during a handover in a mobile communication system to which the present invention is applied. It is a sequence diagram between. 1 to 4, 101, 101a to 101e.
Is a mobile terminal, 102, 102a to 102b are radio base stations, 201 is a mobile network, 202 is a POI, 2
03 is a fixed telephone network, 204 is a police station / fire department, 205 is a wireless line, 206 is a wired line, and 207 is an exchange.

As shown in FIG. 2, a mobile communication system to which the present invention is applied includes a plurality of mobile terminals 101a to 101e.
And a plurality of wireless base stations 102a to 102b,
07 and a mobile network 201 to which the exchange 207 is connected. Wireless base station 102a-
The 102 b communicates with the mobile terminals 101 a to 101 e located in the wireless zone via the wireless line 205 and relays the communication to the exchange 207 connected via the wired line 206. The exchange 207 is connected to the mobile network 201, and the mobile network 201 is connected to the fixed telephone network 203 via the POI 202. By having such a connection path, the mobile communication system shown in FIG.
It is possible to make a call with the police station / fire department 204 connected to.

FIG. 3 shows an example of the slot configuration of the radio line 205 between the above-mentioned mobile terminal and the radio base station. The example shown in FIG. 3 shows an example in which the radio channel 205 is a TDMA-TDD of four-channel multiplexing, and is used in the uplink (mobile terminal → radio base station) and downlink (radio base station → mobile terminal). Each has four slots. Three of the four slots are used as communication slots, and one slot is used as a control slot.

Since the example shown in FIG. 3 has such a slot configuration, three mobile terminals 101 can communicate with one radio base station 102. FIG. 3 shows three mobile terminals 1
01a to 101c show an example in which a call is made with the wireless base station 102. The mobile terminal 101a has a slot S1 as a call slot, and the mobile terminal 101b has a slot S1.
2, a slot S3 is assigned to the mobile terminal 101c, and a slot S4 is used as a control slot.

FIG. 1 shows an example of using slots on a radio line according to the present invention. As described with reference to FIG.
Wireless line 205 when an emergency call is issued from 01d
The example of use of the upper slot is shown. In the mobile communication system to which the present invention is applied, all of the communication slots S1 to S3 on the radio line 205 are in use (the mobile terminal 101).
a to 101c are used), the mobile terminal 101d
It is assumed that an emergency call has been made to the wireless base station 102 from.

In this case, the radio base station 102 replaces the slot S4 used as the control slot with the mobile terminal 1
01d is assigned as a call slot for an emergency call.
As a result, even when an emergency call is issued to the police station / fire department 204 while all the communication slots on the wireless line 205 are in use, an emergency call can be connected. Also, when the mobile terminal 101d performs a handover to another radio base station due to an unstable radio condition during a call by an emergency call, the other handed-over radio station is in the same manner as in FIG. Use slots. That is, the other wireless station allocates the slot S4 used as the control slot to the mobile terminal 101d during the emergency call that has been handed over. As a result, even when an emergency call is handed over to a radio base station whose communication slot is in full use, the connection can be continued, and the emergency call is not disconnected due to the handover failure.

Next, referring to FIG. 4, mobile terminal 1 at the time of making an emergency call in a mobile communication system to which the present invention is applied.
An example of a sequence up to the start of communication between the wireless base station 01 and the wireless base station 102 will be described.

In the mobile communication system according to the prior art, prior to communication between the mobile terminal 101 and the radio base station 102, a procedure for allocating a communication channel on the radio line 205 is executed. This procedure is a link channel establishment phase, taking PHS as an example. In the link channel establishment phase, a call channel assignment request is transmitted by transmitting a link channel establishment request message from the mobile terminal 101, and a call slot and a call carrier number are specified by a link channel assignment message transmitted from the radio base station 102 in response to the request. Consists of

In the embodiment of the present invention, when an emergency call is issued, the mobile terminal 101 informs the radio base station 10 that the call is an emergency call prior to the call channel assignment procedure.
Notify 2. For example, taking a PHS as an example, when making an emergency call, the mobile terminal 101 transmits an emergency call origination notification message to the radio base station 102 prior to a link channel establishment request message. The emergency call origination notification message is, for example, a function channel USCCH (User Specific Control Channel) allocated to a control slot.
Send using. The USCCH is defined as an optional channel allocated to the control slot (step S401).

Thereafter, the normal calling procedure (S402-S41)
0) is executed. Specifically, the mobile terminal 101 transmits a link channel establishment request message to the radio base station 102 after transmitting the emergency call origination notification message (step S401) (step S402). The radio base station 102 that has received the link channel establishment request message
A link channel assignment message designating a call slot and a call carrier number on the wireless line used for this call is transmitted (step S403).

Here, in the case of the mobile communication system to which the present invention is applied, the radio base station 102 designates the control slot as the communication slot if there is no available communication slot. When the processing up to step S403 ends,
A communication channel is established between the mobile terminal 101 and the radio base station 102, and thereafter, processing is performed using this communication channel. Next, the mobile terminal 101 transmits a call setup message to the wireless base station 102 (step S404). When it is confirmed that the reception of the call is valid, the wireless base station 102 transmits a call setting confirmation message to the mobile terminal 101 (step S405). Next, the mobile terminal 101
A secret key is notified by a secret key setting message (step S406). The wireless base station 102 transmits an authentication request message (step S407), and the mobile terminal 101 transmits an authentication response message (step S40).
8) Then, the normality of the mobile terminal 101 is confirmed. When the calling of the destination is started, the radio base station 10
2 transmits a call message to the mobile terminal 101 (step S409), and transmits a response message when the called party answers (step S410). Thereafter, the wireless line between the mobile terminal 101 and the wireless base station 102 is connected and the mobile terminal 101 enters a call state (step S411).

Next, an example of a sequence up to the start of communication between the mobile terminal 101 and the radio base station 102 during an emergency call handover in a mobile communication system to which the present invention is applied will be described with reference to FIG. Note that, in the example shown in FIG.
It is an example of S.

The mobile terminal 101 is connected to the currently connected radio line 20.
5 degrades, the connected radio base station 102
A TCH switching request is transmitted to the terminal (step S1302).
Upon receiving the TCH switching request, the wireless base station 102 transmits a TCH switching instruction to the mobile terminal 101 (step S1).
303). Upon receiving the TCH switching instruction, the mobile terminal 101 performs a handover process to the handover destination radio base station, using a radio base station capable of receiving radio waves with an electric field strength equal to or higher than a specified value as a handover destination radio base station.

Here, if the call has been an emergency call, the mobile terminal transmits to the handover destination radio base station 102.
Prior to sending a link channel establishment request message to
An emergency call notification message indicating that this call is an emergency call is transmitted (step S1304). This emergency call notification message is transmitted by USCCH. Thereafter, the same procedure as that at the time of calling (steps S1305 to S1313) is executed, and the mobile terminal enters a communication state with the handover destination radio base station (step S1314). In the above,
Upon receiving the link channel establishment request message from the mobile terminal 101 that has transmitted the emergency call notification message, the wireless base station 102 recognizes that the emergency call is a handover, and in step S1306, transmits an idle call slot when transmitting the link channel assignment message. If not, specify a control slot.

FIG. 5 is a block diagram showing a configuration example of a radio base station in a mobile communication system to which the present invention is applied.
5 is a flowchart illustrating a processing operation of the wireless base station when accepting a call. In FIG. 5, reference numeral 501 denotes a control microcomputer, 502 denotes a memory, 503 denotes a wireless control unit, 504 denotes a wired control unit, and 505 denotes a network interface (I
An F) portion 506 is an antenna, and other reference numerals are the same as those in FIGS.

As shown in FIG. 5, the radio base station 102
Connection between the control microcomputer 501 for controlling the operation of each unit, the memory 502 for storing various information, the wireless control unit 503 for controlling the wireless line 205, the wired control unit 504 for controlling the wired line 206, and the wired line A network IF unit 505 and an antenna 506.

Next, the processing operation of the radio base station 102 configured as described above when accepting a call will be described with reference to the flowchart shown in FIG.

(1) The radio base station 102
The wireless control unit 503 and the control microcomputer 501 monitor the reception of the emergency call origination notification message and the link channel establishment request message from the control microcomputer 501 (steps S601 and S603).

(2) When an emergency call notification message is received in step S601, the control microcomputer 501
Stores the mobile terminal ID notified as the calling identification code in the emergency call notification message in the memory 502 (step S602).

(3) When the link channel establishment request message is received in step S603, the mobile terminal ID similarly notified as the calling identification code in the link channel establishment request message is stored in the memory 502 (step S603). S604).

(4) Next, the radio control unit 503 and the control microcomputer 501 search for an available call slot to be allocated to the link channel establishment request message received in step S603, and It checks whether or not there is a free communication slot, and if there is a free communication slot, transmits a link channel assignment message designating the slot number and the communication carrier number to the wireless control unit 503.
Via the mobile terminal 101 (steps S605 to S605).
S607).

(5) If there is no empty call slot in step S606, the control microcomputer 501 links the mobile terminal ID from the mobile terminal that transmitted the emergency call origination notification message stored in the memory 502 with the mobile terminal ID. Mobile terminal I from the mobile terminal that transmitted the channel establishment request message
A comparison with D is made, and it is determined whether or not the call is an emergency call (steps S608 and S609).

(6) In step S608, the control microcomputer 501 determines that the mobile terminal ID of the mobile terminal that transmitted the emergency call notification message does not match the mobile terminal ID of the mobile terminal that transmitted the link channel establishment request message. If there is, the link channel establishment request message received in step S603 is determined to be a general call, a link channel assignment rejection message indicating that all slots are in use is transmitted to the mobile terminal 101, and the call acceptance processing ends ( Step S610).

(7) In step S608, the control microcomputer 501 matches the mobile terminal ID of the mobile terminal that has transmitted the emergency call notification message with the mobile terminal ID of the mobile terminal that has transmitted the link channel establishment request message. In this case, the link channel establishment request message received in S603 is determined to be an emergency call, and a link channel assignment message specifying the slot number currently used as the control slot and the communication carrier number is transmitted to the mobile terminal 101. (Step S611).

(8) The control microcomputer 501 activates the communication channel according to the slot number and carrier number specified in the link channel assignment message in step S607 or S611, and executes step S107 described with reference to FIG.
A call acceptance process for executing the sequence of 404 to S410 is performed, and a call is made to the mobile terminal 101 (steps S612 to S614).

In the above, the radio base station 102 at the time of accepting a call is described.
However, the operation at the time of accepting the handover is performed in the same manner. That is, in this case, if step S601 is an emergency call notification message and step S613 is a handover acceptance process, the flow shown in FIG. 6 is an operation flow at the time of handover acceptance.

FIG. 7 is a block diagram showing a configuration example of a mobile terminal in a mobile communication system to which the present invention is applied, and FIG. 8 is a flowchart for explaining a processing operation when the mobile terminal makes a call. 7, reference numeral 701 denotes a control microcomputer;
2 is a wireless control unit, 703 is a radio wave quality monitoring unit, 704 is a memory, 705 is a keyboard, 706 is a display, 7
Reference numeral 07 denotes a microphone, reference numeral 708 denotes a speaker, reference numeral 709 denotes an audio processing unit, and reference numeral 710 denotes an antenna.

As shown in FIG. 7, a mobile terminal 101 includes a control microcomputer 701 for controlling the operation of each unit, a wireless control unit 702 for controlling a wireless line, and a radio quality monitoring unit for monitoring the radio wave state of the wireless line. 703, a memory 704 for storing various information, and a keyboard 70 for inputting telephone numbers and the like.
5, a display 706 for displaying various information such as a radio wave state and a dialed telephone number, a microphone 707 for inputting voice, a speaker 708 for outputting voice, and a voice input from the microphone and a voice for output to the speaker. It comprises an audio processing unit 709 for processing and an antenna 710. The memory 704 stores “11” as the emergency call telephone number.
“0” (police) and “119” (fire department) are registered.
The emergency call telephone numbers are currently “110” (police) and “1”.
19 "(firefighting) only, but if another public emergency contact is made in the future, it is also possible to register it.

Next, the mobile terminal 1 configured as described above
The processing operation at the time of outgoing call 01 will be described with reference to the flow shown in FIG.

(1) The microcomputer 7 for controlling the mobile terminal 101
01 is off-hook, obtains the telephone number input from the keyboard 705, identifies whether the obtained telephone number matches the emergency call telephone number registered in the memory 704, It is determined whether the call is a call (steps S801 to S804).

(2) If the input telephone number matches the emergency call telephone number registered in the memory 704 in step S804, the control microcomputer 701 determines that the call is an emergency call and issues an emergency call notification. Send a message, and then send a link channel establishment request message. If they do not match, a link channel establishment request message is transmitted as a normal call. As described above, the emergency call origination notification message is a function channel USCCH allocated to the control slot.
(Steps S805 and S806).

(3) The mobile terminal 101 communicates with the radio base station 10
2 and waits for a message from the wireless base station until the timer is activated and the timeout occurs. If the timeout occurs, the calling process is terminated (steps S807 and S808).

(4) In step S807, the radio base station 1
02, and checks whether the received message has assigned a link channel,
If the link channel assignment is rejected, the calling process ends (step S809).

(5) If it is determined in step S809 that the received message is a link channel assignment message, a communication channel is activated by a slot number and a communication carrier number specified by the message,
A calling process for executing the sequence of steps S404 to S410 described with reference to FIG. 4 is performed, and a call is made to the wireless base station 102 (S810 to S812).

In the embodiment of the present invention, since the above-described processing operation is performed, if an emergency call is made while all of the communication slots on the wireless line 205 are in use, the process proceeds to step S.
The slot specified in the link channel assignment message received at 807 is a control slot, but the mobile terminal 101 does not need to be aware of this. That is, the embodiment of the present invention only transmits an emergency call origination message prior to transmission of a link channel establishment request message when an emergency call is originated. An emergency call can be connected even when there is no available slot.

In the above, the radio base station 102 at the time of accepting a call is described.
However, the operation at the time of accepting the handover is performed in the same manner. In this case, the mobile terminal 101 is connected to the wireless line 2
The radio wave quality monitoring unit 703 reports that the radio wave condition of
And handover request is made based on the result.
The mobile terminal 101 transmits an emergency call notification message to the handover destination radio base station 102 when the handover is performed due to deterioration of the radio wave condition or when a handover instruction is received from the radio base station 102 and an emergency call is being connected. Thereafter, the processing of steps S806 to S811 may be performed.
That is, the handover during the emergency call connection is performed only by transmitting the emergency call notification message prior to the link channel establishment request message to the handover destination radio base station 102, and the other handover is performed by performing the conventional handover process. Even if there is no vacancy in the call slot on the wireless line, an emergency call can be connected.

The above-described embodiment of the present invention sets the present invention to P
Although described as being applied to the HS, the present invention can also be applied to other mobile communication systems. For example, "Digital car phone system standard RC
In the case of a mobile communication system based on “RSTD-27” (Association of Radio Industries and Businesses), the following method can be applied.

The mobile terminal 101 that issues an emergency call transmits an emergency call origination notification message to the radio base station 102 via UPCH prior to a normal calling procedure. Also, when performing a handover, an emergency call notification message is transmitted to the handover destination radio base station by the UPCH. afterwards,
Processing is performed according to a normal sequence. Wireless base station 102
Specifies a control slot by a radio channel designation message if there is no available slot for a call.

As described above, according to the embodiment of the present invention, there is no emergency call or handover of the emergency call from the mobile terminal 101 in a situation where there is no available communication slot on the radio line 205. In this case, an emergency call can be connected using the control slot.

Next, control channel restart processing when an emergency call using the control slot ends will be described.

When the emergency call using the control slot ends, the radio base station 102 restarts the control channel by using this slot and starts normal control channel processing such as transmission of broadcast information. Further, in a mobile communication system such as a PHS that needs to avoid control channel interference with an adjacent wireless base station, it is determined whether or not there is interference with an adjacent wireless base station when the control channel is restarted. If there is no, the control channel is restarted by the control slot, and if there is interference, operations such as control channel resynchronization are performed after the end of a general call during a call in another communication slot, and operation with the adjacent radio base station The control channel is activated at a timing when no interference occurs.

When an emergency call is connected using the control slot, the control channel cannot be used during the emergency call connection. As a result, the mobile terminal 101 located in the wireless zone of the wireless base station 102 cannot receive the broadcast information from the wireless base station 102, and thus enters the out-of-service state. Therefore, in the embodiment of the present invention, when a control slot is allocated to an emergency call, the mobile terminal 101 located in the wireless zone is notified of a control channel temporary stop. Next, the operation in such a case will be described.

FIG. 9 is a diagram for explaining an example of a sequence between the mobile terminal and the radio base station at the time of making an emergency call when notifying of a control channel temporary stop. FIG. 10 gives a notification of the control channel temporary stop. FIG. 11 is a flowchart for explaining the processing operation of the radio base station 102 when accepting a call, and FIG. 11 is a flowchart for explaining the processing operation of the mobile terminal when receiving the control channel suspension message.

In the example shown in FIG. 9, similar to the sequence shown in FIG. 4, prior to the call channel assignment procedure, an emergency call indicating that the call is an emergency call is made when an emergency call is issued. The mobile terminal 101 notifies the wireless base station 102 of a call notification message. Wireless base station 102
When a control slot is allocated to the emergency call because all of the communication slots on the wireless line 205 are in use, a control channel suspension message notifying of a suspension of the control channel is located in the own wireless zone. To the mobile terminal 101. Hereinafter, the sequence shown in FIG. 9 will be described assuming that the present invention is applied to the PHS.

As in the case of the sequence shown in FIG.
Prior to the link channel establishment request message, the mobile terminal 101 transmits an emergency call origination notification message to the radio base station 10.
Send to 2. This emergency call notification message is transmitted using the function channel USCCH allocated to the control slot. Next, the mobile terminal 101 transmits a link channel establishment request message to the radio base station 102 (steps S901 and S902).

The radio base station 102, having received the link channel establishment request message, searches for a free communication slot and, if there is no free communication slot and allocates a control slot to this emergency call, transmits the link channel allocation message. Before transmitting, the mobile station 101 notifies the mobile terminal 101 located in its own wireless zone of a control channel temporary stop message. This control channel temporary stop message is broadcast using the function channel USCCH allocated to the control slot similarly to the emergency call origination notification message (step S903).

After transmitting the control channel temporary stop message, the radio base station 102 transmits the emergency call to the mobile terminal 10.
A link channel assignment message designating a control slot is transmitted to No. 1 (step S904).

Thereafter, the same calling procedure (steps S905 to S911) as described with reference to FIG. 4 is executed, and the mobile terminal 101 and the radio base station 102 enter a talking state (step S912).

In the above description, when there is a vacant communication slot, a link channel assignment message designating a vacant communication slot may be transmitted without transmitting the control channel temporary stop message in step S903.

Although the sequence at the time of calling has been described above, the same applies at the time of handover. The configuration of the wireless base station 102 that performs the above operation may be the same as that shown and described in FIG.

Next, with reference to the flowchart shown in FIG.
The processing operation when a call is accepted will be described.

Step S1001 of the flow shown in FIG.
The processing of steps S1010 to S1010 is the same as the processing of steps S601 to S610 described with reference to the flow shown in FIG. 6, and the processing of steps S1012 to S1015 is the same as the processing of steps 611 to 614.

The flow shown in FIG. 10 differs from the flow shown in FIG. 6 in that it is determined in step S1009 that the link channel establishment request message received in a state where there is no available communication channel is an emergency call. , The slot currently used as the control slot is allocated to the emergency call, but prior to this, the control channel is temporarily stopped by connection of the emergency call to another mobile terminal 101 located in the own radio zone. That is, a control channel temporary stop message indicating that the process is to be performed is transmitted in the process of step 1011. This control channel suspension message is transmitted to the function channel USCCH assigned to the control slot.
Sent using

Thereafter, steps S612 to S612 shown in FIG.
By performing the same processing of steps S1012 to S1015 as 614, the base station 102 and the mobile terminal 101
Is in a call state.

In the above description, the radio base station 102 at the time of accepting a call is
However, the operation at the time of accepting the handover is performed in the same manner.

Next, the processing operation of the mobile terminal when receiving the control channel temporary stop message will be described with reference to the flow shown in FIG. The configuration of the mobile terminal in this case is as follows:
This is the same as that shown in FIG.

(1) In the standby state, the mobile terminal 101 monitors broadcast information broadcast on the control channel from the radio base station 102, and checks whether or not a control channel temporary suspension notification has been received ( Step S110
1, S1102).

(2) If the control channel temporary stop notification is received in step S1102, the control microcomputer 701
Displays a message on the display 706 indicating that the control channel is temporarily stopped by the emergency call connection. As this message, for example, "out of service area (emergency call is connected)" or the like may be displayed (S1103).

(3) After displaying the message in step S1103, mobile terminal 101 continues to monitor the broadcast information. When receiving the broadcast information, mobile terminal 101 determines that the control channel has been restarted, deletes the message displayed on display 706, and deletes the message displayed on display 706. , And enters a normal standby state (S1104 to S110).
6).

In the above-described processing, the mobile terminal performs
02, when the control channel temporary stop message is received, the radio wave transmitted by the adjacent radio base station 102 is monitored, and if the radio wave condition is good, the mobile station moves to the area where the adjacent radio base station is located in the radio zone, When the radio wave condition is poor, a message indicating that the control channel is temporarily stopped by the emergency call connection, for example, "out of service area (emergency call is connected)" or the like can be displayed on the display 706.

In the above-mentioned embodiment of the present invention where the notification of the control channel suspension is made, the present invention
Although described as being applied to S, the present invention can also be applied to other mobile communication systems. For example, "Digital car phone system standard RC
In the case of a mobile communication system based on “RSTD-27” (Japan Radio Industry Association), the present invention can be applied by transmitting a control channel suspension message using UPCH.

According to the above-described example of the case where the control channel is temporarily stopped in the embodiment of the present invention, when the control slot is used for an emergency call connection, It is possible to notify the other mobile terminals of the suspension of the control channel.
The user 01 can recognize that the reason for the out-of-service area is due to the emergency call connection.

FIG. 12 is a diagram for explaining an example of a sequence between a mobile terminal and a radio base station when an emergency call slot is switched in a mobile communication system to which the present invention is applied. Next, referring to FIG. The operation of switching an emergency call to a vacant communication slot when a general call using the communication slot ends while the emergency call is being connected by the control slot will be described. Switching of the emergency call to a vacant call slot can be realized by a general sequence of switching channels during a call.

(1) When the general call using the communication slot is terminated during the emergency call connection by the control slot, the radio base station, for example, in the case of PHS, the mobile terminal 101 that has issued the emergency call To transmit a TCH switching instruction message to the terminal. In the TCH switching instruction message, a switching destination slot number and a call carrier number are specified. That is, the radio base station 102 transmits a TCH switching instruction message designating the communication slot used by the terminated general call (steps S1201, S1).
202).

(2) Upon receiving the TCH switching instruction message, the mobile terminal 101 immediately executes a switching process to the designated communication slot. As a result, a call is made in the vacant call slot (step S1203).

The above-described operation for switching an emergency call to a vacant communication slot can be applied to a mobile communication system other than the PHS, for example, “Digital car telephone system standard RCR STD-27” ( In the case of a mobile communication system based on the Association of Radio Industries and Businesses, a normal channel switching sequence is executed, and an empty communication slot is designated as the slot number in the switching destination wireless channel designation message. I just need.

That is, when an emergency call is being connected using the control slot, the radio base station 102 monitors the end of the general call using the communication slot, and determines that the general call has ended. Upon detection, only a function of executing a normal channel switching process for instructing switching to a vacant communication slot for an emergency call may be provided.

[0084]

As described above, according to the present invention, when all of the communication slots on the radio line are in use and an emergency call is issued or an emergency call is handed over from the mobile terminal, the control for the emergency call is performed. By allocating the slot as a communication slot for the emergency call, an emergency call can be reliably connected.

According to the present invention, when a control slot is assigned as a call slot for an emergency call, the radio base station notifies another mobile terminal located in the radio zone of the temporary stop of the control channel. By doing so, it is possible to display to other mobile terminals located in the wireless zone that the control channel is temporarily stopped due to the emergency call connection, and to the user of the mobile terminal, the reason why the mobile terminal has gone out of service is the emergency call connection. Can be recognized.

Further, according to the present invention, when a general call using a communication slot is terminated while an emergency call is being connected by a control slot, the emergency call can be switched to an empty communication slot. Therefore, the stop time of the control channel can be minimized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of using a slot on a wireless channel in a mobile communication system to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of a mobile communication system to which the present invention is applied.

FIG. 3 is a diagram illustrating a slot configuration on a wireless channel in a mobile communication system to which the present invention is applied.

FIG. 4 is a sequence diagram between a mobile terminal and a radio base station in a mobile communication system to which the present invention is applied.

FIG. 5 is a block diagram illustrating a configuration example of a radio base station in a mobile communication system to which the present invention has been applied.

FIG. 6 is a flowchart illustrating a processing operation of the wireless base station when accepting a call.

FIG. 7 is a block diagram illustrating a configuration example of a mobile terminal in a mobile communication system to which the present invention has been applied.

FIG. 8 is a flowchart illustrating a processing operation when a mobile terminal makes a call.

FIG. 9 is a diagram illustrating an example of a sequence between a mobile terminal and a radio base station when an emergency call is issued when a notification of a control channel suspension is issued.

FIG. 10 is a flowchart illustrating a processing operation when a call is accepted by the wireless base station 102 when a notification of a control channel suspension is performed.

FIG. 11 is a flowchart illustrating a processing operation of the mobile terminal when a control channel suspension message is received.

FIG. 12 is a diagram illustrating an example of a sequence between a mobile terminal and a radio base station when an emergency call slot is switched in a mobile communication system to which the present invention has been applied.

FIG. 13 is a sequence diagram between a mobile terminal and a radio base station at the time of handover in a mobile communication system to which the present invention is applied.

[Explanation of symbols]

 101, 101a to 101e Mobile terminal 102, 102a to 102b Wireless base station 201 Mobile network 202 POI 203 Fixed telephone network 204 Police station / fire department 205 Wireless line 206 Wired line 207 Switch 501, 701 Control microcomputer 502, 704 Memory 503, 702 Wireless control unit 504 Wired control unit 505 Network interface (IF) unit 506, 710 Antenna 703 Radio wave quality monitoring unit 705 Keyboard 706 Display 707 Microphone 708 Speaker 709 Audio processing unit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoko Yamada 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Information and Communication Division, Hitachi, Ltd. 5K067 AA22 AA34 BB02 DD13 DD28 DD51 EE02 EE10 EE16 EE23 EE63 EE64 EE65 FF18 FF20 FF23 FF27 GG11 HH05 HH12 HH24 JJ13 JJ20 JJ22 JJ35 JJ39

Claims (5)

[Claims] 1. A plurality of mobile terminals, a plurality of wireless base stations accommodating the plurality of mobile terminals via a wireless line, an exchange accommodating the wireless base station via a wired line, and the exchange are connected. An emergency call connection method in a mobile communication system having a network, the mobile terminal notifies an emergency call origination notification message to the radio base station via the radio line when an emergency call is originated. The radio base station receiving the above, if there is no free space in the call slot, allocates a control slot as the call slot for the emergency call, and notifies the allocated terminal to the mobile terminal via the radio line. Characteristic emergency call connection method. 2. A plurality of mobile terminals, a plurality of radio base stations accommodating the plurality of mobile terminals via a radio line, an exchange accommodating the radio base station via a wire line, and the exchange are connected. The mobile terminal during an emergency call, when performing a handover, sends an emergency call notification message indicating that the call is an emergency call to the handover destination radio base station. The handover destination radio base station, which has transmitted and received this, assigns a control slot as the emergency call communication slot if there is no available communication slot, and assigns the allocated slot to the mobile station via the wireless line. An emergency call connection method characterized by notifying a terminal. 3. A plurality of mobile terminals, a plurality of wireless base stations accommodating the plurality of mobile terminals via a wireless line, an exchange accommodating the wireless base station via a wired line, and the exchange are connected. Wireless base station used in a mobile communication system having a wireless network, the wireless base station controls a microcomputer for controlling the operation of each unit of the wireless base station, a memory for storing various information, and controls a wireless line. A wireless control unit, a line control unit that controls a wired line, and a wired interface unit that is a connection unit with the wired line, and an emergency call origination notification message or an emergency call notification from the mobile terminal via the wireless line. When the message is received, if there is no available call slot, a control slot is assigned as the emergency call slot, and the assigned slot is transmitted via the wireless line. And notifying the mobile terminal. 4. A plurality of mobile terminals, a plurality of wireless base stations accommodating the plurality of mobile terminals via a wireless line, an exchange accommodating the wireless base station via a wired line, and the exchange are connected. A mobile terminal used in a mobile communication system having a network, the mobile terminal comprising: a control microcomputer for controlling the operation of each unit of the mobile terminal; a wireless control unit for controlling a wireless line; and monitoring the state of the wireless line. A radio wave quality monitoring unit, a memory for storing various information, a keyboard for inputting telephone numbers, a display for displaying various information, a microphone for inputting audio, a speaker for outputting audio, and a speaker for inputting audio. And a voice processing unit that processes voice output to a speaker, and when an emergency call is made, sends an emergency call notification message indicating that the call is an emergency call. A mobile terminal that transmits to the radio base station via a line and transmits an emergency call notification message to a handover destination radio base station when performing handover during an emergency call. 5. A plurality of mobile terminals, a plurality of radio base stations accommodating the plurality of mobile terminals via a radio line, an exchange accommodating the radio base stations via a wire line, and the exchange are connected. A mobile terminal used in a mobile communication system having a network, the mobile terminal comprising: a control microcomputer for controlling the operation of each unit of the mobile terminal; a wireless control unit for controlling a wireless line; and monitoring the state of the wireless line. Radio wave quality monitoring section, storage section for storing various information, keyboard for inputting telephone numbers, etc., display for displaying various information, microphone for inputting voice, speaker for outputting voice, and input from microphone Sound, comprising a sound processing unit for processing the sound to be output to the speaker, when receiving a control channel pause message from the wireless base station, the notification content is displayed, A mobile terminal, comprising: upon receiving broadcast information broadcast by the radio base station after receiving a control channel suspension message, deleting the display of the content of the control channel suspension message.