JPS6012818B2 - Control information transfer method in mobile communications - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a control information transfer method in mobile communications, and more specifically, a service area is divided into a plurality of service zones, a wireless base station is provided in each service zone, and a mobile station is When you connect to the wireless base station in the service zone where you are currently located and move the service zone, the mobile communication method you purchased will switch channels and switch to the wireless base station in the newly migrated service zone. This invention relates to a method for transferring control information from a mobile station to a wireless base station.

An explanation will be given below using a car telephone system as an example of mobile communication.

FIG. 1 is a diagram schematically showing a known car telephone system 0. In FIG. 1, 1 is a mobile station mounted on a car, 2-1 and 2-2 are radio base stations, 3 is a control station, and 4 is a switching station. Various signals are transmitted between the mobile station 1 and the wireless base stations 2-1, 2-2, etc. using a wireless system. The mobile evening service area of the mobile station 1 is divided into a plurality of service zones, and each service zone is provided with a radio base station. That is, a plurality of wireless base stations 2-1, 2-2, 2-3,
... will be installed. (The wireless base stations 2-3, . . . are not shown.) Each of the wireless base stations 2-1, 2-2,
2-3... is the service zone S, as shown by the dotted line.
SZ2, SZ3... (=wireless zone) (service zone SZ3... is not shown) are formed, and the mobile station 1 is connected to the radio base station forming the service zone where it is located at the time. Therefore, when a mobile station moves to another service zone, the wireless base station changes, and the communication line is automatically switched. The control station 3 centrally controls and manages connection of lines and switching of lines during calls. The switching center 4 has a function of connecting a car telephone line and a general fixed telephone network. For this type of car phone system, see, for example, "Outline of car phone system", published by Nippon Telegraph and Telephone Public Corporation, Telecommunications Research Institute, Research and Practical Application Report No. 2, No. 7, 1977, pages 9 to 24. I want to be Now, there are several types of mobile stations 1, and when it is necessary to change the operation of the wireless base station depending on the type, or depending on the service or function being provided or requested (confidential information, etc.), the wireless base station 2 If it is necessary to change the operation of the mobile station, it is necessary for the wireless base station to store control information indicating the presence or absence of the service or function being provided or requested by the type of mobile station during the duration of the call.

However, when mobile station 1 moves from service zone SZ to service zone SZ in FIG. It changes to radio base station 2-2-control station 3.

In this case, the control information described above is stored in the radio base station 2-1, but not in the radio base station 2-2. will be lost, and the services or functions being provided will also be discontinued. One way to solve this problem is to transfer control information stored in the wireless base station 2-1 to the wireless base station 2-2 prior to line switching.

This is done under the control of the control station 3, and this control information is transferred via the control station 3 through the play control line, which is different from the call line. However, this method requires information transfer between wireless base stations and has the disadvantage of complicated control.
Moreover, if transfer is performed every time line switching control is performed, the traffic on the control line increases.
4. When a mobile station moves to a different service zone and the line connection is switched to a different wireless base station, the present invention determines the type of the mobile station or the presence or absence of services or functions being provided or requested for the mobile station. The control information indicated by the mobile station is directly transferred to the switched wireless base station from the mobile station without being transferred via the control station, thereby preventing the above-mentioned drawbacks, that is, complicating control and increasing control line traffic. The purpose is to Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 is a diagram showing an example of the configuration of a mobile station and a wireless base station in which the present invention is implemented in a car telephone system that enables secret communication.

The purpose of the secret communication is, in this case, to prevent deliberate eavesdropping, especially in the radio section. As one means for this purpose, a method will be described in which a specific disturbance is applied to the call signal on the transmitting side, and the disturbance is removed on the receiving side to restore the original call signal. The method of applying this disturbance and the method of removing the disturbance at the receiving end are known methods, but since these are already well known, their explanation will be omitted.
Therefore, if a highly confidential call is to be made, that is, if a specified disturbance is to be caused to the call signal, the caller at the mobile station should perform the necessary operations using a button switch or the like. In FIG. 2, 1 is a mobile station, 110 is a telephone,
Reference numerals 111 and 112 denote switching circuits, and 113 a circuit for imparting a specified disturbance to the signal, which is used on the transmitting side.

114 is a circuit for removing disturbances (a circuit for restoring a signal subjected to disturbances) and is used on the receiving side.

Reference numeral 115 denotes a secret call request operation section, which is composed of a switch.

Reference numeral 116 is a memory unit that stores control information, and is a circuit that stores whether or not a request has been made by the secret call request operation unit 115.

Note that if the switch circuit of the secret call request operation section 115 is of a type that can maintain the state, it can also serve as a memory function, so the memory section 116 is not separately required.
If the switch circuit is temporary (a type in which the circuit is connected only while the switch is being operated), the memory section 116
Is required. In the former case, it can be considered that the memory section 116 has entered the secret call request operation section 115.
Reference numeral 117 denotes a control unit, which is a circuit that decodes control commands from the wireless base station and performs necessary controls when connecting and disconnecting lines, switching channels, etc. When a secret request is made, the switching circuits 111 and 112 are controlled through the line 118, and the connection of the disturbance producing circuit 113 and the disturbance removing circuit 114 is controlled, and the secret call request signal is converted into a speech signal. The signals are combined and sent to the modulator 119.

119 is a modulator, 120 is a transmitting circuit, 121 is a duplexer, 122 is an antenna, 123 is a receiving circuit, 124 is a demodulator, and 125 is a local oscillator, which is composed of a synthesizer.

2 is a wireless base station, 21 river antenna, 211
2 is a duplexer, 222 is a duplexer, 224 is a receiving circuit, 2
25 is a demodulator, 226 is a secret call request signal detection unit, 22
7, 228 is a switching circuit, Z229 is a disturbance signal removal circuit (signal restoration circuit), 230 is a circuit that gives a specified disturbance, 231 is a speech signal input terminal, 232 is a control signal input terminal, 233 is a synthesis circuit, 234 is a modulator, 235 is a transmitting circuit, 236 and 237 are local oscillators, and 22Z3 is a coupler.

Note that other wireless base stations are similarly configured. Now the second
In the figure, in a normal case, a transmission signal sent from a mobile station 1 is transmitted from a telephone 110 through a switching circuit 111, a control section 117, a modulator 119, a transmission circuit 120, a duplexer 121, an antenna 122, and then a wireless communication signal. Antenna 210 of base station 2, duplexer 211, duplexer 222, receiving circuit 2
24, a demodulator 225, and a switching circuit 227, and is outputted to a call signal output terminal 238, and is further connected to the general fixed telephone network via a control station 3 and a switching station 4, as shown in FIG. .

Also, the call signal input terminal 2 of the wireless base station 2 is connected to the fixed telephone network.
The reception signal input to 31 is sent to the switching circuit 228, the combining circuit 233, the modulator 234, the transmitting circuit 235, and the combiner 22.
3. From the transmitter/receiver duplexer 211 and the antenna 210, the mobile station 1
antenna 122, duplexer 121, receiving circuit 123
, the demodulator 124, the control unit 117, and the switching circuit 112, and the call is received by the telephone 110 in this order. At this time, the switching circuits 111, 112, 227, and 228 are inoperative, and the disturbance-giving circuits 113, 230 and the disturbance-removing circuits 1 14, 229 are not inserted into the telephone line. First, the call is not confidential and takes place normally. Let us consider a case where a caller requests a secret call by operating the secret call request operation unit 115 in order to avoid eavesdropping in the unlikely event that the caller makes a highly confidential call.

This request is stored as control information in the memory unit I16,
This is detected by the control unit 117 and transmitted to the wireless base station as a secret call request signal. At the same time, the switching circuits 111 and 112 operate in the mobile station 1, and the transmission/reception signal route is the telephone 110→switching circuit 111→disturbance circuit 113→switching circuit 111→control unit 117 and control unit 117→ Switching circuit 112→disturbance removing circuit 114→switching circuit 112→telephone 110, and a circuit 113 that applies disturbance and a circuit 114 that removes disturbance are switched to the transmission and reception signal paths, respectively. inserted. In order to transfer the control information for the secret call request from the mobile station 1 to the radio base station 2, this control information can be configured into a digital signal having a block code structure, as shown in FIG. 3, for example. The secret call request signal is converted into a predetermined pulse pattern (for example, 1111101010 of 10 bits) by the control unit 117, and constitutes the information bit portion D of the digital signal. As shown in the figure, the above-mentioned digital signal includes a preamble P (also used for bit synchronization on the receiving side) that indicates the transmission of the signal, a start code S that indicates the start of the information bit, and control information for the secret call request. The control section 117 configures this and sends this signal to the modulator 119. At this time, the start code S, information bit part D, and check code CH are made into a unit block, and in order to improve reliability, this block is configured to be transmitted several times, for example, through three lines as shown in the figure. . The modulator 119 performs FM modulation on the input signal, for example, and the transmission circuit 120 converts it into a radio frequency band and transmits it. The radio base station 2 receives this signal and demodulates it in the demodulator 225 to obtain a signal having the same code structure as the transmitted signal.

The output of the demodulator 225 is also branched to a secret call request signal detection section 226, which detects reception of the signal using the preamble P of the signal, confirms the start code S, and further detects the information bit section D. and determines from the pattern that these are secret call request signals. When determining in this way, the detection unit 226 switches between the switching circuits 227 and 228.
to drive. Then, in the switching circuit 227, the circuit 229 that gives disturbances is changed to the switching circuit 228, and the circuit 230 that removes disturbances is inserted and connected. As a result, the route of the speech signal at the wireless base station 2 is also switched, and the speech signal input section 231→switching circuit 228→disturbance providing circuit 230→switching circuit 228→synthesizing circuit 233→modulator 23
4 and demodulator 225→switching circuit 227→disturbance removing circuit 229→switching circuit 227. That is, in both the mobile station and the wireless base station, circuits 113 and 230 that give specified disturbances and circuits 114 and 229 that remove disturbances (restore signals) are connected and inserted, respectively, and the secret call request function is performed. will be fulfilled. In this state, the mobile station 1 runs, and for example,
When moving from the service zone SZ, shown in the figure, to SZ2, channel switching during a call is performed as described above, and continuous switching is performed from radio base station 2-- to 2-2. In this embodiment, when channel switching is performed during a call, a secret call request is automatically given directly from the mobile station to the newly switched radio base station, and the secret call request is automatically given to the newly switched radio base station. Service will not be interrupted.

Next, the operation at the time of line switching in this embodiment will be explained.

FIG. 4 is an operation time chart at the time of line switching.
In FIG. 1, a mobile station 1 is located in the service zone SZ. of a wireless base station 2-1. From the service zone S of wireless base station 2-2
When shifting to Z, the radio base station 2-1 notifies the control station 3 of the drop in the received electric field from the mobile station 1 (Fig. 4, time L), and the control station 3 changes the radio base station 2-2 to the high received electric field. It takes a channel switching operation. The control station 3 selects and determines the communication line channel to be used from among the available communication channels, notifies the wireless base station 2-2 of this (transmitter/receiver turn-on command for the designated channel), and sends a control signal to the wireless base station 2-1. Input end 2
32, the switching command 3 and the communication channel number to be switched are sent to the mobile station 1 via the synthesis circuit 233 (time t2 in FIG. 4). These signals can be transmitted using the same configuration as shown in FIG. 3 and the same means as described above.
The slave mobile station 1 receives this signal, identifies it in the control unit 117, determines that it is a switching command from the pattern of the received information bits, and controls the local oscillator 125 based on the call channel number sent at the same time. and switch the radio frequency to the one corresponding to the specified channel.

Prior to this, in the radio base station 2-2, devices related to transmission and reception corresponding to the speech channel number received from the control station 3 (time t2 in FIG. 4) are put into operation.
Therefore, when mobile station 1 performs channel switching (Fig. 4,
A line is set up from point 1 to 2 through wireless base station 2-2. On the other hand, the control unit 117 of the mobile station 1 checks the contents of the memory unit 116 at the same time as the channel switching operation ends, and if the secret call request information is stored, the control unit 117 of the mobile station 1 performs a secret call as in the case of the initial setting described above. Send a request signal. This signal is received by the radio base station 2-2, detected by the secret call request detection unit 226, and a circuit 230 for providing disturbance and a circuit 229 for removing disturbance are inserted and connected in the same manner as described above. It is now possible to continue talking with confidentiality. This series of operations can be repeated as long as the secret call request information is stored in the memory unit 116, and even if the mobile station 1 moves widely and channels are repeatedly switched due to transitions between service zones, the secret call request information can be repeatedly executed. Since the requested information is automatically sent each time, secret communication is possible continuously, and there is no need for complicated control on the radio base station or control station side, and the No operation required. In this embodiment, a secret call can be entered by operating the operation unit 115 at any time before or during the call. Furthermore, it is easily possible to configure the system so that by operating the operating unit 115 and clearing the memory unit 116 at any time, the secret call can be returned to a normal call. FIG. 5 is a diagram showing an example of the configuration of a mobile station and a radio base station in an example in which the present invention is implemented in a case where it is necessary to change the operating state of a receiver of a radio base station depending on the type of mobile station. An example will be explained in which a general mobile station for telephones and a mobile station for automobile public telephones are used together as a station.

The numbers in FIG. 5 indicate the same ones as in FIG. 2. However, 226
' is a public telephone identification signal detection section. Furthermore, in the case of a public telephone, the memory unit 116 of the mobile station 1 permanently stores information for identifying the telephone as a public telephone, such as in a ROM. In the embodiment shown in FIG. 5, when the mobile station 1 is connected to the radio base station 2, the transmission signal sent from the mobile station 1 is sent from the telephone 110 to the control unit 117, the modulator 119, the transmission circuit 120, and the transmission/reception signal. The duplexer 121 and the antenna 122 pass through the antenna 210 of the wireless base station 2, the duplexer 211, the duplexer 222, the receiving circuit 224, and the demodulator 225 in this order, and are outputted to the speech signal output terminal 238, and then as shown in FIG. As shown, it is connected to a general fixed telephone network via a control station 3 and a switching center 4.

In addition, the receiving signal input from the fixed telephone network to the call signal input terminal 231 of the wireless base station 2 via the switching center 4 and the control station 3 is
From the combining circuit 233, modulator 234, transmitting circuit 235, coupler 223, duplexer 211, and antenna 210, the antenna 122, duplexer 121, receiving circuit 123, demodulator 124, and control unit 117 of the mobile station 1 are sequentially connected. The call is now being received by the telephone 110 of the mobile station 1. If the mobile station 1 is for a regular telephone, a call is made through the above route, and the memory section 116 does not store any information for identifying this. Further, when the mobile station 1 is used for a car public telephone, information identifying that the mobile station 1 is used for this public telephone is permanently stored in a memory section 116 composed of, for example, a ROM. Then, as described above, mobile station 1
When a telephone line is set up between the wireless base station 2 and the wireless base station 2,
As in the embodiment shown, the contents of the memory section 116 are read, a signal for identifying the public telephone set is constructed, and the signal is sent to the wireless base station 2 along the route through which the outbound call signal flows. In the wireless base station 2, similarly to the embodiment of FIG. 2, this signal is transmitted to a public telephone identification signal detection section 226' (this may be configured similarly to the secret call request signal detection section 226 of FIG. 2).
The receiving circuit 224 can be controlled to change its operating state to one suitable for a public telephone. Similar to the embodiment shown in FIG. 2, the embodiment shown in FIG. 5 exhibits its advantages when channel switching is performed during a call.

When the mobile station 1 changes service zones and performs channel switching, the mobile station 1 receives a channel switching command and switches channels, similarly to the embodiment shown in FIG. Following this, the instant control section 117 checks the memory section 116 and sends out a signal indicating that it is a public telephone. In the radio base station 2 newly connected after channel switching, this signal is detected by the public telephone identification signal detection section 226', and the receiving circuit 224 is set to an operating state suitable for a public telephone. Also in this embodiment, the above operation is automatically repeated every time there is a shift to a service zone, and no operation is required by the caller. The present invention is not limited to the above embodiments, and various modifications can be made within the technical scope thereof.

For example, when a mobile station is used for ordinary telephones and for public telephones, it is possible to enable secret call services for each at the request of the caller. Note that the present invention is generally applied when transmitting control information from a mobile station to a radio base station and changing the operation of the radio base station in accordance with the control information.
The present invention is applicable not only to car telephones but also to mobile communication systems where the service area has a zone configuration as described above, such as trains, ships, etc.
It can be implemented on aircraft etc. As explained above, the present invention allows the mobile station to store specially required control information such as control information indicating the type of mobile station or the presence or absence of a service or function that is being provided or requested by the mobile station. When switching channels due to service zone migration, the above-mentioned stored information is directly notified to the newly connected radio base station immediately after the switching, and the operating status of the radio base station is adjusted to suit the above information. Therefore, when the channel is switched, the radio base station is automatically set to the operating state determined by the above information, and this also simplifies the control sequence, prevents increase in control traffic, and This has the effect of making operations more convenient for callers.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a known car telephone system, FIG. 2 is a diagram showing a configuration example of a mobile station and a wireless base station in an embodiment of the present invention, and FIG. 3 is a mobile station in the embodiment of FIG. 2. FIG. 4 shows an example of the configuration of a control signal sent from
This figure is an operation time chart at the time of channel switching in the embodiment of FIG. 2, and FIG. 5 is a diagram showing an example of the configuration of a mobile station and a radio base station in a different embodiment of the present invention. 1... Mobile station, 2, 2-1, 2-2...
・Radio base station, 3... Control station, 4...
Telephone exchange, SZ, SZ... Service zone,
110...Telephone, 111, 112, 227, 228・
...Switching circuit, 113,230...Circuit for providing disturbance, 114,229...Circuit for removing disturbance, 117...Control unit, 119,234
...Modulator, 120,235...Transmission circuit, 223...Coupler, 121,211...
・・Transmitter/receiver duplexer, 122, 210...・1 antenna, 222... splitter, 123, 224...
Receiving circuit, 124, 225... Demodulator, 115...
Secret call request operation section, 116...Memory section, 125, 2
36,237...Local oscillator, 231...
... Call signal input end, 238 ... Call signal output end, 232 ... Control signal input end, 233 ...
...Composition circuit, 226'...Public telephone identification signal detection section. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1 The service area is divided into multiple service zones, a wireless base station is installed in each service zone, and the mobile station connects to the wireless base station of the service zone in which it is currently located. In a mobile communication system configured to perform channel switching and change connection to a wireless base station in a newly migrated service zone, the mobile station has a memory unit that stores control information, and the mobile station When connected to a radio base station, or when channel switching is performed due to service zone migration and connection is changed to a wireless base station in a newly migrated service zone,
The control information in the memory unit is read and sent to the connected radio base station, and the radio base station has means for detecting the control information, and upon receiving the control information, specifies its operating state using the control information. A control information transfer method in mobile communication characterized by changing the state to a state in which the control information is transferred.