JPH02131631A - On-vehicle mobile radio system - Google Patents

Abstract

PURPOSE:To attain the communication to a subscriber even at the time of leaving an automobile by returning subscriber identification information to a communication station registered with the mobile station when a communication network receives the subscriber identification information at an on-road station and allowing a communication station to revise the present position information of the mobile station. CONSTITUTION:An on-vehicle radio equipment section 30 of a subscriber vehicle 10 driving on a maintenance line 3 of on-road vehicle communication system receives present location information from an on-road station 1 when the vehicle passes through a minimum radio zone 2 of the on-road station 1. The present location information is collated with the content of a fluctuation code column of a subscriber ID card 44 of the radio call communication system. As the result of collation, when the contents are dissident, the content of the fluctuation code column is revised. Thus, the subscriber vehicle 10 driving the maintenance line 3 of the inter-road communication system is set to the state able to radio call service including the district of inter-road communication disable between the road stations 1. Thus, the radio call communication service to a subscriber using mainly the vehicle is extended into a wide area.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mobile radio system, and in particular to a mobile radio system for vehicles suitable for subscribers who operate over a wide area, mainly vehicles such as automobiles. (Prior Art) Currently, the so-called pager system, which calls subscribers within a limited area wirelessly, is in practical use as a means of communication to mobile objects. In such portable mobile radio systems, in order to reduce the size and weight of the portable device, the portable radio device uses a battery with the smallest possible capacity, and is equipped with only a receiving function to transmit information from the base station to the mobile device. This is a form of one-way communication. Also, a so-called intermittent reception method is applied. In this system, subscribers belonging to a registered station are divided into multiple groups, and the base station sends a call signal to each group sequentially, and each subscriber uses the communication time slot assigned to the group to which he or she belongs. It is in the receiving state only at . Recently, methods that can convey simple messages in addition to calling signals are being put into practical use. In addition, mobile communication systems such as a car telephone system that assumes connection to the general public telephone network and an MCA system that targets vehicles of specific corporate users have also been put into practical use. Since these methods are basically based on voice communication,
Increasing the subscriber capacity requires a very large number of radio channels, and an extremely complicated radio channel switching mechanism is required for both base station equipment and in-vehicle equipment. Recently, a portable in-vehicle device of this type is in the process of being put into practical use. With the recent trend of digitalization of information and communication, various mobile radio systems using digital communication are being developed, and the so-called teleterminal system is being planned as an MCA system for two-way digital communication targeting corporate user vehicles. There is. Further, as a means of communication for vehicles traveling on the road, for example, an intermittent wireless zone road-to-vehicle communication system has been proposed in Japanese Patent Application No. 138407/1983. In this system, roadside stations in extremely small wireless zones are placed at intervals along the road, and two-way transmission of digital information is carried out within a short period of time when a vehicle is driving within the extremely small wireless zone. Since this method performs short-distance wireless transmission almost within the line of sight within a very small wireless zone, there is almost no fading effect and relatively high-speed code transmission is possible. (Problems to be Solved by the Invention) These conventional mobile radio systems have the following problems. The car telephone system and MCA system, which are based on voice communication, do not have a large subscriber capacity per channel, and have the disadvantage that the equipment configuration is complicated due to the complicated switching between multiple wireless channels. be. In addition, because conventional pager and teleterminal systems provide wireless paging services only within the registered area, they cannot be an effective means of communication for subscribers who travel over a wide range for business or travel purposes. do not have.

Mobile radio equipment that assumes two-way communication requires a transmitter unit that consumes a relatively large amount of power for both the voice and digital communication systems, and especially in the case of a portable type, a battery with a large current capacity is used. This is a major obstacle to making mobile devices smaller and lighter. The problems with the intermittent wireless zone road-to-vehicle communication system are when passing through roadside areas where traffic is congested, when driving on routes that are not equipped with this system, and when the subscriber is away from the vehicle. Second, communication is not possible. It is an object of the present invention to overcome these drawbacks of the prior art and to provide a vehicle mobile radio system that enables subscribers to communicate even when they leave the vehicle. (Means for Solving the Problems) The mobile radio system for vehicles according to the present invention includes a plurality of radio zones that are spaced apart from each other along a route and define minimal radio zones for performing two-way radio communication with mobile stations on the route. street station, a regional station that accommodates multiple street stations, and a regional station that accommodates
A communication network forming a road-to-vehicle communication system including a communication station in which subscriber information and current location information of a mobile station are registered, and a wireless call connected to the communication network and including a minimal wireless zone. a base station that defines an area and makes a radio call to a mobile station; a portable second radio that is detachably connected to the radio and that responds to a radio call from the base station;
The first radio device is equipped with a first storage means that carries subscriber identification information of the mobile station, and the second radio device has a variable information unit that stores area identification information of the radio calling area. , and a second storage means having a fixed information section carrying subscriber identification information, and when the first radio communicates with any road station, the first radio device stores the on-road information in the variable information section of the first storage means. The communication network stores the area identification information obtained from the station, transmits the subscriber identification information held in the second storage means to the roadside station, and when the communication network receives the subscriber identification information at the roadside station, the communication network stores the subscriber identification information obtained from the station. The information is sent back to the communication station with which the mobile station is registered, and the communication station thereby updates the current location information of the mobile station.
When there is a radio paging call to a mobile station, the communication network makes the radio paging to the mobile station through the local station and base station corresponding to the updated current location information of the mobile station. (Function) According to the present invention, firstly, by utilizing the road-to-vehicle two-way communication function of the road-to-vehicle communication system and the inter-office line network, when the subscriber of the registered station is outside the local station area, However, your current location is always known. This minimizes the number of invalid radio calls, allowing more subscriber capacity per radio channel. Second, there are problems with the road-to-vehicle communication system, such as the inability to communicate while driving in areas on the road during traffic congestion, and the inability to communicate while driving on undeveloped routes with this system.
Furthermore, the problem of inability to communicate while moving away from the vehicle can be resolved by providing a wireless paging service as an auxiliary means of communication. Therefore, rather than simply using the road-to-vehicle communication system and the radio paging system together, they are organically combined to avoid the drawbacks of both systems. (Embodiment) Next, an embodiment of the vehicle mobile radio system according to the present invention will be described in detail with reference to the attached drawings. Figure 1 shows the basic configuration of an embodiment in which the vehicular mobile radio system according to the present invention is applied to automobile traffic. This system consists of a radio paging communication system and a road-to-vehicle communication system. The former is connected to the telephone center 8 by the telephone communication network 9.
The base station 6 forms a small wireless zone 7 with a communication range of approximately 5 to 20 km in diameter, for example. The telephone station 8 may accommodate a plurality of base stations 6. The telephone station 8 has a subscriber list memory t storage means for storing the subscriber numbers of registered subscribers registered therein and their destinations, that is, their current locations. When a radio paging call occurs, the telephone station 8 refers to the subscriber list and sends a radio paging signal through the telephone line network 9 to the base station 6 in the region to which the subscriber is moving. Make a wireless call. Of course, when calling a subscriber who has moved to another telephone station area, the telephone station 8 in that area calls the base station 6.
Access. On the other hand, the road-to-vehicle communication system includes a regional station 4 and a roadside station l accommodated therein. 5 zones 7 for road-to-vehicle communication system
When a vehicle such as a car, for example 10, traveling on a maintenance route 3 within the area passes through the minimal radio zone 2 of a roadside station 1 along it, the on-board radio unit 30 (FIG. 2) of the vehicle IO and the roadside station 1 performs two-way digital communication. The roadside station 1 is located along the maintenance route 3 where the road-to-vehicle communication system is installed.
For example, they are arranged at intervals of about 0.3 to 3 kilometres, forming a very small wireless zone 2 with a communication range of, for example, about 60 to 200 meters in diameter. In this embodiment, approximately 40 on-the-road stations 1 are accommodated in the local station 4 by the on-the-road station line network 5. The regional station 4 connects to the telephone station 8 via the telephone line network 14.
The road-to-vehicle communication system consists of 1 roadside station, 4 regional stations, and 8 telephone stations. For example, the regional stations 4 may be arranged corresponding to the maintenance routes 3 and may accommodate a plurality of road station line networks 5. Furthermore, a plurality of regional stations 4 may be accommodated in one telephone station 8. Therefore, regional station 5 and base station 6
do not necessarily have a one-to-one correspondence. Maintenance route 3
The subscribing vehicle lO traveling on the road performs two-way digital communication using ultra-high-speed code transmission within the short time it takes to pass through the minimal wireless zone 2 of the roadside station l. For example, if the length of the wireless zone in the longitudinal direction of route 3 is 60 layers and the vehicle speed is 50 kph/hour, the time the vehicle 10 remains in effective zone 2 and can communicate is approximately 4.4 seconds. For example 0.5-1.5
Communication at a code transmission rate of about M bits/second is possible.
On the other hand, 11 undeveloped routes with no road-to-vehicle communication system
The subscriber vehicle l2 that is traveling in the area and the subscriber l3 that has left the vehicle and is moving can receive a radio calling service using an intermittent reception method from the base station 6 whose service area is the small wireless zone 7. Both the road-to-vehicle communication system regional station 4 and the radio paging communication system base station 6 are connected to the telephone station 8 that has jurisdiction over this region via telephone line networks 14 and 9, respectively, and furthermore, By connecting to the relay line network, the coverage of both communication systems is expanded. These telephone line networks 9 and 14 are not limited to analog communication networks, but may be integrated digital communication networks that include data as well as voice.
In addition, any 2 of telephone station 8, base station 6, and regional station 4
More than one may physically constitute a single station. The signal configurations of the road-to-vehicle communication system and the radio paging communication system in this embodiment will be explained with reference to FIGS. 3A and 3B. As shown in FIG. 3A, the road-to-vehicle communication system signal has a preamble signal section, a vehicle recognition section, a circular communication section, and a bond-specific communication section. The preamble section receives the synchronization signal sent from the road station 1 side, the road station code, and the road station 1 side.
Contains regional identification information, including the region code to which it belongs. The vehicle recognition unit is a part that recognizes the subscriber identification information such as the subscriber registration number code of the running vehicle IO through the polling-acknowledgement procedure between the road and the vehicle, and specifies the transmission time slot when there is individual communication information transmitted by the vehicle. be. The broadcast communication section is the part that broadcasts information such as traffic information for the area under its jurisdiction from the roadside station to the subscribers. The vehicle transmitting section 32 and the vehicle receiving section 3l perform two-way communication of individual communication information of each participating vehicle 1G while traveling. Referring to FIG. 3B, in the radio paging communication system, following a preamble signal such as a synchronization signal, an area code, and a channel number code, a plurality of groups l to N (N is a natural number)
A paging signal is sent sequentially to each group of subscribers.
The subscriber's mobile radio receives this call information using an intermittent reception method. Referring to Figure tJIJ2, the subscriber-side radio equipment of the vehicle mobile radio system in this embodiment includes an on-vehicle radio unit 30 for the road-to-vehicle communication system, and a portable radio unit 50 for the radio paging communication system. It is composed of
The latter is used for communication with the vehicle 10 while traveling on the maintained route 3, and the latter is used for radio calling while traveling on the undeveloped route 11 and when leaving the vehicle. The portable radio unit 50 is detachably connected to the in-vehicle radio unit 30 through a connector 52, and is configured so that it can be separated from the in-vehicle radio unit 30 and carried when leaving the vehicle. Both radio units 50 and 30 each have a signal processing unit 43.
and 37. The two are connected by a signal connection line 47, and the information code necessary for the radio paging communication system is given from the road-to-vehicle communication system. The portable radio unit 50 uses a secondary battery 48
This means that the portable radio unit 50 is connected to the in-vehicle radio unit 30.
When connected to the connector 52, the power supply connection line 4
It is configured so that it will receive power from now on through 3 and be charged. The in-vehicle radio section 30 is connected to the vehicle's power supply system through a power supply terminal 3B, and is configured to be supplied with power therefrom. The in-vehicle radio section 30 has a transmitter section 32 and a receiver section 31, both of which are connected to an antenna duplexer 33.
The antenna 34 is connected to the antenna 34 via the 91
It sends and receives radio waves to and from the road station l shown in Figure 11.
The in-vehicle radio unit 30 also has an input/output unit 35, which is configured to input a CD-ROM as a road map database. tIII, ^/
D converter, DIA converter. It can be equipped with a voice recognition/synthesizing device, a CRT or liquid crystal display device for image input/output, a printer, a facsimile device, etc., which are arbitrarily selected depending on the communication purpose of the subscriber. The in-vehicle radio unit 30 includes a subscriber identification (In) card A 3
The 10 card 36 is a storage device that stores subscriber identification information for the road-to-vehicle communication system, and may be any memory format such as a magnetic card, an optical card, or a RAM or ROM card. Very good. 10 card 3B records the subscriber's dynamic codes such as the subscriber's subscription registration unique code and the travel destination code necessary for route guidance, and is removably attached to the vehicle radio unit 30 to transmit vehicle aircraft signals. It is connected to the processing section 37.
The vehicle-mounted signal processing unit 37 is a signal processing processor of the vehicle-mounted radio unit, and controls transmission and reception information of the vehicle-mounted radio unit in accordance with a signal configuration as illustrated in FIG. 3A. To explain in more detail, first, when a preamble signal part is received from roadside station 1, it is demodulated and the current position of own vehicle 10 is recognized based on the roadside station code indicating the location of roadside station 1. At the same time, if the input/output unit 35 has a CD device, the database and display device will display a road map of the area, and the current location will be displayed on it. Subsequently, the signal processing unit 37 uses the vehicle recognition unit to poll the subscription registration unique code read from the subscriber In card 38 and a code that informs the roadside station 1 of the presence or absence of individual communication information transmitted from the vehicle. When the roadside station l recognizes the content of the polling, it transmits an acknowledgment code instructing the transmission time slot of the individual information transmitted by the vehicle. Such street station
The boring-understanding procedure between the and the onboard radio unit 30 is
A pending patent application by the same applicant as the present applicant, such as Japanese Patent Application No. 82-1013204 or Japanese Patent Application No. 82-1013-108
This can be done by controlling the wireless line according to the procedure described in 548. Then, the signal processing unit 37 displays the traffic information for the area and its surroundings sent from the roadside station 1 as an image superimposed on the road map on the in-vehicle display device of the input/output unit 35 in the relay communication unit. This traffic information includes traffic regulation information, traffic jam information, disaster information, etc. The in-vehicle radio unit 30 has a storage unit 38, which matches the code rate in road-to-vehicle wireless transmission and the code rate handled by the input/output unit 35 in communication between the roadside station l and the in-vehicle radio unit 30. It is a buffer memory that temporarily stores information for processing and waiting time during transmission and reception procedures. A mobile S line unit 50 used for the radio paging communication system is equipped with a subscriber ID card B 44 and is connected to a base station 6 in the current area.
Receive a radio paging signal from. The ID card 44 has a fixed code column for storing the subscriber's subscription registration number code, registered area code, channel number code, group number code, etc., and a fixed code column for storing the subscriber's subscription registration number code, registered area code, channel number code, group number code, etc. A variable code column is provided to store the area code of the base station 6 that defines the subscriber's current location, and the channel number code. It takes one of the memory formats similar to 0 card 3B. The subscriber 10 card 44 is removably attached to the in-vehicle signal processing section 43 of the portable radio section 50. The portable device signal processing section 43 reads the channel number code from the 10 card 44, and the channel control section 42 controls the receiver section 4l to select the corresponding wireless channel. A receiving antenna 40 for receiving radio waves from the base station 6 is connected to the receiver section 4l. Receiver section 4l
demodulates the paging signal and message intermittently received from the base station 6, and the signal processing section 43 drives the speaker, LED, or lamp of the display section 45 in response to them, and outputs an audible and visible display. As a result, the signal processing unit 43 transmits the base station area information of the preamble signal section received from the base station 6 to
If a discrepancy occurs after checking the contents of the variable code column of the card 44, the display section 45 is driven to generate a sound and
The function is to turn on the ED and notify the subscriber that the location of the portable radio unit 50 is out of the radio calling service area 7, or that it is out of the radio call service area 7. The portable radio unit 50 has an operation section 46, and the operation section 46 is provided with a power switch. Each circuit of the portable radio unit 50 is powered by a secondary battery 48, which is charged by the in-vehicle radio unit 30 through a power connection line 49 when connected to the in-vehicle radio unit 30. Between the on-vehicle device signal processing section 37 and the portable device signal processing section 43, information on the radio paging communication system is output from the road-to-vehicle communication system as follows, and the basic organic operation in this embodiment is performed. ．． First, the subscriber In cards 3B and 44 for the respective communication systems of the subscribers are attached to the radio units 30 and 50. Next, turn on the power switches of both radio units 30 and 50, or operate the reset button of the portable radio unit 50. , the in-vehicle radio unit 30 transfers the subscriber registration area code in the fixed code field of the subscriber 10 card 44 to the variable code field of that card. For example, if a participating vehicle 1O is traveling on a maintenance route 3 where a road-to-vehicle communication system is maintained, its in-vehicle radio unit 30
receives the current location information from the road station l when passing through the minimal wireless zone 2 of the road station l. The current location information obtained through this communication is sent to subscribers of the wireless paging communication system! D card 44
Check against the contents of the variation code field. As a result of the verification, if there is a mismatch, the contents of the variation code column will be updated. Such a function is provided by the in-vehicle device signal processing section 37 or the portable device signal processing section 4.
3. As a result, the participating vehicles 1O traveling on the road-to-vehicle communication system maintenance route 3 are set to a state in which the wireless paging service is possible, even in areas where road-to-vehicle communication between roadside stations 1 is impossible. In addition, when branching from the developed route 3 and entering the undeveloped route 1l, or when leaving the vehicle 10 or 12 and taking action, the variable code field of the subscriber In card 44 of the radio paging communication system is , the current location information received from the roadside station 1 just before branching to the undeveloped route 11 or just before leaving the vehicle is stored in an updated manner. In this way, a state is set in which the wireless paging service within the area 7 can be continuously received. Undeveloped route l1 is replaced by developed route 3, for example within an urban area.
If the route is an undeveloped branch line included in the area surrounded by , the vehicle 12 traveling on this route can be considered to be equivalent to traveling on a somewhat long road between stations. Furthermore, the range in which drivers leave their cars and move around is generally within a relatively narrow range, and in many cases this can also be considered to be within the effective range of services in that area. In this way, in this system, when a subscriber is unable to communicate with the road-to-vehicle communication system, he or she can receive services from the radio paging communication system instead. FIGS. 4^ and 4B show a sequence for collecting current location information of subscribers in the radio paging communication system and distributing radio paging communication information in this embodiment. 4th A
The figure shows a case in which radio paging communication information is transmitted using a road-to-vehicle communication network, and Figure 4B shows a case in which the same information is transmitted through a general public communication network. Referring to FIG. 4A, the in-vehicle radio unit 30 of the moving joining vehicle 1O receives current location information from the roadside station 1, analyzes it, and detects that there is a change in the area of the radio paging communication system. Then, the subscriber's current location information is transmitted to the roadside station l. This current location information is sent to the road-to-vehicle communication line network via the regional station 4 that has jurisdiction over the on-road station 1, and through this, the local station 4 where the subscriber's registration station 8 is located.
will be forwarded to. The current location information is finally transmitted from the local station 4 to the subscriber registration station 8, and is recorded in the subscriber list memory as moving area information. Additionally, when a subscriber returns to his/her own area from another area, this fact is recorded in the subscriber list. When the registration station 8 receives a wireless paging call for a subscriber, the registration station 8 first refers to the subscriber list memory and grasps the current location of the subscriber.
When it is determined that the subscriber is within the local area, for example, by deriving the current location, a paging signal is transmitted from the base station 6 in the local area. Also, if it is in another area,
Information is transferred to the base station 6 at the subscriber's current location using the road-to-vehicle communication line network, and a paging signal is transmitted from the base station 6. In this way, you can access that subscriber. In the example shown in FIG. 4A, the calling signal is transmitted to a subscriber in another station area using a road-to-vehicle communications network, but it may also be transmitted via a general public communications network. The sequence flow in that case is shown in Figure 4B. in this case,
The transmission of the current location information to the subscriber registration station 8 may be the same as in the case of FIG. 4A. Also, a private communication network may be used instead of or in addition to the general public communication network. As explained above, in this mobile radio system for vehicles,
The status of the wireless paging communication area of the subscriber vehicle 1O while it is running is determined by the subscriber registration station 8 using the functions of the road-to-vehicle communication system.
The subscriber list memory is stored sequentially in the subscriber list memory. As a result, wide-area wireless paging communication services for subscribers who mainly use the vehicle 10 can be achieved. Further, the same radio paging service can be provided even when the vehicle is traveling in an area between 1 roadside stations due to traffic congestion, or when the vehicle is traveling on an undeveloped route 1l. Furthermore, wireless paging service can be effectively provided even to subscriber l3 who has left the car. When a subscriber who receives a wireless call responds to the caller, he or she can use the road-to-vehicle communication system while riding in the vehicle IO. This is particularly effective when, for example, for business use, image communication of slips and the like is performed by the input/output section 35. In addition, the power source of the portable radio unit 50 is configured to be able to be charged from the vehicle IO power supply while connected to the vehicle-mounted radio unit 30, so the portable radio unit 50 is made smaller and lighter, improving ease of handling. I'm letting you do it. (Effects of the Invention) As explained above, in the mobile radio system for vehicles according to the present invention, the status of the radio paging communication area of the subscriber vehicle in motion is updated in the storage unit of the subscriber registration station using the road-to-vehicle communication system. is memorized. As a result, wide area wireless paging communication services can be achieved for subscribers who mainly use vehicles. In addition, the same radio paging service is effectively provided when the user is driving in an interoffice area on the road or on an undeveloped route, or when a subscriber leaves the vehicle. For responses after a wireless call, the vehicle-to-vehicle communication system can be used while in the vehicle. This is particularly effective when, for example, image communication is performed using an in-vehicle device. Also,
The portable radio device can be charged from the vehicle's power supply while connected to the vehicle-mounted radio device, making the portable radio device smaller and lighter. With the rapid progress of motorization in recent years,
In both business activities and leisure activities, there are many opportunities to travel over a wide area mainly using a commuter car and leave the car to go around visited destinations or tourist spots, and the vehicle according to the present invention can provide an effective means of communication for such behavior patterns. The social effects of the mobile radio system are extremely large.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram showing the basic configuration of an embodiment of the vehicle mobile radio system according to the present invention. FIG. 2 is a functional block diagram showing an example of the configuration of the subscriber side radio device in the embodiment shown in FIG. Figures 3A and 3
Figure B is a frame configuration diagram showing an example of the configuration of signal frames for the road-to-vehicle communication system and the radio paging system in the same embodiment, and Figures 4A and 4B are diagrams showing subscriber location information in the radio paging communication system in the same embodiment. FIG. 4A is a system diagram showing an example of a sequence flow of collection and call signal distribution, in which FIG. 4A shows a sequence by a road-to-vehicle communication system, and FIG. 4B shows a sequence by a public telephone line network. l. ．． ．． 2. ．． 3. ．． ．． 4. ．． ．． 6. ．． ．． 7. ．． ．． 8. ．． ．． 9,14. ．． 10,11. ．． 30. ．． ．． 31,41. ．． 32. ．． ．． Description of part codes On-road station Minimal wireless zone maintenance route Regional station Base station Small wireless zone Telephone station Telephone line network Traveling vehicle Vehicle-mounted radio section Receiver section Transmitter section 34, 40. ．． 35. ．． ．． 3? ．． ．． ．． 38. ．． ．． 42. ．． ．． 43. ．． ．． 45. ．． ．． 48. ．． ．． S.O. ．． ．． Antenna input/output section Vehicle-mounted device signal processing section Storage section Channel control section Portable device signal processing section Display section Secondary battery portable radio section

Claims (1)

[Claims] 1. A plurality of on-road stations that are spaced apart from each other along a route and define a minimal wireless zone for performing two-way radio communication with mobile stations on the route; and the plurality of on-road stations. a communication network forming a road-to-vehicle communication system including a communication station accommodating the local station and in which subscriber information and current location information of the mobile station are registered; and the communication network. a base station that is connected to a base station that includes and overlaps the minimal wireless zone to define a wireless calling area, and that makes a wireless call to a mobile station, the mobile station being mounted on a vehicle, a first radio device that performs bidirectional radio communication with one of the roadside stations; a portable second radio device that is detachably connected to the first radio device and that responds to radio calls from the base station; , the first radio device is equipped with a first storage means carrying subscriber identification information of the mobile station, and the second radio device stores area identification information of the radio calling area. a second storage means having a variable information section carrying the subscriber identification information and a fixed information section carrying the subscriber identification information; storing the area identification information obtained from the on-road station in the fluctuation information section of the device, and transmitting the subscriber identification information held in the second storage means to the on-road station; Upon receiving the subscriber identification information at the station, the subscriber identification information is sent back to the communication station with which the mobile station is registered, and the communication station thereby updates the current location information of the mobile station; The communication network is characterized in that when there is a radio paging call to the mobile station, the communication network makes the radio paging to the mobile station through the regional station and base station corresponding to the updated current location information of the mobile station. A mobile radio system for vehicles. 2. In the system according to claim 1, the second radio device detects that the received wave from the base station is below a predetermined electric field level, and combines the area identification information obtained from the base station with the second radio device. processing means for comparing the contents of the fluctuation information section of the storage means; when the received wave falls below the predetermined electric field level, or when the area identification information does not match the contents of the fluctuation information section; A mobile radio system for a vehicle, comprising: display means for displaying. 3. In the system according to claim 1, the second radio device includes a secondary battery that supplies power to a circuit of the second radio device, and the secondary battery 1. A mobile radio system for a vehicle, characterized in that when connected to a vehicle, charging is performed from a first radio device.