JPH01311629A - Mobile body communication system - Google Patents

Abstract

PURPOSE:To manage the state of a mobile station appropriately including communication with the mobile station by always updating the storage content of a ground station on which the mobile station is registered by the detection and information of the position of the mobile station. CONSTITUTION:An individual mobile station 16 is registered in advance on the ground station (area station)32. A registration station 32 is informed from the ground station (road station)10 detecting the mobile station 16 registered on the station about the present location of the mobile station, and holds the data of the present location, and the data of the present location is always updated in real time. At the time of connecting incoming to the mobile station 16, the present location is found by making access to the registration station on which the mobile station 16 is registered, and incoming connection from the road station 10 in the periphery to the mobile station 16 is performed, In such a way, it is possible to perform the management of the mobile station including the communication with the mobile station appropriately as long as a targeted mobile station is active.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mobile communication system, and more specifically to a mobile communication system suitable for communication with a vehicle such as an automobile.

(Prior Art) As a conventional mobile communication system to which the present invention is particularly related, there is, for example, a car telephone system6.As is well known, a conventional car phone system has two base stations covering a predetermined service zone. Some base stations employ a cellular system in which the zones of adjacent base stations partially overlap each other to ensure continuity of communication to mobile units.

When terminating a call to a mobile station, it is necessary to identify the current location of the mobile object. In conventional cellular car phone systems, each time a mobile station receives a call, the network makes a simultaneous call in multiple zones, detects the response from the mobile station, determines the current location, and connects the incoming call. I was doing it.

(Problems to be Solved by the Invention) In the cellular system, different frequencies are used between a plurality of adjacent zones, that is, cells, to avoid radio wave interference. In order to effectively utilize a limited frequency band, it is preferable to subdivide the zone configuration and use the same frequency repeatedly. However, the fragmentation of zone configurations increases the frequency of frequency switching associated with movement across zones, placing the burden of frequency switching control on both base stations and mobile stations. I see, it's quite remarkable. To solve this problem, in conventional cellular systems, it was necessary to widen each zone or increase the allocated frequencies. However, as is well known, increasing frequency allocation is extremely difficult.

Conventional cellular car phone systems are designed primarily for voice communications, so they are not necessarily suitable for services that transmit large amounts of data at high speeds. In order to efficiently manage the navigation of large numbers of vehicles and guide them to appropriate routes depending on congestion and weather conditions,
It is necessary to transmit large amounts of data at high speed between vehicles and ground base stations. Conventional car phone systems are not necessarily suitable for a wide variety of services, including high-speed data communications, because the frequency of transmission signals is limited to the voice band.

Furthermore, each time a call arrives, each base station makes a simultaneous call, and after the mobile station responds, the incoming call is connected, making connection control for incoming calls complicated and requiring a relatively long time to set up the connection. Ta. Furthermore, since the current location of a mobile object cannot be known unless the mobile station receives a call individually, it is not suitable for a user such as a transport company that owns a large number of vehicles to efficiently manage the transportation of those vehicles. .

Therefore, if multiple base stations that wirelessly link with a mobile station are placed apart from each other with no radio waves interposed between adjacent base stations, these base stations can transmit a single radio wave as the wireless link radio wave. In such mobile communication systems that may be able to use frequencies, the base stations that can communicate with a mobile station change as the mobile station moves, so it is difficult to properly communicate with the target mobile station. The system must always know the current location of the mobile station.

In view of such demands for mobile communication, it is an object of the present invention to provide a mobile communication system that can appropriately manage the status of a mobile station, including communication with the mobile station.

(Means and effects for solving the problem) According to the present invention, a mobile station and a communication port &!
In a mobile communication system including a plurality of ground stations forming #1, a mobile station is registered with one of the plurality of ground stations, and when one of the plurality of ground stations detects the mobile station, one of the plurality of ground stations The mobile station's location a is notified to the ground station where the mobile station is registered, and the ground station where the mobile station is registered is 1.
The notified location of the mobile station is stored, and by detecting and reporting the location of the mobile station, the stored contents of the ground station where the mobile station is registered are constantly updated.

For example, when communicating with a mobile station, the location stored for that mobile station is obtained at the ground station where the mobile station associated with the communication is registered.

Therefore, the mobile station communicates with the mobile station through a nearby ground station. In this way, as long as the target mobile station is active, including communication with it (Embodiment) Next, an embodiment of the mobile communication system according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 shows an embodiment in which the mobile communication system according to the present invention is applied to land transportation, particularly road traffic for vehicles including automobiles, as a road-to-vehicle individual communication system. In this embodiment, a plurality of roadside stations 1O are usually arranged at predetermined intervals, for example, at intervals of several hundred meters to several kilometers, along a general road or expressway. This interval may be set to an appropriate value depending on, for example, the vehicle speed allowed on the road. The roadside station 10 is a ground station that functions as a base station that communicates wirelessly with the subscriber vehicle 12 on the road. .

The road 10 has a transmitter/receiver 14, which transmits and receives radio waves 18 to and from a mobile station mounted on a subscribing vehicle 12, that is, an in-vehicle device IEI (FIG. 3), and transmits and receives radio waves 18 to and from its service area, that is, a zone 20. It communicates with the vehicle 12 existing inside. One of the characteristics of this embodiment is that the size of the zone 20 is much smaller than the arrangement interval of three roads 10, and the road stations 10 are arranged intermittently.

Its diameter may be, for example, on the order of several tens of meters to 100 meters. Therefore, two adjacent zones 20
In between, there is an area where the mobile station 1G does not substantially respond to the radio waves transmitted by the road station 10, that is, a "no radio wave area", and the vehicle 12 communicates with the road station 1O only while it is included in the zone 20. Can communicate. This communication takes place at high speed.

As will be seen from now on, in this method, the same frequency can be repeatedly and effectively used for the three adjacent roads 10. Therefore, basically, the road station IO and the mobile station 1
6, it is sufficient to use a single frequency for the entire system. In the case of a system that enables full-duplex communication, a pair of different frequencies are used for upper and lower frequencies.

This eliminates the need for frequency zone switching as in conventional cellular systems.Because of these characteristics, this system is called an "intermittent minimum zone system," and zone 20 is called a "minimum zone."

The roadside station IO constitutes a part of the road-to-vehicle individual communication line network 22, and in this embodiment, data exchange 49.1l1 such as the general telephone line network 24 and the general packet switching network is carried out via the line network 22.
125, a system center 26 and a user center 28. In this embodiment, the road-to-vehicle individual communication line network 22 has a station hierarchy configuration as illustrated in FIG. A communications network that performs switching or exchange. This will be explained in detail later.

With such an intermittent minimum zone method, it is possible to increase the speed of communication between the mobile station and the roadside station 1O, and a variety of services including high-speed data communication are provided. For example, the road-to-vehicle individual communication network 22 is used for navigation purposes that guide member vehicles 12 such as cars to appropriate routes depending on road congestion and weather conditions, and for the purpose of efficiently managing the operation of a large number of vehicles 12. Data communication can take place between the centers 26 and 28 and the mobile station 16 via the mobile station 16.

Referring to FIG. 3, the road-to-vehicle individual communication line network 22 in this embodiment includes a district station 30 that accommodates a plurality of roadside stations 1O located in a certain area, and a district station 30 that connects a plurality of district stations 30 over a certain area. It has a hierarchical structure consisting of regional stations 32 and a general office 34 that accommodates several of these regional stations 32. These exchanges 3 including the roadside station 10
0.32.34 is called the ground station. In this embodiment, the lines between the district stations 30, the regional stations 32, and the general office 34 form a tree-like line network consisting of trunk lines and trunk lines 36 such as diagonal lines. The present invention is not limited to this other form, but can also be applied to station hierarchy configurations depending on road types such as general roads and expressways, and other forms such as linear networks. Needless to say, it may take any other form.

Three trunk lines for the general public telephone network 24 and the data exchange network 25 are housed in the central office 34, for example.

The system center 26 is, for example, an information processing system that processes navigation for the participating vehicle 12. Further, the user center 28 is an information processing system that independently manages the operation of the subscribed vehicles 12 belonging to a specific user. Of course, these are regional stations 32 and district stations 30.
may be connected to.

General Bureau 34. Regional stations 32 and district stations 30 each have a unique station code. Among them, by representing the codes of the general station 34 and the regional station 32 in a station hierarchy structure, the registered ground station code 52 (fourth
) is formed. For a subscriber vehicle 12 of a large user who owns a large number of subscriber vehicles 12, a user code unique to that user may be used instead of the local station code.
The mobile station 16 mounted on the participating vehicle 12 is registered, for example, with a regional station 32, and is assigned a unique mobile station code 54 at the local station 32. Therefore, nationwide, the on-vehicle device or mobile station 16 is identified by the ground station code 52 and the mobile station code 54. In addition, participating vehicles 12
may be registered at the general office 34 or the district office 30.

The identification code for identifying the mobile station 16, that is, the vehicle-specific code, is composed of a static code 50 and a dynamic code 60 in this embodiment, as shown in FIG. The static code 50 is a code that identifies the mobile station 16 registered in the regional station 32, and includes a ground station code 52, a mobile station code 54,
The system code 56 includes a system code 56 for identifying this system.The system code 56 is a code that specifies this system to distinguish it from other systems, and may be omitted inside this system. In addition to functioning as an identification number for each mobile station 16 within this system, it also functions closely with the numbering system used when a call is received from the general telephone line network 24, data switching network 25, or center 26, 28 to the mobile station 16. There is a relationship.

The mobile station 16 of the participating vehicle 12 has a vehicle code generator 130 (
3), which is the functional unit that generates the vehicle code assigned to the mobile station 16. This vehicle hood includes a ground station code 52 that identifies the registration station where the mobile station 16 is originally registered, and a mobile station code 54 of the mobile station 16. These codes are sent to the vehicle code generator 130. The information is set, read out, and transmitted in response to polling from the roadside station 10, which will be described later.

For example, as shown in FIG. 1, it is assumed that a mobile station 1B is registered in one regional station B1 accommodated in a central station A1. Ground station code 52 that identifies the area station 32
is rA+B+J, and if the mobile station code 54 of the mobile station 16 in that area station is 1MO3J, then the mobile station is specified by the static vehicle code rA+B+No3J.

The dynamic code 60 is a code corresponding to the movement state of the joining bundle 1i 1912, and is effectively used to grasp the current situation of the joining vehicle 12 and navigate. therefore,
It is a vehicle-specific code related to the driving area and movement status of the subscribed vehicle 12, and is used to search the vehicle location for individual communication from the general telephone line network 24, data exchange network 25, and center 26, 28, and to use the subscribed vehicle. Therefore, in this embodiment, the destination code 62 indicating the operation destination of the participating vehicle 12 plays an important role in providing route guidance information to the 12 travel destinations.
and a driving area code 64 indicating the current driving area.
In this embodiment, the driving location area code 64 includes the station codes of the general station 34, the regional station 32, the district station 30, and the roadside station IO. In addition to this, a link code that specifies the set communication link may also be included.

In this embodiment, as shown in FIG.
0 is prepared in the regional station 32. Running vehicle table 8
0 stores data indicating the current driving area of the local station's member vehicles 12 registered as belonging to the local station 32, by station area, and data indicating the current driving area of the local station's participating vehicles 12 registered as belonging to the local station 32. The data of the subscriber bundle 1ifi12 is stored for each registered station. These data in the running vehicle table 80 are constantly updated. A similar vehicle table is
For example, it may be provided at the district office 30 and the general office 34 as well.

As conceptually shown in FIG.
is arranged, which is a passing vehicle table 82 (FIG. 3).
The zero passing vehicle table 82 includes a storage area in which information to be transmitted and received with the mobile station 16 is stored.
It holds data regarding participating vehicles 12 passing through the minimum zone 20 of . These data are vehicle specific code 50
and BO, and is constantly updated as the joining vehicle 12 passes.

In this embodiment, the mobile station 1B is a subscriber vehicle 12 such as a car.
This is an in-vehicle device that is mounted on a vehicle and transmits and receives data such as navigation information and operation management information, messages, and image signals to and from a roadside station IO, and displays these signals visually and/or audibly to passengers. Preferably, the vehicle is equipped with a video display, a facsimile transmitting/receiving device, a voice synthesizing device, etc., which provide an image and audio interface to the passenger. Furthermore, the mobile station 1B, which may have an automatic operation control function for the control mechanism of the participating vehicle 12, has a random number table function, and according to this function, in response to polling from the road station 10, the mobile station 1B communicates with the road station IO. An available free channel is selected by the road station 10 from among a plurality of channels on the link 18 .

Joined vehicle! Communication between the mobile station 16 of No. 2 and the base station 1O is carried out by polling using a frame 10G having a format as illustrated in FIG. millisecond (+wg)
, the transmission rate is 512 bits/second, and multiple channels are multiplexed into a number of time slots.

In principle, the required bidirectional communication is completed within this 1 frame period. A single frequency is used for wireless link 18. In the case of full-duplex communication, a pair of different frequencies are used for upper and lower frequencies. However, these frequencies may be fixed, and the same frequencies are used no matter which roadside station 10's zone 20 the subscribing vehicle 12 moves to.

An introduction section 102 is located at the beginning of the frame 100, and includes a preamble, a synchronization signal, a polling identification signal, a code for the road station 10, and the like.

Using this, the roadside station 10 polls the mobile station 16 within the zone 20 at a predetermined period, as shown in FIG.

The mobile station 1B is in the receiving mode in the idle state, and becomes the transmitting mode when the introduction section 102 completes the reception.

The introduction section 102 is followed by a vehicle recognition section 104, which includes:
Mobile station 1B responds to polling with vehicle specific code 50.
This is the period during which the road station IO recognizes this. Advantageously? By performing block repetition transmission, the recognition rate of participating vehicles 12 is significantly improved. Mobile station 16 selects one of the plurality of channels from a random number table in response to polling. In response to the polling, the vehicle code generation unit 130 of the mobile station lθ generates the ground station code 52 and mobile station code 54 set therein and registered for the mobile station 16, and uses this channel number k to generate a static The information is transmitted to the roadside station 10 as a vehicle-specific code 50 or a service machine part code (see FIG. 6).

For example, in the example shown in FIG. 1, it is assumed that eight roadside stations 10 are accommodated in one district station C1 housed in regional station AOB+, and station code opening O''D7 is assigned to each of them. 6th street station from the left 1
0 is designated by the station code rAoB+c+DsJ. In this example, the static vehicle code 50 is rAIBIMO3J
When the mobile station 1B increasing its number is polled while passing through the zone 20 of the road stations AoB+C+Ds, the mobile station 16 returns the identification code rAIBIMO3J as the ground station code 52 and the mobile station code 54.

The mobile station 16 travels in the direction of the arrow and reaches the next road station AoBu.
:+06, the mobile station 16 receives polling from the roadside station AoB+CID6 in the same manner as described above, and returns the vehicle code rJIBIMB J.

In this way, as the mobile station AIBIMO3 moves, the successive paths hmlO on its path are successively connected to the mobile station AIBIMO3.
Receive vehicle code rAIB+Mo3J from MO3.

Returning to FIG. 5, in this embodiment, a relay communication unit 10B is arranged following the vehicle recognition unit 104, and this is used to communicate with the roadside station.
0, beacon-type dynamic navigation information such as traffic information, and a registration response signal (CACK or NACK) are transmitted to the mobile station 1B. If the channel selected by mobile station 1B does not conflict with any other channel, it is registered in road station 10 and an ACK signal is transmitted to mobile station IB.

This is followed by the vehicle communication section 108, whereby full-duplex communication is performed between the roadside station 10 and the mobile station 1B in this embodiment. The frequencies are different for the upper and lower stations, and a channel designated by the road station IO is used. However, even if the subscribing vehicle 12 moves to the zone 20 of the adjacent roadside station 10, the same frequency is used. Of course, half-duplex or unidirectional communication may be used, and the vehicle communication unit 108 exchanges data such as navigation information and operation management information, messages, and image signals between the mobile station 16 and the system center 26 or user center 28. is transmitted and received, and the information is displayed to the passenger of the participating vehicle 12 in the form of images and sounds. Communication with the general telephone line network 24, data exchange network 25, or other mobile stations 16 within this system is performed in the same manner.

The roadside station 10 may hold data on the participating vehicles 12 obtained from the mobile stations 16 within the zone 20 in the passing vehicle table 82 at each polling cycle.

The roadside station 10 transfers these data to a district station 30, a regional station 32, or a general station 34 through a line 36. These stations store the thus transferred data in, for example, a running vehicle table 80. In this way, for example, the traveling vehicle table 80 of the regional station 32 is constantly updated with new data.

To explain in more detail, as shown in Figure 3, the district office 30
is equipped with a ground station code 52 that specifies the district station 30, and a station code generator 132 that generates a road station code that specifies the road station 10 within its jurisdiction.

For example, in the district station AOBICI shown in FIG. 1, rAoB+c+J is set as the ground station code 52 in the station code generator 132. The vehicle code rAIBi4oaJ of the mobile station 16 received by the roadside station AoB+C1s is temporarily stored in the passing vehicle table 82 of the roadside station IO, and then transferred to the upper district station AoB+(+. As shown in FIG. The district office AOBICI recognizes this vehicle code rAIBIM.
From O3J to regional station AI whose registered station belongs to general station A1
Identifies that it is Bl, and sets the vehicle code rA+B+Mo
3J to regional station AIB+. At this time, the district station Ao B+ (+ transmits the location information of its own station and the roadside station 10 that detected the mobile station 10 as information indicating the current location of the mobile station 16. This location information is dynamically Vehicle code 60 includes its ground station code rAoB+(:+J) and roadside station code "D5" in the form of driving area code 64.

The exchanges in the L position of the district station AOBIC:l, for example the regional station AoBI, and the central stations AO and A1, transfer the vehicle code rAIBulo of the mobile station location data to be transferred:
+ J to identify its destination and relay it to its registration station, in this example regional station AIBI. Upon receiving the mobile station location data, that is, the static vehicle code 50 and the dynamic vehicle code 60, the registration station AIB+ identifies the target mobile station 16, based on the mobile station code 54.
That is, in this example, station MO3 is identified and these position data are stored in the corresponding storage location of the traveling vehicle table 80.

The current location data of the mobile station 16 is constantly updated.

Focusing on a specific mobile station, for example MO3, its location data is transmitted to the district station 30 as described above each time any roadside station 10 detects the mobile station MO3.
is reported to the registration station AIB+, and the traveling vehicle table 80
The stored contents of mobile station MO3 are updated.

In this embodiment, each time the mobile station 16 moves between two roadside stations 10, it reports its position to the registration station. In that case, the driving location area code 64 as the current location data to be reported to the registration station may include a roadside station code, in this example "D5". AoB+G+0
6 to zone 20, the latter street station AoB+C
+06 detects this by polling, stores the mobile station code rAIBIMO3J in the passing vehicle table 82, and reports this to the district station AOBICI. The district station AOBICI notifies the registration station AIB+ of the driving area code rAoB+ci6J including the roadside station code "D6" as new location information of the mobile station AIBIMO3. Although this method requires a relatively large amount of communication traffic for reporting the current location of the mobile station 16 and the processing load of updating and maintaining it at the registration station, it has the advantage that the current location of the mobile station 16 can be accurately measured at all times. .

Instead of doing this, it may be configured such that when any of the district stations 30 detects the specific mobile station 03 for the first time via the road station 10 within its jurisdiction, it reports this to the registration station AIB+. In that case, the driving area code 64 may be up to the district office code without including the on-road station code. For example, mobile station A
Assume that IBIMO3 continues to travel, passes the street station AoB+C+DI at the end of district station AoBIC1, and enters zone 20 of the first street station AOBIC211° of another adjacent district station AOBI02. This street station AoB+C? D
o reports the vehicle code 50 of the mobile station AlB1Moa to the upper district station AOBIC2, which registers it in the passing vehicle table 82. At that time, the district office
It is checked whether this vehicle code rA+B+Mo3J has been stored in the passing vehicle table 82 so far. If it is determined that it has not been stored, the higher regional station AOB
+ to the registration station AIB+. In this case, the station code rAOBlc2J up to the district station 30 is sufficient as the current location data. In this method,
Communication traffic for reporting the current location of the mobile station 16 is reduced, and the processing of running location management at the registration station is simplified.

Information addressed to the mobile station 16 from the center 28, 28, the general telephone line network 24, and the data exchange network 25 is temporarily stored in the memory 42 of one of the ground stations, for example, the road station IO. The roadside station 10 compares the static vehicle-specific need 50 obtained from the mobile station 16 within its jurisdiction with the destination code of the transmission information, and determines whether there is information to be transmitted to the corresponding mobile station 16. 0 When a match is detected, memory 4 is
The information stored in the mobile station 2 is transmitted to the mobile station 16 using the downlink channel of the vehicle communication section 108. Information transmitted from the mobile station 16 via the uplink channel is stored in the memory 4.
Temporarily stored in 2. This upstream transmission information is later transferred to the center 26, 28, the data exchange network 25, or the general telephone network 24 via the road-to-vehicle individual communication network 22.

When the vehicle communication section 108 finishes, a communication completion section 110 that transmits upper and lower response signals follows. This is a signal confirming the completion of the transmission, not confirmation of the information content.

In this way, one frame 100 of communication is performed while the participating vehicle 12 is traveling within the service zone 20 of the roadside station 10. While the subscribing vehicle 12 is traveling in a radio-free area between two adjacent zones 20, the mobile station 16 cannot communicate with the road-to-vehicle individual communication network 22, using a single frequency. This may make one think of a conventional leaky coaxial cable broadcasting system, but this embodiment is not a broadcasting system, but an individual communication system, and moreover, it is different from a leaky coaxial cable broadcasting system in that there is no radio wave area. It is fundamentally different from that.

In principle, this embodiment is configured such that one communication is completed while the joining vehicle 12 is included in a certain minimal zone 20. Whether it is a general road or an expressway, as long as you are driving normally on that road, several minimal zones 20 are added across the above-mentioned no-radio wave area.
Roadside stations 10 are arranged along the road at such intervals that a considerable amount of communication can be carried out as the Q12 travels. In other words, by arranging the roadside stations 1O in such a remote manner, it is possible to achieve sufficient communication even with the mobile station 12 with a large amount of communication traffic.

By the way, the sequence in which a call arrives from the center 26 or 28 to the mobile station AI BIMo3 using the mobile pre-n data that is constantly updated at the registration station AIB+ will be schematically explained with reference to FIG. Messages addressed to the mobile station AIBIMO3 from the center 26 or 28 are sent via the central station 34 to the registration station A with a header in the form of a static vehicle-specific code 50 containing its destination code rA+B+Mo3J.
Sent to +81. This message transfer is performed by identifying the destination code rA+B+Mo3J of the message at each relay station. When the registration station AIB+ receives this message together with the header, it checks the registration qualification of the mobile station AIBIMO3 to receive the call based on its destination code, and if it satisfies this, it stores the message in a memory (not shown) for a period of time. At this time, the registration station AIB+ returns a reception confirmation response to the center 2e or 28 (140), although it is not shown in the figure.

Then registration station A! 81 refers to the running vehicle table 8o and determines the destination mobile station AIBIMO from the mobile station position data.
Check the current position of 3. As a result, the mobile station AIBIMO
3(') If the current location is found to be, for example, rAoB+c+DsJ, the registration station AIB+ will now assign the address rAoB+[+J of the district office 30 to the driving area need 6
A dynamic vehicle specific code 6o to be included as 4 is created.

The registration station AIB reads the transmitted message from memory, adds a dynamic code 60 to its header, and sends it to the district station Ao.
Send to B+C+.

Relay stations such as the central station 34 and the regional stations 32 identify the message's dynamic vehicle-specific code 6o and forward it to the destination station A6B+C+. District station Ao B+ C+
When it receives this message along with the header, it broadcasts it to all the over-the-air stations IO accommodated therein. This circular includes a delivery request, a message, and the destination code rAIBIMo3J of the message. Each road station 10
Upon receiving this, the message is temporarily stored in the memory 42 and the mobile stations 16 included in the service zone 20 are polled. This polling is performed at the introduction section 102 of the frame 100 as described above.

The active mobile station 16 included within the service zone 20 of the roadside station 10 generates vehicle codes 50 and 6o in the vehicle code generator 130 in response to this polling;
This is sent back to the roadside station IO. This is the vehicle recognition unit 104
is used. The roadside station 10 temporarily stores the vehicle code returned from the mobile station 16 in the passing vehicle table 82, and compares the static vehicle-specific code 50 with the destination code rAIB+Mo3J of the message (142). When the two match in step 10, the station 10 reads the transmitted message from the memory 42 and sends it to the vehicle communication unit 1.
08 on the channel of the mobile station AIBIMO3. Mobile station AIBIMO3 that received the message
returns a reception confirmation response using the communication completion unit 110,
This is finally transferred to the registration station 34 via the ground station.

If the reception acknowledgment includes an acknowledgment ACK, district station A;
BIC cancels the delivery request to other roadside stations 10.

The remaining roadside stations 10 whose vehicle codes do not match in step 142 discard the messages stored in the memory 42 under the control of the district station AOBICI, and the process ends. It should be noted that each station returns an acknowledgment response at each stage of this mobile station incoming sequence, but this is not shown in FIG. 7 to avoid complication of the diagram.

To summarize, in this embodiment, each mobile station 1B is registered in advance with a specific ground station. The registration station is notified of its current location by the ground station that detected the mobile station 16 registered therein, and holds current location data. This current position data is constantly updated in real time. When incoming a call to a mobile station 16, the registration station where the mobile station 16 is registered is accessed to determine its current position, and the incoming call is connected to the mobile station 18 from the nearby roadside station 10.

An embodiment in which the present invention is applied to a road-to-vehicle individual communication system has been described. However, the present invention is not limited thereto, and can be effectively applied to individual communication with any moving object other than a vehicle, such as an individual, ie, a pedestrian in a broad sense.

Note that the embodiments described here are for illustrating the present invention, and the present invention is not necessarily limited thereto. Modifications are within the scope of this invention.

(Effects of the Invention) In the mobile communication system according to the present invention, a mobile station is registered with a specific ground station, and the current location of the mobile station, which changes from moment to moment, is managed by the registration station. As a result, as long as the target mobile station is active, appropriate management of the mobile station including communication with the target mobile station is always possible.

For example, compared to conventional car telephone systems, since there is no simultaneous calling from each base station, connection control for incoming calls is simple and connection setup time is short. In addition, since the current location of a moving object is always known, network services can be used to meet the demands of large users who want to know the moving location of a large number of vehicles in real time for the purpose of efficient operation management. I can handle it.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram schematically showing a mobile communication system according to the present invention, and Fig. 2 shows an embodiment in which the mobile communication system according to the present invention is applied to road traffic for vehicles as a road-to-vehicle individual communication system. 3 is a conceptual block diagram showing an example of the station hierarchy configuration of the road-vehicle individual communication network in the embodiment shown in FIG. 2. FIG. 4 is an example of the format of the vehicle-specific code in the embodiment. FIG. 5 is an explanatory diagram showing an example of a frame format in the same embodiment. FIG. 6 is a sequence diagram showing an example of a sequence for detecting the position of a mobile station in the same embodiment. FIG. 3 is a sequence diagram showing an example of a sequence of incoming calls to a mobile station. Explanation of symbols of main parts 10, Roadside station 12, Participating vehicle 14, Transmitter/receiver 20, Minimum zone 22, Road-to-vehicle individual communication network 30.32,
34. Switching station, ground station 42, Memory 80, Traveling vehicle table 82, Passing vehicle table 130, Vehicle code generation unit 132.
, Bureau code generation section Patent applicant Oki Electric Industry Co., Ltd. Agent Katori Takao Maruyama Takao Gaishinkai Individual Toryo Gorin) Okinaka Usuba, Nanatsuichi Donnodomame) Example No. J Figure - to p- +02 104 106 108
1!0fu L-Muftma, toy guy Figure 5

Claims (1)

[Scope of Claims] A mobile communication system including a mobile station and a plurality of ground stations forming a communication line network for communicating with the mobile station, wherein the mobile station is connected to any one of the plurality of ground stations. When one of the plurality of ground stations detects the mobile station, one of the plurality of ground stations notifies the station to which the mobile station is registered among the plurality of ground stations of the location of the mobile station, and The ground station to which the station is registered stores the notified location of the mobile station, and the memory content of the ground station to which the mobile station is registered is constantly updated by detection and notification of the location of the mobile station. A mobile communication system characterized by: