JP2670086B2 - Mobile station location detection system for mobile communications - Google Patents

Description

The present invention relates to a mobile communication system, and more specifically to a system for detecting the position of a mobile station in mobile communication suitable for communication with a vehicle such as an automobile. Regarding

(Prior Art) As a conventional mobile communication system to which the present invention is particularly relevant, there is, for example, a car telephone system. As is well known, in a conventional car telephone system, base stations covering a predetermined service zone are two-dimensionally arranged, and the zones of adjacent base stations partially overlap with each other.
There is a cellular system that guarantees continuity of communication with a mobile body.

(Problems to be Solved by the Invention) In the cellular system, different frequencies are used between a plurality of adjacent zones, that is, cells, in order to avoid radio wave interference. In order to effectively use the limited frequency band, it is preferable to subdivide the zone structure and repeatedly use the same frequency. However, the subdivision of the zone structure increases the frequency of frequency switching accompanying movement across the zones, and imposes a frequency switching control burden on both the base station and the mobile station. This tendency becomes more remarkable as the moving speed of the moving body increases. In order to solve this problem, it has been necessary in the conventional cellular system to widen each zone or increase the allocated frequency. However, as is well known, increasing the frequency allocation is very difficult.

The conventional cellular car telephone system is designed mainly for voice communication, and is not necessarily suitable for the service purpose of transmitting a large amount of data at high speed. For example, in land transportation such as automobiles, in order to efficiently manage the navigation that guides the route to an appropriate route according to the road congestion and weather conditions, and the efficient management of the operation of a large number of vehicles, the It is necessary to transmit a large amount of data at high speed. The conventional car telephone system is not necessarily suitable for various services including such high-speed data communication because the frequency of the transmission signal is limited to the voice band.

In addition, since the current position of the moving body cannot be grasped unless the mobile station individually receives the call, it is not suitable for a user having many vehicles such as a carrier to efficiently manage the operation of those vehicles. .

Therefore, multiple base stations wirelessly linked to the mobile station
If base stations are spaced apart from each other with a no-radiation area interposed between them, these base stations will be able to use a single frequency as the radio wave of the radio link. In such a mobile communication system, the base station that can communicate with the mobile station changes with the movement of the mobile station. Therefore, in order to properly communicate with the target mobile station, the system must be the current mobile station. It is necessary to keep track of the position.

In view of the demand for such mobile communication, the present invention has
An object of the present invention is to provide a mobile station position detection system that enables appropriate communication with a target mobile station in a new mobile communication system capable of high-speed communication without occupying many frequencies.

(Means and Actions for Solving the Problems) A mobile station position detection system for mobile communication according to the present invention accommodates a plurality of base stations each communicating with a mobile station via a wireless link, and a plurality of base stations. A plurality of exchange stations forming a communication circuit network for exchanging communication with these base stations, and those close to each other among the plurality of base stations have an area in which the mobile station does not substantially respond to the radio wave of the wireless link. Interleaved with each other, the mobile station is registered in any of the plurality of exchange stations in association with an identification code that identifies the mobile station. The mobile station generates an identification code and transmits it to any of the plurality of base stations. Upon receiving the identification code from the mobile station via the base station, one of the plurality of exchanges adds the information regarding the position of the mobile station to the identification code and transfers the identification code to the exchange with which the mobile station is registered. .
The registration exchange stores the transferred position information in association with the identification code of the mobile station.

For example, when communicating with a mobile station, the switching station in which the mobile station related to the communication is registered refers to the information regarding the position stored for the mobile station. Therefore, the mobile station communicates with the mobile station through the base station corresponding to this position information.

(Embodiment) Next, an embodiment of a mobile station position detection system for mobile communication according to the present invention will be described in detail with reference to the accompanying drawings.

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

The roadside station 10 has a transmitter / receiver 14, which transmits and receives radio waves 18 to and from a mobile station mounted on the subscribing vehicle 12, that is, a vehicle-mounted device 16 (FIG. 3), and its service area or zone.
It communicates with the vehicle 12 existing within 20. One of the characteristics of this embodiment is that the size of the zone 20 is much smaller than the arrangement interval of the roadside stations 10 and the roadside stations 10 are intermittently arranged. The diameter may be, for example, on the order of tens of meters to 100 meters. Therefore, between two adjacent zones 20, there is a region where the mobile station 16 does not substantially respond to the radio waves transmitted by the roadside station 10, that is, a "no radio wave region", and the vehicle 12 is included in the zone 20. It is possible to communicate with the roadside station 10 only while it is present. This communication is performed at high speed.

As can be seen from this, in this method, adjacent road stations
The same frequency can be effectively used repeatedly for 10. Therefore, it is basically sufficient for the radio link between the road station 10 and the mobile station 16 to use a single frequency throughout the system. In the case of a system that enables full-duplex communication, a pair of frequencies that are different from each other above and below are used. This eliminates the need for frequency zone switching as in the conventional cellular system. Due to these characteristics, this method is called the "intermittent minimum zone method", and the zone 20 is called the "minimum zone".

The roadside station 10 constitutes a part of the road-to-vehicle individual communication network 22,
In this embodiment, the general telephone line network 24,
It is possible to access other communication facilities such as a data switching network 25 such as a general packet switching network, a system center 26 and a user center 28. In the present embodiment, the road-to-vehicle individual communication network 22 has a station-level structure as illustrated in FIG.
General telephone line network 24, data exchange network 25 and centers 26, 28
Is a communication network that performs switching, that is, exchange between the mobile station 16 and the mobile station 16. This will be described in detail later.

In such an intermittent minimum zone system, communication between the mobile station 16 and the roadside station 10 can be speeded up, and various services including high speed data communication can be provided. For example,
For the purpose of navigation that guides the subscribing vehicle 12 such as a car to an appropriate route according to road congestion and weather conditions, and for the purpose of efficiently managing the operation of a large number of vehicles 12, through the road-vehicle individual communication network 22. Data communication can be performed between the centers 26 and 28 and the mobile station 16.

Referring to FIG. 3, the road-to-vehicle individual communication line network 22 in this embodiment is composed of a plurality of road stations arranged in a certain area.
It has a hierarchical structure composed of a district station 30 in which 10 are accommodated, a regional station 32 in which a plurality of district stations 30 are accommodated over an area, and a general station 34 in which several of these regional stations 32 are accommodated. These exchanges 30, 32, 34 including the roadside station 10 are referred to as ground stations. In the present embodiment, the line between the district station 30, the regional station 32, and the general bureau 34 forms a tree network consisting of trunk lines 36 such as trunk lines and diagonal lines, and the network between the general bureaus 34 is a network. Form a type network. It is needless to say that the present invention is not limited to this network form, and may have a local hierarchy structure according to the road form such as an ordinary road or an expressway, and other forms such as a linear network. Yes.

The trunk line 38 for the general public telephone line network 24 and the data exchange network 25 is accommodated in the general bureau 34, for example. The system center 26 is, for example, an information processing system that processes navigation of the joining vehicle 12. User Center 28
Is an information processing system for independently managing the operation of the belonging vehicles 12 belonging to a specific user. Both are housed in a general bureau 34 by a trunk line 40. Of course, these may be connected to the regional stations 32 and 30.

The general bureau 34, the regional bureau 32 and the regional bureau 30 each have a unique station code. By representing the codes of the general bureau 34 and the regional station 32 among them in the station level structure, the registered ground station code 52 (FIG. 4) for identifying the regional station 32 is formed. For a large number of users' vehicles 12 that have a large number of vehicles 12, a user code unique to the user may be used instead of the regional station code. The mobile station 16 mounted on the joining vehicle 12 is registered in, for example, the regional station 32, and a unique mobile station code 54 is assigned to the regional station 32. Therefore, nationwide, the in-vehicle device or mobile station 16
Are identified by ground station code 52 and mobile station code 54. The joining vehicle 12 may be registered in the general bureau 34 or the district bureau 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. Static code 50 is regional station 32
The code is a code that identifies the mobile station 16 registered in, and includes a ground station code 52 and a mobile station code 54, and a system code 56 for identifying this system. The system code 56 is a code for designating the present system distinguished from other systems, and may be omitted inside the present system.
Therefore, in addition to the function as the identification number of each mobile station 16 inside the system, the static code 50 is added to the mobile station 16 from the general telephone line network 24, the data exchange network 25 or the centers 26 and 28. It is closely related to the number system of.

The mobile station 16 of the subscribing vehicle 12 uses the vehicle code generation unit 130 (the third
), Which is the functional part that generates the vehicle code assigned to that mobile station 16. This vehicle code contains
The mobile station 16 includes a ground station code 52 for specifying a registration station where the mobile station 16 is originally registered, and a mobile station code 54 of the mobile station 16. These codes are set in the vehicle code generation unit 130, and are read and transmitted in response to polling from the road station 10 described later.

For example, as shown in FIG. 1, the mobile station 16 is assumed to be registered in the one region stations B ₁ contained in the regional centers A _1. The ground station code 52 that identifies the regional station 32 is "A
₁ B ₁ ”, and the mobile station code 54 of the mobile station 16 in the regional station is“ M ₀₃ ”, the mobile station is identified by the static vehicle code“ A ₁ B ₁ M ₀₃ ”. It

The dynamic code 60 is a code corresponding to the moving state of the joining vehicle 12, and is effectively used for grasping the current situation of the joining vehicle 12 and navigating. Therefore, the joining vehicle 12
It is a vehicle-specific code related to the traveling area and movement situation of the general telephone line network 24, data exchange network 25 and center 26,
Search for vehicle location for individual communication from 28, joined vehicle 12
It plays an important role in providing route guidance information to travel destinations. Therefore, in the present embodiment, a destination code 62 indicating the operation destination of the joining vehicle 12 and a travel destination area code 64 indicating the current travel destination area are included. Driving area code 64
Consists of station codes of the general bureau 34, regional bureau 32 and district bureau 30. In addition, a link code for specifying the set communication link may be included.

In this embodiment, as shown in FIG.
80 are provided in the regional office 32. In the traveling vehicle table 80, data indicating the current traveling area of each of the participating vehicles 12 of the own station registered as belonging to the local station 32 is stored for each station area. Data on the subscribed vehicles 12 traveling in the area is stored for each registration authority. These data in the traveling vehicle table 80 are constantly updated. Similar vehicle tables may be provided, for example, at the district office 30 at the general office 34.

As conceptually shown in FIG. 2, a memory 42 is provided in the road station 10 and includes a passing vehicle table 82 (FIG. 3),
It includes a storage area in which information to be transmitted to and received from the mobile station 16 is stored. The passing vehicle table 82 holds data on the joining vehicles 12 passing through the minimum zone 20 of the road station 10.
These data include vehicle specific codes 50 and 60,
It is constantly updated with the passage of the subscribing vehicle 12.

In this embodiment, the mobile station 16 is mounted on a subscribing vehicle 12 such as an automobile, transmits and receives data such as navigation information and operation management information, messages and image signals to and from the road station 10, and transmits these signals to the passenger. Visible and / or
It is an in-vehicle device that performs audible display. Preferably, it is provided with a video display, a facsimile transmitting / receiving device, a voice synthesizing device, and the like that interface with the passengers by images and voice. Further, an automatic operation control function for the control mechanism of the joining vehicle 12 may be provided. The mobile station 16 has a random number table function, and in response to polling from the roadside station 10, an available free channel is selected by the roadside station 10 out of a plurality of channels in the link 18 with the roadside station 10. It

Communication between the mobile station 16 of the subscribing vehicle 12 and the base station 10 is carried out by polling with a frame 100 having a format as shown in FIG. 5 in this embodiment. In this embodiment,
Frame 100 has a cycle of 683 milliseconds (ms) and a transmission rate of 512K
At bits per second, multiple channels are multiplexed into the multiple timeslots they contain. In principle, required bidirectional communication is completed within this one frame period. A single frequency is used for wireless link 18. In the case of full-duplex communication, a pair of frequencies that are different from each other at the top and bottom are used.
However, those frequencies may be fixed, and the same frequency is used regardless of which on-road station 10 zone 20 the joining vehicle 12 moves to.

At the beginning of the frame 100 is an introductory part 102, which is
It includes a preamble, a synchronization signal, a polling identification signal, a code of the roadside station 10, and the like. Road station 10 using this
Polls the mobile station 16 in the zone 20 at a predetermined cycle, as shown in FIG. The mobile station 16 is in the reception mode in the idle state, and is in the transmission mode after the reception of the introduction unit 102 is completed.

The introduction 102 is followed by the vehicle recognizer 104, which includes the vehicle-specific codes 50 and 60 in response to the mobile station 16 polling.
Is transmitted and the roadside station 10 recognizes this. Advantageously, by performing the two-block repetitive transmission, the recognition rate of the joining vehicle 12 is significantly improved. The mobile station 16 selects one of the plurality of channels from the random number table in response to the polling. In response to the polling, the vehicle code generation unit 130 of the mobile station 16 generates the ground station code 52 and the mobile station code 54 which are set in the mobile station 16 and registered, and statically using this channel. It is transmitted to the roadside station 10 as a vehicle-specific code 50 or a service function code (see FIG. 6).

For example, in the example of FIG. ₁ , eight regional road stations 10 are accommodated in one regional station C ₁ accommodated in the regional station A ₀ B ₁ , and station codes D _{0 to} D ₇ are respectively assigned to them. And The sixth road station 10 from the left in the figure is designated by the station code “A ₀ B ₁ C ₁ D ₅ ”. In this example, the mobile station 16 having "A ₁ B ₁ M ₀₃ " as the static vehicle code 50 is a roadside station A ₀ B ₁ C.
_When being polled while passing through the ₁ D ₅ zone 20, the mobile station 16 returns the identification code "A ₁ B ₁ M ₀₃ " as the ground station code 52 and the mobile station code 54.

Returning to FIG. 5, in the present embodiment, a broadcast communication unit 106 is arranged following the vehicle recognition unit 104, and using this, a beacon type dynamic navigation information such as traffic information from the roadside station 10,
And a registration response signal (ACK or NACK) is transmitted to the mobile station 16. If the channel selected by the mobile station 16 does not collide with another, this is registered in the road station 10 and an ACK signal is transmitted to the mobile station 16.

This is followed by the vehicle communicator 108, which in this embodiment provides a full duplex path between the road station 10 and the mobile station 16. The frequencies are different from each other in the upper and lower sides, and the channel designated by the roadside station 10 is used. However, even if the joining vehicle 12 moves to the zone 20 of the adjacent road station 10, the same frequency is used. Of course, half-duplex or one-way communication may be used. In the vehicle communication unit 108, the mobile station 16 and the system center 26
Data such as navigation information and operation management information, messages and image signals are transmitted and received to and from the user center 28, and the information is displayed to passengers of the subscribing vehicle 12 as images and voice. Further, communication with the general telephone line network 24, the data exchange network 25, or another mobile station 16 in the present system is similarly performed.

In the road station 10, the zone is thus set for each polling cycle.
The data of the joining vehicle 12 obtained from the mobile station 16 in 20 is temporarily held in the passing vehicle table 82, and is also transferred to the regional station 30, regional station 32 or general station 34 through the line 36. These stations store the data thus transferred in, for example, the traveling vehicle table 80. Thus, for example, regional stations
The traveling vehicle table 80 of 32 is constantly updated with new data.

More specifically, as shown in FIG.
Includes a station code generation unit 132 that generates a ground station code 52 that identifies the regional station 30. For example, in the district station A ₀ B ₁ C ₁ of FIG. ₁ , “A ₀ B ₁ C ₁ ” is set as the ground station code 52 in the station code generator 132. The vehicle code “A ₁ B ₁ M ₀₃ ” of the mobile station 16 received by the on-road station A ₀ B ₁ C ₁ D ₅ is temporarily stored in the passing vehicle table 82 of the on-road station 10 and the upper district station A ₀ Transferred to B ₁ C ₁ . District station A ₀
From this vehicle code "A ₁ B ₁ M ₀₃ ", B ₁ C ₁ identifies that the registration station is the regional station A ₁ B ₁ belonging to the general bureau A ₁ , and the vehicle code "A ₁ B ₁ M ₀₃ To the regional station A ₁ B ₁ . At that time, the regional station A ₀ B ₁ C ₁ transmits its own identification information as information indicating the current position of the mobile station 16. Road station D ₅
Identification information may be added. This location information includes its ground station code "A ₀ B ₁ C ₁ " in the form of a driving area code 64 of the dynamic vehicle code 60.

District stations A ₀ B ₁ C exchange stations in ₁ of the upper, for example, local stations A ₀
B ₁ and the general bureaus A ₀ and A ₁ identify their destinations based on the vehicle code “A ₁ B ₁ M ₀₃ ” of the mobile station position data to be transferred, and their registration stations, that is, regional stations A _{1 in} this example. Relay this to B ₁ . Registration station A ₁ B ₁ is mobile station position data,
That is, when the static vehicle code 50 and the dynamic vehicle code 60 are received, the target mobile station 16, that is, the station M ₀₃ in this example, is identified from the mobile station code 54, and corresponding to that of the traveling vehicle table 80. These position data are stored in the storage positions to be stored.

The current position data of the mobile station 16 is constantly updated. Focusing on a specific mobile station, for example, M ₀₃ , its position data is, for example, from the regional station 30 to the registration station A ₁ as described above every time one of the roadside stations 10 detects the mobile station M _03.
Reported to B ₁ , the memory content of mobile station M ₀₃ in traveling vehicle table 80 is updated. Or one of the district offices
It may be arranged to report this to the registration station A ₁ B ₁ when 30 first detects its mobile station M ₀₃ via the on-road station 10 in its service.

Information addressed to the mobile station 16 from the centers 26, 28, the general telephone network 24, and the data exchange network 25 is temporarily stored in the memory 42 of any ground station, for example, the roadside station 10. In the roadside station 10, the static vehicle specific code 50 obtained from the mobile station 16 in the service area
And the destination code of the transmission information are compared, and the corresponding mobile station
Check if there is any information to send to 16. When a match is detected, the information stored in the memory 42 is transmitted to the mobile station 1 using the downlink channel of the vehicle communication unit 108.
Send to 6. The information transmitted from the mobile station 16 through the uplink channel is temporarily stored in the memory 42. This upstream transmission information will later be sent to the center via the road-vehicle individual communication line network 22.
26, 28, data exchange network 25 or general telephone network 24.

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

Thus, communication of one frame 100 is performed while the subscribing vehicle 12 is traveling in the service zone 20 of the road station 10. The mobile station 16 cannot communicate with the road-to-vehicle individual communication network 22 while the joining vehicle 12 is traveling in the non-radio wave area between two adjacent zones 20. By using a single frequency, a conventional leaky coaxial cable broadcasting system may be envisioned. However, this embodiment is not a broadcasting system but an individual communication system to the last, and is fundamentally different from a leaky coaxial cable broadcasting system in that there is no radio wave area.

In this embodiment, in principle, the minimum zone in which the
It is configured such that one communication is completed while being included in 20. Regardless of whether it is a general road or an expressway, as long as the vehicle is traveling normally on the road, the joining vehicle 12 travels in some minimal zones 20 across the above-mentioned anechoic region, and thus is considerably cohesive. Road stations 10 are arranged along the road at intervals such that communication can be performed. In other words, such a spaced arrangement of the on-road station 10 can sufficiently achieve the required communication even for the mobile station 12 having a large amount of communication traffic.

Now, referring to FIG. 7, a sequence of incoming from the center 26 or 28 to the mobile station A ₁ B ₁ M ₀₃ using the mobile station position data constantly updated in the registration station A ₁ B ₁ will be schematically described. explain. A message addressed to the mobile station A ₁ B ₁ M ₀₃ from the center 26 or 28 is routed through the general station 34 with a header in the form of a static vehicle specific code 50 containing its destination code "A ₁ B ₁ M ₀₃ ". Sent to registration authority A ₁ B ₁ . This message transfer is performed by identifying the destination code "A ₁ B ₁ M ₀₃ " of the message at each relay station. When the registration station A ₁ B ₁ receives this message together with the header, it checks the registration qualification of the mobile station A ₁ B ₁ M _{03 which} should receive from the destination code, and if it is satisfied, stores the message in the memory ( It is temporarily accumulated (not shown) (140). Although not shown in the figure, the registration station A ₁ B ₁ returns a reception confirmation response to the center 26 or 28 at this time.

Therefore, the registration station A ₁ B ₁ refers to the traveling vehicle table 80,
The current position of the terminating mobile station A ₁ B ₁ M ₀₃ is checked from the mobile station position data. As a result, the current position of mobile station A ₁ B ₁ M ₀₃ is
For example, if it turns out to be "A ₀ B ₁ C _1, " the registration authority A ₁ B
_From this, the ₁ creates the dynamic vehicle specific code 60 including the address "A ₀ B ₁ C ₁ " of the district station 30 as the traveling area code 64. Registration station A ₁ B ₁ reads the transmitted message from memory and adds the dynamic code 60 to its header to add to district station A ₀ B ₁ C ₁
Send to.

Relay stations, such as general bureau 34 and regional office 32, identify the dynamic vehicle-specific code 60 in a message and
Transferred to the A ₀ B ₁ C _1. When the district station A ₀ B ₁ C ₁ receives this message together with the header, it broadcasts to all the road stations 10 contained therein. The broadcast includes a delivery request, and a message and a destination code of the messages include "A ₁ B ₁ M _03". Upon receiving this, each roadside station 10 temporarily stores the message in the memory 42,
Poll mobile stations 16 contained within 20. This polling is performed by the introduction unit 102 of the frame 100 as described above.

In response to this polling, the active mobile station 16 included in the service zone 20 of the roadside station 10 generates the vehicle codes 50 and 60 in the vehicle code generation unit 130 and returns the vehicle codes 50 and 60 to the roadside station 10. The vehicle recognition unit 104 is used for this.
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 unique code 50 among them with the destination code "A ₁ B ₁ M ₀₃ " of the message (142). ). When the two match at any of the roadside stations 10, the station 10 reads the transmission message from the memory 42 and transmits it using the vehicle communication unit 108 on the channel of the mobile station A ₁ B ₁ M ₀₃ . Mobile station that received the message A ₁ B ₁ M ₀₃
Returns a reception acknowledgment using the communication completion unit 110, which is finally transferred to the registration station 34 via the ground station. If the acknowledgment of receipt includes an acknowledgment ACK, district station A ₀ B
₁ C ₁ cancels the delivery request to other road station 10.

Under the control of the district station A ₀ B ₁ C ₁ , the remaining road station 10 for which the vehicle code does not match in step 142 discards the message stored in the memory 42 and ends this processing. Although each station returns an acknowledgment at each stage of the mobile station incoming sequence, this is not shown in FIG. 7 in order to avoid complication of the figure.

The embodiment in which the present invention is applied to the road-to-vehicle individual communication system has been described. However, the present invention is not limited to this, and is effectively applied to individual communication with any mobile object other than a vehicle, for example, an individual, that is, a pedestrian in a broad sense.

It should be noted that the embodiments described here are for describing the present invention, and the present invention is not necessarily limited thereto. Modifications and variations that can be made by those skilled in the art without departing from the spirit of the present invention. Modifications are included in the scope of the present invention.

(Effects of the Invention) In the mobile station position detection system for mobile communication according to the present invention, in such an intermittent minimum zone system, the current position of the mobile station, which changes momentarily, is appropriately recognized. This allows proper communication with the target mobile station at all times as long as it is active. In this method,
Various services including high-speed communication are provided without occupying many frequencies.

[Brief description of the drawings]

FIG. 1 is an explanatory view conceptually showing a mobile station position detection system for mobile communication according to the present invention, and FIG. 2 is an embodiment in which the mobile communication system to which the present invention is particularly applied is applied to road traffic of vehicles. Is a conceptual block diagram showing an individual road-to-vehicle individual communication system, FIG. 3 is a relay system diagram showing an example of a station floor configuration of an individual road-to-vehicle individual communication network in the embodiment shown in FIG. 2, and FIG. FIG. 5 is an explanatory view showing an example of a format of a vehicle-specific code in the embodiment, FIG. 5 is an explanatory view showing an example of a frame format in the embodiment, and FIG. 6 is an example of a sequence for detecting the position of a mobile station in the embodiment. FIG. 7 is a sequence diagram showing an example of an incoming sequence to a mobile station. Description of main part code 10 …… Roadside station 12 …… Joined vehicle 14 …… Transceiver 20 …… Minimum zone 22 …… Road-to-vehicle individual communication network 30,32,34 …… Exchange station, ground station 42 …… Memory 80 …… Traveling vehicle table 82 …… Passing vehicle table 130 …… Vehicle code generator 132 …… Station code generator

Continuation of front page (56) Reference JP-A-59-133742 (JP, A) JP-A-58-12089 (JP, A) JP-A-58-62944 (JP, A) JP-A-59-182649 (JP , A) JP 58-60841 (JP, A) JP 62-179230 (JP, A) JP 62-7230 (JP, A) JP 61-293033 (JP, A) Yoshikawa Noriaki Sadao Okasaka and Nitoshi Komagata "Automobile telephone wireless line control" p. 1871-1888, Research Practical Use Report Vol. 26, No. 7, Showa July 22, 1977, Nippon Telegraph and Telephone Public Corporation Musashino Telecommunications Research Institute

Claims (1)

(57) [Claims] 1. A plurality of base stations each communicating with a mobile station via a wireless link, and a plurality of regional stations each accommodating a plurality of units of base stations among the plurality of base stations. A plurality of district stations forming a communication line network for exchanging communication with unit base stations, and a plurality of exchanges accommodating the plurality of district stations and forming a communication line network for converting communication with the plurality of district stations Including a station, the adjacent ones of the plurality of base stations are spaced apart from each other by interposing a region in which the mobile station does not substantially respond to radio waves of the wireless link, In the mobile station position detection system for mobile communication, which is registered in any of the registered exchange stations of the plurality of exchange stations in association with an identification code for identifying the mobile station, the mobile station is the base station. Said wireless link from In response to the polling by the mobile station code assigned to itself, the mobile station transmits an identification code including a registration station code indicating a registered exchange station in which the mobile station is registered, the district station, Upon receiving the identification code from the mobile station via the base station, the registration exchange station of the mobile station is detected based on the registration station code of the identification code, and the district station code of the district station is added to the identification code. The registration exchange that additionally transmits the identification code to the registration exchange, and stores the district station code as information indicating the position of the mobile station in association with the mobile station code of the mobile station. A mobile communication system characterized by the above.