JPH04165897A - Incoming call controlling system for traveling object communication system - Google Patents

Abstract

PURPOSE:To reduce the load of a section station and a road station by selecting the necessary and minimum number of road stations for operating an incoming call connection with an objective traveling station, and operating a multi-address communication, based on the traveling speed of the traveling station and a section distance of base stations. CONSTITUTION:Each traveling station 16 is preliminarily registered in a specific ground station. The present position of the traveling station 16 is communicated from the ground station which detects the traveling station 16 registered in the ground station to a registering station, and the present position data is held. At the time of the incoming call to the traveling station 16, the access to the registering station in which the traveling station 16 is registered is performed in order to search the present position, the irreducible minimum number of road stations 10 to operated for the multi-address communication are selected, the multi- address communication is operated, and the incoming call connection with the objective traveling station 16 is operated, based on the speed of the traveling station 16 and the section distance of the road stations 10 of a multi-address group. Thus, the irreducible minimum number of multi-address communication is sufficient to the road stations 10 at the time of the incoming call to the traveling station 16, so that the multi-address operation of the section station 30 can be reduced, and the effective memory utilization of the road stations 10 can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a mobile communication system, more specifically, a mobile communication system suitable for communication to a vehicle such as a car. This invention relates to a control method for controlling.

(Prior Art) As a conventional mobile communication system to which the present invention is particularly related, there is a car telephone system, for example.As is well known, a conventional car phone system has two base stations covering a predetermined service zone. arranged dimensionally such that the zones of adjacent base stations partially overlap each other;
Some systems use a cellular system that guarantees continuity of communication to mobile units9. By the way, when receiving a call to a mobile station, it is necessary to identify the current location of the mobile unit. In conventional cellular car e-mail systems, each time a mobile station receives a call, the network makes a simultaneous call for multiple zones, detects the response from the mobile station, determines the current location, and connects one incoming call. was being carried out.

In this cellular system, different frequencies are used between multiple adjacent zones or 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, zone segmentation increases the frequency of frequency switching as mobile objects move across zones, placing a burden on both base stations and mobile stations to control frequency switching. This tendency becomes more pronounced as the speed of movement of mobile objects increases. ,For this reason, in conventional cellular systems, each zone has to be expanded or
It was necessary to increase the allocated frequency. However, as is well known, increasing the allocation by one frequency is extremely difficult.

In addition, because conventional cellular car phone systems are designed primarily for voice communications, they are not necessarily suitable for services that require large amounts of data to be transmitted at high speeds, such as those for land transportation such as automobiles. In order to perform navigation that guides people to appropriate routes depending on road congestion and weather conditions, and to efficiently manage the operation of large numbers of vehicles, large amounts of data are transferred between in-vehicle devices and ground base stations at high speed. need to be transmitted. Conventional cellular phone systems are not necessarily suitable for a variety of services, including high-speed data communications, because the frequency of the transmitted signal is limited to the voice band. Furthermore, each time a call arrives, each base station makes a single call, and after the mobile station responds, the incoming call is connected, making it difficult to control the connection for each incoming call. ll, and it took a relatively long time to set up the connection. In addition, the current location of a mobile object cannot be known unless the mobile station receives a call individually, so it is not suitable for a user such as a transportation company that owns a large number of vehicles to efficiently manage the operation of those vehicles. Ta.

Therefore, a mobile communication system, disclosed in Japanese Patent Application No. 63-J3J1407, which can perform high-speed data communication using the same frequency and can efficiently communicate large amounts of data, was proposed by the same applicant as the present application. ing.

This system connects multiple base stations that are wirelessly linked to a mobile station, with vA connections between the base stations! #, These base stations were configured to be spaced apart from each other with an intervening radio wave region, and use a single frequency as the radio wave for the wireless link.

(Problem to be Solved by the Invention) However, in the conventional system, when a mobile station is stopped in an area where it cannot communicate with the base station, or when a situation such as a failure occurs in the mobile station, the base station Messages may remain for a long time in the base station, which may overwhelm the base station's message storage memory and make it impossible to store messages from other mobile stations. In particular, in the cellular system, since a call is made to all cells, there is a problem in that the accumulated amount becomes large.

Therefore, in order to prevent messages from being stored for a long time, it is possible to delete messages if communication is not completed within a certain period of time. In this case, there is a problem that only a part of the message can be sent or messages are often discarded before being sent, resulting in a worsening of the per-call reception rate.

The present invention solves the problems of the prior art as described above, and provides a mobile communication system that can reduce memory pressure on base stations, efficiently receive calls to mobile stations, and reduce message deletion. The purpose is to provide an incoming call control method for the system.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the incoming call control method for a mobile communication system according to the present invention includes a plurality of base stations each communicating with a mobile station via a wireless link, and a plurality of In an incoming call control method for a mobile communication system that includes a plurality of switching stations that accommodate base stations and form a communication line network that exchanges communications for the plurality of base stations, adjacent ones of the plurality of base stations are The mobile stations are spaced apart from each other by intervening areas in which they do not substantially respond to the radio waves of the radio link, and the mobile stations are registered with one of a plurality of exchanges, and the mobile stations are registered with one of a plurality of exchanges. When a mobile station is detected by one of multiple base stations, the station stores the current location information of the detected mobile station, and when incoming a call to this mobile station, stores the location information of the mobile station and its movement. Based on the moving speed of the station and the arrangement interval of the base stations, multiple base stations are selected to make an incoming call connection to this mobile station, and a message to be received by the mobile station is broadcasted to the selected base stations. This feature allows the mobile station to make an incoming call connection.

(Operation) According to the incoming call control method of the mobile communication system according to the present invention, the current location information of the mobile station is detected at the base station, and the current location information is stored in the switching center where the mobile station is registered. do. As a result, when a message is to be received by a certain mobile station, the current location information is checked, and the necessary minimum number of times when a message must be received by that mobile station is checked based on the mobile station's moving speed and the base station placement interval. Select multiple base stations. By distributing messages to the minimum necessary number of base stations, unnecessary distribution is eliminated and efficient incoming call connections are made from these base stations to the corresponding mobile station.

(Example) Next, an example of the incoming call control method for a 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 transportation for vehicles including automobiles, as a road-to-vehicle individual communication system.

In this embodiment, a plurality of roadside stations IO are usually arranged at predetermined intervals, for example, at intervals of several hundred meters to several kilometers, along a general road or expressway. Street station 10
The base station functions as a base station that communicates wirelessly with the supercars 12 on the road.

The roadside station IO has a transceiver I4, which is connected to the participating vehicle 1.
2, i.e., a vehicle-mounted mobile station 1116 (Fig. 3)
It transmits and receives radio waves 18 to and from the vehicle, and communicates with vehicles 12 existing within its service area, ie, zone 20.

One of the characteristics of this embodiment is that the size of the zone 20 is much smaller than the interval at which the road stations IO are arranged, and the road stations IO are arranged intermittently. The diameter may be, for example, on the order of several tens of meters to 100 meters. Therefore, between two adjacent zones 20, there is an area where the mobile station 16 does not substantially respond to the radio waves transmitted by the roadside station IO, that is, "no radio waves". "area" exists,
Vehicle 12 can only access road stations while it is included in zone 20.
Can communicate with O. Because of these characteristics, this method is called the "intermittent minimum zone method" and the zone 20 is called the "minimum zone J."

With such an intermittent minimum zone method, it is possible to increase the speed of communication between the mobile station 16 and the roadside station IO, and it is possible to provide a variety of services including high-speed data communication.

The roadside station IO constitutes a part of the road-to-vehicle individual communication line network 22, and via the line network 22, in this embodiment, the general telephone line network 24. a data switching network 25 such as a general packet switching network;
Other communication facilities such as a system center 26 and a user center 28 can be accessed.

In this embodiment, the road-to-vehicle individual communication line network 22 has one station hierarchy configuration as illustrated in FIG.
, the data exchange network 25 and the center 26, 28 and the mobile station 1
This is a communication line network that performs switching, that is, exchange, with 6.

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 on-road station IOs arranged in a certain district number, and a district station 30 that accommodates a plurality of roadside stations IO located in a certain area number. It has a hierarchical structure consisting of inter-regional stations 32 that accommodate all areas, and a general bureau 34 that accommodates several of these inter-regional stations 32. These switching stations 3G and 32.34 including the road station IO are called ground stations. District Bureau 30. In this embodiment, the lines between regions 32 and between the general stations 34 form a tree-like line network consisting of trunk lines and trunk lines 36 such as diagonal lines, and between the general stations 34 form a set-type line network. are doing.

The present invention is not limited to this network configuration, and may adopt a local hierarchy configuration depending on the road configuration, such as a general road or an expressway, or a network configuration such as a linear network. Needless to say.

A relay &I 38 for the general public telephone line network 24 and data exchange network 25 is housed in the general office 34, for example. The system center 26 is, for example, an information processing system that processes the navigation of the participating vehicle 12. The user center 28 is an information processing system that independently manages the operation of vehicles belonging to a specific user among the subscribed vehicles 12. 40 and is housed in the general office 34. Of course, these may also be connected to the inter-region 32 or district office 30.

General Bureau 34. Interregional 32 and district stations 30 each have a unique station code. By representing the codes of the general station 34 and the inter-regional station 32 in a station hierarchy structure, a registered ground station code 52 (FIG. 4) that specifies the inter-regional station 32 is formed. Mobile station 16 mounted on subscriber vehicle 12
is specified by a ground station code 52 and a mobile station code 54. Hey, the joining vehicle 12 is the general station 34 and the district station 30.
may be registered. 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 the mobile station 1 registered in the inter-region 32
The system code 56 includes a ground station code 52, a mobile station code 54, and a system code 56 for identifying this system. Yes, it may be omitted within the system.

The mobile station I6 of the joining vehicle I2 has a vehicle code generator 13 (1
(FIG. 3), which is the functional unit that generates the vehicle code assigned to the mobile station 16. This vehicle code includes a ground station code 52 that specifies the registration station to which 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 generator 130,
The information is read out and transmitted in response to polling from the road station [O, which will be described later].

For example, as shown in FIG. 8, it is assumed that a certain mobile station +6 is registered in one area B1 accommodated in the central office AI. The ground station code 52 that identifies the area 32 is rAt old.If the mobile station code 54 of the mobile station 16 located between the areas is rMO3J, the mobile station has the static vehicle code rAIBIMO3J.
It is specified by.

The dynamic code 60 is a code that corresponds to the movement state of the subscriber vehicle 12, and is a code that corresponds to the movement state of the subscriber vehicle 12, and is
．． This is an important step in searching vehicle locations for individual communications from the centers 26 and 28, and providing route guidance information to travel destinations for the participating vehicle I2.

Therefore, in this embodiment, a destination code 62 indicating the destination of operation of the participating vehicle 12 and a driving area code 64 indicating the current driving area are included.

In this embodiment, the driving area code 64 is the general office 34, the status office 32, . It consists of the station code of 30 district stations and 10 stations. Other set communication link codes may also be included.

In this embodiment, as shown in FIG. 3, traveling vehicle tables 80 are provided between regions 32. In the traveling Φ table BO, data indicating the current driving area of the participating vehicles 12 of the own station registered as belonging to the region 32 is stored for each station area, and also data indicating the current driving area of the vehicles 12 registered as belonging to the area 32 of the own station is stored. Data on participating vehicles 12 traveling in the area are stored for each registration station. These data in the running vehicle table 80 are constantly updated. Similar vehicle tables may be provided at the district office 30 and the general office 34, for example.

As conceptually shown in FIG. 2, a memory 42 is provided in the roadside station 10, and this stores the 1-pass vehicle table 82 (FIG. 3) and information to be transmitted and received with the mobile station iris 6. A zero passing vehicle table 82 including a storage area holds data regarding joining vehicles 12 passing through the minimum zone 20 of the roadside station IO. These data include vehicle-specific codes 50 and 60, and are constantly updated as the joining vehicle 2 passes.

In this embodiment, the mobile station 16 is mounted on a member vehicle I2 such as a car, and transmits and receives data messages such as navigation information and operation management information and image signals to and from the roadside station IO, and makes these signals visible and visible to passengers. (or an in-vehicle device that provides an audible display.

The mobile station 16 has a random number table function, and according to this function, the mobile station 16
An available empty channel among the plurality of empty channels on the link 18 to the mouth is selected by the roadside station IO.

Communication between the mobile station 16 of the subscribing vehicle 12 and the base station IO is carried out by polling using a frame 100 having a format as illustrated in FIG. is 683 milliseconds and the transmission rate is 512 bits/second, which includes a large number of time slots? i number of channels are multiplexed. In principle, the required bidirectional communication is completed within this one frame period.

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 16 is in the receiving mode in the idle state, and becomes the transmitting mode when it finishes receiving the introduction part I02.

The introduction section 102 is followed by a vehicle recognition section 104, which includes:
Mobile station 16 responds to polling with vehicle specific code 50.
and 60 are transmitted, and the roadside station 10 recognizes this. Advantageously, the recognition rate of participating vehicles 12 is significantly improved by carrying out two-block repeated transmissions. 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 generator 130 of the mobile station 16 generates the ground station code 54 set and registered for the mobile station 16 and uses this channel to generate a static vehicle specific code. 50 or a service function code to the road station 10 (see FIG. 6).

For example, in the example shown in FIG. 8, it is assumed that eight roadside stations 10 are accommodated in one district station Ct, which was previously accommodated in the regional station, and station codes DO to D7 are assigned to them, respectively. 6th street station from the left 15 days a day■
is specified by the station code rAOBlcI port 5J. In this example, if the mobile station 6 with rAIBIMO3J as the static vehicle code 50 is polled while passing through the zone 20 of the old ClO3 to the roadside station, the mobile station 16 will have the ground station code 52jS and the mobile station code 54. The identification code rAIBIMO3J is returned.

Mobile station I6 travels in the direction of the arrow and reaches primary road station AOF1.
When entering zone 20 of 1CI06, mobile station 16
receives polling from the roadside station AOBICID6 in the same manner as described above, and returns the vehicle code ``^lBIMO3J.''

In this way, as the mobile station ^IBIMO3 moves, the successive roadside stations ■ in its path will one after another move to the mobile station ^IBIM
Returning to FIG. 5, in the present embodiment, a relay communication unit 106 is arranged following the vehicle recognition unit 104, and this is used to communicate with the road station 1.
0, beacon-type dynamic navigation information such as traffic information, and a registration response signal IAc or NACKI are transmitted to the mobile station 16. If the channel selected by the mobile station 16 does not conflict with any other channel, it is registered in the road station IO, and an ACK i' signal is sent to the mobile station 16.

This is followed by the vehicle communication section 108, which performs full-duplex communication between the roadside station IO and the mobile station 16 in this embodiment. The frequencies are different for the upper and lower stations, and the channel specified at the roadside station 1O 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. In the vehicle communication unit 10B, the mobile station 16
Data such as navigation information and operation management information, messages, and image signals are transmitted and received between the system center 26 and the user center 2B, and the information is displayed to the passenger of the subscriber vehicle 12 in the form of images and sounds. Also, -
General iSt talk line network 24. Communication with the data exchange network 25 or other mobile stations 16 within this system is performed in the same manner.

The roadside station IO may hold the data of the joining vehicle 12 obtained from the mobile station 16 within the zone 20 in the passing vehicle table 82 for each polling cycle.

The roadside station 10 transmits these data through the line 36 to the district station 30. The information is transferred to the interregional 32 or the general office 34. These stations store the thus transferred data in, for example, a traveling vehicle table 80. Thus, for example, the traveling vehicle table 80 between regions 32.

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 AOBIC+ shown in FIG. 8, rAOBIcIJ is set as the ground station code 52 in the station code generator I32. Mobile station +6 (7) vehicle received by 〇〇ICIO3 to roadside station:] -)' rAIBIMO3
J Li, SO U) On-road station In (7) The vehicle is temporarily stored in the passing vehicle table 82 and transferred to the upper district station AOBICI. As shown in Figure 6, the district station AOBIC+ identifies from this vehicle code rAIBIMO:l J that the registered station is a regional station belonging to the general station AI,
Transfer the vehicle code rAIBIMO3J between regions. At this time, the district station AO1C1 transmits location information of the station 10, including its own station and the route by which the mobile station 16 was detected, as information indicating the current location of the mobile station 16. This location information includes its ground station code rAo old CIJ in the form of driving area code 64 of dynamic vehicle code 60 and roadside station code "D5."

The exchanges located above the district station AOBICI, such as the interregional AOBI and the central stations AO and AI, identify the destination of the mobile station location data to be transferred from the vehicle code rAIBIMO3J, and the registered station, that is, in this example,
This will be relayed to IBI between regions. Once the Registration Authority AI receives the mobile station location data, namely static vehicle code 50 and dynamic vehicle code 60.

The mobile station 16 targeted by 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 Mn2, its location data is transmitted to the district station 3 as described above each time any roadside station 10 detects the mobile station MO3.
Reported from 0 to registration station AI old, running vehicle table δ0
The stored contents of mobile station MO3 are updated.

Information addressed to the mobile station 16 from the center 26, 28, the -H 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 10.

The station F checks whether there is any information to be transmitted to the mobile station I6 within its service area, and when it detects a match between the two,
The information stored in the memory 42 is transmitted to the vehicle communication unit 10.
The data is transmitted to the mobile station 16 using the No. 8 downlink channel. Information transmitted from the mobile station 16 via the uplink channel is temporarily stored in the memory 42. This uplink transmission information is transmitted to the center 26 via the road-to-vehicle individual communication network 22.
．． 2Jl, data exchange network 25 or general electronics line network 24
will be forwarded to.

When the vehicle communication unit 108 completes Y, the upper and lower response? This is followed by a communication completion unit +10 which sends a signal f4, which is a signal f4 confirming the completion of the transmission, and not confirmation of the information content.

In this way, 1 frame + (10 communications are carried out while the participating vehicle 12 is traveling within the service zone 20 of road station 1 (+).
When the subscribing vehicle 12 is traveling in the wave area, the mobile station 16
cannot communicate with the road-to-vehicle individual communication line network 22.

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. Regardless of whether it is a general road or an expressway, as long as the vehicle is driving normally on the road, the vehicle 1 that has joined several minimal zones 20 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 by the traveling of the roadside stations 10. In other words, by arranging the roadside stations IO in such a remote manner, it is possible to sufficiently achieve the required communication even with the mobile station 16 that receives a lot of traffic.

By the way, in this embodiment, in order to efficiently control incoming calls to the mobile station I6, multiple on-the-road stations! 0 has a broadcast group structure depending on the area where it is placed. When a call is received at the mobile station 16, any necessary road station IO from this group is selected and a relay notification <S is performed.

For example, this group structure may include one district station 30 as a unit and all the street stations housed therein as one circular group, or one street station housed in the district station 30.
A number of regionally grouped stations may be used as a unit.

In the latter case, as shown in FIG. 3, the district station 30 is provided with a road station table 134, which stores which road station IO within the area is included in which bulletin group. This table 134 is referred to when a call is connected and a relay message is issued.

For example, the sequence in which a call arrives from the center 26 or 28 to the mobile station A1 old MO3 using the mobile station position data that is constantly updated at the registered station Al old will be schematically explained with reference to FIG. Mobile station A from center 26 or 28
Messages addressed to IBIl 103 are sent via the central station 34 to the registration station AIBI with a header in the form of a static vehicle-specific code 50 containing its destination code [A181MO3J. This message forwarding is carried out at each relay station. , the message's destination code [A181MO3
This is done by identifying J. When the registration station Al receives this message along with the header, it checks the registration qualification of the mobile station Al to send S from the destination hood, and if it satisfies this, it stores the message in memory (not shown). ) to accumulate - hours (+401,
Although not shown in the figure, at this time the registered station ^l returns a reception confirmation response to the center 26 or 28.

Therefore, the registration station A101 refers to the travel weight table δ0 and uses the mobile station position data to identify the destination mobile station AIBIM.
Check the current location of O3. As a result, mobile station AlB11
If it turns out that the current location of 1D3 is, for example, "rAO old C1 port 5", the registered station Al old will now be the road station IO.
address [＾口DICID5J driving area code 6
4, a dynamic vehicle-specific hood 60 is created.

The registration station Al old reads the transmitted message from its memory, adds a dynamic code 60 to its header, and sends it to the district office AO old CI.

Relay stations, such as the central station 348 and the regional stations 32, identify the message's dynamic duplex unique code 60 and forward it to the destination station AOBICI. To District Station 〇〇When the ICI receives this message together with the header, it classifies the roadside station 10 indicated by the driving location area code 64 of the header by 1, and refers to the roadside station table 134 based on this. In this example, since the road station code indicates r D2J, it is determined from the road station table 134 that the coaxial group to be accessed is the group including road stations D3.04 and D5.

Therefore, the district station AOBICI judges the direction of travel and all road stations D3. Apply coax to D4 and D5. This broadcast is.

Upon receiving the delivery request, the message, and the message's destination code [A181MO3J, each roadside station 10 temporarily stores the message in the memory 42 and transmits the message to the mobile station 16 included in the service zone 20.
poll. This polling is performed at the introduction part +02 of frame +00 as described above.

In response to this polling, the active mobile station 16 included within the service zone 20 of the road station IO generates vehicle codes 50 and 60 in the vehicle code generator 130 and sends them back to the road station IO. This is the vehicle recognition unit 10
4 is used. The roadside station IO temporarily stores the vehicle code returned from the mobile station 16 in the passing vehicle table 82, and
If the static vehicle-specific code 50 is compared with the message destination [3181MO3J 42), and if they match at any roadside station IO, that roadside station IO reads the transmitted message from the memory 42 and sends it to the vehicle communication unit. 10
8 on the channel of mobile station AIBIMO3. The mobile station ^IBIMO3 that received the message sends back a reception fIi acknowledgment response using the 1 communication completion unit 110, which is ultimately transferred to the registration station 34 via the ground station. If the reception acknowledgment contains an acknowledgment ACK, the local station AOBICI cancels the delivery request to the other road station IO.

In this way, from the center 26 or 28 the mobile station
I have described the normal sequence of incoming calls to MO3.

When a message is transmitted from the center 26 or 28 to the mobile station 16, if the mobile station 16 is traveling without radio waves or stopped for a long time due to traffic jams, etc., the roadside station 10 forming the relay group will not be able to transmit the message for a long time. There is a possibility that the memory 42 for holding messages is occupied and other traffic is squeezed.

In this embodiment, in order to solve this problem, the road station D3. D4゜D5 is not unconditionally relayed, but among the road stations 10 that form a relay group based on equation (A) that takes into consideration the vehicle speed of the mobile station 16 and the distance between road stations, etc. The roadside station 10 that broadcasts the broadcast is limited to N roadside stations 10 in the direction of travel from the current position. By doing so, there is no need to send information to unnecessary road stations 10, and the memory 42 of the road stations 10 can be used effectively.

・・・・・・・・・・・・(＾Note) α: Coefficient of the number of notifications E (signal delay time) N: Number of notifications (rounded up to the nearest whole number) This formula (A) is, for example, the first In the figure, road station 1
Assuming that all distances between 0 are equal, this can be expressed as D(k/
h), and assuming that the moving speed of the mobile station 16 is also uniform, this is S (km/h), and the maximum delay interval in the actual communication network is α, then the mobile station 16 moves during the delay time α. The distance traveled by the station is given by SXα (km). If we convert this to the location of the road station starting from the road station DI, we get (S
Xa÷d), and by adding [j to this for safety, the above formula (A) can be obtained. For example, the signal delay time is 7.5 minutes (a=0, 125 hours, mobile station!
6's speed is 30ksg/h, and the distance between roadside stations In is 5km.
In this case, from the above formula (^), N will be 175, and rounding up the decimal point will give N = 2.

Distribution will be made from the current location M (road station 01) to the first and second road stations D2.03.

Similarly, delay time a = 0.125. When the speed of the mobile station 16 is 1100 km/h and the interval between roadside stations is 5 km, N
is 3.5, and there are 4 street stations from 02 to D5! Delivered to 0.

If the speed of the mobile station 16 is 30/h and the distance between the road stations 10 is 2 km, then N is 2.25, and distribution will be made to three road stations 10 from 02 to D5.

To summarize, in this embodiment, each mobile station 16 is registered in advance with a particular 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 location data is always available.

Updated in real time. The roadside station IOs that are regionally related constitute a circular group. When incoming a call to the mobile station 16, the registration station where the mobile station 16 is registered is accessed, its current location is determined, and the information is related to the current location.

Or, based on the speed of the mobile station 16 and the section distance of the road station IOs in the coaxial group, the minimum number of road stations IOs to be broadcast are selected and broadcast from among the road stations IOs in the broadcast group estimated from this. Communicate and arrive at the target mobile station +6, 1
Make the connection.

As a result, when a call arrives at mobile station +6, only the minimum number of calls are required to be sent to the roadside station 1O, which reduces the broadcast processing at the district station 30 and makes it possible to use memory more effectively and efficiently at the roadside station 1O. Become.

An embodiment in which the present invention is applied to a road-to-vehicle individual communication system has been described above. However, the present invention is not limited to this,
It is effectively applied to individual communications with all types of moving objects other than vehicles, such as individuals, that is, pedestrians in a broad sense.

The embodiments described here are for illustrating the present invention, and the present invention is not necessarily limited thereto, and modifications that can be made by those skilled in the art without departing from the spirit of the present invention. and josho are included within the scope of the present invention.

[Effects of the Invention] - As explained above, in the mobile communication system according to the present invention, a mobile station is registered with a specific switching center.

The current location of a mobile station is managed by its registration station. For district stations, those that are regionally related constitute a broadcast group, and when an incoming call to a mobile station is received, it accesses the registration station to determine the current location of the mobile station, and then broadcasts the broadcast group related to the current location on the road. From inside the station,
Select the necessary and minimum number of on-road stations to make an incoming connection to the target mobile station based on the moving speed of the mobile station and the interval distance between base stations, and apply coax to two of those on-road station numbers. In this way, an incoming call is connected to the target mobile station. As a result, the number of calls per incoming connection can be kept to a minimum, and the burden on local stations and roadside stations can be reduced. Therefore, even if messages are stored at the base station for a long time, the communication is received efficiently, which reduces memory pressure and eliminates the need to discard messages. This has the effect of increasing communication efficiency.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram conceptually showing an example of the open group configuration of a roadside station using the incoming call control method of the mobile communication system according to the present invention. 1 is a conceptual block diagram showing an embodiment applied to a road-to-vehicle individual communication system. FIG. 3 is a relay system showing an example of the station hierarchy configuration of the road-to-vehicle individual communication line network in the embodiment shown in FIG. 2. FIG. 4 is an explanatory diagram showing an example of the format of the vehicle 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, and Fig. 7 is an explanatory diagram showing an example of a sequence for detecting the position of a mobile station in the same embodiment. a
FIG. 8 is an explanatory diagram conceptually showing a mobile communication system according to the present invention. Major. Description of Uno -] O road station 12 Joined calligraphy (+6., mobile station) 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 section 132, station code generation section 134 Road station table Patent applicant Oki Electric Industry Co., Ltd. Agent Katori Takao Mei-f! In January, the first fish arrived, 15 yen.

Claims (1)

[Scope of Claims] A plurality of base stations that each communicate with a mobile station via a wireless link, and a plurality of base stations that form a communication line network that accommodates the plurality of base stations and exchanges communications for the plurality of base stations. In a call termination control method for a mobile communication system including a switching center, adjacent base stations among the plurality of base stations are arranged such that an area in which the mobile station does not substantially respond to the radio waves of the wireless link is inserted between them. , are arranged at a distance from each other, and the mobile station is registered with one of the plurality of switching centers, and the switching center with which the mobile station is registered detects the mobile station when one of the plurality of base stations detects the mobile station. , stores the location information of the detected mobile station, and when receiving a call to the mobile station, the mobile station A mobile device characterized in that the mobile station is configured to select a plurality of base stations with which the mobile station is to make an incoming call connection, and to deliver a message to the selected base stations to cause the mobile station to make an incoming call connection. Incoming call control method for communication systems.