JPH07101477B2 - Route guidance system for mobile communication systems - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system, and more specifically, to a route guidance system in a mobile communication system for performing route guidance to a vehicle such as an automobile.

(Prior Art) As a route guidance system in a conventional mobile communication system to which the present invention is particularly relevant, there is an automobile navigation system. A car navigation system is provided with map information recorded on an optical recording medium such as a CD-ROM and a CRT display for displaying the map information on the vehicle side, and the current traveling position is displayed on the map. Is a system to display. In this navigation system, for example, a transmitter for transmitting the position information is installed on a road guide board or the like, and a receiver for receiving the position information is arranged on the vehicle side. Each time the vehicle receives position information from the transmitter, it corrects the vehicle position on the map displayed on the display, and autonomously based on the traveling direction and speed of the vehicle until the next position information is received. To update the vehicle position. The passenger recognizes the current position from the position on the map of the vehicle displayed on the display and determines whether or not the driver is moving toward the destination.

(Problems to be Solved by the Invention) As described above, in the conventional technology, the passenger has to select the route to the destination, and it is possible to confirm whether or not the vehicle is traveling on the wrong route to the destination. It was nothing more than
Further, according to the conventional technique, the passenger determines the route to the destination as described above, and thus it is not possible to select an appropriate route according to the traffic situation. Furthermore, the conventional technology requires map information on the vehicle side. As for the map information, it is difficult to record the detailed map information of each area without exception due to the limited storage capacity of the storage medium. Therefore, depending on the destination, the passenger cannot accurately select the route. The map information is originally updated with time, and may be temporarily changed depending on the situation.
Therefore, even if such fluid information is prepared in advance, it is difficult to promptly deal with the change or addition of the content.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks of the prior art and to provide a route guidance system in a mobile communication system that enables guidance of an optimum route to a destination according to traffic conditions.

(Means for Solving the Problems) In order to solve the above problems, the present invention accommodates a plurality of base stations that wirelessly communicate with a mobile station and accommodates a plurality of base stations. The base station includes a communication line network for exchanging communications and a center connected to the communication line network for selecting an optimum route according to traffic flow conditions. When the mobile station sends a route guidance information transmission request, the communication network notifies the center of the transmission request, and the center receives the transmission request.
The optimum route according to the traffic flow situation is selected and the optimum route information indicating the optimum route is sent to the mobile station via the communication network.When the mobile station receives the optimum route information, it sends the optimum route information and the base station. When the mobile station recognizes that the mobile station has deviated from the route indicated by the optimal route information by collating the base station information with the optimal route information, the route guidance information is provided. Resend the request to send.

(Operation) According to the present invention, when the mobile station makes a request for transmission of route guidance information, this request is notified to the center via the communication network. When the center receives this notification, it selects the optimum route on which the mobile station travels in consideration of the traffic flow condition, and sends it as the optimum route information to the mobile station that has made the transmission request through the communication network. When the optimum route information is received, the route is guided by the received route information and the base station information transmitted from the passing base station. Further, when the mobile station recognizes that the intended route has deviated by collating the base station information with the optimum route information, the transmission request for the route guidance information is retransmitted to the center.

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

FIG. 1 shows an embodiment in which the mobile communication system according to the present invention is applied to land traffic, particularly road traffic of vehicles including automobiles, as an individual road-vehicle 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 transceiver 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. 5), and its service area or 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 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, there is an area where the mobile station 16 does not substantially respond to the radio wave transmitted by the base station 10, that is, a “non-radio wave area” between two adjacent zones 20, 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.

As can be seen, in this method, the adjacent roadside stations 20
Also, the same frequency can be effectively used repeatedly. Therefore, it is basically sufficient for the radio link between the roadside 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". Note that the radio communication performed between the roadside station 10 and the mobile station 16 is hardly affected by the fading effect due to radio wave propagation in a very short period. Therefore, 256Kbi
High-speed communication of t / s-1.5 Mbit / s is possible. In particular, in this embodiment, considering the cost minimum, for example, 512 Kbit /
It is desirable to set it to about s.

The roadside station 10 constitutes a part of the roadside-to-vehicle individual communication circuit network 22.
Other communication facilities such as 26 can be accessed. The road-to-vehicle individual communication network 22 is a communication network which has a station level structure as illustrated in FIG. 2 in this embodiment and performs switching, that is, switching between the road-to-vehicle system center 26 and the mobile station 16. is there.

In such an intermittent minimum zone system, the mobile station 16 and
It is possible to speed up the communication with 10 and provide various route guidance services including high-speed data communication. That is, as in the present embodiment, in order to efficiently manage the operation of a large number of vehicles 12 and navigation for guiding the joining vehicles 12 such as automobiles to an appropriate route according to road congestion and weather conditions, Data communication can be performed between the center 26 and the mobile station 16 via the individual communication line network 22.

Referring to FIG. 2, the road-to-vehicle individual communication line network 22 in the present embodiment includes a plurality of roadside stations 10 arranged in a certain area.
Has a hierarchical structure including a regional station 30 in which a plurality of regional stations 30 are accommodated, a regional station 32 in which a plurality of regional stations 30 are accommodated over an area, and a general bureau 34 in which some of these regional stations 32 are accommodated. These stations 30, 32, and 34 including the on-road station 10 are referred to as ground stations. In the 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 between the general bureaus 34 theoretically, It constitutes a net-type circuit 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, or another form such as a linear network. Yes.

The road-to-vehicle system center 26 is, for example, an information processing system that processes navigation of the joining vehicle 12. That is, the system center 26 receives road information and traffic-related information from the communication line 22 and an external information center (not shown), and estimates and predicts the traffic flow condition from these information.
Upon receiving a request from the mobile station 16 to transmit a route guidance code to the destination, the center 26 selects an optimum route from the estimated traffic flow conditions, creates a route guidance code, and sends it to the mobile station 16.
In the present embodiment, the guidance code is a passing roadside station 10 to the destination.
Is stored in the memory 212 (FIG. 5) of the mobile station 16, which will be described later, as a guidance list (FIG. 7). The road-to-vehicle system center 26 is accommodated in the general bureau 34 by a trunk line 40. Of course, these may be connected to the regional office 32 or the district office 30.

The vehicle-specific code that identifies the mobile station 16 is composed of a static code 50 and a dynamic code 60 in this embodiment, as shown in FIG. The static code 50 has a function as an identification number of each mobile station 16 in the system, and also has a close relationship with a number system when the road-to-vehicle communication center 26 receives the mobile station 16. The static code 50 is a mobile station code 54 that identifies the mobile station 16, and a registered ground station code 5 that indicates a registered station.
2. Includes a system code 56 for identifying the system.

The dynamic code 60 is a code corresponding to the moving state of the joining vehicle 12, and is effectively used for grasping and navigating the current situation of the joining vehicle 12. Therefore, it is a vehicle-specific code related to the traveled area and movement status of the subscribing vehicle 12, searching for the vehicle location for individual communication from the system center 26, and route guidance information for the subscribing vehicle 12 to the travel destination. Play an important role. Therefore, in this embodiment,
A destination code 62 indicating the operation destination of the subscribing vehicle 12 and a traveling area code 64 indicating the current traveling area are included.
In this embodiment, when the destination code 62 is set to the travel destination link number code, this is sent to the road-to-vehicle system center 26 as a route guidance code transmission request.

As conceptually shown in FIG. 1, the roadside station 10 is provided with a memory 42, which stores static information including the position / direction of the roadside station 10 and roadside station information around the roadside station. Storage area. The roadside station 10 is all the vehicles that pass
The static information and roadside station peripheral information are transmitted to 12. In the case of the present embodiment, the roadside station information is, for example, “If you go straight, there is a XX intersection crossroad. Go straight at the XX intersection to find a roadside station x, and turn left at the XX intersection to see a roadside station y. ○○ Turn right at the intersection and there will be a roadside station. "
It is the content such as.

The mobile station 16 is mounted on a subscribing vehicle 12 such as an automobile in this embodiment, and transmits and receives data such as navigation information and operation management information, messages and image signals to and from the roadside station 10, and transmits those signals to the passengers. It is an in-vehicle device that can be visually and / or audibly displayed on the. FIG. 5 shows a block diagram of the mobile station 16 in this embodiment. As shown in the figure, the mobile station 16 includes, for example, a key input device 252 for inputting a transmission request for a destination code 62 or a route guidance code, a video display 256 for interfacing passengers with images or voice, a voice. Synthesizer 280, voice recognition device
282, a facsimile transmission / reception device 254 and the like.

Each component of the mobile station 16 is centrally controlled by the control circuit 210. That is, the control circuit 210 includes a transmitter 200 and a receiver 202 that transmit and receive the radio wave 18 to and from the roadside station 10, a voice synthesizer 280, a display controller 230 that controls the display of the display 256 or the facsimile device 254, and a key input device.
252, a facsimile device 254, or a transmission buffer 220 that temporarily stores the contents output from the voice recognition device 252. Further, the control circuit 210 is connected to the memory 212, and stores the route guidance code received from the road-to-vehicle system center 26 in the memory 212 as a route guidance list.

The control circuit 210 of the mobile station 16 which has accumulated the guidance list confirms and selects the traveling route from the static information received from the roadside station 10, and uses the display 256 and / or the voice synthesizer 280 to indicate the traveling direction to the passenger. Inform. Even if the vehicle departs from the traveling route, the control circuit 210 recognizes that the traveling route has deviated from the static information and the guidance list information received from the on-road station 10, and again requests the system center 26 to transmit the route guidance code. Send. In this way, the passenger is always navigated along the optimum route by the mobile station 16, and therefore, it is not necessary to display a map showing the traveling route on the display 256. Of course, if the passenger desires the map information, the latest map information can be obtained from the center 26. The received map information is displayed on the display 256 or output by the facsimile device 254.

The mobile station 16 is provided with a random number table function, and in response to polling from the roadside station 10, among the plurality of channels in the link 18 with the roadside station 10, an available free channel is selected by the roadside station 10. To be done. Then, the mobile station 16 wirelessly communicates with the roadside station 10 on the selected channel.

The communication between the mobile station 16 of the subscribing vehicle 12 and the base station 10 is carried out by polling with the frame 100 of the format illustrated in FIG. 4 in this embodiment. In this embodiment, the frame 100 has a period of 683 milliseconds (ms), and a plurality of channels are multiplexed in a large number of time slots included in the frame 100. 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 above and below each other is 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. In principle, communication is completed within the period of one frame, but when the amount of information is particularly large, such as image information, or when the wireless communication situation is bad, communication by multiple frames is also possible. is there.

An introduction unit 102 is located at the head of the frame 100 and includes a preamble, a synchronization signal, a polling identification signal, a static information code of the roadside station 10, and the like. Using this, the roadside station 10 polls the mobile stations 16 in the zone 20 at a predetermined cycle. 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 unit 102 is followed by the vehicle recognition unit 104, which is a mobile station.
16 is a period in which the vehicle-specific codes 50 and 60 are transmitted in response to polling, and the roadside station 10 recognizes this. Advantageously, the two-block repetitive transmission greatly improves the recognition rate of the joining vehicle 12. The mobile station 16 selects a channel according to the random number table and transmits the static vehicle unique code 50 or the dynamic vehicle unique code 60 to the roadside station 10 using this channel. The on-road station 10 registers the mobile station 16 if the channel selected by the mobile station 16 does not collide with others and can be received correctly.

In the present embodiment, the broadcast communication unit 106 is arranged following the vehicle recognition unit 104, and by using this, beacon type dynamic navigation information such as traffic above from the roadside station 10 and a registration response signal (ACK or NACK) It is transmitted to the mobile station 16. The roadside station 10 adds channel information used by the vehicle communication unit 108, which will be described later, to the mobile station 16 registered by the vehicle recognition unit 104, if necessary, and transmits an ACK signal.

After that, the vehicle communication unit 108 follows, and in this embodiment, full-duplex communication is performed between the roadside station 10 and the mobile station 16. The frequencies are different from each other above and below, and the channel selected by the roadside station 10 is used. However, even if the joining 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 108, the mobile station 16 and the system center 26
Data such as a guidance code indicating navigation information and operation management information, a message, and an image signal are transmitted and received to and from the passengers of the subscribing vehicle 12 and the information is displayed in an image or voice.

FIG. 6 shows an example of the traveling route of the joining vehicle 12 which has requested the route-to-vehicle system center 26 to transmit a route guidance code. When a transmission request for route guidance is made from the mobile station M03 whose mobile station code of the vehicle 12 shown in FIG. 6 is M03, the passenger of the vehicle 12 receives a key from the key input device 252, such as the roadside station 10 at the travel destination. Enter the link number code that is the number. For example, when the link number code of the roadside station E is input as the destination, this code is stored in the transmission buffer 220 as the destination code 62 of the dynamic code 60.

When the destination code 62 is input, the control circuit 210 transmits this code 62 to the road station 10 that first passes after the input. For example, when the mobile station M03 first passes the transmission area 20 of the roadside station A, the control circuit 210 transmits the dynamic code 6 including the destination code 62 to the roadside station A by the vehicle recognition unit 104. Road station A receives the dynamic code 6 received from mobile station M03.
After 0 is temporarily stored in the memory 42, it is sent to the communication network 22 together with other codes of the mobile station M03. These codes are switched by the communication network 22, and a code indicating a route guidance transmission request is transmitted to the roadside-to-vehicle system center 26.

When the destination of the mobile station M03 is input, the road-to-vehicle system center 26 selects an optimum route to the road station E in consideration of the traffic flow situation. The center 26 also predicts the movement of the mobile station M03 and determines the roadside station B that can transmit the guidance code.
When the route shown by the dotted line in FIG. 6 is the optimum route, the guidance code from the roadside station C to the roadside station E, which is next to the ground station B capable of transmitting the guidance code, is sent to the communication network 22. . When receiving the guidance code addressed to the mobile station M03, the roadside station B stores the guidance code in the memory 42 and monitors that the mobile station M03 enters the zone 20.

When the roadside station B detects the mobile station M03, the vehicle communication unit 108 transmits a guidance code addressed to the mobile station M03. When the mobile station M03 receives the guidance code, the control circuit 210 stores this code in the memory 212 as a guidance list as shown on the left side of FIG. In addition, the mobile station M03 is, for example, “If you go straight ahead, there is a crossroad XX intersection 300m ahead. Turns right, there is a road station K. ”, and receives road station information indicating the environment around the road station B.

The control circuit 210 collates the guidance list with the roadside station information,
Instruct the passengers of the direction of travel. In this case, since the roadside station C is recorded in the guidance list, the mobile station M03 is 300 m long.
Instruct the passenger to turn left at the previous XX intersection. For this instruction, for example, the voice synthesizer 280 may give a voice navigation to the passenger saying "There is a XX intersection 300m ahead, so turn left." Instructions may be displayed.

At this time, if the driver mistakenly goes straight through the XX intersection as shown by the solid line, the mobile station M03 enters the zone 20 of the roadside station F and the static information is received by the introduction unit 102. Mobile station M
When the control circuit 210 of 03 recognizes that the vehicle has deviated from the traveling route by collating the position information included in the static information of the roadside station F with the guidance list, it sends a route guidance transmission request to the zone of the roadside station F. It retransmits to the road-to-vehicle system center 26 within 20. When receiving the route guidance transmission request, the road-to-vehicle system center 26 newly selects the optimum route in the same manner as described above,
This is transmitted to the mobile station M03 as a guide code. This guidance code is transmitted to the mobile station M03 by the roadside station G, and the seventh
It is overwritten in the memory 212 as a guide list shown on the right side of the figure.

When the mobile station M03 receives the surrounding environment information transmitted from the roadside station G, the mobile station M03 also instructs the passenger to turn left at the XX intersection, for example. When the mobile station M03 turns left at the XX intersection and enters the zone 20 of the roadside station E, the roadside station E sends a static information code indicating its position information to the mobile station M03 by the introduction unit 102. The control circuit 210 confirms that the traveling route is not wrong by collating the position information of the roadside station E with the guidance list. In addition, the passenger is instructed the route to proceed to next based on the surrounding environment information in the same manner as described above. In this way, the mobile station M03 can reach the destination roadside station E through the roadside station H.

As described above, according to the present embodiment, when the mobile station 16 recognizes that it is out of the route, the mobile station 16 retransmits the route guidance code transmission request to the roadside-vehicle system center 26. Therefore, the center 26 does not need to monitor the traveling status of the mobile station 16. Therefore, the load on the center 26 can be reduced, and the mobile station 16 can always guide the vehicle 12 to the destination by the optimum route according to the traffic flow situation. Further, in this embodiment, the traffic flow can be dispersed because the traffic flow status can be comprehensively grasped and controlled. Although the destination entered in the destination code 62 is the roadside station 10 in this embodiment, it may be another target, for example, the prefectural office location or a specific place name. Further, in the present embodiment, the driving operation is performed by the passenger, but it is also possible to provide the joining vehicle 12 with an autopilot function and perform autopilot according to the direction instruction output from the mobile station 16.

An embodiment in which the present invention is applied to an individual road-vehicle communication system has been described. However, the present invention is not limited to this, and is effectively applied to individual communication 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 explaining the present invention, and the present invention is not necessarily limited thereto, and variations and modifications that can be made by those skilled in the art without departing from the spirit of the present invention and Modifications are within the scope of the invention.

(Effects of the Invention) As described above, according to the present invention, even if the mobile station departs from the traveling route, the mobile station detects this and retransmits the transmission request of the optimum route to the center. Therefore, even if the center does not monitor the traveling route of the mobile station, the mobile station can guide the joining vehicle to the destination. Therefore, the processing load on the center can be reduced.

[Brief description of drawings]

FIG. 1 is a conceptual block diagram showing an embodiment in which a mobile communication system according to the present invention is applied to road traffic of a vehicle as a road-to-vehicle individual communication system, and FIG. 2 is a road-to-vehicle individual in the embodiment shown in FIG. FIG. 3 is a relay system diagram showing an example of a station floor configuration of a communication line network, FIG. 3 is an explanatory diagram showing an example of a format of a vehicle specific code in the same embodiment, and FIG. 4 is an example of a frame format in the same embodiment. Explanatory diagram, FIG. 5 is a functional block diagram showing a configuration example of a mobile station in the same embodiment, FIG. 6 is a traveling route diagram showing an example of a traveling route of a joining vehicle in the same embodiment, and FIG. It is a list block diagram which is an example of a change of a guidance list when the advancing route shown in FIG. 6 is changed. Description of main parts 10 …… Roadside station 12 …… Joined vehicle 14 …… Transceiver 20 …… Minimum zone 22 …… Road-to-vehicle individual communication network 26 …… Road-to-vehicle system center 42 …… Memory 80 …… Running Vehicle table 82 …… Passing vehicle table 210 …… Control circuit 212 …… Memory 252 …… Key input device 256 …… CRT display 280 …… Speech synthesizer

Claims (1)

[Claims] 1. A plurality of base stations wirelessly communicating with a mobile station, wherein the plurality of base stations are respectively arranged on a path along which the mobile station moves, and the plurality of base stations are accommodated. A communication line network for exchanging communication with the plurality of base stations, and a base station connected to the communication line network on a route to a destination of the mobile station, the base station having an optimum route according to a traffic flow situation. A base station information including a first information uniquely identifying the base station and second information representing a route from the base station to the next base station. To the mobile station, when the mobile station transmits a transmission request for requesting route guidance information indicating the optimum route to a base station arranged on a route through which the mobile station passes, the base station sends the transmission request. Notifying the center via the communication network, When receiving the transmission request, a base station arranged on an optimum route according to a traffic flow situation is selected, and route guidance information including first information of the selected base station is transmitted via the communication network. , The route guidance information is transmitted to a base station receivable by the mobile station, and the base station which has received the route guidance information transmits the transmission request to the route guidance information and the base station information of the base station. The mobile station that has transmitted the route guidance information to the mobile station that has received the route guidance information is a route guidance list for passing the route guidance information to a base station on the optimum route, 1 is accumulated as a route guidance list in the order of the optimum route, and the mobile station is stored by the route guidance list and the second information of the base station information transmitted from each base station through which the mobile station passes. The route guidance of the mobile station, The accumulated route guidance list,
When the mobile station recognizes that the route of the mobile station deviates from the optimum route by collating with the first information of the base station information transmitted from each base station through which the mobile station passes, new route guidance information is obtained. Is sent to the center via a base station through which the mobile station passes.