KR20030003431A - Method for providing ITS service using satellites communication and DSRC - Google Patents

Abstract

PURPOSE: A method for implementing an intelligent transport system(ITS) by utilizing a communication satellite and a dedicated short range communication(DSRC) is provided to easily build a broadband network with low costs by configuring the ITS combined with the satellite communication advantageous for a low density area capable of easily securing a visibility range and the DSRC advantageous for a dense area. CONSTITUTION: A method for implementing an intelligent transport system(ITS) for utilizing a communication satellite and a dedicated short range communication(DSRC) includes the steps of: collecting information required for the supply of the ITS transmitted through an information collection network(32) by an information collection server of an ITS operating center(33); transferring a traffic information or the like selected from the collected ITS information to an information distribution server of the ITS operating center(33) and identifying whether the transferred information is a real-time traffic information or not; identifying whether an area built in the transferred DSRC network(34) is the dense area by transferring a road link speed information to a satellite transmit station(35) when the identified result is the real-time traffic information and operating a plurality of automobile terminals(37) in response to the identified result; and displaying the information to an information display device in response to a user's requirement by transferring the information at an occurrence of accident to the DSRC network(34) when the identified result is not the real-time traffic information.

Description

Intelligent transportation service method using satellite communication and short-range dedicated communication {Method for providing ITS service using satellites communication and DSRC}

The present invention relates to an intelligent transportation service method using satellite communication and short-range dedicated communication, and a computer-readable recording medium recording a program for realizing the method. In particular, the present invention uses satellite communication in a small area where visibility is easily secured. Intelligent Transport System (ITS) is advantageous, and Dedicated Short Range Communication (DSRC) system is advantageous in densely populated areas. Therefore, the ITS network combining these two communication methods can be used to provide services. An intelligent traffic service method and a computer-readable recording medium having recorded thereon a program for realizing the method.

Intelligent Transport System (ITS) is a system to realize efficient traffic by integrating traffic systems such as roads and vehicles, and information communication systems such as electronics, telecommunications, and computing. to provide.

In the conventional ITS service method using satellite communication, since the satellite communication effectively transmits data in a broadcast form to a large area, since the stationary satellite is basically used as a repeater, communication effects of wide area and broadcast can be obtained. On the other hand, since the distance from the satellite is far, the output or antenna size is increased on the transmitting side, so it is important to secure a line of sight (LOS) with the satellite on the receiving side in order to solve this problem.

ITS service using satellite is suitable for services such as providing logistics information requiring wide area because it is advantageous to suburban area rather than a city with many large cars and buildings such as buses and trucks rather than passenger cars in order to secure antenna and terminal size and visibility. Detailed description thereof is as follows.

1 is a block diagram of an intelligent transportation system using conventional satellite communication.

As shown in FIG. 1, an intelligent traffic system (ITS) using conventional satellite communication includes a traffic collection sensor 11, an information collection network 12, an ITS operation center 13, a satellite transmitting station 14, and a satellite. 15 and the vehicle terminal 16.

Here, the traffic collection sensor 11 generally recognizes the traffic volume through a loop detector, an ultrasonic detector, an infrared sensor, a beacon, etc. located on a road, and collects them in a traffic information related institution at regular intervals. The database is processed and processed into traffic information.

The information collection network 12 is connected to road traffic related organizations dealing with traffic information, road information, event information, weather information, and other information, and transmits various information to the ITS operation center 13, which is a traffic information. Special events that are transmitted at regular intervals and may affect traffic volume. For example, road works, traffic accidents, and natural disasters are transmitted whenever information occurs.

The ITS operation center 13 is responsible for the most important functions in the ITS, which not only manages and monitors the entire ITS system, but also collects and processes traffic information from a server and distributes it to the satellite transmitting station 14 and where necessary. Currently, government departments and local governments related to road traffic are operating independently, but if ITS service is activated in the future and the collection and provision of traffic information is standardized, general operators can build ITS operation centers (13) and use them for commercial purposes. It is possible.

The satellite transmitter station 14 may be configured as a data generator and a satellite transmitter. The data generator converts the data transmitted from the ITS operation center 13 into the data format of the satellite transmitter. Accordingly, the converted data is modulated to an uplink frequency suitable for satellite communication in the satellite transmitter and transmitted to the satellite.

The satellite 15 converts the uplink frequency transmitted from the ground into a slightly lower downlink frequency, and then serves as a relay for broadcasting data over a large area of the ground. In general, since the ITS information using the satellite 15 is a data broadcasting type, the satellite 15 is located on a geostationary satellite located about 35,000 km above ground to provide wide area information.

The vehicle terminal 16 generally includes a satellite receiver, a GPS (Global Positioning System) receiver, and an information display device. The satellite receiver receives a satellite signal in broadcast to extract nationwide traffic-related information, and then stores the memory of the information display device. Store in At the same time, the GPS receiver also receives GPS signals and stores current vehicle position, time and speed related information in the memory of the information display device. The information display apparatus can provide traffic information conveniently to the user in various forms such as text, graphics, and voice. In this case, the traffic information and the current location information stored in the memory are used. Using GPS's current location information, not only can you track the vehicle's movement on the digital map of the information display device, but also automatically display local information centered on the current location among the nationwide traffic information. Do. In other words, the driver can track his current driving route in real time using GPS and traffic information, and various vehicle operation services such as map search, location search, shortest and best route indication, route time and route reset (CNS) It can provide various traffic related services by adding traffic information to the Car Navigation System.

On the other hand, ITS service method using a conventional short-range dedicated communication (DSRC), one of the latest communication means for providing the ITS service is a small roadside station (RSE: Road Side Equipment) fixed on the road side and the vehicle is located in the vehicle OBE (International Standard) for ITS wireless communication between On Board Equipment. The characteristics of DSRC include bidirectional high speed communication (about 1Mbps), point to multipoint, simple and inexpensive modulation and LOS-enabled communication environment for short-range (about 100m) communication between roadside base station and vehicle. Can be.

The biggest advantage of DSRC in ITS is that the vehicle's location and time information is automatically transmitted to the ITS operation center when the vehicle is driving along the road. It is not necessary. On the other hand, if you build a nationwide wide area network because it is a short-range communication that is impossible to hand off and has a centralized network structure that must distribute all traffic information from the ITS operation center to distribute traffic information of each RSE location. As the number of traffic increases due to the increase in number, the network structure and operation center become complicated, and the infrastructure construction cost increases exponentially. However, ITS is able to solve this problem by constructing DSRC network step by step because it is possible to provide regional service centered on big city.

2 is a block diagram of an intelligent traffic system using a conventional DSRC.

As shown in Figure 2, the intelligent traffic system using a conventional DSRC, traffic collection sensor 21, information collection network 22, ITS operation center 23, short-range dedicated communication network 24, DSRC (25) It consists of.

Here, the traffic collection sensor 21 is not the main purpose of collecting traffic information in the DSRC network, but is used for collecting traffic information in a region without a backup or DSRC network.

The information collection network 22 is the same as the ITS service providing method using satellite communication. Since the real-time traffic information collection is unnecessary and the amount of information is not large, the communication network can be constructed as a low-speed leased line.

The ITS operation center 23 may be classified into an information collection server and an information distribution server. The information collection server processes various types of information transmitted through a data collection network connected to a traffic related institution and a DSRC system located near a road. The information distribution server is responsible for distributing the collected information by classifying data type, data amount, data transmission time, etc. according to the required area and user. Road, event, weather and other information is not a real-time service, so when a certain time or a serious event occurs, the information distribution server of the ITS operation center 23 transmits to the necessary RSE through the short-range dedicated communication network 24 in a broadcast form. Provide immediately. In particular, when using the DSRC, since the DSRC itself has a traffic collection function, the traffic information through the existing traffic collection sensor has a meaning of backup.

Short-range dedicated communication network 24 is responsible for the real-time data transfer function between the DSRC (25) and the ITS operation center (23). The short-range dedicated communication network can build a hierarchical network structure to solve the problem because the load is concentrated in the ITS operation center 23 as the number of RSE increases. That is, by setting up regional servers for each region in the lower layer of the ITS operation center 23 and assigning tasks related to collecting and providing regional traffic information, the load of the ITS operation center 23 can be distributed, and the network length becomes shorter. Easy to build

DSRC (25) is the ITS short-range dedicated communication method between RSE and OBE, OBE location information and time is automatically transmitted to the ITS operation center 23 when the vehicle with the OBE passes around the RSE, processed by each road section of the vehicle The passage speed can be obtained. On the other hand, since the ITS traffic information broadcasts a short distance within a diameter of 100m through the RSE, a mobile vehicle equipped with an OBE can receive various ITS information through an information display device, like the ITS service using conventional satellite communication. In addition, since the various information stored in the RSE can be provided from the ITS operation center 23 at the request of the OBE, it is possible to provide automatic fare collection, traffic information, road guidance and logistics services, which are representative ITS services currently provided. Do.

However, the ITS service, which is currently being used, uses existing cellular communication, satellite communication, and data communication such as cellular and personal communication system (PCS). In order to provide such services, realization of ITS-only network establishment using DSRC is indispensable.

The present invention has been proposed in order to meet the above demands, and since the satellite communication is advantageous in a small area where visibility is easy to secure, and the short-range dedicated communication is advantageous in the subscriber dense area, by combining these two communication methods, It is an object of the present invention to provide an intelligent transportation service method for easily constructing a wide area network at low cost and a computer-readable recording medium recording a program for realizing the method.

1 is a block diagram of an intelligent transportation system using conventional satellite communication.

2 is a block diagram of an intelligent transportation system using a conventional DSRC.

3 is an exemplary configuration of an intelligent transportation system using satellite communication and short-range dedicated communication to which the present invention is applied.

4 is a flowchart illustrating an embodiment of a process for collecting real-time traffic information and backup traffic information in an intelligent traffic service method according to the present invention.

5 is a flowchart illustrating an embodiment of a process for distributing / providing real-time traffic information and other information in an intelligent traffic service method according to the present invention;

* Explanation of symbols for the main parts of the drawings

31: Traffic collection sensor 32: Information collection network

33: ITS operation center 34: Short-range dedicated communication network

35: satellite transmitting station 36: satellite

37: vehicle terminal 38: DSRC

The present invention for achieving the above object, in the intelligent traffic service method using satellite communication and short-range dedicated communication (DSRC) applied to the intelligent transport system (ITS), the information collection server of the ITS operation center through the information collection network A first step of collecting information necessary to provide the delivered ITS service; And a second step of transmitting real-time traffic information or other information among the collected ITS information to an information distribution server of the ITS operation center and confirming whether the transmitted information is real-time traffic information. As a result of the checking of the second step, if the real-time traffic information, the road link speed information is transmitted to the satellite transmitting station to determine whether the short-range dedicated communication (DSRC) network is located in a densely populated area, and the vehicle terminal is operated according to the result. Making a third step; And a fourth step of transmitting the information to the short-range dedicated communication network every predetermined time interval or any occurrence of the event if the information other than the real-time traffic information is the result of the second step, and displaying the information on the information display device according to the user's request. Characterized in that made.

In addition, the present invention, the intelligent transport system having a processor, the information collection server of the ITS operation center for collecting information necessary for providing the ITS service delivered through the information collection network; And a second function of transmitting real-time traffic information or other information among the collected ITS information to an information distribution server of the ITS operation center and confirming whether the transmitted information is real-time traffic information. As a result of the confirmation of the second function, if the traffic information is real-time, the road link speed information is transmitted to the satellite transmitting station to determine whether the short-range dedicated communication (DSRC) network is located in a densely populated area, and the vehicle terminal is operated according to the result. Letting third function; And as a result of confirming the second function, if the information is information other than the real-time traffic information, realizing a fourth function of transmitting information to a short-range dedicated communication network at a predetermined time interval or at any occurrence of an event and displaying the information on the information display device according to a user's request. A computer readable recording medium having recorded thereon a program is provided.

The present invention is a technology that combines two communication methods to simultaneously utilize the advantages of satellite communication and DSRC, it is possible to provide a more diverse and economical service than the conventional ITS service. In other words, it is advantageous to provide ITS service using satellite communication in suburban areas where it is easy to secure the visible distance, while it is advantageous to use DSRC in city centers. It is easy.

Therefore, in the present invention, most of the data in the case of DSRC is downlink information from the ITS operation center to the RSE, the largest amount of data and real-time traffic information is provided in the form of broadcasting using a satellite communication network and other information to the RSE of the short-range dedicated communication network send.

To this end, it is possible to configure the system by combining satellite communication and DSRC with a traffic collection sensor, an information collection network, an ITS operation center, a roadside base station network, a DSRC, a satellite transmitting station, a satellite, and a vehicle terminal. The most important information collection of ITS operation center can be obtained by processing the information collected from the information collection network and the short-range dedicated communication network in the same way as the conventional DSRC method. On the other hand, the information provision of the ITS operation center uses the satellite communication network and the roadside base station network at the same time, so the role of the information distribution server is only responsible for the information classification service provided to the satellite communication network and the roadside base station network. And it can reduce the cost of leased line roadside station. In the suburban area, you can get local traffic information only through satellite receivers, and at the same time, in urban areas where short-range dedicated communication networks are established, OBE-attached vehicles passing through roadsides when RSE connected with satellite receivers provides local traffic information in broadcast form. Can get local traffic information.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram of an intelligent transportation system using satellite communication and DSRC to which the present invention is applied.

As shown in Figure 3, the intelligent traffic system using satellite communication and short-range dedicated communication, traffic collection sensor 31, information collection network 32, ITS operation center 33, short-range dedicated communication network 34, satellite It consists of the transmitting station 35, the satellite 36, the vehicle terminal 37, and the DSRC 38.

Here, the traffic collection sensor 31 and the information collection network 32 can be constructed as a backup traffic information collection and low-speed leased lines, respectively, like the conventional DSRC network.

Since the ITS operation center 33 uses two networks for providing the ITS service, the role of the information collection server is the same as that of the conventional DSRC ITS operation center 33, but the role of the information distribution server is differentiated. To this end, a large amount of data and real-time traffic information is provided in a broadcast form using a satellite communication network, and other information is provided using a short-range dedicated communication network 34. That is, the information collection server processes and stores various information into the information necessary to provide the ITS service, and then transmits to the information distribution server, the traffic information is subdivided by local traffic information and transmitted to the satellite transmitting station (35). Information is transmitted to the RSE via a short-range dedicated communication network 34.

Since the short-range dedicated communication network 34 is a state in which real-time traffic information is excluded, it can be constructed as a low-speed leased line, and can be utilized as a backup network for providing real-time traffic information in case of emergency.

The satellite transmitting station 35 is composed of a data generator and a satellite transmitter in the same manner as the ITS service using conventional satellite communication to perform data format conversion and uplink frequency modulation, respectively.

The satellite 36 utilizes a geostationary satellite excellent in wide area broadcasting data over a large area on the ground, similar to the conventional ITS service using satellite communication.

The vehicle terminal 37 is configured by adding an OBE of DSRC in addition to a conventional GPS receiver, a vehicle satellite receiver, and an information display device. The OBE is used in the city center. That is, since the information display device can directly receive traffic information from the vehicle satellite receiver in the suburban area and traffic information from the RSE in the city area, the configuration device of the vehicle terminal 37 is selected according to the user's vehicle moving environment. Can be attached.

DSRC (38) is a form of the addition of the DSRC satellite receiver to the conventional RSE when the DSRC satellite receiver in real time received by the DSRC satellite receiver and transmits to the RSE RSE extracts only the local information and the short-range broadcast, so that the OBE When a vehicle equipped with a vehicle terminal passes around the RSE, various ITS information may be provided through the information display device as in the case of using conventional satellite communication. However, DSRC satellite receiver is located in close proximity to the RSE, so in order to secure the visible distance to the satellite, care must be taken in selecting the RSE in the city center.

4 is a flowchart illustrating an embodiment of a process for collecting real-time traffic information and backup traffic information in an intelligent traffic service method according to the present invention.

As shown in FIG. 4, first, real-time traffic information can be collected from the DSRC. When a vehicle equipped with an OBE passes through an RSE cell area that broadcasts frame control information, the frame data information is exchanged between the RSE and the OBE. A wireless connection is attempted (401 to 404). In wireless connection, when OBE requests channel allocation to RSE, RSE provides necessary channel and RSE ID to OBE, and OBE transmits its ID to RSE through assigned channel. Here, the RSE ID is used to track the location of the vehicle when providing traffic information in the future.

The RSE, which obtains the OBE ID through the wireless connection, transmits the OBE ID and its ID to the information collection server through the roadside base station network. The information collection server stores the transmitted RSE ID and the current transit time of the OBE vehicle, and collects traffic information of the roadlink by calculating the speed using the distance and the transit time of the road link on which the vehicle operates. The calculated road link speed is stored in the information collection server together with the OBE ID and the RSE ID, and then the road link speed information is transmitted to the information distribution server, where the real-time traffic information collection is completed (405 to 407).

Secondly, the backup traffic information can be collected from the traffic information agency. If the information is collected by the server, the diagnostic RSE ID signal is diagnosed at regular intervals. . However, if the signal is not captured, it is determined that the RSE is broken and immediately starts the backup traffic information collection system. The traffic link is collected through the information collection network to the relevant institutions to collect traffic information (408 to 411). ). This backup traffic information is provided in place of the traffic information of the road link having problems when providing real-time traffic information through the information distribution server in the future. The collected traffic information for backup is stored in the information collection server and then transmitted to the information distribution server, where the information collection process is terminated (412 to 413, 407).

5 is a flowchart illustrating an embodiment of a process for distributing / providing real-time traffic information and other information in an intelligent traffic service method according to the present invention.

As shown in Figure 5, the various ITS information collected by the information collection server is transmitted to the information distribution server to determine the presence of real-time traffic information, real-time traffic information is transmitted to the satellite transmitting station, other information is transmitted through a short-range dedicated communication network (501-502).

First, real-time traffic information is transmitted to the satellite transmitting station with the road link speed information attribute (503). The satellite transmitter station can be composed of a data generator and a satellite transmitter. The data generator converts the data transmitted from the ITS operation center into the data format of the satellite transmitter, and then modulates it to an uplink frequency suitable for satellite communication through the satellite transmitter and transmits it to the satellite. do. The satellite converts an uplink frequency into a downlink frequency to serve as a relay for broadcasting data on the ground (503 to 504).

Subsequently, the terrestrial vehicle terminal receiving the satellite data is composed of a GPS receiver, a vehicle satellite receiver, an OBE, and an information display device. However, the operation of the vehicle terminal differs depending on the presence or absence of a DSRC (505). The DSRC network is mainly built around the city in consideration of the construction cost and does not exist in the suburban area.

Therefore, in the suburban area without the DSRC network, the OBE does not operate because the vehicle terminal directly receives necessary information from the satellite through the vehicle satellite receiver and the GPS receiver without using the DSRC network (506). Vehicle terminals in suburban areas operate vehicle satellite receivers, GPS receivers and information display devices to selectively receive and display only local traffic information on the information display device based on the current location indicated by GPS among the national traffic information broadcasted by satellites. (507). Here, the information display apparatus can express traffic-related information conveniently to the user in various forms such as text, graphics, and voice.

On the other hand, in urban areas where DSRC networks are established, the probability that the satellite and GPS receivers of a vehicle terminal can directly receive satellite signals in a moving vehicle is significantly lower than that in suburban areas, but the DSRC is fixed to street lamps in the city. Since the satellite receiver has a visible distance from the satellite, it is possible to receive traffic information 100% (508).

Traffic information received by the DSRC satellite receiver is transmitted to the RSE in real time and provided in a broadcast form within a 100m cell (509). The vehicle terminal running in the cell may provide the above-mentioned traffic-related services by turning off the vehicle satellite receiver and the GPS receiver and operating only the OBE (510). However, since the vehicle location tracking replaces the GPS as the RSE location tracking using the RSE ID as described with reference to FIG. 4, the location tracking resolution is determined according to the number of RSEs. Therefore, it is more efficient to use GPS and RSE simultaneously for services related to vehicle location tracking.

Second, other information that is not real-time traffic information is transmitted from the information distribution server to the DSRC using a short-range dedicated communication network. Most information other than real-time traffic information is stored in RSE through short-distance dedicated communication network such as road information, event information, weather information, and other necessary information. It is provided at (511 ~ 512).

Subsequently, when the OBE-equipped vehicle terminal travels in the cell, this information is stored in the vehicle terminal and displayed on the information display device when the user requests the necessary information, thereby providing various ITS services (513 to 514).

The method of the present invention as described above may be implemented as a program and stored in a computer-readable recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

The present invention as described above, by constructing an intelligent transportation system (ITS) that combines two communication methods are advantageous in a small area where it is easy to secure the visible distance, and a short distance dedicated communication (DSRC) in the subscriber concentrated area, The wide area network can be easily constructed at low cost.

In addition, the present invention, other than the traffic information ITS information uses a short-range dedicated communication network, can be used as a back-up network when satellite communication is not possible in case of emergency, and can use the advantages of satellite and DSRC at the same time It is effective to provide various and cheap ITS services.

Claims (4)

In the intelligent traffic service method using satellite communication and short-range dedicated communication (DSRC) applied to the intelligent transportation system (ITS), A first step of collecting, by the information collection server of the ITS operation center, information necessary to provide the ITS service delivered through the information collection network; And A second step of transmitting real-time traffic information or other information among the collected ITS information to an information distribution server of the ITS operation center and confirming whether the transmitted information is real-time traffic information; As a result of the checking of the second step, if the real-time traffic information, the road link speed information is transmitted to the satellite transmitting station to determine whether the short-range dedicated communication (DSRC) network is located in a densely populated area, and the vehicle terminal is operated according to the result. Making a third step; And A fourth step of transmitting the information to the short-range dedicated communication network at a predetermined time interval or at any occurrence of an accident if the information other than the real-time traffic information is displayed as the result of the second step; Intelligent traffic service method using satellite communication and short-range dedicated communication comprising a. The method of claim 1, The third step, A fifth step of confirming whether the short-range dedicated communication (DSRC) network is formed in a dense area; As a result of confirming in the fifth step, in a dense area where a short-range dedicated communication network is established, real-time traffic information received by the DSRC satellite receiver through satellite communication is transmitted to the roadside base station (RSE) and provided in the form of data broadcasting in a cell. A sixth step of providing an ITS service related to location tracking of a vehicle by turning off a vehicle satellite receiver and a GPS (Global Positioning System) receiver of a vehicle terminal operating in a cell; As a result of the checking of the fifth step, if the small area where the short-range dedicated communication network is not established, the vehicle terminal device directly receives necessary information from the satellite through the vehicle satellite receiver and the GPS receiver without using a DSRC network and installs the vehicle-mounted device. (OBE) is not operated, and the vehicle satellite receiver, the GPS receiver, and the information display device of the vehicle terminal are operated to selectively only local traffic information based on the current location displayed by the GPS among the national traffic information broadcasted by the satellite. Seventh step of receiving and displaying on the information display device Intelligent traffic service method using satellite communication and short-range dedicated communication comprising a. The method of claim 2, ITS service related to the location tracking of the vehicle, Intelligent traffic service method using satellite communication and short-range dedicated communication, characterized in that the simultaneous use of the GPS and the roadside base station (RSE). In an intelligent transportation system equipped with a processor, A first function of collecting information necessary for providing the ITS service delivered through the information collection network by the information collection server of the ITS operation center; And A second function of transmitting real-time traffic information or other information among the collected ITS information to an information distribution server of the ITS operation center and confirming whether the transmitted information is real-time traffic information; As a result of the confirmation of the second function, if the traffic information is real-time, the road link speed information is transmitted to the satellite transmitting station to determine whether the short-range dedicated communication (DSRC) network is located in a densely populated area, and the vehicle terminal is operated according to the result. Letting third function; And A fourth function of transmitting information to the short-range dedicated communication network at a predetermined time interval or at any occurrence of an accident if the information other than the real-time traffic information is confirmed as the result of the second function; A computer-readable recording medium having recorded thereon a program for realizing this.