KR100446743B1 - Continuous service method and system between base stations - Google Patents

Abstract

The present invention relates to a method and system for inter-base station interworking service. In particular, a plurality of base stations are assigned to one base station by assigning the same time slot to adjacent base stations for a specific vehicle terminal having a large amount of information to be transmitted and a cell plan for overlapping communication areas. In order to operate together, a large amount of information can be transmitted to a specific vehicle terminal. The present invention for this purpose is a method of providing a service of the traffic information system to perform the communication with the vehicle terminal in the DSRC method to provide the desired information to the traffic information collection and the driver, when there is a request for information from the vehicle terminal 440 In the first step of checking the requested amount of information in the server 410, and if the requested amount of information is equal to or greater than a reference amount of information that can be transmitted from one base station to the vehicle terminal, the DSRC server 410 determines that the current vehicle terminal is located. A second step of sharing the same information (channel information / packet data) with a plurality of base stations adjacent to the vehicle traveling direction with respect to the base station; and a plurality of base stations entering the own communication area as the vehicle proceeds. A third step of subsequently transmitting the same packet data while allocating a channel is performed.

Description

Interworking service method and system between base stations {CONTINUOUS SERVICE METHOD AND SYSTEM BETWEEN BASE STATIONS}

The present invention relates to an intelligent traffic information system, and more particularly, to an inter-base station interworking service method and system in a BIS system using Dedicated Short Range Communication (hereinafter, referred to as 'DSRC').

1 is a block diagram showing an embodiment of a conventional traffic information system using a DSRC, as shown in the first, the first and second to exchange information in a DSRC method whenever the vehicle terminal 140 enters a predetermined range; 2 base stations 131 and 132 and the first and second base stations 131 and 132 are connected to the dedicated line 120 to collect information from the first and second base stations 131 and 132. DSRC server 110 to manage is provided is configured.

The first and second base stations 131 and 132 operate in a state in which communication areas do not overlap each other.

The vehicle terminal 140 is configured to exchange information desired by the subscriber while transmitting and receiving channel requests, channel assignments, message transmissions, and acknowledgment signals whenever the base stations 131 and 132 enter a predetermined range.

Referring to the operation flowchart of FIG. 2, the operation process for the embodiment of the related art is as follows.

Since the communication areas of the first and second base stations 131 and 132 are not overlapped, the vehicle terminal 140 requests a channel assignment every time the base station enters a predetermined range and receives a new channel to receive information. Exchanged.

Here, the channel allocation operation for exchanging information between the first and second base stations 131 and 132 and the vehicle terminal is the same, so that the vehicle terminal 140 enters a predetermined range of the first base station 131. Will be explained.

That is, the first base station 131 broadcasts an FCMS broadcast message for the vehicle terminal, and the vehicle terminal 140 receiving the request requests a channel allocation to the first base station 131 using an ACTS time slot and requests a channel allocation. The first base station 131 receiving the signal allocates an empty time slot to the vehicle terminal 140 as a channel using an FCMS broadcast message.

Thereafter, the first base station 131 transmits the information about the vehicle terminal 140 to the DSRC server 110 through the dedicated line 120.

At this time, the DSRC server 110 checks the presence or absence of information on the vehicle terminal 140 in the database, and if there is information to be transmitted, packetizes it and transmits it to the first base station 131.

The first base station 131 packetizes the information received from the DSRC server 110, assigns a number to the packet, and loads the information in a message data slot (MDS) allocated to the vehicle terminal 140 to transmit the information to the vehicle terminal 140.

Accordingly, the vehicle terminal 140 returns the acknowledgment signal ACK to the first base station 131 using the acknowledgment channel slot, and the first base station 131 receives the acknowledgment signal ACK. The next packet is loaded into the message data slot and transmitted to the vehicle terminal 140.

Thereafter, when there is a packet to be transmitted to the vehicle terminal 140, the first base station 131 continuously allocates a message data slot (MDS), and when there is no packet to transmit, the vehicle terminal 140 signals that there is no packet to transmit. Recover the timeslot channel that was used after the transmission.

Thereafter, when the transmission is completed, the first base station 131 transmits a message indicating that the packet transmission is completed to the DSRC server 110, and the DSRC server 110 stores in the database that the information transmission of the corresponding vehicle terminal is completed.

3 is a block diagram showing another embodiment of a conventional traffic information system using a DSRC, as shown in the drawing, each time the vehicle terminal 340 enters a predetermined range, the vehicle terminal 340 in a DSRC manner. First and second base stations 331 and 332 that exchange information with the first and second base stations 331 and 332 are connected to the dedicated line 320 by the first and second base stations 331. The BIS service center 310 collects and manages information from 332 is provided.

The BIS service center 310 is a DSRC server 311 for collecting and managing information from a plurality of DSRC base stations (331,332), and the source data from the DSRC server 311 receives the data to provide the information desired by the subscriber The BIS server 312 for processing and managing the connection, and the DSRC server 311 and the BIS server 312 is connected to the Ethernet (Ethernet), and the DSRC server 311 is connected to the dedicated line 320 by A hub switch 313 for transmitting and receiving data with the first and second base stations 331 and 332 is provided.

The first and second base stations 331 and 332 operate in a state in which communication areas do not overlap each other, and transmit and receive channel requests, channel assignments, message transmissions, and acknowledgment signals whenever a vehicle terminal enters a predetermined range. Is configured to provide the desired information.

The vehicle terminal 340 is configured with various functions for the BIS service.

Referring to the operation of the other embodiment of the prior art as follows.

First, the first and second base stations 331 and 332 have a Continuous Communication Zone (CCZ) number of 0, a Transmit / Receive ID (TRI) of 00, and a TDI in a frame control message slot (FCMS) broadcast message frame defined in the DSRC protocol. Set the (Time Division ID) to 0 to use.

In this case, the order of the time slot and the base station is not specified, and each base station 331 and 332 independently communicates with the DSRC server 311 and transmits the information to the vehicle terminal without sharing information with neighboring base stations. 340 or information received from the vehicle terminal 340 and transmitted to the DSRC server 311.

In another exemplary embodiment of the prior art, a process of transmitting and receiving information between the first and second base stations 331 and 332 and the vehicle terminal 340 is performed in the same manner as in the operation flowchart of FIG.

However, in the related art, since a base station must provide information to a plurality of vehicle terminals at the same time, it is impossible to transmit information packets at high speed. Also, a vehicle terminal mounted on a vehicle running only within a communication area of a base station transmits information packets. Since the amount of information to be transmitted to the vehicle terminal is greater than the amount of reference information that can be transmitted from one base station to the vehicle terminal, the channel may be disconnected in a state in which the entire data cannot be transmitted.

Accordingly, the present invention provides a plurality of base stations to operate like one base station by making a cell plan so that communication areas overlap and allocating the same time slots between adjacent base stations for a specific vehicle terminal having a large amount of information to transmit in order to improve the conventional problem. Accordingly, a first object of the present invention is to provide a method and system for interworking between base stations, which are designed to transmit a large amount of information to a specific vehicle terminal.

In addition, the present invention is to connect the adjacent base stations by Ethernet to improve the conventional problem and when a large amount of information to be transmitted to a specific vehicle terminal by sharing information to be transmitted between adjacent base stations to a specific vehicle terminal A second object is to enable transmission.

1 is a block diagram showing an embodiment of a traffic information system using a conventional DSRC.

FIG. 2 is a flowchart illustrating an operation of transmitting and receiving information between a base station and a vehicle terminal in FIG. 1; FIG.

Figure 3 is a block diagram showing another embodiment of a traffic information system using a conventional DSRC

4 is a block diagram of a traffic information system for an embodiment of the present invention.

5 is an operation flowchart for transmitting packet data by allocating the same channel to a plurality of base stations in FIG.

Figure 6 is a block diagram of a traffic information system for another embodiment of the present invention.

7 is an operation flowchart for transmitting packet data by allocating the same channel to a plurality of base stations in FIG.

8 is a flowchart illustrating an operation for transmitting packet data by allocating different channels to a plurality of base stations in FIG.

9 is a detailed block diagram of a DSRC base station in FIG.

10 is an exemplary view showing a structure of a protocol stack for each device for providing a wireless Internet service using a DSRC system according to the present invention.

11 is an exemplary view showing a DSRC frame structure in an embodiment of the present invention.

12 is an exemplary view showing the structure of FCMS in FIG.

FIG. 13 is an exemplary view showing the structure of an MDS in FIG. 11; FIG.

14 is an exemplary view showing the structure of an ACTS in FIG.

15 is an exemplary view showing a frame structure of TDMA / TDD and TDMA / FDD schemes.

16 is a signal flowchart showing a communication procedure between a DSRC base station and a vehicle terminal in FIGS. 4 and 6;

17 shows an example of a message format between a base station and a vehicle terminal.

18 shows an example of an IP datagram format for an Internet service.

19 is an exemplary view showing an IP datagram format for DSRC type internet data transmission.

Explanation of symbols on the main parts of the drawings

410,611: DSRC server 431 ~ 433,631,632: base station

440,640: vehicle terminal 650: Ethernet

In order to achieve the above object, the present invention provides a method for verifying the requested amount of information in a DSRC server when there is a request for information from a vehicle terminal, and the requested amount of information is equal to or greater than a reference amount of information that can be transmitted from one base station to the vehicle terminal. If determined, the DSRC server shares the same information (channel information / packet data) to a plurality of adjacent base stations in the vehicle traveling direction; and as the vehicle progresses, the plurality of base stations allocates the same channel to the vehicle terminal and transmits the same packet data. Then it is characterized in that the step of transmitting.

The system of the present invention for performing such a step includes a plurality of base stations for transmitting and receiving packet data to a vehicle terminal having an overlapping communication area with an adjacent base station and entering a communication area thereof, and its own communication area among the plurality of base stations. If there is a request for confirmation of transmission information to the vehicle terminal from any base station that has allocated a channel to the vehicle terminal entering the terminal, the amount of information to be transmitted is checked, and if the amount of information is determined to be greater than or equal to the reference information that can be transmitted from one base station to the vehicle terminal, And a DSRC server configured to share the same packet data in a vehicle traveling direction with respect to the base station of FIG.

In order to achieve the above object, the present invention provides the steps of connecting adjacent base stations to a dedicated circuit network for a plurality of base stations that are continuously adjacent to each other in a vehicle traveling direction, and wherein, Determining whether a vehicle terminal enters into a communication area of an arbitrary base station; if there is a request for information from the vehicle terminal entering the communication area of an arbitrary base station, checking, by the DSRC server, the requested amount of information; If the amount of information requested from the base station is greater than the amount of information that can be transmitted from the base station to the vehicle terminal, the step of sharing the same packet data to a plurality of base stations adjacent to the vehicle traveling direction based on the base station requested information; As the vehicle progresses, multiple base stations And it transmits the transmission packet data by assigning a channel to a terminal adjacent the vehicle transmission information to the vehicle traveling direction, and then the base station is then the same packet data from a plurality of base stations, characterized by carrying out the step of transmitting to the vehicle terminal.

In the system of the present invention for performing such a step, whenever a vehicle terminal enters a predetermined range, the packet data is exchanged with the vehicle terminal in a DSRC manner, and the amount of packet data to be transmitted to the vehicle terminal is transmitted from one base station to the vehicle terminal. When the amount of information is larger than the reference information, the base station transmits packet data to the vehicle terminal and transmits the communication contents with the vehicle terminal to the adjacent base station in the vehicle traveling direction, and to the vehicle terminal entering its own communication area among the plurality of base stations. If there is a request for confirmation of transmission information from any base station to which a channel has been allocated to the vehicle terminal, the amount of information to be transmitted is checked and if the information amount is greater than the reference information that can be transmitted from one base station to the vehicle terminal, the vehicle is referred to the base station. Adjacent to the direction of travel DSRC server for sharing the same packet data to a plurality of base stations, and a dedicated circuit for interworking a plurality of base stations in the vehicle traveling direction based on the base station with the information request for continuous packet data transmission to the vehicle terminal It is characterized by the configuration of Ethernet (Ethernet).

Hereinafter, the present invention will be described in detail with reference to the drawings.

In the embodiments of the present invention, a detailed description of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

4 is a block diagram of an apparatus for an embodiment of the present invention, as shown in FIG. 4, each time the vehicle terminal 440 enters a predetermined range, continuously exchanges information with the vehicle terminal 440 in a DSRC manner. In order to interwork with each other, the first to third base stations 431 to 433, the first to third base stations 431 to 433, and the dedicated line 420 are connected to each other. 433) is configured to include a DSRC server 410 to collect and manage information.

The first to third base stations 431 to 433 are configured by installing a communication area in a state where they overlap each other.

The first to third base stations 431 to 433 operate in the vehicle terminal 440 to determine a communication area in charge of each base station as one communication area.

When entering the communication area, the vehicle terminal 440 transmits a channel allocation request signal only to the first base station 431, which is the first base station, and passes through the third base station 433 at a time slot allocated by the first base station 431. Until you use it.

Referring to the operation and effects of the embodiment of the present invention configured as described above are as follows.

In general, if the communication area of the DSRC base station, that is, the cell radius is 100m and the vehicle terminal is running at a speed of 60 km, the corresponding DSRC base station may transmit approximately 1 Mbyte of information to the vehicle terminal for 6 seconds.

In the embodiment of the present invention, it will be described on the assumption that 1 Mbyte of reference information that can be transmitted from one DSRC base station to a vehicle terminal.

When the amount of information to be transmitted to the vehicle terminal 440 is greater than the amount of reference information that can be transmitted from one base station to the vehicle terminal. For example, assuming that the amount of information to be transmitted is 3 Mbytes, the communication areas are set to overlap the base stations 431 to 433.

For convenience, it is assumed that the base station of the first position is the first base station 431 and the last base station is the third base station 433 when the three base stations 431 to 433 are bundled into one communication area to view the vehicle traveling direction.

When the first base station 431 transmits an FCMS broadcast message and requests channel allocation from the vehicle terminal 440 using the ACTC time slot, the first base station 431 provides an empty channel to the vehicle terminal 440. It allocates and receives the information (OBU ID) of the vehicle terminal 440 and transmits it to the DSRC server 410 through the dedicated line 420.

The DSRC server 410 searches the database and checks whether there is information to be transmitted to the corresponding vehicle terminal ('440' in FIG. 4). If there is information to be transmitted, the DSRC server 410 determines that the information amount is greater than the reference information amount (for example, 3 Mbytes). The packetized information is transmitted simultaneously to the first to third base stations 431 to 433.

Thereafter, when the first base station 431 receives the information to be transmitted to the vehicle terminal 440, the first base station 431 packetizes the number and transmits the packet data to the message data slot allocated to the vehicle terminal 440.

Accordingly, the vehicle terminal 440 returns an acknowledgment signal (ACK) using the acknowledgment time slot.

Thereafter, when the first base station 431 receives the acknowledgment signal ACK from the vehicle terminal 440, the first base station 431 transmits the next packet using the same message data slot MDS, and receives the packet. Transmits an acknowledgment signal (ACK) to the first base station 431.

Thereafter, when the driving vehicle enters into the communication area of the second base station 432, the second base station 432 loads the packet data using the same message data slot MDS used in the first base station 431. Transmit to vehicle terminal 440.

At this time, the vehicle terminal 440 transmits an acknowledgment signal (ACK) to the second base station 432.

If the vehicle terminal 440 is located in the communication area of the second base station 432, the second base station 432 transmits the next packet data until the vehicle terminal 440 is out of the communication area. Done.

Thereafter, when the driving vehicle enters into the communication area of the third base station 433, the third base station 433 loads packet data using the same message data slot MDS used by the first base station 431. Transmit to vehicle terminal 440.

At this time, the vehicle terminal 440 transmits an acknowledgment signal (ACK) to the third base station 433.

If the vehicle terminal 440 is located in the communication region of the third base station 432, the third base station 432 transmits the next packet data until the vehicle terminal 440 is out of the communication region. Done.

Thereafter, when all the packet data to be transmitted to the vehicle terminal 440 is transmitted, the third base station 433 recovers the channel allocated to the vehicle terminal 440 and simultaneously transmits the channel to the vehicle terminal 440 by the DSRC server 410. It sends a message that the packet data transmission is completed.

The DSRC server 410 transmits the packet data to the vehicle terminal 440 and stores the information in the database.

6 is a block diagram of a traffic information system for another embodiment of the present invention. As shown in FIG. 6, whenever the vehicle terminal 640 enters a predetermined communication range, the vehicle terminal 640 is connected to the vehicle terminal 640 in a DSRC manner. First and second base stations 631 and 632 exchanging information, and the first and second base stations 631 and 632 are connected to the dedicated line 620 by the first and second base stations 631. The BIS service center 610 which collects and manages information from the 632 and the first and second base stations 631 and 632 interwork with each other to transmit and receive packet data with the vehicle terminal 640. (650) is configured.

The BIS service center 610 is a DSRC server 611 that collects and manages information from the first and second base stations 631 and 632 of the DSRC method, and receives the source data from the DSRC server 611 to receive information desired by the subscriber. The BIS server 612 processes and manages data to provide data, and connects the DSRC server 611 and the BIS server 612 by Ethernet and connects the DSRC server 611 to a dedicated line 620. And a hub switch 613 for transmitting and receiving data to and from the first and second base stations 631 and 632.

The first and second base stations 631 and 632 operate in a state in which communication areas do not overlap each other, and transmit and receive channel requests, channel assignments, message transmissions, and acknowledgment signals whenever a vehicle terminal enters a predetermined range. To provide the desired information.

The vehicle terminal 640 is configured with various functions for the BIS service.

The Ethernet 650 defines information for sharing a base station, information on a packet data transmission order of a base station, and information on a time slot operating method in a frame for transmission from the base stations 631 and 632 to the vehicle terminal 640. Configure to

Referring to the operation and effect of the other embodiment of the present invention configured as described above are as follows.

In general, if the communication area of the DSRC base station, that is, the cell radius is 100m, and the vehicle terminal is traveling at a speed of 60 km, the corresponding DSRC base station can transmit approximately 1 Mbyte of information to the vehicle terminal for 6 seconds, so it is transmitted from one DSRC base station to the vehicle terminal. Assume that the possible reference information amount is 1 Mbyte.

In another embodiment of the present invention will be described on the assumption that the amount of information to be transmitted to the vehicle terminal 2Myte.

Another embodiment of the present invention will be described by dividing the case of assigning the same channel and the case of assigning different channels to provide continuous information from the adjacent base station to the vehicle terminal without passing through the DSRC server.

First, an operation for transmitting packet data by allocating the same channel to a specific vehicle terminal in another embodiment of the present invention will be described with reference to the operation flowchart of FIG. 7.

In FIG. 6, it is assumed that a first base station is referred to as a first base station ('631' in FIG. 6) and a second base station is referred to as a second base station ('632' in FIG. 6) based on the driving direction of the vehicle.

At this time, in order to continuously transmit the information to the vehicle terminal 640 without interruption, the parameters of the transmission frame of the first base station 631 based on the vehicle traveling direction are set to CCZ = 1, TRI = 10 and TDI = 1. The parameters of the two base stations 632 set CCZ = 1, TRI = 01 and TDI = 1.

Thereafter, the first and second base stations 631 and 632 are connected to each other through the Ethernet 650.

Thereafter, the first and second base stations 631 and 632 receive and share information to be transmitted to the vehicle terminal 640 from the DSRC server 611 and store it in a memory.

Thereafter, when the vehicle enters its own communication area, the first base station 631 checks whether there is an ACTS channel allocation request from the vehicle terminal 640 that receives the FCMS broadcast message transmitted by the first base station 631.

Then, when the first base station 631 receives a channel allocation request from the vehicle terminal 640, the first base station 631 allocates a specific timeslot to the vehicle terminal 640 and transmits the specific time slot to the vehicle terminal 640. The acknowledgment signal (ACK) is sequentially received while transmitting the information sequentially.

In this case, the first base station 631 provides the communication contents (channel information / transmitted packet number) with the vehicle terminal 640 to the second base station 632.

Accordingly, the second base station 632 may leave a specific channel provided from the first base station 631 to the vehicle terminal 640 for the specific vehicle terminal 640 and the vehicle terminal 640 may communicate with its own. It enters the area and checks if the channel allocation is requested.

Subsequently, when the vehicle terminal 640 entering the communication area requests the channel allocation, the second base station 632 allocates the same channel as the first base station 631 to the vehicle terminal 640 and the first base station. Packet data not transmitted at 631 is then transmitted to the vehicle terminal 640.

Subsequently, when the transmission of the information to the vehicle terminal 640 is completed, the second base station 632 transmits an end signal to the vehicle terminal 640 to receive an acknowledgment signal ACK, and then assigns it to the vehicle terminal 640. The communication is terminated by retrieving the channel (time slot), and the DSRC server 611 transmits a message indicating that the packet data transmission is completed to the vehicle terminal 640.

In addition, in another exemplary embodiment of the present invention, an operation for transmitting packet data by allocating a different channel from each base station to a specific vehicle terminal will be described with reference to the operation flowchart of FIG. 8.

In this case, only the channel allocation process is different from the case of allocating the same channel from each base station to a specific vehicle terminal, and the process of transmitting packet data is the same.

In order to continuously transmit information to the vehicle terminal 640 without interruption of information, the parameters of the transmission frame of the first base station 631 are set to CCZ = 1, TRI = 10 and TDI = 0 based on the traveling direction of the vehicle. In addition, the parameters of the transmission frame of the second base station 632 set CCZ = 1, TRI = 01 and TDI = 0.

Then, the first and second base stations 631 and 632 are connected by Ethernet 650.

Thereafter, information to be transmitted to the vehicle terminal 640 is received from the DSRC server 611 and shared by the first and second base stations 631 and 632 and stored in the memory.

Thereafter, the first base station 631 checks whether there is a channel allocation request from the vehicle terminal 640 as the vehicle enters its communication area while transmitting the FCMS broadcast message.

Subsequently, when there is a channel allocation request from the vehicle terminal 640, the first base station 631 allocates a specific time slot to the vehicle terminal 640 and sequentially acknowledges the information transmitted to the vehicle terminal 640. Receive a signal ACK.

In this case, the first base station 631 provides the communication contents (channel information / transmitted packet number) with the vehicle terminal 640 to the second base station 632.

Thereafter, the second base station 632 enters the vehicle terminal 640 out of the communication area of the first base station 631 into the communication area of the second base station 632 and transmits the vehicle terminal 640 to its FCMS broadcast message. Checks if there is a channel allocation request.

At this time, if there is a channel allocation request from the vehicle terminal 640, the second base station 632 may assign an empty channel (time slot) to the vehicle regardless of the channel allocated by the first base station 631 to the vehicle terminal 640. After allocating to the terminal 640, the packet data not transmitted by the first base station 631 is then transmitted to the vehicle terminal 640.

Subsequently, when the transmission of the information to the vehicle terminal 640 is completed, the second base station 632 transmits an end signal to the vehicle terminal 640 to receive an acknowledgment signal ACK, and then assigns it to the vehicle terminal 640. The communication is terminated by retrieving the channel (time slot), and the DSRC server 611 transmits a message indicating that the packet data transmission is completed to the vehicle terminal 640.

In addition, in the embodiment of the present invention and another embodiment described that the adjacent base stations are connected in advance before the vehicle enters the communication area of the first base station, when the vehicle enters the communication area of the first base station The connection range of the base station may be set according to the amount of information to be transmitted to the vehicle terminal.

Meanwhile, in one embodiment and another embodiment of the present invention, the base stations 431 to 433 and 631 and 632 are DSRC base stations, which can transmit data with a vehicle terminal at a speed of up to 1 Mbps, and enhance channel setting and information exchange effects. In order to communicate with multiple vehicle terminals at the same frequency using TDMA / FDD or TDMA / TDD multiple access protocols, it is possible to use ISM (Industrial, Scientific and Medical) band frequency and low power RF And to perform communication.

As shown in the detailed block diagram of FIG. 9, the DSRC base station provided in the embodiment and the other embodiment is configured by integrating the high frequency unit 910 and the control unit 920.

The high frequency unit 910 includes an antenna 911 that radiates a transmission frequency or receives a frequency, an up converter for converting an ASK (Amplitude Sequence Keying) modulated signal to a predetermined radio signal, and an ASK modulated radio. An RF converter (912) including a down converter (RF) (Down Converter) for converting a signal into a demodulating ASK signal, and an ASK modem for demodulating the data signal and demodulating the received ASK signal (ASK MODEM). 913, and a sensor 914 for identifying an operation state of the base station.

The control unit 920 transmits a CPU 921 for arithmetic processing, and transmits the data generated from the CPU 921 to the ASK modem 913 by forming a communication frame suitable for an active DSRC protocol. A medium access control field-programmable gate array (FPGA) 922 including a reception FPGA (RX, 922b) for extracting only the data required by the CPU 921 from the demodulated signal from the 922a and the ASK modem 913; A memory 923 including a RAM 923a and a PROM 923b, a buffer 924 for transmitting a signal sensed by the detector 915 to the CPU 921, and a user; A display unit 926 consisting of an LCD indicator 926a and an LED 926b for informing the user of the base station's status to inform status and operation, an RS-232 927 in serial communication with a PC or server, and a remote server And an interface unit 928 for communication.

The high frequency unit 910 and the control unit 920 share a power supply unit 915 to receive power and radiate heat generated therein by the heat radiation pad 940.

Therefore, since the base station provided in the embodiment of the present invention is configured as described above, the high frequency unit and the control unit are installed at different positions with a predetermined distance in the prior art, respectively, the power unit and the heat radiating fan are respectively provided to the high frequency unit and the control unit. In addition to the problem of adding a component to be provided, and in addition to the conventional technology to solve the problem of having to provide RS422 in each of the high frequency unit and the control unit for long-distance communication, the control, signal transmission, For monitoring purposes, problems such as line loss and noise deterioration due to the installation of many cables can be solved.

Referring to the operation and operation of the DSRC base station provided in the embodiment of the present invention configured as described above are as follows.

Each DSRC base station provided in an embodiment of the present invention transmits wireless data information, and when a vehicle equipped with a vehicle terminal enters a predetermined range, the multiple access protocol of the TDMA / TDD scheme or the TDMA / FDD scheme is performed with the vehicle terminal. Channel setup and information exchange are performed using.

That is, when the vehicle equipped with the vehicle terminal enters a predetermined range, the DSRC base station converts the signal received by the high frequency unit 910 through the antenna 911 into an ASK signal that can be demodulated by the down converter of the wireless converter 912. And demodulate the converted ASK signal through an ASK modem 913.

The signal demodulated by the ASK modem 913 is directly input to the MAC FPGA 922 of the controller 920.

The MAC FPGA 922 receives the demodulated signal from the ASK modem 913 to the receiving FPGA 922b, and the receiving FPGA 922b extracts only the data needed by the CPU 921 to the CPU 921. To pass.

The CPU 921 performs an operation for monitoring and control operation of the vehicle terminal according to the received data. At this time, the operation is performed using the programs and parameters recorded in the RAM 923a and the PROM 923b of the memory 923, and the result is RS-232C 927 and the interface (Ethernet / ADSL / MODEM / PCS_Network) ( Through 928).

When the controller 920 transmits the data to the vehicle terminal, data is generated and output from the CPU 921, and the data is transmitted to the ITS active short-range wireless communication protocol by the transmit FPGA 922a of the MAC FPGA 922. Suitably forms and outputs a communication frame.

The communication frame is directly input to the ASK modem 913 of the high frequency unit 910, the ASK modem 913 ASK-modulated the communication frame data to the wireless converter 912, the wireless converter ( 912 converts the ASK-modulated radio signal into a predetermined radio signal in the up-converter and radiates it to the vehicle terminal at the transmission frequency through the antenna 911.

In addition, the high frequency unit 910 and the control unit 920 are operated by receiving power from one power supply unit 915, and heat generated from the internal components by the heat radiation pad 940 installed inside the case. It effectively dissipates through the side case.

In this way, the high frequency unit 910 transmits and receives a frequency with the vehicle terminal mounted in the vehicle, and communicates with the control unit 920 through the connector 901, the control unit 920 communicates with the vehicle terminal, and integrates the existing RS422 can be removed to communicate with each other. In addition, the structure of the antenna 911 may be a patch antenna using a substrate (PCB).

In addition, the DSRC base station may simultaneously communicate with up to eight vehicle terminals at one frequency using a multiple access protocol of TDMA / FDD or TDMA / TDD.

The TDMA scheme is a multiple access technique that can divide one frequency into several time slots and allocate one channel per timeslot.

The time division duplex (TDD) scheme is a technology that enables bidirectional communication by enabling transmission and reception on a time axis using one frequency.

In the FDD scheme, when a DSRC base station and a vehicle terminal communicate in both directions, a transmission channel and a reception channel are determined using different frequencies, and then communication is performed using a designated time slot.

In the DSRC system, a DSRC frame for transmitting and receiving a message between a base station and a vehicle terminal includes a frame control message slot (FCMS), a message data slot (MDS), and an activation slot (ACTS), as shown in FIG. 11. Using the DSRC frame, a communication information broadcast, channel request, channel assignment, data transmission, and reception information acknowledgment (ACK) message are transmitted.

As shown in the exemplary diagram of FIG. 12, the FCMS (Frame Control Message Slot) includes a Preamble (PR), a Frame Sync Word (FSW), a Signaling (SIG), a Fixed Equipment ID (FID), and a Frame Structure ID (FSI). , Release Timer ID (RLT), Service Code (SC), Control Information of SCI (CI), Link ID (LID), Cyclic Redundancy Check (CRC), Guard Time Start (GTS), and Guard Time End (GTE) .

The FCMS includes eight slot control IDs (SCIs) each consisting of a CI and an LID.

As shown in the example diagram of FIG. 13, the MDS (Message Data Slot) is composed of MDC and ACKC, and the MDC (Message Data Channel) includes PR (Preamble), CSW (Channel Sync Word), and MAC (Medium Access). Control (ACK), MSDU (MAC Service Data Unit), CRC (Cyclic Redundancy Check) and the ACK Channel (ACKC) is PR (Preamble), CSW (Channel Sync Word), AI (Acknowledgement ID), CRC (Cyclic Redundancy Check) )

GT3 (Guard Time 3) exists between the MDS and ACKC, and GT4 (Guard Time 4) exists behind the ACKC.

The ACTS (Activation Slot) is composed of a plurality of ACTCs (Activation Channels), GT5 (Guard Time 5) is present between the ACTC and GT6 (Guard Time 6) is present after the last ACTC.

By the way, the frame structure of the TDMA / TDD scheme and the TDMA / FDD scheme used in the DSRC system is as shown in the exemplary diagram of Fig. 15 (a) (b).

In the embodiment of the present invention, the TDMA / FDD communication process between the DSRC base station and the vehicle terminal will be described with reference to the signal flowchart of FIG.

The frame structure of the TDMA / FDD scheme includes a frame control message slot (FCMS), an activation slot (ACTS), and a message data slot (MDS), as shown in the exemplary diagram of FIG. 15 (b). 8B illustrates a process of transmitting a communication information broadcast, channel request, channel assignment, data transmission, and reception information acknowledgment (ACK) message using the frame structure shown in FIG.

In brief, this process, when the information on the communication channel using the FCMS time slot is broadcasted to the various vehicle terminals in the DSRC base station is assigned to the DSRC base station to receive the channel assignment in the vehicle terminal receiving the broadcast After requesting, the channel request selects a time slot, which is a channel available at the DSRC base station, and notifies the vehicle terminal, and transmits data in the time slot determined by the DSRC base station to the vehicle terminal. Acknowledgment (ACK or NACK) is performed on the transmitted data.

That is, the process is performed between the DSRC base station and the vehicle terminal when the vehicle enters / exits or passes through a specific area.

However, the structure of a protocol stack for each device for providing a wireless Internet service to a vehicle terminal in a DSRC system is shown in the example of FIG.

In FIG. 10, an Internet-enabled terminal (eg, a portable computer) connected to the vehicle terminal OBU has a structure capable of receiving Internet information from an IP server in an external agent FA, and a roadside base station apparatus RSU. The air interface between the OBU and the vehicle terminal is to transmit Internet data at the LLC layer.

At this time, the message format between the vehicle terminal and the DSRC base station to provide the Internet service to the vehicle terminal is the same as the example of FIG.

17 is a message format for transmitting an IP datagram to the MSCU in the MDC shown in the example of FIG. Here, the MSDU consists of a total of 65 bytes. The first 1 byte is used for LLC (Logical Link Control) and the next 64 bytes are used for transmitting an IP datagram.

In addition, the IP datagram for providing the Internet service must maintain the message format of FIG. In order to transmit the IP datagram in the DSRC radio section, it should be transmitted with the LLC as the header before the MSDU divided by 64 bytes.

When the MAC in the MDC includes the message order of the MSDU and transmits it sequentially, the counterpart device, that is, the DSRC base station or the vehicle terminal, decodes the sequence number assigned by the MAC, stores it in the memory sequentially, and then stores it again in TCP / IP. It is transmitted by the communication protocol.

That is, in the embodiment of the present invention, when an Internet service is provided to a vehicle terminal, an Internet-enabled terminal such as a notebook is connected to perform communication using a TCP / IP communication protocol, and an Ethernet connection between a DSRC server and an ISP (Internet Service Provider) is performed. Internet communication is performed by the TCP / IP communication protocol.

In other words, a protocol stack for an Internet service should be established between an Internet server (ISP) and an Internet-enabled terminal, and an IP server, a DSRC base station (RSU), and a terminal (OBU) existing between the Internet server (ISP) and the Internet-enabled terminal. Communicate in a manner that passes IP data.

In addition, the IP datagram for the Internet service in the above manner is the same as the example of FIG. Therefore, in the DSRC wireless communication, the IP data format for internet data transmission is divided into 64 bytes for transmission as shown in the example of FIG.

As described in detail above, in the present invention, when there is a large amount of information to be transmitted from a DSRC server to a specific vehicle terminal, the same channel is allocated between a plurality of base stations adjacent to each other in the vehicle traveling direction, or a plurality of base stations are connected by Ethernet to a specific vehicle terminal. By sharing the data to be transmitted and allowing the next base station to transmit data that the previous base station could not transmit as the vehicle progresses, it can send a lot of information to the vehicle terminal continuously and continuously to provide the desired information to the driver. It works.

Claims (12)

In the service providing method of the traffic information system to perform the communication with the vehicle terminal by the DSRC method to collect the traffic information and provide the desired information to the driver, A first step of confirming the requested amount of information in a DSRC server when there is a request for information from the vehicle terminal; If it is determined that the requested amount of information is greater than the amount of information that can be transmitted from one base station to the vehicle terminal, the DSRC server allows the same packet data to be shared among a plurality of base stations adjacent in the vehicle traveling direction based on the base station where the vehicle terminal is currently located. The second step, And a third step of sequentially transmitting the same packet data while allocating a channel to the vehicle terminal entering the communication area as the vehicle progresses. In the service providing method of the traffic information system to perform the communication with the vehicle terminal by the DSRC method to collect the traffic information and provide the desired information to the driver, A first step of executing a cell plan such that a communication area overlaps a plurality of base stations consecutively adjacent in a vehicle traveling direction; A second step of determining whether a vehicle terminal enters a communication area of a base station among a plurality of base stations in which communication areas overlap; A third step of confirming the requested amount of information in the DSRC server when there is a request for information from the vehicle terminal entering the specific communication area; If it is determined that the requested amount of information is greater than the amount of reference information that can be transmitted from one base station to the vehicle terminal, the DSRC server sharing the same packet data to a plurality of adjacent base stations in the vehicle direction based on the requested base station; And a third step of sequentially transmitting the same packet data while allocating channels to the vehicle terminals as the vehicle progresses. In the service providing method of the traffic information system to perform the communication with the vehicle terminal by the DSRC method to collect the traffic information and provide the desired information to the driver, A first step of connecting adjacent base stations with a dedicated line network to a plurality of base stations continuously adjacent in a vehicle traveling direction; A second step of determining whether the vehicle terminal enters a communication area of an arbitrary base station among a plurality of base stations connected by a dedicated line network between adjacent base stations; A third step of the DSRC server confirming the requested amount of information when there is a request for information from a vehicle terminal entering the communication area of any base station; A fourth step in which the DSRC server shares the same packet data to a plurality of adjacent base stations in the vehicle traveling direction based on the information requested base station if it is determined that the requested information amount is greater than the reference information amount that can be transmitted from one base station to the vehicle terminal; Steps, As the vehicle proceeds, a plurality of base stations allocate a channel to the vehicle terminal to transmit packet data, and transmit the transmission content to the next base station adjacent to the vehicle traveling direction, and then transmit the same packet data to the vehicle terminal. The inter-base station interworking service method comprising the step of performing a fifth step. The inter-base station interworking service method according to claim 1 or 2 or 3, wherein a plurality of base stations for transmitting the same packet data to the vehicle terminal allocate the same channel to the vehicle terminal. The inter-base station interworking as claimed in claim 1 or 2 or 3, wherein a plurality of base stations for transmitting the same packet data to the vehicle terminal allocate an empty channel instead of the same channel to the vehicle terminal. Service method. The method of claim 1, wherein when providing an Internet service, an IP datagram for an Internet service between a vehicle terminal and a plurality of base stations is transmitted by dividing a predetermined byte in accordance with a DSRC scheme. Interworking method between base stations. In the traffic information system to communicate with the vehicle terminal in the DSRC method to collect traffic information and provide the desired information to the driver, A plurality of base stations for transmitting and receiving packet data to a vehicle terminal having a communication area overlapping an adjacent base station and entering a communication area thereof; If there is a request for confirmation of transmission information to the vehicle terminal from any base station that has allocated a channel to the vehicle terminal entering its communication area among the plurality of base stations, the amount of information to be transmitted is checked and the information amount is transmitted from one base station to the vehicle terminal. And a DSRC server configured to share the same packet data to a plurality of base stations adjacent in the vehicle traveling direction based on the predetermined base station if it is determined to be equal to or greater than the amount of possible reference information. In the traffic information system to communicate with the vehicle terminal in the DSRC method to collect traffic information and provide the desired information to the driver, Whenever the vehicle terminal enters a predetermined range, the packet data is exchanged with the vehicle terminal by a DSRC method. When the amount of information to be transmitted to the vehicle terminal is determined to be greater than the reference information that can be transmitted to the vehicle terminal, the packet data is transmitted to the vehicle terminal. A plurality of base stations which transmit contents of communication with the vehicle terminals to adjacent base stations in the advancing direction; If there is a request for confirmation of transmission information to the vehicle terminal from any base station that has allocated a channel to the vehicle terminal entering its communication area among the plurality of base stations, the amount of information to be transmitted is checked and the information amount is transmitted from one base station to the vehicle terminal. A DSRC server for sharing the same packet data to a plurality of base stations adjacent to each other in the vehicle traveling direction based on the predetermined base station if it is determined to be equal to or greater than the amount of reference information possible; Inter-base station interworking service, characterized in that for configuring the continuous packet data transmission to the vehicle terminal by the Ethernet-type dedicated circuit network means for interworking a plurality of base stations in the vehicle traveling direction based on the base station with the information request in the above system. The inter-base station interworking system according to claim 7 or 8, wherein the dedicated circuit network means is formed of Ethernet. The terminal of claim 7 or 8, wherein the base station includes a high frequency unit performing near field communication with a terminal mounted on the vehicle through an antenna, and a terminal connected to the high frequency unit through a connector and mounted on the vehicle through the high frequency unit. Inter-base station interworking service system, characterized in that each configuration by integrating the control unit to perform the monitoring and control. The inter-base station interworking service system according to claim 7 or 8, wherein the DSRC server transmits a message to allocate the same channel to a plurality of base stations for transmitting the same packet data to the vehicle terminal. The inter-base station interworking service system according to claim 7 or 8, wherein the DSRC server transmits a message to a plurality of base stations for transmitting the same packet data to the vehicle terminal to allocate an empty channel instead of the same channel. .