KR100283083B1 - Method for transmitting the reception acknowledgement signal by frame unit - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method of transmitting an acknowledgment signal on a frame basis.

2. The technical problem to be solved by the invention

The present invention provides an acknowledgment signal transmission method which improves transmission efficiency by performing acknowledgment that is performed by one slot unit conventionally, and a computer-readable recording medium recording a program for realizing the method. For that purpose.

3. Summary of Solution to Invention

The present invention provides an acknowledgment signal transmission method for transmitting an acknowledgment signal on a frame basis, wherein a downlink reception acknowledgment slot (DACKS) separated from a message data slot (MDS) in a downlink section is allocated within a frame. Transmission of acknowledgment information for confirming whether data transmitted through the message data slot (MDS) of the uplink is transmitted through at least one downlink acknowledgment channel (DACKC) allocated to the downlink acknowledgment slot (DACKS). A first step of making; And assigning an uplink reception confirmation (UACK) field to a next frame of a frame in which an uplink data message slot (MDS) is used, and transmitting data through the uplink data message slot (MDS) in the used frame. And transmitting the acknowledgment information for confirming reception of the downlink through the uplink acknowledgment (UACK) field allocated to the next frame.

4. Important uses of the invention

The present invention is used in a protocol of a communication system such as an intelligent transportation system.

Description

Method of transmitting acknowledgment signal in frame unit {METHOD FOR TRANSMITTING THE RECEPTION ACKNOWLEDGEMENT SIGNAL BY FRAME UNIT}

The present invention relates to a method of operating a protocol in a media access control (MAC) layer such as dedicated short range communication (DSRC), and more particularly, such as an intelligent transportation system (ITS). In the operation of a protocol such as short-range dedicated communication (DSRC), a message is transmitted from a transmitting side in the transmission and reception of a message between a transmitting and receiving device in a data link layer, which is a second layer of the OSI (Open System Interconnection) protocol, in particular, a medium access control (MAC) sublayer. And then the acknowledgment signal transmission method that improves the throughput by changing the conventionally proposed method for transmitting the acknowledgment signal at the receiving side, and a computer-readable recording recording the program for realizing the method. It is about the medium.

The conventional message data slot (MDS) is composed of a message data channel (MDC) and an acknowledgment channel (ACKC) corresponding thereto (see FIG. 1A described later). The reason for the existence of the acknowledgment channel (ACKC) is to quickly transmit an acknowledgment signal (ACK) of the data transmitted through the message data channel (MDC) in the reverse direction of the message data channel (MDC). This separation of one slot into two channels is for acknowledgment of a slot unit, but there is a problem in that efficiency is reduced due to overhead.

In this case, 11 octets of channel guard time are required to switch the transmission and reception within one slot, and acknowledgment is not necessary depending on the nature of the data (for example, broadcast type or group type data). In the case of transmitting), the efficiency is reduced by 18 octets because 7 octets of the acknowledgment channel (ACKC) are fixedly allocated.

After all, due to this slot structure of the message data slot (MDS), the maximum data size that can be transmitted through the message data channel (MDC) is limited to 65 octets. In this case, under the premise that the length of one packet of most traffic information is less than 65 octets (including headers), the efficiency reduction is not expected to be relatively large, but considering the expansion of ITS service in the future, the maximum of 65 octets or more is expected. As the type of the service requiring the packet length and the frequency of the service request increase, the efficiency decrease in terms of the overhead and the number of slots required by data division and assembly will increase.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and records an acknowledgment signal transmission method which improves transmission efficiency by performing acknowledgment that was performed in a conventional slot unit on a frame basis, and a program for realizing the method. Its purpose is to provide a computer readable recording medium.

In addition, the present invention removes the acknowledgment channel (ACKC) from the message data slot (MDS) to increase the maximum data size (65 to 85 octets) in the message data channel (MDC), the acknowledgment for the up slot Through the next frame header, an acknowledgment signal for a downlink slot can be read by a computer that records an acknowledgment signal transmission method and a program for realizing the method collectively through a separately assigned downlink acknowledgment slot (DACKS). The purpose is to provide a recording medium.

1A is a structural diagram of a conventional message data slot (MDS).

1B is a structural diagram of an embodiment of a message data slot (MDS) according to the present invention.

2A is a diagram illustrating an embodiment of a short-range dedicated communication media access control (MAC) sublayer frame according to the present invention;

Figure 2b is a structure diagram of an embodiment of a downlink reception confirmation slot (DACKS) according to the present invention.

Figure 2c is a structure diagram of an embodiment of an uplink reception acknowledgment (UACK) field in accordance with the present invention.

3 is a flowchart illustrating an embodiment of an uplink and downlink acknowledgment signal transmission method according to the present invention;

4A is a flowchart illustrating an embodiment of a downlink reception confirmation procedure in an intelligent transportation system according to the present invention;

Figure 4b is a flow diagram of an embodiment of an uplink reception confirmation procedure in the intelligent transportation system according to the present invention.

* Explanation of symbols for the main parts of the drawings

401: ITS server 402: leased line

403: roadside device 404: vehicle mounting device

ACK (Acknology): Acknowledgment signal

ACKC (Ack Channel): Acknowledgment Channel

MDS (Message Data Slot): Message Data Slot

MDC (Message Data Channel): Message Data Channel

UACK (Uplink Ack): Confirmation of Receive Uplink

DACKS (Downlink Ack Slot): Downward Segment Acknowledgment Slot

Downlink Ack Channel (DAKC): Downlink Acknowledgment Channel

MSDU (MAC Service Data Unit): Media access control layer service data unit

In order to achieve the above object, the present invention provides an acknowledgment signal transmission method for transmitting an acknowledgment signal on a frame-by-frame basis, wherein a downlink reception acknowledgment slot (DACKS) separated from a message data slot (MDS) in a downlink section is included in a frame. At least one downlink reception acknowledgment channel allocated to the downlink reception acknowledgment slot (DACKS) is acknowledgment information for allocating the received data through the downlink message data slot (MDS). A first step of transmitting uplink through DACKC); And assigning an uplink reception confirmation (UACK) field to a next frame of a frame in which an uplink data message slot (MDS) is used, and transmitting data through the uplink data message slot (MDS) in the used frame. And a second step of transmitting acknowledgment information for confirming reception of the downlink through the uplink interval acknowledgment (UACK) field allocated to the next frame.

In addition, the present invention, a method for transmitting an acknowledgment signal applied to an intelligent transportation system, the first step of broadcasting the frame information through the header of the first frame to the vehicle-mounted device adjacent to the roadside device; A second step of the vehicle-mounted device receiving the frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; A third step of the roadside apparatus receiving a link connection request of the onboard vehicle and allocating a message data slot (MDS) to the onboard vehicle in a second frame following the first frame to transmit a message; And a fourth step of transmitting the acknowledgment information to the roadside apparatus by using the downlink reception acknowledgment slot (DACKS) of the second frame after the vehicle-mounted device receives the message.

In addition, the present invention, a method for transmitting an acknowledgment signal applied to an intelligent transportation system, the first step of broadcasting the frame information through the header of the first frame to the vehicle-mounted device adjacent to the roadside device; A second step of the vehicle-mounted device receiving the frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; If the roadside device receives the link connection request of the vehicle-mounted device and allocates one message data slot (MDS) to the vehicle-mounted device in a second frame following the first frame, the vehicle-mounted device is assigned Transmitting a message to the roadside apparatus through a message data slot; And a fourth step of transmitting the acknowledgment information to the on-vehicle device through a UACK field of a header portion of the third frame following the second frame after the roadside device receives the message. Characterized in that made.

Meanwhile, in the present invention, a communication system having a processor allocates a downlink reception acknowledgment slot (DACKS) separated from a downlink message data slot (MDS) in a frame, but includes the downlink message data slot (MDS). A first function of transmitting acknowledgment information for confirming reception of data transmitted through the at least one downlink acknowledgment channel (DACKC) allocated to the downlink acknowledgment slot (DACKS); And assigning an uplink reception confirmation (UACK) field to a next frame of a frame in which an uplink data message slot (MDS) is used, and transmitting data through the uplink data message slot (MDS) in the used frame. Providing a computer-readable recording medium having recorded thereon a program for realizing a second function of transmitting acknowledgment information for confirming reception of a downlink through the uplink reception acknowledgment (UACK) field allocated to the next frame. do.

The present invention also provides an intelligent transportation system having a processor, comprising: a first function of broadcasting frame information through a header of a first frame to a vehicle-mounted device adjacent to a roadside device; A second function of the vehicle-mounted device receiving a frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; A third function of receiving, by the roadside device, the link connection request of the vehicle-mounted device and assigning one message data slot (MDS) to the vehicle-mounted device in a second frame following the first frame to transmit a message; And a program for realizing a fourth function of transmitting acknowledgment information to the roadside apparatus using the downlink reception acknowledgment slot (DACKS) of the second frame after the vehicle-mounted apparatus receives the message. Provides a record medium that can be.

The present invention also provides an intelligent transportation system having a processor, comprising: a first function of broadcasting frame information through a header of a first frame to a vehicle-mounted device adjacent to a roadside device; A second function of the vehicle-mounted device receiving a frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; If the roadside device receives the link connection request of the vehicle-mounted device and allocates one message data slot (MDS) to the vehicle-mounted device in a second frame following the first frame, the vehicle-mounted device is assigned A third function of sending a message to the roadside device via a message data slot; And after the roadside device receives the message, transmitting the acknowledgment information to the on-vehicle device through an uplink reception acknowledgment (UACK) field of the header portion of the third frame following the second frame. A computer readable recording medium having recorded thereon a program is provided.

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.

First, the technical gist of the present invention will be briefly described. In the present invention, the message transmission efficiency may be increased by changing the frame structure, which is the message transmission / reception unit of the MAC layer, as follows.

That is, in the case of the existing protocol, two channels are included by including a message data channel (MDC) and an acknowledgment channel (ACKC) in the same message data slot (MDS). Unnecessary losses occur, such as loss of the channel by guard time (Guard Time) between the data and data that does not require acknowledgment such as broadcast data, including the acknowledgment channel (ACKC) collectively.

However, referring to the intelligent transportation system (ITS) which is one of the short-range dedicated communication (DSRC) as an example, in the present invention, the acknowledgment information of the on-vehicle device for downlink data transmission from the roadside device to the on-vehicle device is separate (dedicated). The downlink acknowledgment slot (DACKS) is assigned to the downlink ACK slot, and the acknowledgment information of the roadside device for data transmission from the vehicle-mounted device to the roadside device is included in the frame header (FH) of the next frame. As a result, the message data slot (MDS) can be dedicated to the message data channel (MDC). This can improve the transmission rate. That is, by adopting this method, the transmission efficiency can be increased by about 10% when the maximum traffic occurs. In particular, it may have a greater effect when the amount of data exchanged between the vehicle-mounted device and the roadside device increases in the future.

Next, referring to FIGS. 1A and 1B, the message data slot MDS according to the present invention is compared with the existing message data slot MDS.

1A is a structural diagram of a conventional message data slot (MDS).

As shown in FIG. 1A, the size of the message data slot MDS is 100 octets. In one message data slot (MDS: 100 octets), a message data channel (MDC: 73 octets) and an acknowledgment channel (ACKC: 7 octets) are arranged with a guard time (11 octets) in between. In this case, the size of the medium access control layer service data unit (MSDU) field representing pure data that can actually be transmitted is 65 octets.

1B is a structural diagram of an embodiment of a message data slot (MDS) according to the present invention.

As shown in FIG. 1B, the size of the message data slot MDS is equal to 100 octets as in the existing message data slot MDS, but does not include an acknowledgment channel (ACKC). The size of the medium access control layer service data unit (MSDU) field has been increased to 85 octets.

FIG. 2A is a structural diagram of an embodiment of a short-range dedicated communication media access control (MAC) sublayer frame according to the present invention, and is a medium access control (MAC) sublayer protocol in an intelligent transportation system (ITS), which is one of short-range dedicated communications. Represents a structure of a frame that is a transmission unit of.

One frame includes a frame header (FH) indicating information on the frame configuration, a downlink section for transmitting a message from the roadside apparatus to the on-vehicle device, and an uplink segment for message transmission and link connection request from the onboard apparatus to the roadside apparatus. It consists of.

In this case, the downlink section consists of one or more message data slots (MDS). The uplink section is composed of one or more message data slots (MDS), a link connection request slot (RAS), and a downlink reception acknowledgment slot (DACKS). And, the link connection request slot (RAS) is a slot used for transmitting the link connection request signal to the roadside device. In the present invention, it is assumed that the number of message data slots (MDSs) in one frame cannot exceed a maximum of eight.

Figure 2b is a structure diagram of an embodiment of a downlink reception confirmation slot (DACKS) according to the present invention.

As shown in FIG. 2B, there are eight downlink acknowledgment channels (DAKC) in the downlink acknowledgment slots (DACKS), and the number of each channel is sequentially numbered with a consecutive integer starting with one from the beginning of the slot. Each channel carries an acknowledgment (ACK / NACK) for the message data slot (MDS) in the downlink section of the frame.

FIG. 2C is an exemplary structural diagram of an uplink reception acknowledgment (UACK) field according to the present invention, and is inserted into a frame header (FH) of a next frame to confirm uplink reception for a previous frame. Represents a field.

As shown in FIG. 2C, an uplink reception acknowledgment (UACK) field includes eight bits, and each bit indicates whether a message data slot (MDS) is received during an uplink of a previous frame. '1' indicates normal reception and '0' indicates abnormal reception.

As shown in FIG. 2A and FIG. 2B, the unit-by-slot acknowledgment is performed by the uplink section acknowledgment (UACK) field of the frame header (FH) and the downlink section acknowledgment channel (DAKC) of the downlink section acknowledgment slot (DACKS). Is done. That is, in the conventional method, the acknowledgment of the message data channel MDC in one message data slot MDS is performed by the acknowledgment channel ACKC in the same slot. Confirm.

The acknowledgment of the uplink section of the current frame is collectively processed by the uplink acknowledgment (UACK) field of the frame header (FH) of the next frame. In this case, since acknowledgment is possible with only one bit for each uplink slot, it can be seen that the conventional scheme is very efficient compared to the 18 octets of overhead consumed by the acknowledgment channel (ACKC).

The acknowledgment of the message data slot (MDS) of the downlink section of the current frame is collectively processed by the downlink reception acknowledgment slot (DACKS) located at the end of the frame. At this time, the number of allocated downlink reception confirmation slots (DACKS) is dynamically changed according to the characteristics of the data of the downlink slot. Since one downlink acknowledgment slot (DACKS) includes eight downlink acknowledgment channels (DAKC), acknowledgment of eight downlink message data slots (MDSs) with one or more downlink acknowledgment slots (DACKS). If the data of all the downlink slots does not require acknowledgment, no downlink acknowledgment slot (DACKS) is allocated.

On the other hand, the present invention has the disadvantage that the overhead is larger when the traffic is small and the downlink slot requiring acknowledgment is larger than when the traffic is large, but as the traffic increases, the overhead decreases, and the maximum traffic (in the frame When all seven message data slots are used), a channel throughput of about 10% is increased compared to the conventional method.

3 is a flowchart illustrating an uplink and downlink acknowledgment signal transmission method according to an embodiment of the present invention. 3 is an example in which a roadside device transmits and receives a message with a total of eight vehicle-mounted devices. The left side shows a corresponding configuration slot of a frame according to time zones, and the top-down direction on a vertical axis shows time flow.

In the embodiment shown in FIG. 3, a total of seven message data slots (MDSs), such as four downlink message data slots (MDS) and three uplink message data slots (MDS), are allocated to one frame, and link connection is performed one by one. A request slot (RAS) and a downlink acknowledgment slot (DACKS) are allocated. The composition of the frame and the allocation and synchronization of slots are determined by the roadside device, and this information is broadcast through the frame header.

One frame starts transmission starting with the frame header FH. The first to fourth message data slots (MDSs) are the downlink sections, where the mount unit 1, mount unit 2, mount unit 3, and mount unit 4 were used to receive downlink data from the roadside unit, respectively. The fifth message data slot (MDS) to the seventh message data slot (MDS) are uplinks, and the mounting apparatus 5, the mounting apparatus 6, and the mounting apparatus 7, respectively, perform uplink data transmission from the mounting apparatus to the roadside apparatus. Was used for.

After seven message data slots (MDSs) are allocated, a link connection request slot (RAS) is allocated. In the figure, the mounting apparatus 8 newly transmits a link connection request (slot allocation request). The allocation and timing of the message data slot for this link connection request is determined by the roadside unit.

On the other hand, after the link connection request slot (RAS) is allocated, a downlink reception confirmation slot (DACKS) for downlink sections made in this frame is continuously allocated. Each channel from the downlink reception confirmation channel 1 to the downlink reception confirmation channel 4 in the downlink reception acknowledgment slot (DACKS) is mounted on the first equipment, the first equipment, the first equipment, the first equipment, the third equipment, and the first equipment. Used to send an acknowledgment to the device. Each onboard device checks whether the received data is normally received and then transmits the acknowledgment information to the roadside device using the assigned channel. This completes the transmission and acknowledgment for the downlink section.

When one frame is completed, the roadside device determines whether the information received from the on-vehicle device is normally received in the message data slot (MDS) used as the uplink of the previous frame, and then, in the frame header (FH) of the next frame. By setting the corresponding bit of the uplink reception confirmation (UACK) field corresponding to the message data slot (MDS) transmitted in the uplink of the previous frame to '1', the roadside apparatus broadcasts that the corresponding data has been normally received. The vehicle-mounted device receives the acknowledgment signal by checking the uplink section acknowledgment (UACK) field for the bit corresponding to the message data slot allocated to the previous frame while receiving the frame header FH.

4A is a flowchart illustrating a downlink reception confirmation procedure in an intelligent transportation system according to the present invention, in which an ITS server 401 is connected to a roadside device 403 through a dedicated line 402 and the roadside device 403. The conceptual diagram of the intelligent transportation system to which the vehicle-mounted device 404 is wirelessly connected is shown an example of the use of a downlink reception confirmation slot.

As described in FIG. 3, it is complicated to describe all the processes of communicating with multiple vehicle-mounted devices. Here, two frames (first frame: t1, t2, second frame) transmit and receive messages according to time sequence while one vehicle proceeds. : The process performed over t3, t4) will be described as an example.

First, at time t1, the roadside apparatus broadcasts comprehensive frame information to the adjacent vehicle mounting apparatus through the frame header FH, and the vehicle mounting apparatus receives and interprets it.

Then, the on-vehicle device receiving the frame header FH from the roadside device at time t2 requests the roadside device to allocate the downlink message data slot MDS using the link connection request slot RAS in the frame. do.

Then, when the roadside device receives the link connection request of the vehicle-mounted device at time t3, one downlink message data slot (MDS) is allocated to the vehicle-mounted device in the next frame to transmit a message through this slot.

Then, at time t4, the on-vehicle device transmits the acknowledgment information to the roadside apparatus using the downlink reception acknowledgment slot (DACKS) of the next frame after receiving the message.

4B is a flowchart illustrating an upstream section acknowledgment procedure in an intelligent transportation system according to the present invention, in which an ITS server 401 is connected to a roadside device 403 through a dedicated line 402 and the roadside device 403. The conceptual diagram of the intelligent transportation system to which the vehicle-mounted device 404 is wirelessly connected is shown an example of the use of an uplink reception confirmation field.

As described in FIG. 3, it is complicated to describe all the processes of communicating with multiple vehicle-mounted devices. Here, the transmission and receipt of a message are performed in three frames (first frame: t1, t2, second frame) in accordance with time sequence as a vehicle progresses. The third frame t3) will be described as an example.

First, at time t1, the roadside apparatus broadcasts comprehensive frame information to the adjacent vehicle mounting apparatus through the frame header FH, and the vehicle mounting apparatus receives and interprets it.

Thereafter, the on-vehicle device receiving the frame header (FH) from the roadside device at time t2 requests the roadside device to allocate the uplink message data slot (MDS) using the link connection request slot (RAS) in the frame. do.

Then, if the roadside device receives the link connection request of the vehicle-mounted device at time t3, it assigns one uplink message data slot (MDS) to the vehicle-mounted device in the next frame, and the vehicle-mounted device passes through this slot to the roadside device. Send a message.

Then, at time t4, the roadside apparatus transmits the result to the vehicle-mounted apparatus through the uplink reception acknowledgment (UACK) field of the next frame header of the frame to which the message data slot is assigned.

Although the present invention has been described with an example of an intelligent transportation system, it can be used in various communication systems for similar short-range dedicated communication (DSRC).

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made 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, in the operation of protocols such as short-range dedicated communication (DSRC), such as intelligent traffic systems, broadcast information by separating the acknowledgment channel (ACKC) from the message data slot (MDS) to a separate slot As described above, when the roadside device does not need the acknowledgment information of the on-vehicle device, the unnecessary acknowledgment channel (ACKC) is not consumed, thereby improving the transmission rate.

In addition, the present invention provides the size of acknowledgment overhead for up to eight message data slots (MDSs) used for transmitting and receiving messages in a frame in one downlink acknowledgment slot (100 octets) and one uplink interval. By minimizing the acknowledgment field (8 bits), the overhead ratio is reduced, thereby improving the total data rate.

Claims (10)

In the acknowledgment signal transmission method for transmitting an acknowledgment signal in units of frames, An acknowledgment for allocating a downlink reception acknowledgment slot (DACKS) separated from the downlink message data slot (MDS) in a frame and receiving data transmitted through the downlink data message slot (MDS). A first step of transmitting information upward through at least one downlink acknowledgment channel (DACKC) allocated to the downlink acknowledgment slot (DACKS); And An uplink region acknowledgment (UACK) field is allocated to a frame next to a frame in which an uplink data message slot (MDS) is used, and the data transmitted through the uplink data message slot (MDS) in the used frame. A second step of transmitting downlink acknowledgment information for confirming reception through the uplink interval acknowledgment (UACK) field allocated to the next frame; Acknowledgment signal delivery method comprising a. The method of claim 1, The uplink transmission of the acknowledgment information of the first step, A plurality of downlink acknowledgment channels assigned to the downlink acknowledgment slot (DACKS) for respective acknowledgment information for confirming receipt of each data transmitted through the plurality of message data slots (MDSs) of the downlink. Acknowledgment signal transmission method characterized in that for transmitting in a batch via (DACKC). The method according to claim 1 or 2, The uplink reception confirmation (UACK) field, An acknowledgment signal transmission method, wherein the acknowledgment signal is allocated to a header portion of the next frame and used to broadcast uplink acknowledgment information of a preceding frame. In the method of transmitting the acknowledgment signal applied to the intelligent transportation system, A first step of broadcasting the frame information through the header of the first frame to the adjacent vehicle mounting apparatus; A second step of the vehicle-mounted device receiving the frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; A third step of the roadside apparatus receiving a link connection request of the onboard vehicle and allocating a message data slot (MDS) to the onboard vehicle in a second frame following the first frame to transmit a message; And A fourth step of transmitting the acknowledgment information to the roadside apparatus by using the downlink reception acknowledgment slot (DACKS) of the second frame after the vehicle-mounted apparatus receives the message; Acknowledgment signal transmission method in an intelligent transportation system made, including. In the method of transmitting the acknowledgment signal applied to the intelligent transportation system, A first step of broadcasting the frame information through the header of the first frame to the adjacent vehicle mounting apparatus; A second step of the vehicle-mounted device receiving the frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; If the roadside device receives the link connection request of the vehicle-mounted device and allocates one message data slot (MDS) to the vehicle-mounted device in a second frame following the first frame, the vehicle-mounted device is assigned Transmitting a message to the roadside apparatus through a message data slot; And A fourth step of transmitting the acknowledgment information to the on-vehicle device through the uplink reception acknowledgment (UACK) field of the header portion of the third frame following the second frame after the roadside device receives the message; Acknowledgment signal transmission method in an intelligent transportation system made, including. In a communication system having a processor, An acknowledgment for allocating a downlink reception acknowledgment slot (DACKS) separated from the downlink message data slot (MDS) in a frame and receiving data transmitted through the downlink data message slot (MDS). A first function of transmitting information uplink through at least one downlink acknowledgment channel (DACKC) allocated to the downlink acknowledgment slot (DACKS); And An uplink region acknowledgment (UACK) field is allocated to a frame next to a frame in which an uplink data message slot (MDS) is used, and the data transmitted through the uplink data message slot (MDS) in the used frame. A second function of transmitting acknowledgment information for confirming reception down through the uplink interval acknowledgment (UACK) field allocated to the next frame; A computer-readable recording medium having recorded thereon a program for realizing this. The method of claim 6, In the uplink transmission of the acknowledgment information of the first function, A plurality of downlink acknowledgment channels assigned to the downlink acknowledgment slot (DACKS) for respective acknowledgment information for confirming receipt of each data transmitted through the plurality of message data slots (MDSs) of the downlink. A computer-readable recording medium having a program recorded thereon, characterized in that being transmitted in a batch through (DACKC). The method according to claim 6 or 7, The uplink reception confirmation (UACK) field, A computer-readable recording medium having recorded thereon a program, the program being assigned to a header portion of the next frame and used to broadcast the uplink acknowledgment information of the preceding frame. In an intelligent transportation system equipped with a processor, A first function of broadcasting the frame information through the header of the first frame to the adjacent vehicle-mounted device; A second function of the vehicle-mounted device receiving a frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; A third function of receiving, by the roadside device, the link connection request of the vehicle-mounted device and assigning one message data slot (MDS) to the vehicle-mounted device in a second frame following the first frame to transmit a message; And A fourth function of transmitting acknowledgment information to the roadside apparatus using the downlink reception acknowledgment slot (DACKS) of the second frame after the vehicle-mounted apparatus receives the message; A computer-readable recording medium having recorded thereon a program for realizing this. In an intelligent transportation system equipped with a processor, A first function of broadcasting the frame information through the header of the first frame to the adjacent vehicle-mounted device; A second function of the vehicle-mounted device receiving a frame header (FH) from the roadside device requesting the roadside device to allocate a message data slot (MDS) using a link connection request slot (RAS) in the first frame; If the roadside device receives the link connection request of the vehicle-mounted device and allocates one message data slot (MDS) to the vehicle-mounted device in a second frame following the first frame, the vehicle-mounted device is assigned A third function of sending a message to the roadside device via a message data slot; And A fourth function of transmitting acknowledgment information to the on-vehicle device through an uplink reception acknowledgment (UACK) field of a header portion of a third frame following the second frame after the roadside device receives the message; A computer-readable recording medium having recorded thereon a program for realizing this.