KR100735049B1 - Downlink and uplilk data retry method in dedicated short range communication - Google Patents

Abstract

A method for retransmitting downlink data and uplink data in a DSRC(Dedicated Short Range Communication) system is provided to perform a re-transmission of data irrespective of a service and a subject of RSE(Road Side Equipment) by re-transmitting data based on an assignment of down/up MDS(Message Data Slot) in an FCMC(Frame Control Message Channel) transmitted from an RSE base station. A method for retransmitting downlink data and uplink data in a DSRC system includes the steps of: receiving an FCMC from RSE and checking whether a downlink MDC(Message Data Channel) exists in a frame(S20); if the downlink MDC does not exist in the frame, checking whether the reception of the previously consecutive downlink data is completed(S30); if the reception of the previous consecutive downlink data is not completed, treating the reception of the consecutive downlink data which is not completed previously as a failure(S40); and if the downlink MDC exists in the frame, and the consecutive downlink data which is not completed previously exists in the frame, treating the previous uplink data as a failure(S70).

Description

DOWNLINK AND UPLILK DATA RETRY METHOD IN DEDICATED SHORT RANGE COMMUNICATION}

1 is a diagram illustrating a downlink processing method for transmitting data from an RSE to an OBE according to the related art.

2 is a diagram illustrating an uplink processing method for transmitting data from an OBE to an RSE according to the related art.

3 is a diagram illustrating a downlink processing method for transmitting data from an RSE to an OBE according to the present invention.

4 is a diagram illustrating an uplink processing method for transmitting data from an OBE to an RSE according to the present invention.

The present invention relates to a method for processing downlink data and uplink data retransmission in a DSRC system, and in particular, an uplink / downlink maximum retransmission parameter (DRCmax /) with an RSE base station in a Layer2-MAC unit of an OBE terminal performing 5.8 ms DSRC communication. The present invention relates to a method for retransmission processing of downlink data and uplink data without exchanging URCmax.

In general, the L2 MAC portion of the roadside base station RSE performing 5.8 ms DSRC communication generates a frame and allocates a data slot of a down / up link.

In addition, when retransmission is required due to communication failure, the retransmission is defined by the number of retransmissions defined in the retransmission parameters DRCmax and URCmax.

That is, in 5.8 ㎓ DSRC communication, the RSE and the roadside base station, which are the base stations, are defined to exchange the DRCmax (Max Downlink Retry Count) / URCmax (Max Uplink Retry Count) parameters in the communication initialization procedure. have.

Here, the downlink refers to transmitting downlink data from the roadside base station device RSE to the in-vehicle terminal OBE, and uplink refers to transmitting uplink data from the OBE to the RSE.

However, in practice, the method of exchanging retransmission parameters between RSE and OBE is not clearly defined in the DSRC protocol standard. Therefore, the parameter value is different depending on the development subject and the object (service) of DSRC communication. do.

Accordingly, an object of the present invention is to solve the above problems, the FCMC (Frame Control Message) transmitted from the RSE that the OBE terminal is a roadside base station without exchanging retransmission parameters between the RSE base station and the OBE terminal for 5.8 ㎓ DSRC wireless communication The present invention provides a method for processing downlink data and uplink data retransmission in a DSRC system capable of processing data retransmission of up / down only using slot allocation information of a channel.

In addition, the present invention provides a method for processing downlink data and uplink data retransmission in a DSRC system to ensure compatibility by implementing within a range that conforms to the 5.8 ㎓ DSRC Layer2 national standard (TTAS.KO-06.0025). have.

According to an aspect of a method for processing downlink data retransmission of a short-range dedicated communication system according to the present invention for achieving the above object, a vehicle-mounted device (OBE) receives a frame control message channel (FCMC) from a roadside base station (RSE) Checking whether there is a downlink MDC in the frame; if there is no downlink MDC in the frame; checking whether reception of continuous downlink data has ended previously; and as a result of the check, Failing to receive continuous downlink data that has not been previously terminated, if the reception of consecutive downlink data has not ended and the downlink MDC is present in the frame and not previously terminated. If there is uplink data, characterized in that the step of failing the previous uplink data (Fail) All.

If there is no downlink MDC in the frame, checking whether the reception of the continuous downlink data has ended, and if the reception of the continuous downlink data has ended, wait (ILDE). It further comprises the step of maintaining.

And if there is uplink data not previously terminated while there is a downlink MDC in the frame, failing the previous uplink data.

In addition, if there is a downlink MDC in the frame and there is no previously terminated uplink data, the method may further include checking a reception state after receiving the MDC.

The method may further include checking down the sequence of data when the MDC reception state is normally received and storing down data when the sequence of data is correct.

In addition, as a result of checking the MDC reception state, when a problem occurs in the MDC reception or the sequence of the data is not correct, when the DRC value is smaller than the DRCmax value by checking the DRC (Downlink Retry Counter) and DRCmax value The method further includes a step of waiting for the next frame after increasing the DRC value by 1 and ending the current data reception when the DRC value is larger than the DRCmax value.

On the other hand, according to an aspect of the uplink data retransmission processing method of the short-range dedicated communication system according to the present invention for achieving the above object, the vehicle-mounted device (OBE) is a FCMC (Frame Control Message Channel) from the roadside base station (RSE) Determining whether an uplink MDC is allocated in the frame by receiving the received signal; and checking whether transmission of continuous uplink data is terminated when no uplink MDC exists in the frame; and the check result. If there is uplink data that has been previously started and is in progress, failing to transmit the uplink data; and the uplink MDC generates two frames while the uplink data is not being started and is waiting. Failing to allocate the pending uplink data, and uplink MDC is allocated within the frame. If there is, there is a step of failing the previous downlink data if there is no downlink data that has not been previously terminated.

And if there is no uplink MDC in the frame, checking whether a previous continuous uplink data transmission has ended, and in the case where the previous continuous data transmission ends, an idle state (ILDE) It further comprises maintaining.

In addition, when the uplink data is not waiting to be transmitted and the uplink MDC is allocated more than 2 frames, the URC value is determined by checking the Uplink Retry Counter (URC) and the URCmax value. And increases the value of 1 and waits for the next frame, and ending the current data reception when the URC value is greater than URCmax.

In addition, in the step of determining whether the uplink MDC is allocated in the frame, when the Uplink MDC is allocated in the frame, if the downlink data that has not been previously terminated fails the previous downlink data (Fail). And if there is no previously terminated downlink data, checking the transmission status after Up MDC transmission and waiting for the next frame if the transmission is normally performed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, detailed descriptions of preferred embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a diagram illustrating a downlink processing method of transmitting data from an RSE to an OBE according to the related art.

As shown in FIG. 1, in the downlink process, when the OBE receives a Frame Control Message Channel (FCMC) from the RSE (S1), the OBE checks whether there is a Down Message Data Channel (MDC) (S2).

As a result of the check, if there is a Down MDC in the frame (S3), the reception status is confirmed after receiving the MDC (S3), if the Down MDC does not exist in the frame (Frame) maintains the ILDE state (S4).

Subsequently, if there is a Down MDC in the frame, the reception status is checked after MDC reception, and if the reception is normally performed, the sequence of data is checked (S5).

As a result of the check, when the sequence of data is correct, the down data is saved (S6).

On the other hand, if a problem occurs in the MDC reception in the S3 process of checking the MDC reception status, or if the sequence is not correct in the S4 process of checking the sequence of the data (Downlink Retry Counter DRC) ) And the DRCmax value (S7).

If the DRC value is smaller than the DRCmax value, the DRC value is increased by one (DRC + 1) (S8) and the next frame is waited.If the DRC value is larger than the DRCmax value, the current data is received. To exit.

However, if the DRCmax value of the RSE is larger than the DRCmax value of the OBE, the RSE retransmits, but the OBE retransmits downlink data re-transmitted by the RSE after Down Fail (S9) processing. Will be recognized as).

2 is a diagram illustrating an uplink processing method for transmitting data from an OBE to an RSE according to the related art.

As shown in FIG. 2, in the uplink process, when the OBE receives a frame control message channel (FCMC) from the RSE (S1), the OBE checks whether there is an Up Message Data Channel (MDC) (S2).

As a result of the check, if there is an Up MDC in the frame (S3), the transmission status after the MDC transmission is confirmed (S3), if the Up MDC does not exist in the frame (Frame) maintains the ILDE state (S4).

Subsequently, when there is an Up MDC in the frame, the MDC transmission checks the transmission status and waits for the next frame if it is normally transmitted (S5).

However, if there is a problem in Up MDC transmission, check the Uplink Retry Counter (URC) and URCmax values (S6) and increase the URC value by 1 (URC + 1) (S7) when the URC value is smaller than the URCmax value. Wait for the next frame.

However, if the URC value is greater than URCmax, the current data reception is terminated.In this case, if the URCmax value of the RSE is greater than the URCmax value of the OBE, the RSE allocates an Up MDC to a frame for receiving uplink data, but the OBE is Up. The transfer is stopped after the Fail (S8) processing.

3 is a diagram illustrating a downlink processing method for transmitting data from an RSE to an OBE according to the present invention.

As shown in FIG. 3, in the downlink process, when the OBE receives a frame control message channel (FCMC) from the RSE (S10), downlink data (Downlink Data) in a frame is received through the received FCMC. It is determined whether or not there is (S20).

As a result of the determination, if there is no downlink MDC in the frame as a result of checking the currently received FCMC, it is checked whether reception of continuous downlink data has ended previously (S30). It is determined that the retransmission has ended, Fail processing (S40) of receiving the downlink data of the previous frame, otherwise maintains the ILDE state (S50).

On the other hand, in the process of determining whether the downlink data (Downlink Data) in the frame (Frame) via the received FCMC, if there is a downlink MDC (Downlink MDC) in the frame, the uplink data that has not been terminated before It is checked whether (Uplink Data) exists (S60).

As a result of the check, if there is uplink data that has not been previously ended, the previous uplink file is processed (S70), and the DRCmax value for checking the number of downlink retry is set to use any large value.

On the other hand, in the step S60 of checking whether there is no previously terminated uplink data (Uplink Data), if there is no previously terminated uplink data (Uplink Data), if the presence of the MDC checks the reception state after receiving ( S80).

As a result of the check, if the data sequence is correctly received, the data sequence is checked (S90). If the data sequence is correct, the down data is stored (S100). .

However, if a problem occurs in MDC reception in step S80 of checking the MDC reception state or the sequence is not correct in step S90 of checking the sequence of data, DRC (Downlink Retry Counter) ) And the DRCmax value (S110).

If the DRC value is smaller than the DRCmax value, the DRC value is increased by one (DRC + 1) (S120) and the next frame is waited. If the DRC value is larger than the DRCmax value, the current data is received. To exit.

However, if the DRCmax value of the RSE is larger than the DRCmax value of the OBE, the RSE retransmits, but the OBE re-transmits downlink data re-transmitted by the RSE after Down Fail (S40) processing. Will be recognized as).

4 is a diagram illustrating an uplink processing method for transmitting data from an OBE to an RSE according to the present invention.

As shown in FIG. 4, in the uplink processing, when the OBE receives a frame control message channel (FCMC) from the RSE (S10), the OBE determines whether an uplink MDC is allocated in the frame through the received FCMC (S20). )do.

As a result of the determination, when the uplink MDC is not allocated in the frame as a result of confirming the currently received FCMC, it is checked whether the transmission of the continuous data previously has been terminated (S30).

As a result of the check, if the transmission of the previous continuous data is terminated, the ILDE state is maintained (S40).

However, in the case where the transmission of the continuous data has not been terminated previously, it is checked whether there is uplink data that has been started and is in progress (S50).

As a result of the check, if there is uplink data that has been started and is being transmitted previously, the RSE determines that retransmission is terminated and fails to transmit the uplink data (S60). .

However, if there is no uplink data in progress before the transmission has been started, it is determined whether the uplink MDC is allocated more than 2 frames while there is uplink data not currently being started. Check (S70).

As a result, if there is uplink data that is not currently started to be transmitted and the Uplink MDC is not allocated more than 2 frames, it is determined that communication is not normally performed from the RSE. Fail process (S60).

However, if the uplink MDC is allocated more than 2 frames, the uplink retry counter (URC) and the URCmax value are checked (S80). Wait for the next frame.

However, if the URC value is greater than URCmax, the current data reception is terminated.In this case, if the URCmax value of the RSE is greater than the URCmax value of the OBE, the RSE allocates an Up MDC to a frame for receiving uplink data, but the OBE is Up. After the Fail (S60) processing, the transmission is stopped.

Meanwhile, in the process of determining whether the uplink MDC is allocated in the frame through the received FCMC, if the uplink MDC is allocated in the frame, whether downlink data that has not been terminated previously exists. Check (S100).

As a result of the check, if there is downlink data that has not been terminated previously, the previous downlink data is failed (S110), and the URCmax value for checking the number of Uplink Retry is set to use any large value. .

However, if there is no downlink data that has not been terminated before, the transmission status is confirmed after the Up MDC transmission (S120). If the transmission is normally transmitted, the next frame is waited (S130).

However, if the transmission is not normally performed, the S80 process of checking the Uplink Retry Counter (URC) and URCmax values is performed.

As described above, in the present invention, the OBE terminal does not use the maximum retransmission parameters of DRCmax and URCmax when retransmitting downlink and uplink, and downlinks in the FCMC (Frame Control Message Channel) transmitted by the RSE base station. The success / failure of retransmission is determined by whether / Up MDS (Message Data Slot) is allocated and whether the transmission / reception of the current data is continuously performed.

In the above, specific preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention attached to the claims. will be.

According to the present invention, the retransmission process can be performed on the up / down data without exchanging retransmission parameters of the Layer2-MAC unit of the RSE and the DRCmax URCmax in the OBE terminal, so that the retransmission process can be performed regardless of the subject and service of the RSE. .

In addition, the present invention is in compliance with the standard of the domestic standard (TTAS.KO-06.0025) has the effect of ensuring the compatibility.

Claims (10)

Receiving, by the on-vehicle device OBE, a Frame Control Message Channel (FCMC) from a roadside base station (RSE) to check for the presence of a downlink MDC in a frame; If there is no downlink MDC in the frame, checking whether reception of previous consecutive downlink data has ended; Failing to receive the continuous downlink data that has not been terminated before when the reception of the continuous downlink data has not been terminated as a result of the check; And If downlink MDC is present in the frame and there is uplink data that has not been terminated previously, failing to process the previous uplink data, the downlink data retransmission processing method according to claim 1, wherein the uplink data is failed. . The method of claim 1, If there is no downlink MDC in the frame, in the step of checking whether reception of consecutive downlink data has ended, The method of claim 1, further comprising: maintaining an idle state when the reception of downlink data continues in succession. The method of claim 1, If there is downlink MDC in the frame and there is uplink data that has not been previously terminated, failing to process the previous uplink data, further comprising: failing downlink data retransmission of the short-range dedicated communication system. Treatment method. The method of claim 1, If there is no downlink MDC present in the frame and previously terminated uplink data does not exist, the method further includes checking a reception state after receiving the MDC. Way. The method of claim 4, wherein Short-term dedicated communication, characterized in that further comprising the step of checking the sequence of the data (Sequence) when the result of the MDC reception state is confirmed, and storing the down data if the sequence of the data (Sequence) is correct. How to handle downlink data retransmission in the system. The method of claim 4, wherein As a result of checking the MDC reception status, if a problem occurs in the MDC reception or if the sequence of the data is not correct, the DRC (Downlink Retry Counter) and the DRCmax value are checked to determine that the DRC value is smaller than the DRCmax value. And increasing the value by 1 and waiting for the next frame, and ending the current data reception when the DRC value is greater than the DRCmax value. Receiving a frame control message channel (FCMC) from a roadside base station (RSE) to determine whether an uplink MDC is allocated in a frame; If there is no uplink MDC in the frame, checking whether a transmission of previously consecutive uplink data has ended; Failing to transmit the uplink data when there is uplink data that has been started and is being transmitted before as a result of the check; Failing the pending uplink data if the uplink data is not being started and is in a waiting state and an uplink MDC is not allocated for more than two frames; And If uplink MDC is allocated in the frame, if downlink data that has not been terminated previously exists, failing to process the previous downlink data. Treatment method. The method of claim 7, wherein If there is no uplink MDC in the frame, checking whether transmission of successive uplink data has ended, And maintaining an idle state when the transmission of the previous continuous data is terminated. The method of claim 7, wherein When uplink MDC is allocated more than 2 frames while the uplink data is not started and is waiting for transmission, the URC value is determined by checking the Uplink Retry Counter (URC) and the URCmax value. Waiting for the next frame after increasing, and ending the current data reception when the URC value is greater than URCmax. The method of claim 7, wherein In the step of determining whether the allocation of the uplink MDC in the frame, When Uplink MDC is allocated in the frame, if downlink data that has not been terminated previously exists, fail the previous downlink data, and if there is no previously terminated downlink data, Up MDC retransmission processing method of the short-range dedicated communication system, characterized in that further comprising the step of waiting for the next frame when the transmission state is confirmed after the normal transmission.

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