WO2007023520A1

WO2007023520A1 - Communication apparatus and communication method

Info

Publication number: WO2007023520A1
Application number: PCT/JP2005/015226
Authority: WO
Inventors: Junya Yamazaki
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-08-22
Filing date: 2005-08-22
Publication date: 2007-03-01
Also published as: JPWO2007023520A1

Abstract

A communication apparatus wherein the delay caused in a case of successive error occurrences is reduced, while the number of timers to be activated is reduced. In this communication apparatus (100), a threshold value establishing part (106) establishes, based on a predetermined condition, a threshold value. A counter (107) counts received packets in which errors are detected. A timer management part (108) activates a timer (109) when the count value of the counter (107) reaches the threshold value. The timer (109) starts timing in response to the activating instruction of the timer management part (108). When having timed a predetermined time period (T), the timer (109) outputs a signal indicative of that effect to a status report generating part (110). When the number of the received packets, in which errors are detected, reaches the threshold value, the status report generating part (110) starts generating a status report. When the timer (109) has timed the predetermined time period (T), the status report generating part (110) outputs the status report to a frame generating part (151).

Description

Specification

Communication apparatus and communication method

Technical field

The present invention relates to a communication apparatus and a communication method for a system that detects an error in a received packet and notifies a communication partner of a packet transmission status.

Background art

[0002] Currently, in the field of mobile communication systems, the 3GPP (3rd Generation Partnership Project) worldwide common standard is being developed. 3GPP stipulates that a layer 2 RLC (Radio Link Control) uses a system that detects errors in received packets and notifies ACK (Acknowledgement) ZNAC K (Non-Acknowledgement) to the communication partner. . Note that ACK is information indicating that the packet has been successfully received (success), and NACK is information indicating that the packet has not been successfully received (failure, error).

In data of AM (Acknowledge Mode) which is one of RLC (Radio Link Control) modes, a status report is used for data arrival confirmation. The role of the status report is to notify the communication partner of the current packet transmission status (success or failure, how many have reached) by SUFI (SUper Field). SUFI N

Figure 1 shows the effect of each field. Using these SUFIs, the receiving side device notifies ACKZNACK of continuous packet data to the transmitting side device.

[0004] It should be noted that in the status report in RLC, multiple ACKZNACK reports can be made by various methods. For example, in the ACK field, the sequence number up to the part where the packet was successfully received can be written. In addition, in the LIST field, in addition to the part that received the packet normally, a list of powerful sequence numbers that could not receive the packet normally can be written. In the BITMAP field, ACK / NACK can be written in the bitmap format (0: ACK, 1: NACK). In the RLIST field, ACKZNACK can be written using the error-related list method.

[0005] As a status report transmission timing, 3GPP has a periodical status report that sends a status report at regular intervals, and a status prohibit 2 that starts a timer when an error occurs and sends a status report after a predetermined time has elapsed. The type is specified. In addition, periodical status report and status prohibition can be used in combination.

[0006] In 3GPP, only one timer is operated with status prohibit, and the timer length is a fixed value. For example, as shown in Fig. 2, if the sending device continuously sends packets and the receiving device cannot successfully receive packet # 1, the receiving device will start a timer when an error occurs. Start (TS) and send a status report (S) after a predetermined time (T).

[0007] However, in status prohibition, if only one timer is operated, an upper limit occurs in the throughput, and if errors occur continuously, the delay will increase and retransmission jitter will occur. The problem remains.

[0008] For example, as shown in FIG. 3, if an error occurs for packet # 1 and an error occurs for packet # 2 before the predetermined time (T) elapses, an error occurs for packet # 1. Then, after measuring the predetermined time (T) and measuring the predetermined time (T) again for packet # 2, until the status report is sent after an error occurs for the packet # 2. Will be longer than the predetermined time (T).

[0009] Therefore, a NACK ProWbit method has been proposed in which a plurality of timers are prepared to solve the above-described problems, and each time an error occurs, the timer is started.

Non-Patent Document 1: 3GPP contribution R2-051442, RLC Reporting Enhancements, Quale omm

Disclosure of the invention

Problems to be solved by the invention

[0010] Here, in the 3GPP LTE (Long Term Evolution) specification, the data rate increases as the communication method changes, and as a result, the number of transmitted packets per unit time increases. this In this case, if the NACK Prohibit method is applied, a very large number of timers are operated, and the control becomes complicated.

An object of the present invention is to provide a communication device and a communication method capable of reducing the delay when errors continuously occur while reducing the number of timers to be operated. Means for solving the problem

[0012] In order to solve the problem, the communication apparatus of the present invention includes an error detection unit that detects an error in a received packet, a threshold setting unit that sets a threshold based on a predetermined condition, A counter that counts the number of received packets in which an error is detected and determines whether the count value has reached the threshold value, a timer that measures a predetermined time, and the count value reaches the threshold value. A timer management means for starting the timer in the event of a failure, a status report generation means for generating a status report indicating a current packet transmission status before the timer measures the predetermined time, and the timer After measuring the time, a configuration is provided that includes a transmission unit that transmits the status report generated by the status report generation unit.

[0013] In addition, the communication method of the present invention includes a step of detecting an error in a received packet, a step of setting a threshold value based on a predetermined condition, a received packet in which an error is detected by a counter, Counting a number, determining whether the count value has reached the threshold value, measuring a predetermined time predetermined by a timer, and when the count value reaches the threshold value, Starting a timer; generating a status report indicating a current packet transmission status until the timer measures the predetermined time; and generating the status report after the timer measures the predetermined time. A method of sending a status report.

The invention's effect

[0014] According to the present invention, it is possible to reduce a delay when errors continuously occur while only one timer is operated.

Brief Description of Drawings

[0015] [Figure 1] Diagram showing the effect of each field in the status report

[Figure 2] Diagram for explaining the transmission timing of a conventional status report [Figure 3] Diagram for explaining the transmission timing of a conventional status report

FIG. 4 is a block diagram showing a configuration of a communication apparatus according to Embodiment 1 of the present invention.

FIG. 5 is a diagram for explaining the transmission timing of the status report of the communication apparatus according to Embodiment 1 of the present invention.

FIG. 6 is a block diagram showing a configuration of a communication apparatus according to Embodiment 2 of the present invention.

FIG. 7 is a diagram for explaining the transmission timing of the status report of the communication apparatus according to Embodiment 2 of the present invention.

FIG. 8 is a block diagram showing a configuration of a communication apparatus according to Embodiment 3 of the present invention.

FIG. 9 is a diagram for explaining the transmission timing of the status report of the communication apparatus according to Embodiment 3 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

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

[0017] (Embodiment 1)

FIG. 4 is a block diagram showing a configuration of the communication apparatus according to Embodiment 1 of the present invention. Figure

The communication device 100 of 4 is a device that receives a packet and transmits a status report.

[0018] Communication apparatus 100 includes antenna 101, RF receiving unit 102, demodulating unit 103, error correction decoding unit 104, error detection unit 105, threshold setting unit 106, counter 107, and timer management unit 108. And the timer 109, the status report generation unit 110, the frame configuration unit 151, the error detection code addition unit 152, the error correction coding unit 153, the modulation unit 154, the RF transmission unit 155, and the power mainly. Composed.

[0019] The antenna 101 receives a signal that is wirelessly transmitted from the communication partner, and outputs the signal to the RF receiver 102, and wirelessly transmits the radio frequency signal output from the RF transmitter 155 to the communication partner. To do.

[0020] RF receiving section 102 performs radio processing such as down-conversion and amplification on the radio frequency signal received by antenna 101, and outputs the baseband signal to demodulation section 103. Demodulation section 103 performs demodulation processing on the output signal of RF reception section 102 and outputs the result to error correction decoding section 104. The error correction decoding unit 104 applies a bucket to the output signal of the demodulation unit 103. Error correction decoding processing is performed on a unit basis and output to the error detection unit 105.

The error detection unit 105 performs error detection processing such as CRC detection on the packet output from the error correction decoding unit 104. If no error is detected as a result of the error detection process, the error detection unit 105 outputs the received data of the packet to the device in the subsequent process, and outputs the ACK information to the counter 107. On the other hand, if an error is detected as a result of the error detection process, the error detection unit 105 outputs the NACK information to the counter 107 and the status report generation unit 110 without outputting the received data of the packet to the subsequent device. .

[0022] The threshold setting unit 106 sets a threshold based on a predetermined condition. The predetermined conditions include, for example, QoS (Quality of Service) class, number of retransmissions, communication environment represented by SIR (Signal to Interference Ratio), PER (Packet Error Rate), etc., line congestion, moving speed, handover , Status prohibit timer length, etc. If the threshold is set to “1”, backward compatibility with status prohibition can be easily obtained.

[0023] Counter 107 counts the number of NACK information output from error detection section 105, and when the number of NACK information reaches the threshold set by threshold setting section 106, counter 107 indicates a signal indicating that fact. The data is output to the management unit 108 and the status report generation unit 110, and the count value is reset.

When the timer management unit 108 receives a signal from the counter 107, the timer management unit 108 activates the timer 109. When the timer 109 starts measuring time in response to an activation instruction from the timer management unit 108 and measures a predetermined time (T), the timer 109 outputs a signal indicating that to the status report generation unit 110 and resets the measurement value.

[0025] The status report generation unit 110 starts generating a status report when the number of NACK information reaches a threshold, and when the timer 109 measures a predetermined time (T), the status report is generated as a frame configuration unit. Output to 151.

Frame configuration section 151 configures a frame by multiplexing control information, a status report, and the like on transmission data, and outputs the frame to error detection code addition section 152. Error detection code adding section 152 adds error detection bits such as CRC to the output signal of frame configuration section 151 and outputs the result to error correction code section 153. The error correction code key unit 153 performs error correction coding processing on the output signal of the error detection code adding unit 152 and outputs the result to the modulation unit 154. Modulator 154 performs modulation processing on the output signal of the error correction code key unit 153 and outputs it to the RF transmitter 155. The RF transmission unit 155 performs radio processing such as up-conversion and amplification on the output signal of the modulation unit 154, and outputs a radio frequency signal to the antenna 101.

Next, the status report transmission timing of the communication apparatus according to the present embodiment will be described with reference to FIG.

In FIG. 5, it is assumed that the threshold is set to “3”. Further, in communication apparatus 100 (reception side apparatus), a strong packet in which no error is detected is indicated by “◯”, and a packet in which an error is detected is indicated by “X”.

[0029] In this case, the communication device 100 counts the number of packets in which an error is detected in the counter 107, starts the timer 109 when the number reaches "3" (TS), and generates a status report generation unit. At 110, generation of a status report is started. Then, the communication device 100 starts the timer 109 and transmits a status report (S) to the transmission-side device of the communication partner after a predetermined time (T) has elapsed.

As described above, according to the present embodiment, generation of a status report is started after the number of NACK information reaches a threshold value, and the operation is performed by transmitting the status report after a predetermined time has elapsed. Although there is only one timer, it is possible to reduce the delay when errors occur continuously.

[0031] (Embodiment 2)

FIG. 6 is a block diagram showing a configuration of a communication apparatus according to Embodiment 2 of the present invention. In the communication device 300 shown in FIG. 6, the same components as those in the communication device 100 shown in FIG. 4 are denoted by the same reference numerals as those in FIG.

Compared with communication apparatus 100 shown in FIG. 4, communication apparatus 300 shown in FIG. 6 has a configuration in which threshold setting section 106, counter 107 and timer management section 108 are deleted and reset instruction section 301 is added. Adopt the composition.

[0033] If an error is detected as a result of the error detection process, error detection section 105 does not output the received data of the packet to the device in the subsequent process, and sends NACK information to reset instruction section 301 and status report generation section. Output to 110.

[0034] Upon receiving the NACK information from the error detection unit 105, the reset instruction unit 301 sets the timer 109. Start. Also, if NACK information is input from the error detection unit 105 while the timer 109 is counting, the timer 109 is reset and then started again.

[0035] When the timer 109 starts counting in response to an activation instruction from the reset instruction unit 301 and measures a predetermined time (T), the timer 109 outputs a signal indicating that to the status report generation unit 110, and resets the measurement value. When the timer 109 receives a reset instruction from the reset instruction unit 301 during measurement of the predetermined time (T), the timer 109 once resets the timer value and starts measuring the force.

[0036] The status report generation unit 110 starts generating a status report when the NACK information is input from the error detection unit 105, and when the timer 109 measures a predetermined time (T), the status report is generated by the frame configuration unit 151. Output to.

In FIG. 7, in the communication device 300 (reception side device), a strong packet in which no error is detected is indicated by “◯”, and a packet in which an error is detected is indicated by “X”.

[0039] In this case, the communication device 300 starts the timer 109 (TS) at a timing when an error is detected in the received packet (TS), and starts generating the status report to the status report generator 110! . Then, the communication device 300 activates the timer 109 and transmits a status report (S) to the transmission-side device of the communication partner after a predetermined time (T) has elapsed. In addition, when an error is detected in a later received packet while the timer 109 is measuring the predetermined time (T), the communication device 300 resets the timer value of the timer 109 to measure the force. Start.

[0040] Thus, according to the present embodiment, when an error is detected in a later received packet while counting by the timer, the timer value is reset and started again, and after a predetermined time has elapsed, By sending a status report, it is possible to reduce the number of timers to be operated, reduce the delay when errors occur continuously, and prevent the occurrence of retransmission jitter.

[Embodiment 3]

FIG. 8 is a block diagram showing a configuration of a communication apparatus according to Embodiment 3 of the present invention. In the communication device 500 shown in FIG. 8, the same components as those in the communication device 100 shown in FIG. 4 are assigned the same reference numerals as those in FIG.

A communication device 500 shown in FIG. 8 is different from the communication device 100 shown in FIG. A configuration with 301 added is adopted.

[0043] If an error is detected as a result of the error detection process, error detection section 105 does not output the received data of the packet to the device in the subsequent process, and NACK information is output to counter 107, reset instruction section 301 and Output to status report generator 110.

[0044] Counter 107 counts the number of NACK information output from error detection section 105, and NAC

When the number of K information reaches the threshold set by the threshold setting unit 106, a signal indicating that is output to the timer management unit 108, and the count value is reset. The counter 107 also resets the count value when the timer 109 measures a predetermined time (T) before the number of NACK information reaches the threshold value.

When a signal is input from counter 107, timer management section 108 starts timer 109 and controls reset instruction section 301 so as not to issue a reset instruction to timer 109.

[0046] When the NACK information is input from the error detection unit 105, the reset instruction unit 301 starts the timer 109. Also, if NACK information is input from the error detection unit 105 while the timer 109 is counting, the timer 109 is reset and then started again. However, the reset instruction unit 301 does not issue a reset instruction to the timer 109 when instructed by the timer management unit 108. The reset instruction unit 301 cancels the instruction from the timer management unit 108 when the timer 109 measures a predetermined time (T).

[0047] The timer 109 starts timing in response to a start instruction from the timer management unit 108 or the reset instruction unit 301 and measures a predetermined time (T). Output to report generator 110 to reset measurement values. When the timer 109 receives a reset instruction from the reset instruction unit 301 during measurement of the predetermined time (T), the timer 109 once resets the timer value and starts force measurement.

[0048] The status report generation unit 110 starts generating a status report when the NACK information is input from the error detection unit 105, and when the timer 109 measures a predetermined time (T), the status report is generated by the frame configuration unit 151. Output to.

Next, the transmission timing of the status report of the communication apparatus according to the present embodiment will be described using FIG.

In FIG. 9, it is assumed that the threshold value is set to “3”. Communication device 500 (receiving device) In FIG. 8, a packet with no error detected is indicated by “◯”, and a packet with an error detected is indicated by “χ”.

[0051] In this case, the communication device 500 starts the timer 109 (TS) at the timing when an error is detected in the received packet (TS), and starts generating the status report to the status report generator 110! . Then, the communication device 500 starts the timer 109 and transmits the status report (S) to the transmission-side device of the communication partner after the predetermined time (T) has elapsed. In addition, when an error is detected in a later received packet while the timer 109 is measuring the predetermined time (T), the communication device 500 resets the timer value of the timer 109 to measure the force. Start. However, the communication device 500 measures the predetermined time (T) without resetting the timer value of the timer 109 during the measurement when the count value power of the counter 107 becomes “3”.

[0052] Thus, according to the present embodiment, the timer value is reset when an error is detected in a subsequent received packet while the timer is counting until the number of NACK information reaches the threshold. By restarting the system and sending a status report after a lapse of a predetermined time, it is possible to reduce the delay when consecutive errors occur while preventing the occurrence of retransmission jitter, while operating only one timer. it can.

Industrial applicability

The present invention is suitable for use in a communication device of a system that detects an error in a received packet and notifies ACKZNACK to a communication partner.

Claims

The scope of the claims

[1] error detection means for detecting an error in the received packet;

A threshold setting means for setting a threshold based on a predetermined condition determined in advance; a counter for counting the number of received packets in which an error is detected; and determining whether the count value has reached the threshold;

A timer for measuring a predetermined time determined in advance;

Timer management means for starting the timer when the count value reaches the threshold, and status report generation for generating a status report indicating the current packet transmission status before the timer measures the predetermined time Means,

Transmitting means for transmitting a status report generated by the status report generating means after the timer measures the predetermined time;

A communication apparatus comprising:

[2] Reset instruction means for starting the timer when an error is detected in a received packet, and resetting the timer and starting again when an error is detected in the received packet while the timer is timing The communication apparatus according to claim 1, wherein the timer management unit controls the reset instruction unit not to issue a reset instruction to the timer when the count value reaches the threshold value.

[3] detecting an error in the received packet;

Setting a threshold based on a predetermined condition determined in advance;

Counting the number of received packets in which an error is detected by a counter, and determining whether or not the count value has reached the threshold;

Measuring a predetermined time predetermined by a timer;

Starting the timer when the count value reaches the threshold; generating a status report indicating a current packet transmission status before the timer measures the predetermined time;

Transmitting the generated status report after the timer measures the predetermined time;

A communication method comprising: