CN104518852A - Transmission feedback method - Google Patents

Abstract

The invention discloses a transmission feedback method. The method comprise: when a receiving end receives data, according to current received protocol data unit conditions, generating a corresponding RLC STATUS PDU data package on the basis of the format of a preset second radio link control state protocol data unit (RLC STATUS PDU), and sending the RLC STATUS PDU data package to a data transmitting end. An E3 domain and an E4 domain are added in the second RLC STATUS PDU format, so as to realize optimized indication for RLC continuous PDU loss and loss of a plurality of segments of a same PDU. Using the method can greatly reduce cost of wireless resources of the RLC STATUS PDU, and improvise transmission efficiency.

Description

A method of transmitting feedback

technical field

The invention relates to mobile communication technology, in particular to a transmission feedback method.

Background technique

At present, the 230MHz frequency band is mainly used in data transmission stations to undertake remote data collection work. Because the provided rate is very low, it can only be used for some simple communication applications, and cannot meet the growing business needs of smart grids and sensor networks. According to the future planning of the State Grid, it is required to find a new broadband communication technology to meet the business needs of its distribution network automation, load management, electricity consumption information collection, smart grid user services, emergency repairs, and video surveillance in special areas.

The 230MHz frequency band products based on TD-LTE technology provide a better solution for the above requirements, and constitute a new generation of flexible multi-service communication system with low power consumption, high spectrum utilization and high reliability. It can meet the business requirements of the power load monitoring system to the greatest extent, and at the same time provide a solid technical accumulation and application demonstration for the next generation network planning of the State Grid.

In the current TD-LTE230 wireless broadband access system, when the data receiving end feeds back the data transmission status, it adopts the transmission format of the radio link control status protocol data unit (RLC STATUS PDU) defined in the standard TD-LTE protocol, and transmits relevant information sent to the data sender.

Figure 1 is a schematic diagram of the RLC STATUS PDU transmission format defined in the standard TD-LTE protocol.

Among them, the data/control (Data/Control, D/C) field, with a length of 1 bit, is used to indicate that the radio link control-protocol data unit (RLC PDU) is a radio link control-data-protocol data unit (RLC data The PDU is also a radio link control-control-protocol data unit (RLC control PDU). The specific value definition of the D/C field is shown in Table 1 below.

field value instructions 0 control PDU 1 Data PDU

Table 1

The control PDU format (Control PDU Type, CPT) field, with a length of 3 bits, is used to indicate the RLC control PDU format. The specific value definition of the CPT field is shown in Table 2 below.

Table 2

The Acknowledgment SN (ACK_SN) field is used to indicate the sequence number (SN) of the first RLC Data PDU that has not been received and has not been reported lost in the STATUS PDU, with a length of 10 bits.

The Negative Acknowledgment SN (NACK_SN) field is used to indicate that the receiving side of the radio link control (RLC) entity in the acknowledgment mode (AM) has detected a lost acknowledgment mode data PDU (AMD PDU), or AMD PDU Part of the SN, the length is 10bit.

Extension 1 (Extension1bit, E1) domain: Indicates whether to include a set of NACK_SN domains, E1 domains and E2 domains, with a length of 1 bit. The specific value definition of the E1 field is shown in Table 3 below.

table 3

The extension 2 (Extension2bit, E2) field is used to indicate whether there is a set of SOstart and SOend fields after it, and the length is 1 bit. The specific value definition of the E2 field is shown in Table 4 below.

field value instructions 0 There is no set of SOstart and SOend fields following the current NACK_SN 1 The current NACK_SN is followed by a set of SOstart and SOend fields

Table 4

The lost segment start (Segment Offset start, SOstart) field is used to indicate the position of the first byte of the lost part in the AMD PDU data field (calculated in bytes), and the length is 15bit.

The lost segment end (Segment Offset end, SOend) field is used to indicate the position of the last byte of the missing part in the AMD PDU data field (calculated in bytes), and the length is 15bit.

The above method of using the RLC STATUS PDU transmission format to indicate the transmission status is suitable for wireless broadband access systems, but when applied to wireless narrowband access systems, there will be the following problems:

1. For multiple PDUs that are lost continuously, the corresponding NACK_SN domain information needs to be given for each PDU. In this way, when the radio link control (RLC) layer loses packets continuously, the STATUS PDU fed back will be larger, which will This leads to a large wireless resource overhead.

2. For multiple different lost segments of a PDU, it is necessary to assign corresponding NACK_SN domain information to each lost segment. In this way, when the number of lost segments in the PDU is large, the overhead of repeated NACK_SN domains is large. As a result, the feedback STATUS PDU will be large and the wireless resource overhead will be large.

In view of the fact that the 230 system based on the TD-LTE standard needs to support wireless narrowband access transmission, the bandwidth provided to each user is small at this time. In order to adapt to the transmission of small TB blocks and improve the effective data transmission efficiency, it is necessary to reduce the overhead of RLCSTATUS PDU as much as possible. Therefore, the above-mentioned RLC STATUS PDU transmission format applicable to the wireless broadband access system cannot meet the transmission performance requirements of the 230 system due to the existence of the above-mentioned problems.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a transmission feedback method, which can effectively reduce the overhead of RLCSTATUS PDU.

In order to achieve the above object, the technical scheme proposed by the present invention is:

A transmission feedback method comprising:

After receiving the data, the receiving end generates a corresponding RLC STATUS PDU packet according to the currently received protocol data unit and according to the preset format of the second radio link control status protocol data unit RLC STATUS PDU;

Wherein, when performing the generation, if there is a protocol data unit PDU that satisfies: the data of the PDU is all lost and there is at least one PDU with data loss thereafter, then an E3 domain is added after the E2 domain corresponding to the PDU, so The above E3 field is used to indicate the continuous loss of PDUs within the range from the PDU sequence number indicated by the NACK_SN field corresponding to this PDU to the PDU sequence number indicated by the next NACK_SN field, or to indicate that the next NACK_SN field is not used for joint The NACK_SN field corresponding to this PDU indicates that the PDU is continuously lost; if multiple segments of a PDU are lost, the SOstart field and SOend field of each segment are added sequentially after the NACK_SN field corresponding to the PDU, and after each SOend field Add an E4 field respectively, and the E4 field is used to indicate whether this E4 field is followed by the SOstart field and Soend field of other segments of the PDU indicated by the current NACK_SN field;

The receiving end sends the RLC STATUS PDU data packet to the sending end of the data.

In summary, the transmission feedback method proposed by the present invention introduces the E3 field in the RLC STATUS PDU data packet to indicate consecutively lost PDUs, and introduces the E4 field to indicate multiple segments lost by the same PDU. The repeated overhead of the NACK_SN field in the RLC STATUS PDU data packet realizes the optimization indication of consecutive lost PDUs and multiple segments of the same PDU, which can effectively reduce the overhead of RLC STATUS PDUs and improve data transmission efficiency.

Description of drawings

Figure 1 is a schematic diagram of the RLC STATUS PDU transmission format defined in the standard TD-LTE protocol;

Fig. 2 is a schematic flow chart of the method in Embodiment 1 of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

The core idea of the present invention is: increase the E3 field and the E4 field, and realize the optimized indication of RLC continuous PDU loss and multiple segment loss of the same PDU, so that the RLC STATUS PDU is as small as possible, so as to reduce wireless resource overhead and improve transmission efficiency the goal of.

FIG. 2 is a schematic flow chart of Embodiment 1 of the present invention. As shown in FIG. 2 , the transmission feedback method of this embodiment mainly includes the following steps:

Step 201: After receiving the data, the receiving end generates a corresponding RLC STATUS PDU packet according to the currently received PDU according to the preset format of the second radio link control status PDU (RLC STATUS PDU) .

Wherein, when performing the generation, if there is a protocol data unit PDU that satisfies: the data of the PDU is all lost and there is at least one PDU with data loss thereafter, then an E3 domain is added after the E2 domain corresponding to the PDU, so The E3 field is used to indicate that the PDUs within the range from the PDU sequence number indicated by the NACK_SN field corresponding to this PDU to the PDU sequence number indicated by the next NACK_SN field are continuously lost, or used to indicate that the next NACK_SN field is not used for joint The NACK_SN field corresponding to this PDU indicates the function of continuous loss of PDU; if multiple segments of a PDU are lost, the SOstart field and SOend field of each segment are added sequentially after the NACK_SN field corresponding to the PDU, and each SOend field Afterwards, an E4 field is added respectively, and the E4 field is used to indicate whether this E4 field is followed by the SOstart field and Soend field of other segments of the PDU indicated by the current NACK_SN field.

In this step, a new RLC STATUS PDU format, namely the second RLC STATUS PDU format, is introduced to generate the RLC STATUS PDU packet. The difference between the second RLC STATUS PDU format and the existing system's RLCSTATUS PDU format is that the E3 domain is introduced It is the same as the E4 field, and the meanings of other fields are the same, and will not be repeated here.

Here, when all data of a PDU is lost and there is at least one subsequent PDU with data loss, the E1 field after the NACK_SN field corresponding to the PDU is 1 and the E2 field is 0. At this time, the PDU with data loss occurring after the PDU may be several PDUs with all data loss occurring immediately thereafter. In this way, the indication of continuous loss of PDUs can be realized by using the E3 field. In this way, it is not necessary to use multiple NACK_SN fields to indicate multiple consecutively lost PDUs, but only need to use the first and last two NACK_SN fields to indicate, so that the overhead of the NACK_SN field can be greatly reduced.

After the E4 field is introduced in this step, only one NACK_SN field can be used to indicate multiple lost segments of the same PDU. In this way, the overhead of repeating the NACK_SN field can be reduced, thereby greatly reducing the overhead of the NACK_SN field.

Preferably, the value of the E3 field can be configured as 1 to indicate that the PDUs within the range from the PDU sequence number indicated by the NACK_SN field corresponding to this PDU to the PDU sequence number indicated by the next NACK_SN field are continuous Lost; configure the value of the E3 field as 0 to indicate that the next NACK_SN field is not used to combine the NACK_SN field corresponding to this PDU to indicate the continuous loss of PDUs.

Preferably, the value of the E4 field can be configured as 1 to indicate that the E4 field is followed by the SOstart field and the Soend field of other segments of the PDU indicated by the current NACK_SN field; the value of the E4 field is set to The value is configured as 0 to indicate that there is no SOstart field and Soend field of other segments of the PDU indicated by the current NACK_SN field after this E4 field.

Step 202, the receiving end sends the RLC STATUS PDU data packet to the sending end of the data.

Preferably, in order to improve the compatibility between the present invention and the existing system, the control PDU type CPT field in the RLC STATUS PDU data packet can be used to indicate that the format type of the RLC STATUS PDU data packet is the second RLC STATUS PDU format. Specifically, any unused value may be selected from the reserved field values in the RLC STATUS PDU format of the existing system as the CPT field value used to indicate the second RLC STATUS PDU format. For example, it can be set to 001.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. transmit a feedback method, it is characterized in that, comprising:

After receiving terminal receives data, according to the protocol Data Unit situation be currently received, according to the second rlc status pdu format unit R LC STATUS PDU form preset, generate corresponding RLC STATUSPDU packet;

Wherein, when carrying out described generation, if there is a protocol Data Unit PDU to meet: the data of this PDU are all lost and be there is thereafter the PDU that loss of data occurs at least one, then after the E2 territory that this PDU is corresponding, increase an E3 territory, the PDU that described E3 territory is used to indicate from the PDU sequence number indicated by NACK_SN territory corresponding to this PDU to the PDU sequence number indicated by next NACK_SN territory in scope loses continuously, or is used to indicate the NACK_SN territory that next NACK_SN territory is not used in this PDU of associating corresponding and loses continuously to indicate PDU; If multiple fragment loss of a PDU, after the NACK_SN territory that this PDU is corresponding, then increase SOstart territory and the SOend territory of each segmentation successively, and increase an E4 territory respectively after each SOend territory wherein, SOstart territory and the Soend territory of described E4 territory whether followed by other segmentations of PDU indicated by current NACK_SN territory after being used to indicate this E4 territory;

Described RLC STATUS PDU Packet Generation is given the transmitting terminal of described data by described receiving terminal.

2. method according to claim 1, it is characterized in that, when the value in described E3 territory is 1, the PDU from the PDU sequence number indicated by NACK_SN territory corresponding to this PDU to the PDU sequence number indicated by next NACK_SN territory in scope is indicated to lose continuously;

When the value in described E3 territory is 0, the NACK_SN territory indicating next NACK_SN territory to be not used in this PDU of associating corresponding is lost continuously to indicate PDU.

3. method according to claim 1, is characterized in that, when the value in described E4 territory is 1, followed by the SOstart territory of other segmentations of PDU indicated by current NACK_SN territory and Soend territory after indicating this E4 territory;

When the value in described E4 territory is 0, after indicating this E4 territory, there is not SOstart territory and the Soend territory of other segmentations of PDU indicated by current NACK_SN territory.

4. method according to claim 1, is characterized in that, described method comprises further:

The control PDU Type C PT territory in described RLC STATUS PDU packet is utilized to indicate the form of described RLCSTATUS PDU packet to be the 2nd RLC STATUS PDU form.

5. method according to claim 1, is characterized in that, the value in described CPT territory is 001.