CN106559912B

CN106559912B - Triggering method and device of RLC reset procedure

Info

Publication number: CN106559912B
Application number: CN201510615426.2A
Authority: CN
Inventors: 曲晨
Original assignee: Leadcore Technology Co Ltd; Datang Semiconductor Design Co Ltd
Current assignee: Chenxin Technology Co ltd
Priority date: 2015-09-24
Filing date: 2015-09-24
Publication date: 2020-03-20
Anticipated expiration: 2035-09-24
Also published as: CN106559912A

Abstract

The invention relates to a triggering method and a triggering device for an RLC reset process, which are suitable for a non-discarding mode of RLC. The method comprises the following steps: if the Timer _ poll Timer is overtime when the state protocol data unit of the opposite terminal is not received, the last packet of RLC protocol data unit is sent to the opposite terminal once; accumulating the overtime times of the Timer _ poll Timer; and entering the RLC into a reset procedure when the number reaches Max _ Dat-1, where Max _ Dat is a maximum number of transmissions.

Description

Triggering method and device of RLC reset procedure

Technical Field

The present invention relates to an RLC reset procedure in a 3GPP protocol, and in particular, to a method and an apparatus for triggering the RLC reset procedure.

Background

The 3GPP mainly defines a third generation technical specification with a GSM core network as a basis and Universal Terrestrial Radio Access (UTRA) as a Radio interface. The 3GPP aims to realize smooth transition from a 2G network to a 3G network, ensure backward compatibility of future technologies, and support easy network establishment and roaming and compatibility between systems.

A Radio Link Control (RLC) layer in 3GPP is located above a Media Access Control (MAC) layer, and provides a segmentation and retransmission service for user and Control data.

In the 25.331 protocol of 3GPP, there are four ways of transmitting RLC Discard (Transmission RLC Discard), the last of which is No Discard (No Discard) mode. In the non-discard mode, when a certain packet of RLC Protocol Data Unit (PDU) reaches the maximum transmission number Max _ DAT, the RLC entity that sends the packet needs to send a RESET PDU to the opposite end, trigger a RESET procedure, and further trigger an RLC unrecoverable error (unrecoveraror) procedure.

In the existing network test, sometimes, the opposite end of the sending end does not send Status PDU or send but cannot receive Status PDU due to reasons such as sudden signal degradation or some problems occurring in the uplink and downlink. The timeout of Timer _ poll triggers the retransmission of the last RLC PDU packet, and when the retransmission caused by Timer _ poll exceeds Max _ Dat, the RLC reset procedure is triggered. However, in reality, it is found that there are situations where the reset procedure cannot be triggered as expected, and even the reset is delayed seriously.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a method and an apparatus for triggering an RLC reset procedure, which can avoid the delay of the reset procedure.

The technical scheme adopted by the invention for solving the technical problems is a triggering method of an RLC reset process, which is suitable for a non-discarding mode of RLC, and comprises the following steps: if the Timer _ poll Timer is overtime when the state protocol data unit of the opposite terminal is not received, the last packet of RLC protocol data unit is sent to the opposite terminal once; accumulating the overtime times of the Timer _ poll Timer; and entering the RLC into a reset procedure when the number reaches Max _ Dat-1, where Max _ Dat is a maximum number of transmissions.

In an embodiment of the present invention, if the status protocol data unit of the peer is received, the number is cleared.

In an embodiment of the present invention, when the number reaches Max _ Dat-1, the RLC enters a reset procedure, regardless of whether the number of last packet RLC protocol data unit retransmissions reaches Max _ Dat.

In an embodiment of the present invention, the method is performed in a mobile terminal.

In an embodiment of the present invention, the method is performed at the base station side.

In an embodiment of the invention, the mobile terminal is a 3G or 4G mobile terminal.

In one embodiment of the present invention, the base station is a 3G or 4G base station.

The invention also provides a triggering device of the RLC reset procedure, which is suitable for the non-discarding mode of the RLC, and the device comprises: a first module, configured to send a last RLC pdu to the peer end each time when the Timer _ poll Timer expires without receiving a status pdu of the peer end; a second module, configured to accumulate the timeout times of the Timer _ poll Timer; and a third module for causing the RLC to enter a reset procedure when the number reaches Max _ Dat-1, where Max _ Dat is a maximum number of transmissions.

In an embodiment of the present invention, the apparatus is incorporated in a mobile terminal.

In an embodiment of the present invention, the apparatus is incorporated in a base station.

Compared with the prior art, the invention combines the scenes in the actual sending process, considers the problem that the resetting process does not occur as expected under the condition that the PDCP sends the new SDU, and realizes triggering the resetting process at the expected time point by counting the overtime times of the Timer _ Poll, thereby avoiding the delay and recovering the RLC link.

Drawings

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, wherein:

fig. 1 is a flow of a triggering method of an RLC reset procedure according to an embodiment of the present invention.

Fig. 2 is a trigger reset procedure when PDCP sends a new SDU according to an embodiment of the present invention.

Fig. 3 is a process for triggering a reset for multiple timeouts as contemplated by the prior art protocol.

Fig. 4 is a trigger reset procedure when PDCP sends a new SDU under the existing protocol.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.

The embodiment of the invention describes a triggering method and a triggering device of an RLC (radio link control) resetting process, aiming at solving the problems that the resetting process cannot be triggered as required and delay exists.

The existing 3GPP protocol specifies that the uplink shall send the RLC reset procedure only if a certain packet of RLC Protocol Data Unit (PDU) reaches the maximum number of sending times Max _ Dat. If the retransmission caused by Timer _ poll timeout is caused by the peer non-return status PDU, and the last packet reaches the maximum transmission time Max _ Dat, the RLC reset is triggered. Fig. 3 is a process for triggering a reset for multiple timeouts as contemplated by the prior art protocol. Referring to fig. 3, each time the Timer _ poll times out, the last packet PDU is retransmitted, the number of retransmissions vt (dat) plus 1. After a number of delays, vt (dat) reaches the maximum number of transmissions, RLC enters the reset procedure.

There are special cases, however, where the reset procedure cannot be triggered as desired. When the above scenario occurs, the higher layer Packet Data Convergence Protocol (PDCP) may also send Service Data Units (SDU) sequentially, and according to the Protocol, under the condition that the RLC transmission window is not full, these new Data packets need to be sent, so that each time Timer _ poll Timer is overtime, the last Packet retransmitted is different Sequence Numbers (SNs), each PDU cannot reach the maximum transmission frequency, and the reset procedure cannot be triggered until the RLC transmission window is full, and new Data cannot be sent. If the RLC transmission window is configured in a large scene, the reset delay is very serious.

Fig. 1 is a flow of a triggering method of an RLC reset procedure according to an embodiment of the present invention. Referring to fig. 1, the triggering method may be performed in a device such as a mobile terminal or a base station. When the method is executed at a mobile terminal, the base station is taken as an opposite terminal. Conversely, when the method is executed at the base station, the mobile terminal is taken as the opposite terminal. The triggering method of the embodiment is applicable to the non-discard mode of the RLC, and includes the following steps:

in step 101, each time the Timer _ poll Timer expires without receiving a status PDU of the peer, the last RLC PDU packet is sent to the peer;

in step 102, accumulating the timeout times of the Timer _ poll Timer;

in step 103, when the accumulated number of times reaches Max _ Dat-1, the RLC enters a reset procedure, where Max _ Dat is the maximum number of transmissions.

In step 103, the accumulated time-out times reaching Max _ Dat _ 1 is equivalent to the last PDU packet sent Max _ Dat times in the scenario without new SDU, and the RLC enters the reset procedure. Since the timeout of the Timer _ poll Timer does not depend on the retransmission time of the last PDU packet, even if the last PDU packet cannot reach the maximum transmission time Max _ Dat due to a new SDU, the RLC reset procedure is triggered in this embodiment. That is, the present embodiment will make the RLC enter the reset procedure as long as the accumulated time-out number reaches Max _ Dat-1, regardless of whether the number of retransmissions of the last RLC PDU packet reaches Max _ Dat. The triggering method of the present embodiment is therefore able to trigger the RLC reset procedure at a desired point in time, thereby avoiding delays.

In addition, if the device receives the status PDU of the peer end in the above process, the number of times of timeout of the Timer _ poll Timer is cleared, that is, the number of times of timeout of the Timer _ poll Timer is restarted to be calculated.

Fig. 2 is a trigger reset procedure when PDCP sends a new SDU according to an embodiment of the present invention. Referring to fig. 2, each time the Timer _ Poll Timer expires, after the last packet of PDU is sent, the number of times of timeout is increased by 1, and after several times of timeout, the number of times of timeout > becomes Max _ Dat-1, so that the RLC enters a reset procedure. In this process, the transmission of new SDUs does not affect the count of the number of timeouts.

In contrast, fig. 4 is a trigger reset procedure when PDCP sends a new SDU under the existing protocol. Referring to fig. 4, since PDCP often transmits new SDUs during the Timer _ Poll Timer, the last packet retransmitted each time the Timer _ Poll expires is different from the previous one (or new SDUs appear if the maximum transmission time is not reached), for example, in the transmission from 1 st to 3 rd times, the SN numbers of the retransmitted last packet are SN1, SN2 and SNi, respectively, so that the retransmission times SN1 VT (DAT), SN2 VT (DAT) and SNi VT (DAT) need to be calculated for the three packets, respectively, and Max _ DAT specified by the protocol is not satisfied, in which case, it is necessary to wait until there is no new SDU or the RLC transmission window is full. If a new SDU always exists, the condition for triggering the reset procedure is satisfied only if the RLC transmission window is full and the Timer _ Poll times out MaxDAT-1 more times. If the RLC window configuration is large (e.g., 2048), then the time to reach transmission window full may be long, not coinciding with the time at which a transmission reset is expected.

Therefore, compared with the prior art, the embodiment of the invention can avoid the delay of the RLC reset procedure.

The triggering method of the RLC reset procedure according to the above embodiment of the present invention can be implemented in a computer readable medium, such as computer software, hardware, or a combination of computer software and hardware. For a hardware implementation, the embodiments described herein may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), digital signal processing devices (DAPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic devices designed to perform the functions described herein, or a selected combination thereof. In some cases, such embodiments may be implemented by a controller.

For a software implementation, the embodiments described herein may be implemented by separate software modules, such as program modules (procedures) and function modules (functions), each of which performs one or more of the functions and operations described herein. The software codes may be implemented by application software written in a suitable programming language, and may be stored in a memory and executed by a controller or processor. For example, the triggering apparatus of the RLC reset procedure according to an embodiment of the present invention is applicable to a non-discard mode of the RLC, and includes a first module, a second module, and a third module, where the first module is configured to send a last packet of RLC protocol data unit to an opposite terminal each time a Timer _ poll Timer times out without receiving a status protocol data unit of the opposite terminal; the second module is used for accumulating the overtime times of the Timer _ poll Timer; and a third module for causing the RLC to enter a reset procedure when the number reaches Max _ Dat-1, where Max _ Dat is a maximum number of transmissions.

The triggering device of the RLC reset procedure of the present invention may be incorporated into a mobile terminal or a base station.

In an embodiment of the present invention, the mobile terminal to which the method and apparatus are applied may be a 3G or 4G mobile terminal, and the base station to which the method and apparatus are applied is a 3G or 4G base station. In the case of 3G standard, it may be WCDMA or TD-SCDMA, and in the case of 4G, it may be TDD-LTE or FDD-LTE.

Although the present invention has been described with reference to the present specific embodiments, it will be appreciated by those skilled in the art that the above embodiments are merely illustrative of the present invention, and various equivalent changes and substitutions may be made without departing from the spirit of the invention, and therefore, it is intended that all changes and modifications to the above embodiments within the spirit and scope of the present invention be covered by the appended claims.

Claims

1. A triggering method of RLC reset procedure is applicable to non-discard mode of RLC, and comprises the following steps:

if the Timer _ poll Timer is overtime when the state protocol data unit of the opposite terminal is not received, the last packet of RLC protocol data unit is sent to the opposite terminal once;

accumulating the overtime times of the Timer _ poll Timer; and

when the number reaches Max _ Dat-1, the RLC enters a reset procedure, where Max _ Dat is the maximum number of transmissions.

2. The method of triggering of an RLC reset procedure of claim 1, wherein the number is cleared if a status protocol data unit of the peer is received.

3. The method of claim 1, wherein when the number reaches Max _ Dat-1, the RLC enters the reset procedure regardless of whether the number of last packet RLC protocol data unit retransmissions reaches Max _ Dat.

4. The method of triggering of the RLC reset procedure of claim 1, performed at a mobile terminal.

5. The method of triggering of the RLC reset procedure of claim 1, performed at the base station side.

6. The method of claim 4, wherein the mobile terminal is a 3G or 4G mobile terminal.

7. The method of claim 5, wherein the base station is a 3G or 4G base station.

8. A triggering device of RLC reset procedure is applicable to non-discard mode of RLC, said device includes:

a first module, configured to send a last RLC pdu to the peer end each time when the Timer _ poll Timer expires without receiving a status pdu of the peer end;

a second module, configured to accumulate the timeout times of the Timer _ poll Timer; and

and a third module, configured to enter the RLC into a reset procedure when the number reaches Max _ Dat-1, where Max _ Dat is a maximum number of transmissions.

9. The apparatus for triggering of an RLC reset procedure of claim 8, incorporated in a mobile terminal.

10. The apparatus for triggering of an RLC reset procedure of claim 8, wherein the apparatus is incorporated in a base station.

11. The apparatus of claim 9, wherein the mobile terminal is a 3G or 4G mobile terminal.

12. The apparatus of claim 10, wherein the base station is a 3G or 4G base station.