Background
Currently, the current state of the art commonly used in the industry is such that: in the current protocol, both the sender (Transmitting Entity or Receiving Side) and the receiver (Receiving Entity or Receiving Side) in the Re-establishment procedure (Re-establishment procedure) of the PDCP are required to lose data (discard all the SDUs or pdus) with respect to the data of the SRB. When the PDCP is re-established (re-establishment), both the sender and the receiver discard unsent SDUs and PDUs on the SRB, and for NAS PDUs received by the RRC, due to the introduction of the CU-DU architecture, the link change on one DU causes the re-establishment of the PDCP, thereby causing all the data of the SRB to be discarded and failing to embody the advantages of the CU-DU architecture. Meanwhile, because the current RAN introduces the transceiving of multi-connection data, when the channel of one PDCP fails, there may be other available PDCP channels, and the sending of all NAS PDUs also ensures the correct receiving of the receiving end without the sequence error.
In summary, the problems of the prior art are as follows:
(1) when the PDCP is rebuilt, the CU-DU architecture is introduced, and the rebuilding of the PDCP caused by the link change on one DU causes the data of the SRB to be completely discarded, so that the advantage of the CU-DU architecture cannot be embodied.
(2) When the PDCP is reestablished, because the current RAN introduces the transceiving of multi-connection data, when a PDCP tunnel fails, there may be other available PDCP tunnels, and all NAS PDUs need to be sent to ensure correct reception by the receiving end without a wrong sequence.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for sending new transmission and retransmission of NAS PDU of RRC and an information data processing terminal.
The invention is realized in such a way, the new transmission and retransmission method of the NAS PDU of the RRC introduces a sequential transmission mechanism and a retransmission mechanism aiming at the NAS PDU in an RRC protocol sublayer, and when the PDCP is rebuilt, the RRC can quickly retransmit the NAS PDU which is not successfully transmitted.
Further, the method for sending new transmission and retransmission of NAS PDU of RRC specifically includes:
(1) RRC entity of sending end: introducing a simple sending sequencing data window in RRC, and distributing a sequence number SN to each NAS PDU;
(2) the RRC entity at the receiving end: the PDCP still discards the SRB according to the existing protocol, relying on the retransmission at the sending end.
Further, the (1) specifically includes:
when the NAS PDU is sent: the RRC sends a new NAS PDU every time, a latest idle SN number is used, the SN is used as additional information of an SRB data packet sent by the RRC to the PDCP, only a join primitive between the PDCP and the RRC is used, and the influence on a normal SRB data packet is avoided; the latest SN number is increased by one;
the PDCP uses the SN numbers in an ascending order and sends the SN numbers to a lower layer;
when the PDCP protocol sublayer determines that the RRC PDU on the SRB is successfully sent, a feedback response is sent to the RRC to inform the RRC that the RRC is successfully sent;
after the RRC receives the confirmation message sent by the PDCP protocol sublayer, the RRC moves the whole sending window to the next SN position for confirming correct receiving, and prepares for next sending;
when in reconstruction: when the PDCP is rebuilt, aiming at the SRB data packets which are not successfully sent and need to be discarded, the information of the data packets is fed back to the RRC;
after receiving the data packet, the RRC determines the sequence of the data packet retransmitted next time according to the SN number of the data packet;
further, each NAS PDU is allocated with a sequence number SN;
the Length of the sequence number is LengthSNThe unit: the number of bits;
SNmax: the largest SN number;
Lengthwin: the total length of the send window;
then:
Lengthwin(LengthSN+1)/2nwherein n is 2,3,4, 5.
Another object of the present invention is to provide a computer program for implementing the method for transmitting new transmission and retransmission of NAS PDU of RRC.
Another object of the present invention is to provide an information data processing terminal for implementing the RRC NAS PDU new transmission and retransmission transmission method.
Another object of the present invention is to provide a computer-readable storage medium, which includes instructions that, when executed on a computer, cause the computer to execute the RRC NAS PDU new transmission and retransmission transmission method.
In summary, the advantages and positive effects of the invention are: the invention realizes that the RRC can quickly send the existing NAS PDU on a new PDCP entity after the NAS PDU transmitted on the SRB is discarded because of the reconstruction of the PDCP, thereby realizing the quick data transmission. The loss of data is reduced as much as possible, so that the retransmission of NAS signaling is reduced; for Inter-DU or Intra-DU switching under Intra-CU under CU/DU architecture, the retransmission of NAS signaling is greatly reduced.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
When the PDCP is rebuilt, the data of the SRB are completely discarded, and the advantages of the CU-DU framework cannot be embodied; all the NAS PDUs are sent to ensure correct reception by the receiving end without the problem of wrong sequencing. The invention realizes that the RRC can quickly send the existing NAS PDU on a new PDCP entity after the NAS PDU transmitted on the SRB is discarded due to the reestablishment of the PDCP, thereby realizing the quick data transmission.
The following detailed description of the principles of the invention is provided in connection with the accompanying drawings.
As shown in fig. 1, a method for sending new transmission and retransmission of NAS PDU of RRC according to an embodiment of the present invention includes the following steps:
s101: introducing a simple sending sequencing data window in RRC, and distributing a sequence number SN to each NAS PDU;
s102: the PDCP still discards the SRB according to the existing protocol, relying on the retransmission at the sending end.
The application of the principles of the present invention will now be described in further detail with reference to the accompanying drawings.
An in-sequence sending mechanism and a retransmission mechanism aiming at the NAS PDU are introduced into an RRC protocol sublayer, and when the PDCP is rebuilt, the RRC can quickly retransmit the NAS PDU which is not successfully sent.
1. RRC entity of transmitting end (as shown in fig. 2):
a simple send ordering data window is introduced at RRC.
Each NAS PDU is assigned a sequence number, sn, (sequence number).
The Length of the sequence number is LengthSNThe unit: the number of bits. E.g., 4bits, 8bits, etc.
SNmax: maximum sn (sequence number) number.
Lengthwin: the total length of the transmission window.
Then:
Lengthwin(LengthSN+1)/2nwherein n is 2,3,4, 5. For example if the sequence number LengthSNIs 8bits, then SNmax255, the transmission window of RRC is 256/22There may be 64 serial numbers.
As shown in fig. 3, when sending NAS PDU:
and the RRC sends a new NAS PDU every time, a latest idle SN number is used, the SN is used as additional information of the SRB data packet sent by the RRC to the PDCP, only the joining primitive between the PDCP and the RRC is used, and the influence on the normal SRB data packet is avoided. The latest SN number is increased by one.
The PDCP uses SN numbers in ascending order and transmits to a lower layer.
And when the PDCP protocol sublayer determines that the RRC PDU on the SRB is successfully transmitted, a feedback response is sent to the RRC to inform the RRC that the RRC is successfully transmitted.
After the RRC receives the confirmation message sent by the PDCP protocol sublayer, the RRC moves the whole sending window to the next SN position for confirming correct receiving, and the preparation for next sending is made.
When in reconstruction:
when the PDCP is rebuilt, the information of the SRB data packets which are not successfully transmitted and need to be discarded is fed back to the RRC.
And after receiving the data packet, the RRC determines the sequence of the data packet retransmitted next time according to the SN number of the data packet.
2. The RRC entity at the receiving end:
the processing mode remains unchanged, and the PDCP still discards the SRB according to the existing protocol, depending on the retransmission of the sending end.
In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When used in whole or in part, can be implemented in a computer program product that includes one or more computer instructions. When loaded or executed on a computer, cause the flow or functions according to embodiments of the invention to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website site, computer, server, or data center to another website site, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL), or wireless (e.g., infrared, wireless, microwave, etc.)). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that includes one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.