RLC Buffer Reduction via Network Coding Parity

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G NR, face challenges in efficiently managing radio link control (RLC) buffers to ensure reliable data transmission and error correction, leading to inefficiencies in packet assembly and retransmissions.

Innovation Solution

The implementation of a method that generates RLC protocol data units (PDUs) and RLC parity PDUs based on encoding procedures for RLC service data units (SDUs), storing parity PDUs in buffers for retransmissions, and providing feedback for assembling SDUs with acknowledgment or negative acknowledgment sequence numbers, allowing for efficient error correction and reduced buffer sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RLC buffer stores parity PDUs for retransmission, then reliability of data transmission is improved, but buffer size increases

Engineering Contradiction:

Improvereliability of data transmissionVSAvoidbuffer size

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the RLC SDU into multiple RLC PDUs before encoding, allowing the buffer to store only the parity PDUs corresponding to individual segments rather than waiting for complete retransmissions. This segmentation enables more efficient use of buffer space while maintaining reliability through targeted error correction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs encoding of RLC PDUs into parity PDUs in advance before transmission. By pre-computing and storing these parity PDUs in the RLC buffer, the system prepares error correction data ahead of time, enabling reliable retransmission without requiring large buffer sizes for complete data storage.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If network coding is used for encoding, then error correction capability is improved, but device complexity increases

Engineering Contradiction:

Improveerror correction capabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces network coding as an intermediary layer between the RLC layer and the physical layer. This intermediary uses linear combinations of source PDUs to create parity PDUs, providing error correction capability without requiring complex retransmission mechanisms. The network coding approach simplifies the overall system by using mathematical operations rather than complex protocol overhead.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS20240356683A1RLC buffer reduction based on network coding and outer code

Publication Date: 2024.10.24 QUALCOMM INC

AI summary

This disclosure provides systems, devices, apparatus, and methods, including computer programs encoded on storage media, for RLC buffer reduction techniques. A wireless transmitter may generate at least one RLC PDU and at least one RLC parity PDU based on an encoding procedure for an RLC SDU. The wireless transmitter may store, in an RLC buffer, the at least one RLC parity PDU for the RLC SDU and transmit, to a MAC layer, at least one of the segmentation of the RLC SDU or the at least one RLC PDU. A wireless receiver may generate RLC PDU feedback for at least one of the RLC SDU, the segmentation of the RLC SDU, or the at least one RLC PDU and transmit, to an RLC layer, the RLC PDU feedback including an indication of an additional number of encoded RLC PDUs and at least one of an ACK_SN or a NACK_SN.