PDCP Entity Duplicated PDU Transmission Timing
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Solution Overview
Problem
The increasing number of user equipment (UEs) in wireless communication systems requires efficient transmission and reception of uplink/downlink data and control information using limited radio resources, while also necessitating reduced latency and effective signal handling in new radio access technology systems.
Innovation Solution
A method for transmitting data that involves duplicating Packet Data Convergence Protocol (PDCP) PDUs with a timing difference to achieve time diversity, allowing for efficient use of limited radio resources and reduced latency by configuring PDCP entities to submit duplicated PDCP PDUs at different time instances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PDCP PDUs are transmitted using conventional methods without duplication, then device complexity is reduced, but reliability and throughput are insufficient for URLLC requirements
Solution Approach 1:
The patent implements packet duplication at the PDCP layer by creating copies of PDCP PDUs and transmitting them through multiple RLC entities and logical channels. This copying mechanism ensures that if one transmission path fails, the duplicate copy can still be received, thereby improving reliability without requiring complex retransmission protocols
Solution Approach 2:
The patent segments the transmission path by dividing the duplicated PDCP PDUs into different logical channels and RLC entities. This segmentation allows independent transmission through multiple paths, increasing the probability that at least one copy will be successfully delivered while maintaining manageable device complexity
2Productivity
If multiple duplicated PDCP PDUs are transmitted simultaneously, then throughput is improved, but latency increases due to processing overhead
Solution Approach 1:
The patent employs periodic transmission of duplicated PDCP PDUs through different logical channels at scheduled intervals. This periodic action allows the system to achieve diversity gain across multiple transmission opportunities while controlling latency by avoiding continuous simultaneous transmission of all duplicates
Solution Approach 2:
The patent dynamically selects which duplicated PDCP PDU to transmit based on current channel conditions and buffer status. This dynamic approach optimizes throughput by transmitting duplicates only when beneficial while minimizing latency by avoiding unnecessary transmission delays
3Reliability
If PDCP entities are configured to submit duplicated PDCP PDUs at different time instances, then time diversity is achieved, but device complexity increases
Solution Approach 1:
The patent configures PDCP entities in advance to submit duplicated PDCP PDUs at different time instances through pre-defined transmission timing patterns. This preliminary configuration enables time diversity without requiring complex real-time decision-making, as the transmission schedule is predetermined based on channel conditions and QoS requirements
Data Source
Figure 1~2
Figure 3
Figure 4(a)~4(b)
AI summary
A transmitting device of the present invention submits, from a packet data convergence protocol (PDCP) entity configured with a PDCP duplication function, a PDCP protocol data unit (PDU) (duplicated PDCP PDU 1) to a lower layer and starts a prohibit timer for the duplicated PDCP PDU 1. The transmitting device submits, from the PDCP entity, the same PDCP PDU (duplicated PDCP PDU 2) to the lower layer if the prohibit timer expires. The transmitting device transmit the duplicated PDCP PDU 1 and the duplicated PDCP PDU 2.