PDCP Data Recovery for Wireless Communication Systems
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Solution Overview
Problem
5G communication systems experience significant data transmission delays, which hinder efficient data processing and delivery, particularly when a terminal supporting dual access changes connected base stations.
Innovation Solution
A method and apparatus for efficiently retransmitting data in wireless communication systems by re-establishing radio link control entities and performing selective or sequential retransmissions of unacknowledged packet data units when a base station change occurs, utilizing a user equipment (UE) that receives a request for packet data convergence protocol (PDCP) data recovery and confirms successful delivery through status reports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional retransmission procedures are used in 5G communication systems, then data reliability is maintained, but data transmission delay increases significantly
Solution Approach 1:
The patent applies preliminary action by having the UE proactively determine and store PDCP PDUs that need retransmission before the actual retransmission occurs. When a base station changes, the UE has already identified the unacknowledged PDCP PDUs and prepared them for immediate retransmission, eliminating the delay of determining which packets need retransmission after the handover occurs.
Solution Approach 2:
The patent introduces an intermediary mechanism by using a separate determination unit that identifies PDCP PDUs requiring retransmission, acting as a mediator between the lower layer (which sends status reports) and the upper layer (which performs retransmission). This intermediary layer optimizes the retransmission process by pre-identifying problematic packets without disrupting the overall protocol structure.
2Reliability
If all PDCP PDUs are retransmitted sequentially after base station change, then data completeness is ensured, but transmission time increases
Solution Approach 1:
The patent applies partial action by retransmitting only the specific PDCP PDUs that were not successfully delivered, rather than retransmitting all PDCP PDUs. The determination unit identifies exactly which PDCP PDUs need retransmission based on status reports from the lower layer, and only those specific packets are retransmitted, reducing unnecessary retransmission time while ensuring data completeness.
Solution Approach 2:
The patent uses preliminary action by pre-determining which PDCP PDUs require retransmission before the actual retransmission process begins. This allows the system to prepare the exact set of packets that need to be sent, avoiding the time overhead of determining packet requirements during the retransmission process itself.
3Loss of time
If selective retransmission of PDCP PDUs is performed, then data transmission delay is reduced, but system complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the retransmission control function into separate components: a determination unit that identifies which PDCP PDUs need retransmission, and a retransmission unit that executes the retransmission. This segmentation allows each component to focus on a specific task, reducing the overall system complexity while enabling selective retransmission. The determination unit handles the complex decision-making, while the retransmission unit handles the straightforward execution.
Data Source
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AI summary
Provided is a user equipment method of transmitting and receiving data in a wireless communication system, comprising receiving a request for a packet data convergence protocol (PDCP) data recovery from an upper layer, determining at least one PDCP packet data unit (PDU), previously submitted to a re-established radio link control (RLC) entity, for which a successful delivery has not been confirmed by a lower layer, and performing a retransmission of the determined at least one PDCP PDU.