PDCP Entity Re-establishment for Header Decompression Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In next-generation mobile communication systems, the packet data convergence protocol (PDCP) layer's header compression protocol fails to decompress headers correctly during handover or radio link failure procedures due to unsynchronized header compression information between the transmitting and receiving PDCP layers, leading to errors.
Innovation Solution
A method for correct PDCP entity re-establishment is proposed, which includes configuring and activating uplink semi-persistent scheduling across multiple serving cells using a single radio resource control (RRC) message, ensuring synchronized header compression information and preventing decompression errors during handovers or radio link failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the PDCP layer performs header decompression during PDCP re-establishment procedure, then data transmission can be restored after handover or radio link failure, but header decompression errors occur due to unsynchronized header compression information between transmitting and receiving PDCP layers
Solution Approach 1:
The patent applies preliminary action by performing header decompression on stored PDCP data units before the PDCP re-establishment procedure is triggered. By pre-decompressing headers and storing the decompressed data units in a buffer, the receiving PDCP layer ensures that when re-establishment occurs, the header compression information is already synchronized, preventing decompression errors during the critical handover or radio link failure recovery phase.
2Reliability
If the receiving PDCP waits for PDCP re-establishment completion before decompressing headers, then header compression information is synchronized, but data transmission delay increases
Solution Approach 1:
The patent performs header decompression in advance before the PDCP re-establishment procedure is triggered. By pre-decompressing headers and buffering the decompressed data units, the system eliminates the waiting time that would otherwise be required for synchronization, thus reducing data transmission delay while maintaining decompression accuracy.
Solution Approach 2:
The patent creates a buffer of pre-decompressed data units as a cushion against potential delays. This buffered data can be transmitted immediately after decompression without waiting for the PDCP re-establishment procedure to complete, providing a time cushion that reduces overall transmission delay while ensuring decompression accuracy is maintained through prior synchronization.
3Reliability
If header compression protocol information is updated during PDCP re-establishment, then synchronization is achieved, but decompression errors occur for previously received out-of-order data
Solution Approach 1:
The patent applies preliminary action by decompressing headers of stored PDCP data units before the PDCP re-establishment procedure updates the header compression protocol information. This ensures that out-of-order data received before re-establishment is decompressed using the old (correct) header compression information, preventing decompression errors that would occur if the updated information were used retroactively.
Data Source
Figure 1A~1B
Figure 1C
Figure 1D
AI summary
A communication technique for converging a 5G communication system, which is provided to support a higher data transmission rate beyond a 4G system with an IoT technology, and a system therefor applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety related service, or the like) based on the 5G communication technology and the IoT related technology by re-establishing a PDCP entity for a header compression protocol and activating uplink semi-persistent scheduling.