Relay Terminal Identifier Alignment for Asynchronous U2N Updates
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Solution Overview
Problem
In the process of updating local identifiers for remote and relay UEs in UE-to-network relay communication, asynchronous reception times of RRC reconfiguration messages can lead to data packet loss due to mismatched identifier updates.
Innovation Solution
The relay terminal device processes data packets using a consistent identifier, either by replacing or aligning local identifiers based on configuration information, and performs error handling to avoid packet loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station sends updated local ID to remote UE and relay UE via RRC reconfiguration message, then the local ID update is completed, but data packet loss occurs due to asynchronous reception time
Solution Approach 1:
The relay UE performs preliminary actions by storing both the old local ID and new local ID configuration information before the remote UE completes its update. This allows the relay UE to be ready to handle data packets with either ID, preventing packet loss during the transition period.
Solution Approach 2:
The relay UE acts as an intermediary between the base station and remote UE during the ID update process. It receives and buffers data packets from the base station, and can forward them using either the old or new local ID depending on which ID the remote UE currently recognizes, thus mediating the asynchronous update issue.
2Productivity
If the relay UE uses the new local ID for processing data packets, then the update is efficient, but packets with old local ID are lost
Solution Approach 1:
The relay UE dynamically switches between using the old local ID and new local ID for processing data packets based on the update status. It maintains flexibility in ID selection, adapting to the remote UE's current state rather than rigidly following a single ID, thus preventing packet loss while maintaining update efficiency.
Solution Approach 2:
The relay UE changes the parameter of local ID usage based on configuration information received from the base station. It can process packets with either the old or new local ID depending on which ID is currently valid for the remote UE, allowing efficient updates without packet loss through parameter adaptation.
3Reliability
If the relay UE waits for remote UE to complete update before switching ID, then packet loss is avoided, but transmission delay increases
Solution Approach 1:
The relay UE performs preliminary preparation by storing both old and new local ID configurations and being ready to process packets with either ID simultaneously. This eliminates the need to wait for the remote UE to complete its update before switching IDs, as the relay UE is already prepared to handle both ID formats, thus avoiding both packet loss and transmission delays.
Data Source
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AI summary
Embodiments of this application provide a communication method and apparatus, to avoid a data packet loss caused by asynchronous time of updating local IDs by remote UE and relay UE. This can be applied to a U2N or multipath relay communication system. The method includes: A relay terminal device receives first configuration information from a network device. The first configuration information includes a first local identifier and a first identifier, the first local identifier is an identifier that is allocated by the network device and that identifies a remote terminal device, the first identifier is an identifier that is allocated by the remote terminal device and that identifies the remote terminal device, and the remote terminal device communicates with the network device via the relay terminal device. The relay terminal device receives a first data packet based on the first identifier, and processes the first data packet based on the first configuration information. The first data packet carries a second local identifier, and the second local identifier is an identifier that is configured by the network device for the remote terminal device and that identifies the remote terminal device.