Timing Advance Pre-Acquisition for Low-Interruption Handover
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Solution Overview
Problem
Conventional handover procedures in low-capability mobile devices with a single receiver chain induce significant delay due to multiple handover control steps, leading to interruptions in communication sessions.
Innovation Solution
A method involving a radio access network node that analyzes signal strength and initiates a pre-handover measurement indication to determine a timing advance, allowing for a seamless handover by establishing a connection with a neighboring node using a predetermined timing advance, thereby reducing handover interruption delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional handover control steps are performed for low-capability devices with a single receiver chain, then handover procedure completeness is ensured, but handover interruption delay increases significantly
Solution Approach 1:
The patent applies preliminary action by performing timing advance determination before the actual handover execution. The serving network node determines the timing advance in advance based on signal strength indications, so that when handover is needed, the timing advance is already ready and can be applied immediately, eliminating the delay that would otherwise occur while determining timing advance during the handover process.
Solution Approach 2:
The patent uses an intermediary approach by introducing a timing advance determination request message as a mediator between the user equipment and the serving network node. This message carries timing advance information from the target network node to the serving network node, enabling the serving network to proactively prepare timing advance without requiring the user equipment to perform complex measurements during handover.
2Reliability
If multiple handover control steps are performed to ensure complete handover procedure, then handover reliability is improved, but communication session continuity deteriorates
Solution Approach 1:
The patent performs the timing advance determination action in advance before the handover is executed. By determining the timing advance beforehand and storing it in the user equipment, the system ensures that when handover occurs, the timing information is already prepared, allowing the communication session to continue without interruption while still completing all necessary handover control steps.
3Device complexity
If timing advance is determined during handover execution, then handover procedure simplicity is maintained, but handover interruption delay increases
Solution Approach 1:
The patent resolves this contradiction by performing timing advance determination as a preliminary action before handover execution. The serving network node determines timing advance in advance based on signal strength indications from the user equipment, so that when handover is needed, the timing advance is already calculated and can be applied immediately, eliminating the delay that would occur if timing advance were determined during handover execution.
Data Source
AI summary
During a communication session with a serving radio access network node, a user equipment transmits coverage level reports corresponding to nodes neighboring the serving node as the user equipment moves. The serving node configures the user equipment with a timing advance gap period and suspends availability of resources for the communication session during the gap. The serving node may schedule the gap to coincide with a period with no traffic of the communication session to be communicated with the user equipment. During the gap, the user equipment transmits one or more configured timing advance preambles respectively corresponding to one or more neighboring nodes that, based on receiving the preambles, each prospectively determine one or more timing advance values with respect to the user equipment. After the gap, the user equipment resumes the communication session with the serving node and may use a prospectively determined timing advance during a later-instructed handover.