Handover Between Terrestrial and Non-Terrestrial Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for a seamless handover method between terrestrial and non-terrestrial networks, particularly as discussions on 5G and 6G advancements and the use of satellites as base stations in aerial communication systems progress, requiring efficient signal power management to ensure continuous connectivity.
Innovation Solution
The method involves user equipment receiving configuration information for handover conditions from base stations or satellites, measuring Reference Signal Received Power (RSRP) of reference signals from both networks, and transmitting measurement reports to determine optimal handover based on predefined thresholds and hysteresis parameters to manage signal power transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If handover conditions are set with low RSRP thresholds to enable frequent handovers between terrestrial and non-terrestrial networks, then network adaptability and coverage are improved, but handover stability deteriorates due to excessive handover occurrences and signal fluctuations
Solution Approach 1:
The patent applies preliminary action by configuring handover parameters (RSRP thresholds, hysteresis values, timing conditions) in advance before handover is needed. The network pre-configures multiple handover conditions with different thresholds and the UE prepares measurement reports beforehand, so when handover is actually needed, the decision can be made quickly and stably without reactive adjustments that cause fluctuations.
Solution Approach 2:
The patent utilizes parameter changes by dynamically adjusting RSRP thresholds, hysteresis parameters, and timing conditions based on network state and UE characteristics. Different parameter sets are configured for different scenarios (e.g., terrestrial-to-non-terrestrial vs. non-terrestrial-to-terrestrial handovers), allowing the system to adapt to varying conditions while maintaining stability through optimized parameter selection.
2Speed
If handover parameters are configured to be sensitive to signal changes to respond quickly to network conditions, then handover responsiveness is improved, but measurement precision requirements increase leading to more frequent and unnecessary handovers
Solution Approach 1:
The patent applies beforehand cushioning by introducing hysteresis margins and offset values in handover parameter configurations. These cushioning parameters create a buffer zone around threshold values, preventing the system from reacting to minor signal fluctuations. The UE is configured with handover parameters that include hysteresis components, which cushion against measurement noise and prevent premature or unnecessary handovers while maintaining responsive behavior for genuine signal changes.
3Adaptability or versatility
If multiple handover conditions and parameters are configured to manage complex terrestrial and non-terrestrial network transitions, then handover management capability is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing handover management into distinct conditional scenarios: terrestrial-to-non-terrestrial handover conditions, non-terrestrial-to-terrestrial handover conditions, and cancel conditions for each direction. Each scenario has its own set of parameters (RSRP thresholds, hysteresis values, timing conditions). This segmentation allows the complex handover management to be organized into manageable, independent condition sets that can be configured and processed systematically without overwhelming the UE.
Data Source
AI summary
A method of a user equipment in a wireless communication system, includes: receiving, from a base station, configuration information including at least one of a pre-condition, a trigger condition, and a cancel condition for a handover from the base station to a satellite; receiving a first reference signal from the base station and a second reference signal from the satellite, respectively; measuring Reference Signal Received Power (RSRP) of each of the first reference signal and the second reference signal; and transmitting a first measurement report to the base station, based on a determination that the trigger condition related to the first reference signal and the pre-condition related to the second reference signal are satisfied.