Terminal Device L1 Neighbor Cell Measurement for Handover

The patent segments the measurement process into two independent parts: L1 measurements for rapid signal quality assessment and L3 measurements for reliable cell identification and selection. The terminal device performs L1 measurements on reference signals from neighbor cells to quickly evaluate signal quality, while L3 measurements are used only when handover decisions need to be made. This segmentation allows the system to benefit from both the speed of L1 and the reliability of L3 without paying the full cost of L3 processing continuously.

The patent implements preliminary L1 measurements as a preparatory step before committing to L3 measurement processing. The terminal device continuously monitors neighbor cell signal quality through L1 measurements and pre-evaluates potential target cells. When a neighbor cell's signal quality exceeds a threshold, the device has already completed preliminary assessment work, so the subsequent L3 measurement and handover decision can be made rapidly. This preliminary action reduces the effective processing time required when handover is actually needed.

The patent applies partial action by using L1 measurements for the majority of monitoring scenarios where full L3 measurement accuracy is not required. L3 measurements are performed only partially - specifically, only when L1 measurements indicate a potential handover candidate or when the network explicitly requests detailed measurement reports. This partial application of L3 measurement reduces signaling overhead while maintaining sufficient measurement accuracy for critical decisions.

The patent introduces L1 measurements as an intermediary layer between the physical signal and the L3 measurement process. Instead of directly performing L3 measurements on all neighbor cells, the system first uses L1 measurements to filter and identify promising candidates. This intermediary step reduces the number of L3 measurements required, thereby reducing signaling overhead while preserving measurement accuracy for the most relevant cells.

The patent performs preliminary L1 measurements and signal quality assessments before handover decisions are required. The terminal device continuously evaluates neighbor cells using L1 measurements and maintains a pre-processed list of potential target cells with their signal quality metrics. When handover becomes necessary, the device can quickly select from pre-evaluated candidates without needing to perform full L3 filtering at the moment of handover, thus reducing service interruption delay while maintaining reliability through the preliminary assessment work.

The patent extracts the time-consuming L3 filtering process from the critical handover execution path and relocates it to a preliminary assessment phase. By separating the filtering operation from the handover decision moment, the system can perform L3 measurements and filtering in advance when there is no service interruption pressure. During actual handover, only the final selection and execution steps are needed, which are much faster and do not require intensive filtering computation.