Inter-RAT Handover Detection Using PCI and Frequency Identifiers
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Solution Overview
Problem
Current wireless communication networks face challenges in reducing unnecessary handovers between different radio access technologies (RATs) due to the need for pre-configuration of target nodes with global cell identifiers and the inefficiency of measurement configurations, leading to increased configuration efforts and unnecessary measurements.
Innovation Solution
Incorporating Physical Cell Identifiers (PCI) and frequency information into the Handover Report IE, allowing target nodes to identify detected cells without pre-configured global cell identifiers, and providing indicators for E-UTRAN frequency-specific measurement configurations to limit UE measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If global cell identifiers (ECGI) are pre-configured in target nodes for handover detection, then handover detection accuracy is improved, but configuration effort and device complexity increase
Solution Approach 1:
The patent extracts only the necessary identification elements (PCI and frequency information) from the complete global cell identifier (ECGI), allowing target nodes to identify detected cells without storing comprehensive neighbor cell configurations. This reduces configuration effort while maintaining sufficient detection capability.
Solution Approach 2:
The Handover Report IE is enhanced to carry multiple types of cell identification information (ECGI, PCI, frequency) in a unified structure, allowing the same message to serve both precise handover detection and reduced configuration requirements across different network scenarios.
2Measurement precision
If comprehensive measurement configurations are provided to UEs, then measurement precision is improved, but unnecessary measurements and energy consumption increase
Solution Approach 1:
The patent applies frequency-specific measurement configurations, where UEs are instructed to perform measurements only on specific E-UTRAN frequencies indicated in the IRAT Measurement Configuration IE, rather than all possible frequencies. This localizes the measurement requirement to only relevant frequencies, reducing unnecessary measurements and energy consumption while maintaining detection precision for those frequencies.
3Reliability
If pre-configuration of neighbor cell information is performed in target nodes, then handover reliability is improved, but configuration effort and operational costs increase
Solution Approach 1:
The patent enables target nodes to perform preliminary identification of detected cells using PCI and frequency information included in the Handover Report IE, without requiring advance pre-configuration of complete neighbor cell databases. This preliminary action maintains handover reliability by allowing timely identification while reducing the burden of extensive preconfiguration.
Data Source
AI summary
According to an aspect, a network node operating in a first RAN according to a first RAT is the target of an inter-RAT (IRAT) handover. The network node receives a handover request for a user equipment from a cell in a second RAN operating according to a second RAT. After handover of the user equipment to a cell in the first RAN is completed, the network node configures the user equipment to measure one or more frequencies corresponding to the second RAN. Based on measurements reported by the user equipment for the one or more frequencies, the network node identifies one or more detected cells exceeding a measurement threshold, and sends a handover report towards the second RAN. The handover report includes, for at least one detected cell exceeding the measurement threshold, a physical cell identifier for the detected cell and a frequency identifier for the detected cell.