Dual-Frequency Dual-Cell Mobility Management via Virtual Active Sets
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Solution Overview
Problem
Current wireless communication networks face challenges in managing mobility events in dual-frequency dual-cell environments, particularly in maintaining optimal uplink signal strength and balancing carrier usage, leading to potential uplink imbalances and unreliable control channel decoding.
Innovation Solution
The method involves maintaining an active set for a primary carrier and a virtual active set for a secondary carrier, with the network node determining which carrier to use as the anchor based on uplink signal strength measurements to minimize uplink imbalance, allowing for independent mobility event reporting and anchor carrier selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If independent mobility events are managed for both primary and secondary carriers in dual-frequency dual-cell networks, then mobility management performance is improved, but system complexity increases
Solution Approach 1:
The patent segments mobility management by maintaining separate active sets for primary and secondary carriers. The UE independently manages mobility events for each carrier frequency, allowing differentiated handling of mobility scenarios without requiring complete re-evaluation of all carriers for each event.
Solution Approach 2:
The patent introduces a new dimension to mobility management by adding carrier-specific active sets and virtual active sets. This multi-dimensional approach (carrier frequency × cell) enables more granular control over mobility events, allowing the system to track which cells are active on which carriers independently.
2Reliability
If anchor carrier is selected based on uplink signal strength to minimize uplink imbalance, then uplink performance is improved, but measurement and determination complexity increases
Solution Approach 1:
The patent performs preliminary measurements of uplink signal strength from multiple cells on both primary and secondary carriers before anchor carrier selection. The UE reports measurement results (such as Ec/I0 values) to the network, which then determines the optimal anchor carrier based on these pre-collected measurements, minimizing uplink imbalance.
Solution Approach 2:
The system implements feedback mechanisms where the UE continuously measures and reports uplink signal strength parameters to the network. The network uses this feedback to dynamically select the anchor carrier that minimizes uplink imbalance, creating a closed-loop control system for optimal uplink performance.
Data Source
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AI summary
A method operable at a user equipment configured for wireless communication over a dual-frequency, dual-cell network is disclosed includes a primary carrier and a secondary carrier. The method includes maintaining an active set corresponding to the primary carrier; maintaining a virtual active set corresponding to the secondary carrier; and transmitting a control signal including a virtual mobility event corresponding to a change in the virtual active set. An apparatus for performing the method is also disclosed.