SK-Counter Rules for Monotonic Dual-Connectivity Handover
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing communication systems face challenges in determining secondary node counters (sk-counters) during intra-SN/inter-SN handovers, leading to unnecessary updates and non-monotonic increments, especially in NR-NR Dual Connectivity scenarios, due to uncertain movement paths of terminal devices.
Innovation Solution
A method for determining secondary node counters based on first information, including secondary node counter delta values and candidate cell grouping, to avoid unnecessary updates and ensure monotonic increments, by distinguishing intra-SN and inter-SN handovers through specific rules for Conditional PSCell Addition and Change.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal device updates the secondary node counter during every handover, then the security key consistency is maintained, but unnecessary updates occur during intra-SN handovers causing increased signaling overhead and processing complexity
Solution Approach 1:
The patent applies local quality by differentiating the counter update behavior based on the type of handover. For intra-SN handovers, the sk-counter remains unchanged, while for inter-SN handovers, the sk-counter is updated. This localized differentiation resolves the contradiction by applying updates only where necessary (inter-SN) rather than universally, thus maintaining security key consistency while avoiding unnecessary updates during intra-SN handovers.
Solution Approach 2:
The patent inverts the conventional approach by not updating the sk-counter during handovers by default, and only updating it when specifically required (inter-SN handovers). This inversion resolves the contradiction by reversing the update logic from 'update always' to 'update only when necessary', thereby maintaining security while reducing unnecessary updates and processing complexity.
2Speed
If the sk-counter is pre-configured for candidate cells, then the terminal device can quickly switch cells, but the sk-counter may be reused or not monotonically incremented due to uncertain movement paths
Solution Approach 1:
The patent applies preliminary action by pre-configuring the sk-counter for candidate cells before the terminal device actually switches to them. This allows the terminal to quickly switch cells without waiting for counter reconfiguration. The pre-configured counters are designed with monotonic increment relationships to ensure that even with uncertain movement paths, the counter values will increase monotonically as the terminal moves through different cells, thus resolving both the speed and reliability requirements.
Solution Approach 2:
The patent uses parameter changes by assigning different sk-counter values and increment patterns to different candidate cells based on their hierarchical relationships. The counter parameters are configured to increase monotonically across cells in a specific sequence, ensuring that regardless of the terminal's movement path, the counter values will follow a monotonic increment pattern, thereby maintaining reliability while enabling fast switching.
3Ease of operation
If the terminal device cannot distinguish intra-SN/inter-SN handover types, then the handover process is simplified, but unnecessary PDCP and RLC entity re-establishment occurs
Solution Approach 1:
The patent applies local quality by configuring different sk-counter update behaviors for different handover types (intra-SN vs. inter-SN) at specific network nodes. The MN and SN are configured to recognize handover types and apply appropriate counter update rules locally, enabling the terminal to maintain simplified operation while avoiding unnecessary PDCP and RLC entity re-establishment that would occur with generic counter updates.
Solution Approach 2:
The patent introduces the sk-counter as an intermediary mechanism that carries information about handover type and security requirements. By embedding handover type information in the sk-counter configuration and update rules, the system enables the terminal to perform simplified handovers without explicitly distinguishing handover types, while still preventing unnecessary entity re-establishment through the intermediary counter mechanism.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present application provides a method for determining a secondary node counter, a communication device, and a storage medium. The method for determining the secondary node counter includes determining the secondary node counter based on first information. Through the technical solution of the present application, the terminal device can avoid unnecessary updates to the secondary node counter, and/or, when an update to the secondary node counter is required, the secondary node counter is not reused and/or the secondary node counter monotonically increases.