Adaptive Synchronization for LBT-LBE Nodes to Resolve Access Starvation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems using a Listen Before Talk Load-Based Equipment (LBT-LBE) protocol, intra-operator competition for access to a shared radio frequency spectrum band can lead to unfair access scenarios, where some base stations are starved of access due to differing random values of N used in extended Clear Channel Assessment (CCA) procedures, causing synchronization issues among nodes.
Innovation Solution
Adaptive synchronization techniques are employed to identify and mitigate interference between nodes, allowing synchronization only when interference thresholds are not met, ensuring fair access by aligning contention access protocol timings and enabling synchronization between nodes to access the shared radio frequency spectrum band in a coordinated manner.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If nodes use different random values of N in extended CCA procedures, then some nodes can win contention for access to the shared radio frequency spectrum band, but other nodes are starved of access due to intra-operator competition
Solution Approach 1:
The patent implements dynamic synchronization where nodes adaptively adjust their extended CCA procedures based on detected interference levels. When interference is detected, nodes dynamically synchronize their N values and timing; when interference is absent, nodes use random N values. This dynamic adaptation resolves the contradiction by making the system flexible enough to ensure fairness when needed while maintaining normal contention when not needed.
Solution Approach 2:
The patent changes the parameter N from a purely random value to a synchronized value based on interference detection. By monitoring interference levels and adjusting the N parameter accordingly, the system ensures that nodes use consistent N values when interference is present, preventing access starvation, while allowing random N values when interference is absent, maintaining normal contention dynamics.
2Reliability
If nodes synchronize their extended CCA procedures, then fair access is ensured among nodes, but synchronization complexity increases
Solution Approach 1:
The patent applies synchronization locally and selectively rather than globally and continuously. Nodes synchronize only with nearby nodes that detect similar interference patterns, and only when interference is actually present. This localized approach reduces synchronization complexity while maintaining fairness where it is needed.
Solution Approach 2:
Each node independently monitors its own interference level and autonomously decides whether to synchronize with other nodes. This self-service mechanism eliminates the need for centralized synchronization control, reducing system complexity while ensuring fairness through distributed decision-making.
3Device complexity
If nodes perform extended CCA procedures independently, then device complexity is reduced, but access starvation occurs due to interference from other nodes
Solution Approach 1:
The patent implements feedback through interference detection, where nodes monitor the shared radio frequency spectrum band for interference signals. Based on this feedback, nodes adaptively adjust their behavior - synchronizing when interference is detected to prevent starvation, and operating independently when no interference is present to maintain low complexity.
4Reliability
If nodes use random values of N, then contention fairness is maintained, but access efficiency decreases due to repeated failed contentions
Solution Approach 1:
The patent dynamically switches between random N values and synchronized N values based on interference detection. When interference is present, nodes use synchronized N values to coordinate access attempts and reduce repeated failures. When interference is absent, nodes use random N values to maintain fairness. This dynamic approach reduces time loss while preserving fairness.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Techniques are described for wireless communication. A method for wireless communication may include identifying interference at a first node operating in a shared radio frequency spectrum band. The interference may be caused by a second node operating in the shared radio frequency spectrum band. The second node may operate asynchronously to the first node in the shared radio frequency spectrum band. The method may also include adaptively enabling, based at least in part on the identified interference, a synchronization of the first node with at least a third node in the shared radio frequency spectrum band.