PCI Collision Avoidance via PSS Waveform Selection
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Solution Overview
Problem
In wireless networks, PCI collisions between neighboring cells can lead to reference signal differentiation issues and timing synchronization problems for user equipment, resulting in decoding failures due to shared PCI assignments, especially in Integrated-Access-Backhaul networks with zero-network planning or mobile node movements.
Innovation Solution
A method where a scheduling entity, such as a base station or IAB node, autonomously or upon instruction, changes its physical cell identifier (PCI) from a first PCI to a second PCI by selecting a different primary synchronization signal (PSS) waveform to avoid collisions with neighboring cells, ensuring distinct PSS waveforms for each cell.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If PCI is assigned based on zero-network planning or mobile node movements, then network deployment flexibility is improved, but PCI collision between neighboring cells occurs
Solution Approach 1:
The system performs preliminary PCI collision detection by comparing the PCI of the current cell with PCIs of neighboring cells before finalizing the PCI assignment. This preliminary action prevents PCI collisions from occurring in the first place, resolving the contradiction between deployment flexibility and collision avoidance.
Solution Approach 2:
The system implements feedback mechanisms where PCI collision information from neighboring cells is continuously monitored and fed back to the PCI assignment process. This feedback loop enables dynamic adjustment of PCI assignments to prevent collisions while maintaining deployment flexibility.
2Productivity
If same PCI is assigned to neighboring cells, then resource utilization is improved, but reference signal differentiation fails
Solution Approach 1:
The system applies local quality by ensuring that while PCIs can be reused in distant cells (improving resource utilization), neighboring cells that require signal differentiation are assigned distinct PCIs. This localized differentiation resolves the contradiction between resource utilization and reference signal differentiation.
3Device complexity
If PCI collision occurs, then network configuration simplicity is maintained, but timing synchronization and channel estimation fail
Solution Approach 1:
The system performs preliminary PCI collision detection and resolution during network configuration, preventing timing synchronization and channel estimation failures before they occur. This preliminary action maintains configuration simplicity while ensuring synchronization reliability.
4Extent of automation
If PCI collision is detected, then autonomous PCI change is implemented, but network signaling overhead increases
Solution Approach 1:
The system implements self-service by enabling cells to autonomously detect PCI collisions and change their own PCIs without requiring extensive network signaling. This reduces information loss and signaling overhead while maintaining high automation capability.
Data Source
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AI summary
Aspects relate to a physical cell identifier (PCI) change within a wireless network based on a primary synchronization signal (PSS) waveform. A scheduling entity, such as an integrated-access-backhaul (IAB) node within a radio access network (RAN), may communicate with a set of one or more scheduled entities, such as other IAB nodes and/or user equipment (UEs), utilizing a first PCI. The scheduling entity may then change from the first PCI to a second PCI, where the second PCI corresponds to a different PSS waveform than the first PCI. In some examples, the scheduling entity may change the PCI as a result of a PCI collision and/or PSS collision with a neighboring scheduling entity.