Timing Advance Compensation for 5G Split Node Propagation Delay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the split CU-DU architecture of 5G networks, accurately compensating for propagation delay (PD) in timing advance (TA) measurements is challenging, leading to inaccurate positioning and timing relationships between the 5G system clock and TSN time.
Innovation Solution
The method involves the CU requesting and acquiring up-to-date TA measurements from the DU for UEs, allowing for accurate compensation of DL propagation delay in reference time information. This includes periodic or on-demand reporting of TA measurements, with uncertainty values, to ensure precise timing adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the gNB provides timing information to the UE without propagation delay compensation, then the timing information can be delivered to the UE, but the timing relationship between 5GSC and TSN time becomes inaccurate due to RF propagation delay
Solution Approach 1:
The gNB performs propagation delay compensation in advance by calculating the RF distance between itself and the UE, then adjusting the timing information before transmission. This preliminary adjustment ensures that the UE receives accurate timing information without experiencing timing offset, resolving the contradiction between delivering timing information and maintaining timing accuracy.
2Measurement precision
If the gNB compensates for propagation delay using RF distance calculation, then timing accuracy is improved, but the complexity of the timing compensation mechanism increases
Solution Approach 1:
The patent introduces an intermediary mechanism where the gNB uses existing RF distance measurement capabilities (already present in the system for other purposes) to calculate propagation delay. This intermediary approach allows timing compensation to be achieved without building a completely new complex system, thereby reducing the increase in device complexity while still improving timing accuracy.
3Adaptability or versatility
If the serving gNB changes or the UE moves, then the UE can maintain connectivity, but the propagation delay changes causing timing inaccuracy
Solution Approach 1:
The timing compensation mechanism is designed to be dynamic, automatically recalculating the RF distance and propagation delay whenever the UE moves or switches serving gNB. This dynamic adjustment ensures that timing accuracy is maintained adaptively across different mobility scenarios, resolving the contradiction between supporting UE mobility and maintaining timing precision.
Data Source
AI summary
Embodiments include methods for a centralized unit (CU) of a radio access network (RAN) node. Such methods include sending, to a distributed unit (DU) of the RAN node, a request for one or more timing advance (TA) measurements for a user equipment (UE) with respect to one or more cells served by the DU. Such methods include receiving from the DU one or more responses that include the respective one or more TA measurements and for each received TA measurement, determining a corresponding downlink (DL) propagation delay (PD) between the DU and the UE. Other embodiments include complementary methods for a DU of a RAN node, as well as CUs and DUs configured to perform such methods.