Signaling Clock Accuracy via PTP TLV Extensions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current IEEE 1588v2 protocols lack the ability to convey clock accuracy to downstream devices or applications, which is essential for 3GPP Radio Access Network (RAN) applications, particularly in 5G fronthaul environments, where Radio Units (RUs) and Distributed Units (DUs) need to exchange precise timing information to configure advanced services.
Innovation Solution
Extending the IEEE 1588v2 protocol with a Type-Length-Value (TLV) extension to the ANNOUNCE Protocol Data Units (PDUs) to signal the G.8273.2 or G.8273.4 class of clock accuracy, allowing downstream devices to identify clock accuracy within specific nanosecond ranges (5 ns, 10 ns, 30 ns, or 50 ns) relative to Coordinated Universal Time (UTC), enabling precise clock synchronization and service configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If IEEE 1588v2 protocol is used for clock synchronization, then clock synchronization is achieved, but clock accuracy information cannot be conveyed to downstream devices
Solution Approach 1:
The patent segments the clock accuracy information into discrete class values (Class A: 50ns, Class B: 30ns, Class C: 10ns, Class D: 5ns) that can be independently transmitted through the protocol, allowing downstream devices to receive and utilize specific accuracy information without requiring complete protocol redesign
Solution Approach 2:
The patent introduces an intermediary mapping mechanism between the IEEE 1588v2 clockClass enumeration and the G.8273.2/G.8273.4 accuracy classes. This intermediary layer translates the existing 1588v2 clockClass values into meaningful accuracy classifications that convey precise timing accuracy information to downstream devices
2Measurement precision
If the existing clockAccuracy enumeration in IEEE 1588v2 is used, then Grand Master clock configuration is enabled, but it cannot convey accuracy for non-GM clocks with insufficient granularity
Solution Approach 1:
The patent applies local quality by introducing accuracy class-specific information only where needed in the protocol stack - at the Boundary Clock and Time Slave Clock levels - rather than requiring changes throughout the entire IEEE 1588v2 protocol. This allows precise accuracy representation for non-GM clocks without complicating the overall protocol structure
Solution Approach 2:
The patent makes the existing clockClass field multi-functional by mapping it to serve both the original IEEE 1588v2 synchronization function and the new G.8273.2/G.8273.4 accuracy indication function simultaneously, eliminating the need for separate dedicated fields and reducing protocol complexity
3Adaptability or versatility
If 3GPP RAN applications require precise timing accuracy information, then service configuration capability is improved, but the existing protocol lacks the necessary timing accuracy conveyance
Solution Approach 1:
The patent implements feedback by enabling downstream 3GPP RAN applications to receive timing accuracy information from upstream network elements through the enhanced protocol. This feedback loop allows RAN applications to make informed service configuration decisions based on the actual timing accuracy available in the network
Data Source
AI summary
A network element includes circuitry configured to receive information related to clock distribution from Precision Time Protocol (PTP) messages from an upstream network element, determine a delta between a network clock from the information and a Primary Reference Time Clock (PRTC), and transmit the delta in PTP messages to downstream network elements. The circuitry can be further configured to receive a configuration of a clock class of a clock at the network element, and transmit the clock class in the PTP messages with the delta. The clock class can be one of A, B, C, and D from G.8273.2 or G.8273.4.