Network Measurement for GNSS-Denied One-Way Delay Accuracy
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Solution Overview
Problem
Conventional network measurement systems face challenges in performing high-precision one-way delay measurements when one end of the communication network, such as a device in a data center, cannot acquire time information from a Global Navigation Satellite System (GNSS) due to environmental constraints, leading to decreased accuracy.
Innovation Solution
A network measurement system and method that utilizes a first and second network measurement device connected to a terminal and server device, respectively, to perform one-way and two-way delay measurements, with a time error estimation mechanism to correct for time errors in the server device's clock, allowing accurate measurements even in environments where GNSS signals are unavailable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a GNSS receiver is used to acquire UTC as a common clock for one-way delay measurement, then time synchronization accuracy is improved, but measurement capability is lost in environments where GNSS signals are unavailable (e.g., data centers)
Solution Approach 1:
The patent introduces a time error estimation mechanism that acts as an intermediary between the server device's local clock and the common clock (UTC). By estimating and compensating for time errors through two-way delay measurements, the system enables accurate one-way delay measurements without requiring direct GNSS signal access at all measurement locations.
Solution Approach 2:
The system changes the measurement approach from direct time synchronization via GNSS to indirect time error estimation through two-way measurements. This parameter change allows the system to operate in environments where GNSS signals are unavailable by using available local clocks and compensating for their drift through measurement-based error estimation.
2Measurement precision
If multiple network measurement devices are placed at transmission and reception sides for one-way delay measurement, then measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The network measurement devices are designed to perform multiple functions: they can conduct both one-way delay measurements and two-way delay measurements, and they can operate with or without GNSS signal access. This multi-functionality reduces the need for separate specialized devices for different measurement scenarios.
Solution Approach 2:
The system uses the server device's existing clock and timing infrastructure to perform measurements, rather than requiring completely independent measurement devices at each location. The measurement devices leverage available local resources (server clocks, network infrastructure) to enable accurate measurements without adding excessive device complexity.
Data Source
AI summary
The network measurement system has a first network measurement device and a second network measurement device respectively having a GNSS receiving function, and with the first network measurement device connected to the UE and the second network measurement device arranged outside the data center and connected to the server device, both devices measure the one-way delay between the UE and the server device. In accordance with this, the second network measurement device simultaneously measures the one-way delay and two-way delay between the server device and estimates the time error of the server device based on the results of the one-way delay and two-way delay measurements.