# Time Synchronization in 5G Wireless Edge: Requirements and Solutions for Critical-MTC

## TL;DR

This paper analyzes the synchronization requirements for time-critical machine-type communication in 5G wireless edge, proposing an OTA synchronization scheme and evaluating error sources to improve timing accuracy in diverse environments.

## Contribution

It introduces an OTA synchronization scheme for 5G edge devices and evaluates timing errors, addressing dense multipath environments for critical MTC applications.

## Key findings

- Proposed OTA synchronization scheme using 5G air interface parameters
- Analyzed estimation errors in device-to-base station delay from timing advance
- Identified countermeasures for errors in dense multipath fading environments

## Abstract

Wireless edge is about distributing intelligence to the wireless devices wherein the distribution of accurate time reference is essential for time-critical machine-type communication (cMTC). In 5G-based cMTC, enabling time synchronization in the wireless edge means moving beyond the current synchronization needs and solutions in 5G radio access. In this article, we analyze the device-level synchronization needs of potential cMTC applications: industrial automation, power distribution, vehicular communication, and live audio/video production. We present an over-the-air (OTA) synchronization scheme comprised of 5G air interface parameters, and discuss their associated timing errors. We evaluate the estimation error in device-to-base station propagation delay from timing advance (TA) under random errors and show how to reduce the estimation error. In the end, we identify the random errors specific to dense multipath fading environments and discuss countermeasures.