Time transfer is a fundamental concept in PNT systems, as result of the need to provide timing information to applications enabled by those systems. Time transfer refers to the distribution of time, generally from (and possibly within) some originating node, across a network, and at a receiving node where the timing application is enabled. Synchronization refers to node(s) in the system acquiring what is generally referred to as the “system time”, by means of the time transfer process. Synchronization challenges can arise as a result of delays introduced at various stages in the process of time transfer.

Today’s PNT systems include solutions that are satellite based, particularly GPS/GNSS which are commonly used, however that can also be unavailable or exposed to vulnerabilities, and terrestrial, leveraging dedicated networks such as those based on wireless beacons. This poster focuses on time transfer and synchronization in terrestrial PNT solutions, exploring system design and challenges for both LOS and NLOS wireless scenarios.