The Single Frequency Network (SFN) mode of operation within the ATSC 3.0 standard provides for a significantly more efficient usage of the available transmission frequency bands. As transmission frequencies are a regulated and limited resource, the importance of the SFN mode of operation is of vital importance to the longevity of digital terrestrial transmission standards such as ATSC 3.0.
ATSC 3.0 SFN operations require highly accurate synchronous transmission within the same frequency. Consequently, a much stricter performance level is required from the synchronization reference equipment. A typical solution uses a non-network based system such as a GNSS (Global Navigation Satellite System) receiver as the UTC source reference at the transmission site. In such a deployment it is necessary to place or integrate the GNSS receiver at each and every transmitter in order for required microsecond-level precision and accuracy to be achieved.
This paper will introduce alternative and complementary operational modes for providing UTC using an IP network based technology called Time Transfer. Time Transfer is a two-way time and frequency transfer method, showing how a stable, robust absolute time representation across the network is achieved, including automatic corrections for intrinsic delays and diurnal wander.
The paper will continue to describe how the Time Transfer method supports mission-critical services and large scale distribution networks with the delivery of GNSS-independent UTC. As the method enables distribution of real-time information over the same IP infrastructure that is used for transport of media and other data payloads, it is highly secure, cost-effective and can be built resiliently at scale. Moreover, this approach provides the accuracy and precision needed (that is, approximately one microsecond) for any real-time wide-area network applications including those based on SMPTE ST2110 and LTE-TDD. The solution is at the same time, more resilient than satellite-based systems and more accurate and scalable than traditional network synchronization methods.
Technical Depth of Presentation
I would describe the paper as a combination of the levels, for a general technically literate audience. The technical depth will reach intermediate level.
What Attendees will Benefit Most from this Presentation
The ideal audience will be technology literate on ASTC and/or other digital terrestrial technology standards. Audience members would ideally be senior managers with a combination of technology and business sense as the application of the technology can bring extremely large economic benefits to the business based on efficient spectrum utilisation.
Take-Aways from this Presentation
Attendees and their teams will understand that there is an IP network solution to delivering precise and accurate time to any receiving device, such as an ATSC 3.0 transmitter operating in Single Frequency Network mode, a SMPTE ST2110 workflow dependent upon PTP, or a LTE-TDD mobile cell. The primary take-away is the understanding that there is a robust and necessary alternative tool provide accurate time other than to completely rely upon GNSS (more commonly known as GPS) and IEEE 1588 based references.