S&T's ATCaster is an ATSC 3.0 broadcast stream generator. It provides ATSC 3.0 Low Level Signaling (LLS), ROUTE, MMT and ESG delivery.
The ROUTE (Real-time Object delivery over Unidirectional Transport) protocol is used to deliver content packaged in MPEG DASH Segments. In addition to ROUTE, ATSC 3.0 content can be MPEG Media Transport (MMT) based, in such cases MMT protocol (MMTP) is used to deliver Media Processing Units (MPU).
ATCaster generates the ATSC 3.0 low level signaling (LLS) on the well-known multicast address (184.108.40.206:4937).
ATCaster builds the Service Layer Signaling (SLS) and all related ROUTE and MMTP sessions containing audio, video and Non-Realtime (NRT) data.
Tyipically ATCaster receives MPEG DASH segments pushed to it via WebDAV PUSH. Usually, this data is provided by a HEVC encoder, such as the ATEME TITAN Live, or possibly from a DASH Packager. ATCaster generates the appropriate UDP multicast outputs containing the ROUTE sessions and signaling.
For a broadcast scenario, these multicast transmissions are sent to an ATSC 3.0 Scheduler (such as the Enensys ATSCheduler).
ATCaster uses UniSoft's ATSC SFG via streaming service interfcace to allow ATSC 3.0 signaling and applications to be signed at the time of delivery.