Originally Posted by bobchase
You are close.
You certainly need new exciters.
The mux is optional. Statistical multiplexing helps if you own all the streams. If you cost share with other stations it can cause problems like "we paid for 12 mbs but last night we only got 6 ~ 9 mbs during prime". The lighthouses are more likely to be CBR.
Ah - I guess because I'm used to 'coding and mux' being done in the same process (whether CBR or statmuxed) in the realms of DVB-T/T2/S/S2 which all use transport streams I'd kind of ignored that ATSC 3.0 is more IP based so doesn't 'mux' into a single transport stream in the same way. By mux I meant creating a single multiplex stream, not statmuxing. Here all OTA services are statmuxed apart from the local TV mux. It's agreed that statmuxing is overall 'a good thing' so you don't pay for a fixed bitrate, but for carriage.
After that signal goes to Route Encapsulation or MMT encapsulation where it gets it's multicast IP and port numbers.
Then comes Signaling/Signing equipment. Signaling sets the Major/Minor, short and long subscriptions, adds the stream to the ESG,etc. Signing is to ensure that the TV is authorized to receive the channel.
Finally it goes to the Scheduling(Gateway) for the STLTP output. The scheduler sets the modulation scheme for each of the PLP's. STLTP is yet another layer of multicast encapsulation.
The STLTP feed goes to an IP based microwave. It could go to a fiber feed but they are rare at transmitter sites.
Ah - big difference to here. Microwave distribution died with analogue transmission here. Since 1998 all digital TV transmitters have been fibre fed, and that continued when we switched a mux from T to T2.
At the far end of the microwave a station will need two new exciters certainly. They will also most likely need a new transmitter because most transmitters do not have the extra headroom required for 1.0 to 3.0 conversion. So it's a new xmitter or de-rate your transmit power by 20%
A station will also require a PTP Master Clock.
That's going to be a steep learning curve. Broadcast PTP use is relatively early - but understanding it is vital for AES67, ST.2110 etc. IP production standards.
they will need at least one piece of equipment to measure, monitor, and record the various IP streams through the layers. (Unicast, Multicast, STLTP, and RF demod)
If they are doing 4k, they should also invest in outboard 2k-to-4k upconverters for the legacy feeds.
Same if they are doing 2k HFR (high frame rate) and/or HDR.
We haven't even touched IMSC1 that is just coming on line now or AEAS that is still vaporware.
1080p HDR is a good fit for OTA (and with HLG you are SDR compatible) - and with HEVC compression quite a good bandwidth compromise.