Andrew's Inner Sanctum

My thoughts about what's happening in my world

Some Q&A About Digital TV!

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by Andrew

There’s been a lot going on with digital TV in the last few weeks. There has also been a lot of questions I’ve been asked about certain aspects of the switchover and why certain things have occured. So I thought I’d answer a few questions that I’ve been asked.

1. Why did the TV networks get rid of their high definition channels and replace them with new channels? Why didn’t they just add a new channel and keep the existing ones?

There is legislation about how many TV channels each network is allowed to broadcast. The current rules are that each network can only have 2 Standard Definition (SD) and 1 High Definition (HD) channel with exception of the ABC & SBS who can have more (ABC currently have 3SD and 1HD). This means that to launch their 3rd multi-channel, one existing one had to go. They also must keep their main channel in SD because it needs to be viewable by people switching from analog TV to an SD digital box. Their second SD channel was already being used (7Two and Go!) so their HD channel was the only one left to replace & because it was only a duplicate of the main channel in SD – it made sense to replace it with new content. So that’s why the HD simulcasts have been replaced with new channels. This may change in the next few years (definitely by 2013) but that’s the limitations at the moment.

2. Why is there 5 channel 7 stations. I thought they were only allowed to have 3? (same case with there being 2 One HDs and 2 ABC1s)

That’s a concept called Logical Channel Numbers (LCN). Each station in their signal broadcasts send out a list of numbers that they would like to assign their channels to when you scan your digital TV or set top box. This is so that every TV has the channels on the same numbers so that you can switch from one TV to another and still find all the channels (fixing a big problem from the days of analog TV and especially important when you’ve got around 20 channels to keep track of). The thing about this is – each channel can be assigned more than one LCN so while a network might only broadcast 3 channels, the network might decide to use 5 numbers, with the same channel on several different numbers. They’re kind of like shortcuts on your computer, you can have several shortcuts pointing to the same program. Channel 7 has a major problem with this. They have Channel Seven on LCN 7, 70 and 71 (labelled 7Digital on 7 + 70 & 7Digital 1 on 71) and then 7Two on 72 and 7Mate on 73. Same with ABC1 being on 2 and 21 and One HD on 1 and 11 (although 11 will be used for channel Eleven next year so that won’t be a duplicate from next year). You can safely delete the extra numbers if you wish (that’s what I’ve done, cleans it up a bit).

3. Why is Channel 10 showing the Commonwealth Games all day when it’s on One HD and One Digital anyway? (Supplementary Question: Why don’t Network Ten put the content normally on One HD onto One Digital?)

There’s some legal obligations as to how networks can use their digital multi-channels at the moment. For sport they’re called the “Anti-Siphoning Laws”. Although Network Ten would love to simply dump their Commonwealth Games coverage onto One HD and continue normal programming on Ten – they legally can’t do that. Until the laws are updated (and these specific laws may not be updated until 2013) they legally have to broadcast all major sporting events on their main channels at the same time if they wish to broadcast it on their digital multi-channels. This is because not everyone in the country has access to these multi-channels quite yet so if they put major events onto digital multi-channels then some people would miss out. So that explains why the Commonwealth Games are on Ten, One HD and One Digital. I personally think though that Network Ten should have changed One Digital to show alternate content, because the Commonwealth Games are already available on One HD and Ten. Maybe they can’t due to technology reasons (although they will have to next year when they launch Eleven since One Digital is going way, but One HD is staying) or maybe they simply didn’t want to. It just seemed a bit strange 😛

4. Why does GEM keep switching to Channel 9 when the NRL and Cricket are on (and 7Mate during the AFL)?

Well there are requirements for each channel to broadcast a certain amount of sport in HD each year and when they were simply simulcasts of the main channel, those requirements were met, but these new multi-channels show content that’s separate to the main channel, but they still have to show the sport in HD, so they simply switch to 9 (or 7) to broadcast the event in HD. In Perth and Adelaide where there are delays but they still wish to show the sport live, they simply keep simulcasting the main channel until they reach the correct time to switch back into normal programming.

If I get any more questions from people, then I’ll add them here!

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3 Responses to Some Q&A About Digital TV!

  1. Pingback: Tweets that mention Some Q&A About Digital TV! « Andrew's Inner Sanctum --

  2. Mwilliams

    Today the f1 gp was on 1HD live however ch10 continued the comm games live at the same time. Why so, and why can’t they put the replay of the gp on at a reasonable time while the comm games is on 1HD

  3. Wow! Thanks! This is a great way of providing information. Some of my question about Digital tv on computer are really answered. Thanks a lot for sharing this.