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RF over IP: Is it possible?
Posted: Mon Jul 22, 2019 12:01 pm
by F-Squared
My family doesn't want to have a 40 foot tall antenna mast in our yard so we want to put it up in some property we have in Riley Township. Problem is, we obviously can't run a coaxial cable that far and I don't want to deal with network tuners compressing the hell out of the signal, so is there any way to send raw RF signals over IP and have a device at home that can decode the RF signals and turn it back into RF over coaxial?
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Re: RF over IP: Is it possible?
Posted: Mon Jul 22, 2019 1:35 pm
by CK-722
I think you could do it with antenna on the property and a software remote controlled TV. It would probably be expensive for the bandwidth necessary to send the TV video over the internet. Maybe if you could put it on a hill, as some kind of head end for cable or TV station programming, you could find some way to make money off it. That might make it possible to have a microwave link to send it to your location.
It would be better if it were about 15 miles further West.
Re: RF over IP: Is it possible?
Posted: Tue Jul 23, 2019 7:55 pm
by RingtailedFox
You MIGHT be able to get away with this sort of setup if you had an HD HomeRun box and a high-speed VPN link between the remote site and your home... but that might go down if there's a power outage at either location (or in between)... You'll also need to make sure that the network link can handle at least 20 Mbps (broadcast is 19.39 Mbps, so give yourself a bit of overhead for dropped packages and such)
Here's the HD HomeRun Scribe Quattro:
https://www.silicondust.com/product/hdh ... be-quatro/
USA:
https://www.amazon.com/SiliconDust-HDHR ... way&sr=8-5
CAN:
https://www.amazon.ca/SILICONDUST-HDHR5 ... =8-1-fkmr0
You could try with two wifi routers running OpenWRT and having massive-gain parabolic antennas... how far are we talking, anyway? 200 feet? 300 feet?
You also have to bare in mind that if you're crossing property lines, this may or may not be legally doable. In some jurisdictions (such as Canada), if you cross property lines while sending or receiving audio or video, you'll then be treated as an unlicensed cable television provider. I think the USA has similar ideas, with exemptions for apartment building Master Antenna Television setups....
Re: RF over IP: Is it possible?
Posted: Wed Jul 24, 2019 12:21 pm
by km1125
We used to joke about doing that, after we started doing "ATM over IP" and "video over IP", it seemed to be the logical next step!
It is possible but not really practical. You can "record" raw RF (digitized) to disk, so it would not be that hard to take that digitized stream and transport it with IP. You'd also would have to deal with the data rate though, as it's "massive" compared to the actual content that you're trying to view.
As others have suggested, there are probably other ways to solve the problem you have.
How far is it from the Riley site to the destination?
Re: RF over IP: Is it possible?
Posted: Wed Jul 24, 2019 3:03 pm
by F-Squared
km1125 wrote:We used to joke about doing that, after we started doing "ATM over IP" and "video over IP", it seemed to be the logical next step!
It is possible but not really practical. You can "record" raw RF (digitized) to disk, so it would not be that hard to take that digitized stream and transport it with IP. You'd also would have to deal with the data rate though, as it's "massive" compared to the actual content that you're trying to view.
As others have suggested, there are probably other ways to solve the problem you have.
How far is it from the Riley site to the destination?
They're under 50 miles apart
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Re: RF over IP: Is it possible?
Posted: Wed Jul 24, 2019 3:11 pm
by F-Squared
I have an idea. Perhaps I could have it so whatever is capturing the RF signals only captures one channel at a time (6 MHz of bandwidth) and from the client-end, there's an uplink to the other end that tells the other device what channel to switch to. Theoretically, this can only be done with a modification to a TV's tuner, or if I'm using a PC tuner, it could be software on the PC. If not, I would manually have to control the channel unless I do some other trickery that I don't know would work or not.
And on the client end, there is something that relays the RF signals back over coaxial, allowing it to be picked up by a tuner.
I know this is overly complicated for a TV signal, but I really don't want to deal with the compression network tuners and Slingboxes bring. Besides, I like crazy projects like this that aren't practical unless you're an enthusiast.
Edit: Another theory:
So for turning the signal back into coaxial, what if I used a wideband RF modulator? Technically it's analog but we would be sending digital signals analogously without decoding/re-encoding the ATSC signal. Technically, it would just be relaying a signal that already exists over an analogous medium. This could work.
The main problem is, I'm going to need some insane upload speeds at the capture center in order to do this. The most I have ever had (and currently have with my home internet) is 10 Mbps and that definitely won't cut it. Hell, I might need as much as 100 Mbps up, so this isn't looking cheap, but I'm up for the task.
Well, sh*t. There are hardly any ISPs up there and the ones that are (ie Comcast and a few small ones) aren't transparent about their upload speeds so this is going to be tricky.
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Re: RF over IP: Is it possible?
Posted: Thu Jul 25, 2019 11:09 am
by km1125
To send one full ATSC channel, you're going to need about 19MbPS (plus a little more for overhead) to get that channel from location "A" to location "B" with zero degradation. It would be best if you could just demod the signal with an ATSC decoder, encapsulate that stream and transport it to location "B". At that location you could re-encode it to an ATSC channel of your choosing and distribute via RF. You would need some mechanism to switch the receiving ATSC demod remotely too, which shouldn't be too hard.
50 miles is a long way. I was thinking it was thousands of feet or maybe a couple miles, which you could do with WiFi and some good antennas. There were even some laser-based RF transport systems that could have been used for a few miles, but 50 is too long for them too. Even with single-mode fiber you'd have a challenge to do that in one hop (possible, but lots of $$$)
Re: RF over IP: Is it possible?
Posted: Thu Jul 25, 2019 2:55 pm
by F-Squared
km1125 wrote:To send one full ATSC channel, you're going to need about 19MbPS (plus a little more for overhead) to get that channel from location "A" to location "B" with zero degradation. It would be best if you could just demod the signal with an ATSC decoder, encapsulate that stream and transport it to location "B". At that location you could re-encode it to an ATSC channel of your choosing and distribute via RF. You would need some mechanism to switch the receiving ATSC demod remotely too, which shouldn't be too hard.
50 miles is a long way. I was thinking it was thousands of feet or maybe a couple miles, which you could do with WiFi and some good antennas. There were even some laser-based RF transport systems that could have been used for a few miles, but 50 is too long for them too. Even with single-mode fiber you'd have a challenge to do that in one hop (possible, but lots of $$$)
You're right. Thankfully I'm not going to need 90 Mbps because that information that I found about it being 90 was incorrect. Phew. This should be much easier
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Re: RF over IP: Is it possible?
Posted: Thu Jul 25, 2019 3:01 pm
by F-Squared
Okay so here's the deal. Turns out up in Riley Twp, a 40 foot tower will hardly do any good for getting a half decent signal so I might stick with my current setup, which makes things slightly less practical. However, I still really want to try this project. I currently only have 10 Mbps of upload speed at home, so I'm definitely going to need more in order to be able to send one entire RF channel.
Newer (and possibly cheaper) idea: what if I just try this on my network? It's definitely a lot cheaper than having to upgrade to 20 Mbps up.
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Re: RF over IP: Is it possible?
Posted: Thu Jul 25, 2019 4:17 pm
by km1125
Not sure what your "current setup" is, so no way to compare.
You could definitely test any idea you come up with on your own network. If you get it to work there, then you can measure exactly what bandwidth you'd need in order to use that same system over some larger transport.
You could also just transport the program stream you're interested in, vs the entire transport stream. Within that 6MHz or 19Mbps of capacity, everyone is running multiple program streams. I haven't measured them in quite a while, but I'd doubt any of the broadcasted 1080i streams are even over 9Mbps, with the SD streams substantially less.
Re: RF over IP: Is it possible?
Posted: Thu Jul 25, 2019 6:42 pm
by F-Squared
km1125 wrote:Not sure what your "current setup" is, so no way to compare.
You could definitely test any idea you come up with on your own network. If you get it to work there, then you can measure exactly what bandwidth you'd need in order to use that same system over some larger transport.
You could also just transport the program stream you're interested in, vs the entire transport stream. Within that 6MHz or 19Mbps of capacity, everyone is running multiple program streams. I haven't measured them in quite a while, but I'd doubt any of the broadcasted 1080i streams are even over 9Mbps, with the SD streams substantially less.
According to rabbitears, WDIV uses 12.2-14.2 Mbps for its main subchannel. I'd rather have 20 Mbps so it can handle any channel; I don't want to cut corners here.
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Re: RF over IP: Is it possible?
Posted: Fri Jul 26, 2019 11:10 am
by km1125
F-Squared wrote: ↑Thu Jul 25, 2019 6:42 pm
According to rabbitears, WDIV uses 12.2-14.2 Mbps for its main subchannel. I'd rather have 20 Mbps so it can handle any channel; I don't want to cut corners here.
Well, they also show "Me TV" at 0Mbps. Not sure how they can do that and still get a decent SD picture.
But it is better to have more bandwidth if there's a way to do it.
Re: RF over IP: Is it possible?
Posted: Sun Jul 28, 2019 7:46 am
by audiophile
F-Squared wrote: ↑Thu Jul 25, 2019 3:01 pm
Okay so here's the deal. Turns out up in Riley Twp, a 40 foot tower will hardly do any good for getting a half decent signal so I might stick with my current setup, which makes things slightly less practical. However, I still really want to try this project. I currently only have 10 Mbps of upload speed at home, so I'm definitely going to need more in order to be able to send one entire RF channel.
Newer (and possibly cheaper) idea: what if I just try this on my network? It's definitely a lot cheaper than having to upgrade to 20 Mbps up.
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I have put 5' tripods on single story roofs with regular TV antennas at distances much greater than Riley Twp and have no major problems with reception.
An decent attic mounted antenna may also give satisfactory results at that distance.