# New HDTV Frequencies & UHF wireless



## jkowtko (Jul 28, 2007)

I've heard that the FCC is allocating more of the UHF frequency band for HDTV broadcasting, and that it's going to interfere with many of the UHF wireless systems, forcing us to new 2.4 or 5.8gHz bands. However the FCC site still shows the 614-806 mHz allocated to "broadcasting", and I can't find any more info on this.

Does anyone have more info on what frequences, when this will happen, etc?

Thanks. John


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## avkid (Jul 28, 2007)

This has been beat to death over at the LAB.
http://srforums.prosoundweb.com/


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## Van (Jul 28, 2007)

Yeah we have a two year old Wireless mic system that is going to be useless in two more years. I'm betting the best idea is going to be, sell it to some group in the middle of Nebraska, where they'll get decent use out of it for the next 10 years.


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## Traitor800 (Jul 28, 2007)

For once im grateful that i go to school in the middle of nowhere


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## mbenonis (Jul 28, 2007)

I have not heard anything along these lines, and highly doubt it's true. For the record, the problem we face is NOT digital* broadcasting, but rather a combination of re-banding of the upper part of the UHF TV broadcast spectrum and interference from part 15 devices which may be allowed to transmit in the TV spectrum in the future, after the Feb. 2009 digital cutoff. Please see my many previous posts on this subject if you'd like to learn more.

*Digital does NOT equal high definition. The FCC is mandating that all television broadcasts be in digital, but not necessarily HD, format by Feb. 2009.


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## avkid (Jul 29, 2007)

The reallocation has nothing to do with HDTV transition.
See www.dtv.gov for the real scoop on digital television broadcasting.


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## mbenonis (Jul 29, 2007)

The reallocation has nothing to do with HDTV.
The FAQ about DTV is located here:
http://www.dtv.gov/

Yes and no. Essentially what the FCC is doing is re-allocating the band from 698-806 MHz to wireless companies (this is the part of the spectrum Google, Verizon, and AT&T are bidding on) and to the public safety two-way radio service. What it means for us is that wireless systems operating in this part of the spectrum will be illegal* to operate when the reallocation is complete. Information on these reallocation efforts are available here:

http://wireless.fcc.gov/services/index.htm?job=service_home&id=lower700 (Wireless - lower 700 MHz)
http://www.fcc.gov/pshs/spectrum/700mhz/ (Public Safety - upper 700 MHz)

*Technically, all wireless microphone systems are illegal to operate unless you are a television station or a movie studio and have a license for every frequency you operate on. However, the FCC looks the other way if you're not interfering with any TV stations. However, the risk for interference will be much, much greater once the reallocation takes place and wireless and public safety radio's are operating in the 700 MHz band.


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## jkowtko (Jul 30, 2007)

Thanks Mike -- that article on "lower 700" seems to state it pretty clearly. The FCC ruling was in 2002 though, so do you think that means it's going to take a long time for the airwaves to get congested, or are we already there and have a good chance of our wireless continuing to work even after the transition is complete? I live in the SF Bay Area where there are a zillion stations, and I know that for our AKG units they recommended calling tech support and looking up on the FCC sites to find out what stations are in your area and selecting frequencies to stay clear of them. If that's all that is needed going forward then these units may still be okay.


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## mbenonis (Jul 30, 2007)

jkowtko said:


> Thanks Mike -- that article on "lower 700" seems to state it pretty clearly. The FCC ruling was in 2002 though, so do you think that means it's going to take a long time for the airwaves to get congested, or are we already there and have a good chance of our wireless continuing to work even after the transition is complete? I live in the SF Bay Area where there are a zillion stations, and I know that for our AKG units they recommended calling tech support and looking up on the FCC sites to find out what stations are in your area and selecting frequencies to stay clear of them. If that's all that is needed going forward then these units may still be okay.



Well, if your units operate in what will become the new wireless spectrum, you'll have to replace your gear with something operating lower in frequency in the TV band (470 -698 MHz). Unlike the TV band, it's not going to be a matter of dodging stations, but rather avoiding creating interference for LICENSED users of the spectrum (when this happens, you get a nasty letter from the FCC and a bill for thousands of dollars, even for once alleged case of interference). It's not worth it. Besides, when everyone starts carrying 700 MHz wireless devices, you're going to have tons of interference anyway.


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## museav (Jul 30, 2007)

mbenonis said:


> *Technically, all wireless microphone systems are illegal to operate unless you are a television station or a movie studio and have a license for every frequency you operate on. However, the FCC looks the other way if you're not interfering with any TV stations. However, the risk for interference will be much, much greater once the reallocation takes place and wireless and public safety radio's are operating in the 700 MHz band.


This is an important issue as the vast majority of VHF and UHF microphones use has never been technically 'legal' and has simply been accepted as long as it is not a problem. This is likely a factor in the frequency reallocations as in the eyes of the FCC and elected officials the vast majority of the existing wireless mic users are a non-entity and have no real claim to that bandwidth. So any argument on our behalf has had to be somewhat indirect through legitimate users such as licensed broadcasters or by less direct methods such as identifying to elected officials how this will affect their entertainment, worship, etc.


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## Bob (Jul 30, 2007)

Just remember that some of the large manufacturers, like Shure, can re-program the more expensive professional lines of transmitters. Granted it may cost a little money, but instead of throwing $20,000 of mics in the trash, for a couple hundred dollars they can re-tune the entire system into a different band of TV freqs. and extend the life of the product.

-Bob


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## mbenonis (Jul 30, 2007)

Bob said:


> Just remember that some of the large manufacturers, like Shure, can re-program the more expensive professional lines of transmitters. Granted it may cost a little money, but instead of throwing $20,000 of mics in the trash, for a couple hundred dollars they can re-tune the entire system into a different band of TV freqs. and extend the life of the product.
> -Bob



This is a good point that I hadn't thought of - especially for folks who just bought new systems.

However, U.Va.'s old Vega 700 MHz system is going to need to be transitioned out, sadly. ::evilgrin::


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## icewolf08 (Aug 26, 2008)

I am bumping this thread up, because I had an interesting idea related to the DTV transition and wireless mics. I was having lunch with our resident sound designer and we were unpacking some of the new gear he got this season, which includes some new wireless mics. We were thinking that since the FCC wants to sell the new "free space" in the spectrum we should get together the big users of wireless gear and buy some of the space.

What do I mean? Well, you have industries like ours (theatre) and you have industries like TV, and you have sports (yup, all those nice com systems for coaches and teams). All of these industries use essentially the same chunk of spectrum for their wireless devices. So, could we get some of these people to group together and buy the space that we use. I was thinking if we could get some of the theatre organizations like USITT or ESTA or I don't know who, and some of the sports leagues and the TV networks to band together and buy some space. This could guarantee us the bandwidth we need for our wireless gear, and help spread out the cost.

Is this a crazy idea, or is this something that with some organization could actually happen. Has anyone else thought about this?


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## mbenonis (Aug 27, 2008)

Unfortunately, this idea is pretty much crazy.  Here's why. The cost of buying the amount of spectrum we'd need (about 50 MHz worth) would be in the tens of billions of dollars (billion with a b). AT&T and Verizon paid over ten billion for the 700 MHz land, and they each got ~15-25 MHz of bandwidth. So it would take come companies with really deep pockets to even think about this idea (and if big broadcasters DID do it, do you think they'd want the little guys running their mics in the space too?).

My solution is far simpler - either buy UHF wireless gear capable of rejecting noise from white space devices (i.e., Lectrosonics or Sennheiser 5k), or better yet, move back to the VHF TV band where there won't be any white space devices.


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## museav (Aug 27, 2008)

icewolf08 said:


> We were thinking that since the FCC wants to sell the new "free space" in the spectrum we should get together the big users of wireless gear and buy some of the space.


If you are talking about frequencies where most existing UHF wireless mic systems could operate, I believe that other than one or two odd bands that did not go in the 700MHz auctions, there is no available "free space" for sale. The FCC may dedicate some specific bandwidth for wireless mics, that is one option being explored, but I believe the frequencies being mentioned are outside the range used by many existing wireless systems.


> What do I mean? Well, you have industries like ours (theatre) and you have industries like TV, and you have sports (yup, all those nice com systems for coaches and teams). All of these industries use essentially the same chunk of spectrum for their wireless devices.


TV and film, including major sporting events, are using the frequencies for which they have already paid for broadcasting rights, so I don't see them being part of anything like this.


I agree that it would likely take several groups together to even think about affording such an endeavour, but it being multiple groups that in turn represent multiple entities seems to represent some real challenges. Are you suggesting that these groups pay for the bandwidth rights and then open it up to everyone with no control? Or that it somehow be limited to members of the groups involved?

If open to anyone, then we might be right back to the same problems. Most assigned frequency bands are single users or groups who are trying to communicate with one another, frequency coordination within that band is not an issue. Currently wireless mic users either have the rights for those frequencies or don't, you don't have a situation with two legitimate users of the same frequencies. Frequency coordination within a limited bandwidth with a multitude of legitimate users could be interesting.

If limited to 'approved' users, how would you identify those users? Say USITT is part of the group, would that then be seen as covering all theatrical related users or only systems operated by people who are USITT members or what? What groups would represent the schools, corporations, churches, rental and staging houses, convention centers, hotels, etc.? Would a school being part of this through any one group address just that specific use or all of their wireless systems? How about a rental house that rent the same systems to theatres, churches, schools and corporate users, do they have to be members of the organizations representing every area or just one and how do you control that? How would you tell if an entity is a legitimate user or not? And who is going to manage and enforce any of this, at that point is a not an FCC issue.


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## FMEng (Aug 30, 2008)

I suspect that the industry is waiting for the new FCC and Congress next year, before attempting to resolve this issue. Right now, the FCC is primarily in money making mode rather that in the spectrum management mode. That happens when you replace most of the engineers with lawyers. Hopefully, that will change under President Obama (the President appoints the Commission). 

I'd like to think that the new FCC commissioners will jump in and fix this, but more likely Congress will have to force them to do it.


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## museav (Aug 30, 2008)

I think the FCC is actually being quite proactive right now, including the ongoing testing of prototype "white space" devices in real environments, the recent proposed prohibition on low power transmitters in the '700MHz' band, etc. Some people may want an answer right now but the last thing we need is a knee-jerk reaction that we'll then have to live with and I applaud the FCC for apparently taking their time and trying to get all the information before moving ahead.

I think too many people are mixing the "white space" and '700 MHz' issues, likely intentionally in some cases where it serves their purposes. I believe that the '700MHz' issue is pretty much resolved, the FCC always intended to protect the successful bidders for that bandwidth and to prohibit other use of it, that was stated before the auctions ever began and the latest proposed legislation is really just the paperwork to make it formal. The number of people with wireless systems that operate only in the 698-806MHz range is relatively limited, I know that doesn't help those that fall into that group, but realistically that is probably a rather small percentage of the overall users. I believe that as of 02/19/2009 the whole 700MHz issue is pretty much over and done with and is not really that much of an impact relative to some of the other issues.

The "white space" fight over what to do about wireless mic/IEM/etc. systems (currently represented primarily by the manufacturers of those systems) and the proposed broadband devices that the "public" (represented by groups that are in many cases conveniently spearheaded by the very companies that could most profit from their agenda) supposedly demands may go on for some time. Given the parties potentially affected and the technology involved it is both a political and technological effort that needs to be approached carefully. The FCC may be postponing addressing the political aspects pending the elections (you know that thing that in a free society has to happen before you start awarding the presidency to anyone) but in the meantime I believe they are moving forward on assessing the technical aspects.


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