[Alex1978]

http://www.fcc.gov/Daily_Releases/Daily_Business/2010/db0924/FCC-10-174A1.pdf

The FCC today has decided to allow wireless broadband devices to operate on any "vacant" television channel. But the FCC's definition of "vacant" is the problem. They'll permit a wireless device to operate on any channel as long as it is outside of the longley-rice 50/50 contour of a television station.

I live in Bellingham, Washington and I get excellent reception of television stations from Seattle and Tacoma -- but I am well outside the 50/50 contour of those stations. Now, thanks to this ruling, wireless devices can operate on the same frequency as the OTA television station I'm trying to watch from Seattle -- which could totally screw-up my reception of all the major network affiliates.

There are places where tropo is pretty reliable and viewers are relying on television stations from well outside of it's 50/50 contour. For those viewers this is a disaster.

This is "big brother" come to life. The wireless devices are logged into a geo-location database in order to determine their location in relation to TV transmitters. The devices are required to report their location back to the geo-location database, which means that conceivably the government could track your movements via your wireless device. I really hope the ACLU or some privacy advocacy group sues the government to stop this. I don't care about the politics, but I do care about my free TV reception getting screwed-up.

I hope the Canadians don't follow the US lead on this. I'd like to see them take a hard line and demand the American government ban operation of these devices within a 20 mile buffer along the Canadian border.

What is the point of mandating a DTV transition if the government is going to come along 15 months later and implement a retarded ruling like this that could make DTV reception impossible for a lot of viewers. What were these clowns thinking?

 

[Jase88]

Unfortunately, the Canadian government tends to rubber-stamp whatever initiatives the FCC develops.

I have mixed feelings on this issue. As an OTA'er, I don't want any potential to exist where my reception can be compromised. But I also understand the need for spectrum.

Spectrum is a valuable resource. We need to use technology whenever possible (digital, geo-location databases/awareness, other tech) to maximize the efficiency of it's use. If there are vacant channels in a given region, I see no reason why a "smart" technology, using very low power, cannot use the channel.

Alex1978, to address your concern: it appears that technology which detects available TV signals is to be used prior to transmitting on a given channel. This would likely prevent interference, even beyond the protected contour.

Ultimately, devices utilizing these "white spaces" are unlicensed. Should they cause interference, the FCC is obligated to investigate and resolve the interference. It's clearly stated in the document that these devices may not cause interference to licensed services, and must accept whatever interference may be present from said licensed services.

Perhaps--if these devices do in fact cause harmful interference--the FCC will receive enough complaints to abandon the initiative. Or, hopefully, no problems will be noted. I suppose we'll find out.

 

[ScaryBob]

which means that conceivably the government could track your movements via your wireless device.

This is possible with almost all wireless cell devices. Many have GPS locators that can pinpoint locations. Phone companies can also track your general location using cell towers. Many new vehicles also have GPS devices that can be used for tracking location in real time.

Should they cause interference, the FCC is obligated to investigate and resolve the interference.

Nice on paper. Next to useless in practice. I have tried to get IC to track down interference from licensed communications services. They made me jump through several hoops and prove it was a problem before they would even take it seriously (basically do half their work for them.) I wish you luck with getting anyone to track down unlicensed devices.

 

[Alex1978]

It's clearly stated in the document that these devices may not cause interference to licensed services.

Yes, but only in the 50/50 contour. That's what I'm on about. Unless you live within the area that the FCC considers to be the 50/50 contour of the TV station you have no interference protection. And let me tell you the l-r 50/50 contours that the FCC comes up with aren't real world accurate at all.

Alex1978, to address your concern: it appears that technology which detects available TV signals is to be used prior to transmitting on a given channel. This would likely prevent interference, even beyond the protected contour.

Yes, the technology exists, but the FCC isn't requiring that it be used. In fact they are explicitly eliminating the sensing requirement for TVBDs. This is a real disaster for OTA. You can forget about picking-up stations from adjacent markets. You can forget about skip signals from far away markets on good tropo days. This is a real kick in the teeth if you like free TV.

They're taking away a free service to make way for a pay service. I'm sure they're not going to give us all wireless broadband for free.

 

[Jase88]

You really think a device transmitting with an EIRP measured in milliwatts will kill good tropo?!

I believe the initiative will fail. The equipment utilizing this spectrum will be more expensive, due to the complexity necessary to make it work. And it will be subject to strong interference at times. And should the equipment cause widespread interference for TV users, it will most certainly result in complaints.

There is widespread mistrust of the FCC. After all, their engineers were the ones that would have us believe VHF DTV would be successful with very low ERP's. And they've been eyeing up TV spectrum quite a bit lately...

 

[Alex1978]

You really think a device transmitting with an EIRP measured in milliwatts will kill good tropo?!

That depends on how good the tropo is and where the device is in relation to your antenna. If the device is able to function on the same frequency as the TV signal then it must be capable of over-powering the incumbent signal. Otherwise it wouldn't be able to operate on that frequency.

 

[Jase88]

Nice on paper. Next to useless in practice. I have tried to get IC to track down interference from licensed communications services. They made me jump through several hoops and prove it was a problem before they would even take it seriously (basically do half their work for them.) I wish you luck with getting anyone to track down unlicensed devices.

My comments were in reference to the FCC, not IC. These devices have not yet been approved in Canada for use. Either way, your situation appears to refer to the opposite situation: interference from a licensed service. Devices utilizing white space TV spectrum will not be licensed.

Further, in the document, there are provisions to require fixed-location devices to broadcast an identifier that includes location data--to help identify the source of the interference, if so caused.

 

[Blackburst]

Alex1978...

Like somebody else posted, Canada will just rubber stamp the FCC ruling.

While you on the US side of the border can actually do something. You have a Congressman & a Senator for your area that can be contacted. You can also contact the ACLU about your concerns. You can even contact NAB, and the local area TV stations that you are worried about loosing reception.

You are actually in a better position to raise a stink about this than we up here. There is even a Tea party movement of some very angry people that might find your concerns something worth adding to their list of complaints.

 

[Dave Loudin]

Yes, but only in the 50/50 contour. That's what I'm on about. Unless you live within the area that the FCC considers to be the 50/50 contour of the TV station you have no interference protection. And let me tell you the l-r 50/50 contours that the FCC comes up with aren't real world accurate at all.

Those 50/50 contours are not l-r based, and do not consider terrain past 16 km. They tend to be over predictive, especially in hilly areas. The real problem is the sneaky way a secondary service is being redefined. Other secondary services, like translators and LPTV, cannot cause any interference to reception of a primary service, no matter the predicted field strength of that primary service.

 

[JamesK]

I wonder if this will follow the same path as what happened with Broadband Over Power Line? The FCC was really bending the rules to accomodate BOPL, until they got slapped down by the courts for neglecting their duty as defined by Congress. It was made quite clear that licenced users must always be protected from unlicenced users.

 

[Jase88]

JamesK, good point. I could certainly see that happening.

One of the proposed uses of this spectrum plan is wireless microphones.

Imagine planning a summer concert for a big name. During the day, the wireless stuff all tests fine. Then at night, just as the concert gets underway, tropo rolls in and kills your stuff. You know it'll happen.

My thinking is that potential users will abandon this idea before long.

 

[ScaryBob]

My comments were in reference to the FCC, not IC.

My comments were meant to illustrate the futility of getting any government agency to track down any type of interference. My example was with a licensed service that was emitting a spurious harmonic, essentially a licensed signal interfering with a signal on a band it was not licensed to use. Like I said, good luck getting *anyone* to track down interference from an unlicensed device, be it IC or the FCC, in Canada or the US.

 

[majortom]

good luck getting *anyone* to track down interference from an unlicensed device

99 times out of a hundred, the interferer won't even have a clue.
So, the interferee, winds up having to chase it down.

 

[classicsat]

JamesK, good point. I could certainly see that happening.

One of the proposed uses of this spectrum plan is wireless microphones.

Imagine planning a summer concert for a big name. During the day, the wireless stuff all tests fine. Then at night, just as the concert gets underway, tropo rolls in and kills your stuff. You know it'll happen.

My thinking is that potential users will abandon this idea before long.

If I were a manuafacturer of wireless microphone sets, at least, I would have a built in spec-an, to check for unused channels.

 

[cptmds]

Interference

I think that any manufacturer that wants their device to work properly will have to have something that does a frequency scan, if only to make sure the device can work. If these devices can interfere with TV signals, the TV signals will do the same to the device.

Let's say someone sets up their wifi, but they live near a powerful broadcaster. However, according to computer calculations, there is virtually no OTA signal in that location when there actually are a number of stations available. I don't think any device with the power of a couple of mW on say, channel 22, will overcome a broadcaster with something like 650kW, even if it's far away. The effect would be like trying to get wifi in your kitchen with the microwave on. You might get something, but it will be very weak, and no consumer will want to put up with that.

Most likely tropo can and will do the same.

As it is, my router already has a channel scan to determine the best frequency to use. If manufacturers don't bother to use a frequency scan, you can be sure that they will be getting a lot of complaints from people affected by weak signals, as people will automatically blame the device.

 

[Alex1978]

While you on the US side of the border can actually do something. You have a Congressman & a Senator for your area that can be contacted. You can also contact the ACLU about your concerns. You can even contact NAB, and the local area TV stations that you are worried about loosing reception.

I've done that. NAB has already voiced their objections, but they were ignored.

Those 50/50 contours are not l-r based, and do not consider terrain past 16 km. They tend to be over predictive, especially in hilly areas. The real problem is the sneaky way a secondary service is being redefined. Other secondary services, like translators and LPTV, cannot cause any interference to reception of a primary service, no matter the predicted field strength of that primary service.

My problem is that people outside of the 50/50 contour have no interference protection. My guess is that there are a lot of people here who live outside the 50/50 contour of their favorite television stations. I live outside the 50/50 contour of all the major network affiliates. I can get good reception of them right now, but I am well outside of the 50/50 contour so I don't have any protection from these wireless devices.

 

[stampeder]

I highly recommend a read through the following earlier OTA Forum thread that contains some very informative posts and articles about the struggle for/against White Space use in the U.S.A.:

U.S. DTV News & Discussion

We'll keep this new thread focused on the technical and OTA reception issues facing Canadian consumers like we've been doing. We'll keep discussing the regulatory struggles in that previous thread, and if the issue comes up in Canada we'll discuss that on its own merits probably in its own thread.

cheers

 

[tvlurker]

I think that any manufacturer that wants their device to work properly will have to have something that does a frequency scan, if only to make sure the device can work. If these devices can interfere with TV signals, the TV signals will do the same to the device.

Let's say someone sets up their wifi, but they live near a powerful broadcaster. However, according to computer calculations, there is virtually no OTA signal in that location when there actually are a number of stations available. I don't think any device with the power of a couple of mW on say, channel 22, will overcome a broadcaster with something like 650kW, even if it's far away. The effect would be like trying to get wifi in your kitchen with the microwave on. You might get something, but it will be very weak, and no consumer will want to put up with that.

Most likely tropo can and will do the same.

As it is, my router already has a channel scan to determine the best frequency to use. If manufacturers don't bother to use a frequency scan, you can be sure that they will be getting a lot of complaints from people affected by weak signals, as people will automatically blame the device.

Channel scan is not sufficient, since you could be in a location where the White Space Device is shileded from the broadcast source, but other may be able to receive both the boradcast and the WSD transmissions.

 

[Dave Loudin]

My problem is that people outside of the 50/50 contour have no interference protection. My guess is that there are a lot of people here who live outside the 50/50 contour of their favorite television stations. I live outside the 50/50 contour of all the major network affiliates. I can get good reception of them right now, but I am well outside of the 50/50 contour so I don't have any protection from these wireless devices.

You have never had protection from interference from primary services beyond the 50/50 curves. Those define a station's service area.

 

[Alex1978]

You have never had protection from interference from primary services beyond the 50/50 curves. Those define a station's service area.

That is certainly true, but until now, unlicensed devices were not permitted to operate on those frequencies so there was a de-facto protection.