UHF Bands – POTs and PANs

ATSC 3.0 – More Spectrum for Broadband?

This past February the FCC approved the voluntary adoption of the new over-the-air standard for ATSC 3.0. for television stations. There will be around twenty different standards included within the final protocol that will define such things as better video and audio compression, picture improvement using high dynamic range (HDR), a wider range of colors, the ability to use immersive sound, better closed captioning, an advanced emergency alert system, better security through watermarking and fingerprinting, and the ability to integrate IP delivery.

The most interesting new feature of the new standard is that it allows programmers to tailor their TV transmission signal in numerous ways. The one that is of the most interest to the telecom world is that the standard will allow a TV broadcaster to compress the existing TV transmission into a tiny slice of the spectrum which would free up about 25 Mbps of wireless bandwidth per TV channel.

A TV station could use that extra frequency themselves or could sell it to others. Broadcasters could use the extra bandwidth in a number of ways. For example, it’s enough bandwidth to transmit their signal in 4K. Stations could also transmit their signal directly to cellphones and other mobile devices. TV stations could instead the extra bandwidth to enhance their transmissions by the addition of immersive sound and virtual reality. They could also use the extra bandwidth to transmit additional digital channels inside one slice of spectrum.

But my guess is that a lot of TV stations are going to lease the spectrum to others. This is some of the most desirable spectrum available. The VHF bands range from 30 MHz to 300 MHz and the UHF bands from 300 MHz to 3 GHz. The spectrum has the desirable characteristics of being able to travel for long distances and of penetrating easily into buildings – two characteristics that benefit TV or broadband.

The first broadcasters that have announced plans to implement ATSC 3.0 are Sinclair and Nexstar. Together they own stations in 97 markets, including 43 markets where both companies have stations. The two companies are also driving a consortium of broadcasters that includes Univision and Northwest Broadcasting. This spectrum consortium has the goal of being able to provide a nationwide bandwidth footprint, which they think is essential for maximizing the economic value of leasing the spectrum. But getting nationwide coverage is going to require adding a lot more TV stations to the consortium, which could be a big challenge.

All this new bandwidth is going to be attractive to wireless broadband providers. One has to think that the big cellular companies will be interested in the bandwidth. This also might be an opportunity for the new cellular players like Comcast and Charter to increase their spectrum footprint. But it could be used in other ways. For instance, this could be used by some new provider to communicate with vehicles or to monitor and interface with IoT devices.

The spectrum could provide a lot of additional bandwidth for rural broadband. It’s likely that in metropolitan areas that the extra bandwidth is going to get gobbled up to satisfy one or more of the uses listed above. But in rural areas this spectrum could be used to power point-to-multipoint radios and could add a huge amount of bandwidth to that effort. The channels are easily bonded together and it’s not hard to picture wireless broadband of a few hundred Mbps.

But this may never come to pass. Unlike WiFi, which is free, or 3.65 GHz, which can be cheaply licensed, this spectrum is likely to be costly. And one of the major benefits of the spectrum – the ability to travel for long distances – is also a detriment for many rural markets. Whoever is using this spectrum in urban areas is going to worry about interference from rural uses of the spectrum.

Of course, there are other long-term possibilities. As companies are able to upgrade to the new standard they will have essentially have reduced their need for spectrum. Since the TV stations were originally given this spectrum to transmit TV signals I can’t think of any reason that they should automatically be allowed to keep and financially benefit from the freed spectrum. They don’t really ‘own’ the spectrum – it was provided to them originally by the FCC to launch television technology. There are no other blocks or spectrum I can think of that are granted in perpetuity.

TV station owners like Sinclair and Nexstar are watering at the mouth over the huge potential windfall that has come their way. I hope, though that the FCC will eventually see this differently. One of the functions of the FCC is to equitably allocate spectrum to best meet the needs of all users of spectrum. If the TV stations keep the spectrum then the FCC will have ceded their spectrum management authority and it will be TV stations that determine the future spectrum winners and losers. That can’t be in the best interests of the country.

Recovering Television Spectrum

Lately, the FCC finds itself in sales mode as it works to convince television station owners to sell their existing spectrum. For those not familiar with what the FCC is doing, this process is being referred to as an incentive auction for the 600 MHz band of spectrum. This spectrum today is owned by UHF TV stations.

This is spectacular spectrum and probably has the best characteristics for delivering wireless data. The spectrum easily carries to the horizon and it blasts through just about anything. I remember as a kid watching TV in a basement from a transmitter that was on a mountain on the far horizon. There is no better spectrum for the cellular companies than these bands.

This is called an incentive auction because TV stations are not being mandated to leave this spectrum. So the FCC is now engaged in a series of regional meetings to try to convince the stations to sell their spectrum. The auctions are expected to be lucrative, and station owners and the FCC will share the auction revenues. The AWS auction last November was wildly successful for the FCC. The FCC had set a minimum threshold on the spectrum at just over $10 billion and the final auction raised over $34 billion, and AWS spectrum is not even close to the great coverage characteristics of the 600 MHz spectrum. The TV spectrum should be far more lucrative since this is basically the holy grail of spectrum.

But many stations are hesitant to sell their spectrum, even at the billions they are likely to reap. The FCC has put together a complicated proposal to ‘repack’ the spectrum so that a station that sells its spectrum can stay on the air. But that is the part of the whole process that has stations nervous. It’s possible that a station could be given a slice of spectrum that is used by somebody else, such as sharing the space with wireless microphones. The repacked spectrum also doesn’t have as much of a cushion around each channel as exists today, which makes stations worried about out-of-band interference.

Having no interference is vital for television stations for several reasons. Historically, local stations got their revenues from advertising, and the rates they can charge are based upon how many theoretical eyeballs can watch them plus their rating in the local market. TV transmission is a tricky thing. For homes near the base transmitter, the power of most TV stations can overpower most interference. But, as you get to the further edges of the transmission path interference becomes a real issue. And in TV, interference is manifested by poor reception and pixelization. So TV stations are worried that their effective delivery circle will get smaller and that there will be significant interference in parts of that area.

The financial issue is further complicated by the fact that local stations (or their corporate owners) today make a lot of money from local transmission agreements. These are fees that are charged to cable providers that want to retransmit their station on cable systems. The fear here is the same in that they are worried that cities near the fringes of their service area might argue that they no longer owe retransmission fees due to degraded quality.

Unfortunately there is no way to pre-test the delivery in one of the repacked blocks. Spectrum engineering is really complicated stuff and the quality of a transmission will vary widely in different pockets of a spectrum delivery area based upon local conditions. The only way to test it is to send out the signal and see what kinds of complaints you get from viewers.

The FCC is putting everything they have into these meetings with Chairman Tom Wheeler attending most of these regional meetings to talk with television station owners. There are already a number of stations that have said that they are interested in joining the auction, but the FCC needs a significant number of them to join before the auction can proceed.

Big cellular companies won’t be the only ones to benefit from the spectrum; the FCC has promised that there will be slices of this spectrum set aside for WiFi and other public uses. So the whole country is on hold waiting to see if the FCC can convince enough stations to move. The billions that the stations can collect from the auction is certainly an incentive, but we are going to have to wait to see how many of them actually make the big leap. It ought to be an interesting summer.

Share this:

Share this: