Advertisement
Articles
Advertisement

The new DBS band

Mon, 07/31/2006 - 8:00pm
Jeffrey Krauss, President of Telecommunications and Technology Policy

A year ago (see "Capital Currents," August 2005), I wrote about the new DBS frequency band at 17 GHz, wondering when the FCC would start the multi-year rulemaking process necessary to adopt technical standards and award licenses. The process has now begun. It includes some unique technical issues, but it ignores the juicy political issues–like who will be eligible for licenses, and whether adult programming will be prohibited.

Jeffrey Krauss
This new allocation will have 17.3-17.7 GHz as the downlink broadcast band, and a band at 24.75-25.25 GHz for the "feeder link" Earth-to-space band. The current DBS band, used by DirecTV and EchoStar, is 12.2-12.7 GHz for the downlinks and 17.3-17.8 GHz for the uplinks.

So one unique issue is that, for the first time, the FCC is faced with "reverse band operations," whereby a frequency band (in this case, 17.3-17.7 GHz) is being used for both satellite uplinks and downlinks. There is a risk of interference from the 17 GHz feeder link stations into nearby 17 GHz DBS subscriber receivers in the new band. This is a particular problem during rainy conditions, because the raindrops ("hydrometeors") will scatter the uplink transmissions, and some of the signal will be deflected downward.

The FCC believes this kind of operation is feasible because DirecTV and EchoStar have only a few feeder link earth stations. But the new generation of spot-beam satellites will change that. The DBS obligations to carry local broadcast stations will require more feeder link stations, and some will be located in or near major metropolitan areas. For example, DirecTV recently added feeder link stations in Los Angeles, Calif.; Castle Rock, Colo.; Winchester, Va. and St. Paul, Minn. And if the FCC ever acts on the pending proposals to create additional orbital slots for the 12.2-12.7 GHz band, even more uplink earth stations will be needed.

But in addition to earth-station-to-earth-station interference, there is the risk of space-station-to-space-station interference. Satellites operating in the new band will be transmitting downlink signals at 17 GHz, in the same band that the DirecTV and EchoStar satellites are already using to receive the uplink programming. That's a particular problem if some of the orbital slots for the two bands are co-located, or if they are close to one another. If the FCC does not impose any ownership restrictions on the new band licensees, it's easy to conceive of DirecTV wanting to operate a 17 GHz DBS satellite at the same orbital location as its 12 GHz satellite, so that its customers can use the same dish to receive both satellites. But it isn't clear whether that's technically feasible.

And that leads to the question of what orbital spacing will be required for the new band. The 12 GHz band uses an orbital spacing of 9 degrees. That allows the use of very small dishes, about 18 inches in diameter. If the satellites were closer together, bigger dishes would be needed, because smaller dishes have a wider beamwidth, and would receive interference from the adjacent satellite, while larger dishes would be able to reject that interference. But the beamwidth or resolving power of a dish varies with frequency, and improves as the frequency increases. So at 17 GHz, an 18-inch dish could work with satellites spaced as close as 4 degrees apart.

If the FCC were to allow DirecTV and EchoStar to operate satellites in the new band, the optimal spacing might be 4.5 degrees, so that some of them could be co-located with existing DBS satellites–provided, of course, that co-location is technically feasible. If existing DBS operators are not eligible, then co-location is less important.

But here's the odd thing about this new FCC Notice of Proposed Rulemaking. This 65-page document has only one page discussing licensing procedures, and it never mentions the issue of eligibility. In contrast, in the past, the FCC has prohibited some existing licensees and operators (for example, cable operators and broadcasters) from applying for certain kinds of licenses.

There are evidently three licensing approaches under consideration: First-come, first-served; a processing round; or an auction. Under a recent court decision, DBS auctions might be illegal, so scratch that. The FCC says that it has three pending license applications for the new band: from DirecTV in 1997, from Echostar in 2002 and from Intelsat in 2005. It's possible that the FCC will grant the DirecTV, EchoStar and Intelsat applications under the first-come, first-served policy. That should still leave a few orbital slots for Canada, Mexico and other U.S. companies. Oh, but wait, I forgot. Under commitments the U.S. made to the World Trade Organization in 1997, non-U.S. companies can also own satellites that operate over the U.S. and can provide service to U.S. locations. Anyway, licensing procedures and eligibility are likely to be a very controversial area in this proceeding.

Finally, there was nothing in the FCC's Notice about a "family tier" or adult programming. According to rumors, every decision the current FCC chairman makes is colored by his desire to constrain adult programming. So, don't be surprised if there is a second round–a political round–in this FCC proceeding, after the technical issues are resolved. That's when licensee eligibility, adult programming and other political issues will be handled. And that's when the fireworks will start.

Have a comment? Contact Jeff via e-mail at: jkrauss@krauss.ws

Advertisement

Share This Story

X
You may login with either your assigned username or your e-mail address.
The password field is case sensitive.
Loading