Spectrum Sharing Talks Must Be Band Specific, Nebbia Says

"Focusing on the specific opportunities we have and pouring our resources into that is probably a better use of … our efforts and staff time than trying to create the larger guidebook or crib sheet or whatever for all the bands and all the services,” Nebbia said. “I just think they're too numerous to try to create that construct. Even with the work we're doing in one band we've had to create five different working groups.”

Industry-government discussions on spectrum sharing take a lot of time, but are critical, NTIA Administrator Larry Strickling said. “I think we've made terrific progress,” he said. “I couldn’t be happier with the level of effort, the level of commitment that people have made to the process.”

Strickling said CSMAC members must keep a few key points in mind. Work so far has shown the importance of “making sure that the data that each side needs is provided as promptly as possible,” Strickling said. “I think it’s incumbent on everybody in the process to make sure that they are raising the issues early in the process … so that we don’t get surprised at the end by someone who may have been keeping their powder dry,” he said. “I haven’t seen much of that, but it’s important for everybody to keep that in mind.”

Everybody must start with the assumption “that we can make this work and there is the possibility of greatly increasing the use of spectrum to provide much, much higher capacity for commercial and government at the same time, that this can be a win-win situation,” said Gregory Rosston of Stanford University, CSMAC co-chair.

Janice Obuchowski of Freedom Technologies, a CSMAC member and former NTIA administrator, said having some broader principles in place is important. “Federal users are a very complex lot,” she said. “We're not talking about people who are inefficient in their use of trunking technology. We're talking about some of the most sophisticated systems in the world.” Trust and enforcement are important, she said.

"If everything is going to be kind of case-by-case, looking at the parameters on both sides, and, eventually, arriving at a technology handshake, there has to be a magnificent amount of trust in both directions,” Obuchowski said. “When you're talking about commercial players of enormous sophistication, with the ability to go to Congress or the courts, sharing with feds it’s really difficult to foresee how the enforcement scenarios might move forward,” she said. “But that’s the issue that really is profound.”

CSMAC also got early feedback from the five working groups looking at sharing issues in the 1695-1710 MHz and 1755-1850 MHz bands.

Dennis Roberson, vice provost at the Illinois Institute of Technology, who represents CSMAC on the working group on weather satellite receive Earth stations at 1695-1710 MHz, said the band offers a “prime opportunity” for time-based sharing. Roberson said the group has been unable to reach any agreement on whether to recommend exclusion zones that would protect communications in a few areas, but the better alternative may be temporal sharing, he said.

"This is a very well-known environment -- these are not moving targets,” Roberson said. “We have 18 very, very fixed sites, quite large sites. The satellites are few in number. They're quite predictable in their path though they can be moved. … But the movement time is in hours at minimum, sometimes days.” The opening for sharing is that sites that need to be protected receive information “less than five hours a day, actually considerably less in most cases” and most transmissions are “in the middle of the night,” Roberson said. “So from a temporal sharing standpoint, this is a poster child. … If we can’t temporally share in this circumstance, where can we share?”

Strickling said the group’s work on the band is important. “We're now confronting the challenges that we have in trying to execute on what we all know we have to do … which is to find a way to share spectrum,” he said. “The absolute wrong response to this would be to say, ‘This is getting too hard. Let’s go home.’ I don’t hear anybody saying that."

Other working groups have made less progress to date, according to presentations at the CSMAC meeting. CSMAC member Rick Reaser of Raytheon, representing the working group on 1755-1850 MHz satellite control links and electronic warfare, said the group has had trouble getting basic information from the government.

"At the end of the day what we're going to try to do, or what we need to do, is define what the interference scenario is in a technical way, that a cell tower would have to experience, and that would actually go into the auction rules,” Reaser said. “It’s been very difficult to get that information. We don’t have enough right now. … It would be nice if we could get that sort of answers to our questions.” Reaser said the working group is also having a tough time getting the federal agencies to focus on the report the group will write. “We have draft text that’s never been looked at by the federal side and that needs to happen,” he said.

Nebbia offered brief comments on a report approved by CSMAC calling for fundamental changes to how “cheap, dumb” unlicensed devices like garage-door openers are viewed and regulated in a shared-spectrum world (CD July 25 p9). CSMAC may want to rethink use of the word dumb, he said. “Out of the many recommendations that the CSMAC has put on the table before, this is probably the only one where I've gotten spontaneous calls from the outside, saying things like, ‘What do you mean you're calling us dumb devices?'” Nebbia said. “There is an industry out there and I'm not sure there was full understanding and evaluation of who they are and what they provide.”