More Efficient Use, Transparency Said Needed to Address Spectrum Gap

Trends in demand and supply suggest a looming spectrum gap that needs to be fixed through a spectrum policy revamp, Knapp said. Trust is an issue in spectrum time-sharing, Knapp acknowledged, saying the agency plans look into this issue. Research and development plays an important role in adoption of dynamic spectrum access, he said. “People need to be convinced that it’s going to work,” he said, noting federal agencies and non-federal entities are approaching the issue with a positive attitude.

Plans to review both federal and non-federal spectrum holdings could offer a better understanding of the possible options to address spectrum demand, said the report by the Committee’s Spectrum Inventory Working Group. Potential results may include redistribution of existing spectrum assignments from entities that aren’t using their entire spectrum; encouragement of capacity-enhancing techniques for existing spectrum holders to permit them to manage future growth and curtail the need for additional spectrum assets; and introduction of spectrum sharing technologies in specific frequency bands. The working group suggested that the precept of redistribution needs to be challenged, said inventory working group subcommittee member Jennifer Warren. Redistribution isn’t the only option, said Warren, a Lockheed Martin vice president. “We emphasized that the spectrum isn’t fixed or unchanging,” she said. It’s crucial that licensees are obliged to use advanced techniques to increase spectrum capacity, the report said. But some members had concerns over putting in technology mandates.

The inventory report urged the public portions of the FCC and NTIA inventories be available through a common portal. It recommended that NTIA, and the FCC through the NTIA, undertake to determine what information regarding existing and planned system characteristics, receiver information (ability to reject interference) and duty-cycle information (near-constant transmission or intermittent use), in addition to relevant transmitter locations, emitted power and transmit masks, can be made available in any public inventory. It also recommended NTIA and FCC seek federal appropriations to support the development of their respective databases and inventories. But each database should be based on a common data format, standards.

Meanwhile, one of the big challenges is to define efficiency, Knapp said. What efficiency means for different services and different users is critical, he said. The National Broadband Plan recommends the FCC evaluate the effectiveness of the secondary spectrum market and rules to promote access to unused and underutilized spectrum, Knapp noted. The agency is still in the early stage of reviewing the issue, he said. Spectrum measurement is another important but tough task due to the diversity of services, Knapp said. But measurement of spectrum efficiency in land mobile services (including cellular services) is achievable with known techniques that can identify potential solutions for improved spectral efficiency in that service, said the spectrum inventory report.

The current system has little transparency in spectrum allocation and utilization and there’s also no framework to identify future spectrum, Knapp said. CSMAC’s Spectrum Transparency Working Group recommended defining transparency and creating a subcategory of internal spectrum transparency. Other recommendations include requiring federal agencies to report how much spectrum they use and to confirm the specific spectrum assignment data at least every two years, making “non-classified and non-FOIA exempt” data on spectrum assignments available to the public, ensuring security-cleared staff be able to see internal spectrum transparency data outputs.

The Incentive Subcommittee hasn’t reached consensus on spectrum fees, said Michael Calabrese, vice president of the New America Foundation. But subcommittee members agreed that positive incentives for spectrum sharing include expanding the Commercial Spectrum Enhancement Act eligibility and options to replenish the fund, he said.

Cognitive radio and spectrum sensing technology may become an important tool in spectrum sharing policies in the future, said the report by the Interference and Dynamic Spectrum Access Subcommittee. It urged establishing procedures to examine the efficacy of spectrum sensing devices to protect services that employ different architectures and modulation systems. It also urged devoting substantial resources to establish a wide-ranging evaluation process for new devices that use spectrum to transmit or receive signals. Subcommittee member David Donovan, president of the Association for Maximum Service TV, emphasized enforcement, saying NTIA and government entities with spectrum management responsibilities need to shift from interference prevention to both prevention and enforcement.

Meanwhile, the new Unlicensed Subcommittee seeks to exam spectrum allocation in the U.S. and internationally, evaluate spectrum use involving different technologies and identify technology best suited for unlicensed spectrum, said Gerald Salemme, a Clearwire vice president. A final work plan would be available by June, he said. The first draft of recommendations will be complete in August with final report expected by September, he said. The work plan for the new Sharing Subcommittee would be very general, said Gary Epstein, a SkyTerra executive vice president.