MITRE TESTS FAIL TO RESOLVE DBS-MVDDS SPECTRUM DEBATE

It was unclear whether results in report were enough to allow Commission to move forward to license Northpoint and other terrestrial companies seeking to operate in 12.2-12.7 GHz band, industry officials said. Northpoint said it was only company to submit technology for testing. “The Mitre report is very fuzzy,” industry lawyer said: “Neither side got the knockout it needed to prove its claim. This controversy is definitely going to continue until the talking heads at the Commission do something.” Report, which had been expected to clear up interference issues between terrestrial operators such as Northpoint and DBS industry, didn’t give either side clear-cut victory and stopped short of making definitive decision for Commission that issued rulemaking and order. “We never supported the FCC proposal to allow MVDDS operators in the band without specialized technology,” Northpoint CEO Sophia Collier said.

Report did offer clear view of how 2 systems might co-exist and what circumstances might cause interference to DBS operators. Report was based on comprehensive analysis that included extensive lab and field measurements, Mitre said. It said it gave special attention to degradation of service availability in rain. Comments on report are due at FCC May 15, reply comments May 23. FCC is expected to make decision on Northpoint license afterward.

Tests were conducted at Mitre labs in Bedford, Mass. Mitre measured radiation patterns of 3 DBS antennas and 2 MVDDS antennas in its anechoic chamber, which has been used extensively to measure critical defense systems, report said. DBS receiver susceptibility to MVDDS interference was measured by connecting MVDDS transmitter to DBS receiver through attenuator and varying MVDDS signal level to generate set of susceptibility curves. DBS receiver was operating with live signal from satellite at time of measurements. Limited field measurements of MVDDS signal level at terminals of DBS antenna were made for variety of DBS antenna orientations. Mitre’s Fort Monmouth, N.J., laboratory used Signal Processing Workstation software package to model DBS/MVDDS interference environment in order to provide independent verification of laboratory measurements. Runs were made for combination of code rate, interleaver length and Reed-Solomon error correction that are in use by DBS vendors.

Interference can be reduced, it said, by: (1) Selection of MVDDS operational parameters. (2) MVDDS system design changes. (3) Corrective measures at DBS receiver locations. Report said most important parameters that could be adjusted to control interference in existing MVDDS system designs were transmitter power, frequency offset, tower height, elevation tilt, azimuthal orientation. Real-time power control, use of multiple MVDDS transmitting antenna beams, circularly polarized MVDDS transmitting antennas and larger MVDDS receiving antennas proposed by Pegasus also would reduce interference impact on DBS downlinks. Mitre suggested relocation of DBS receiving antennas to put nearby buildings between them and nearby MVDDS interferers while still leaving satellites in view. It suggested interference levels could be reduced by: (1) Use of absorptive or reflective clip-on shielding for existing DBS antennas to block any direct lines of sight. (2) Replacement of DBS receiving antenna. (3) Replacement of older DBS set-top boxes.

Other Mitre recommendations included: (1) Requiring MVDDS operators to measure interference levels and provide mitigation solutions to new DBS customers in mitigation-interference area. (2) Not allowing new DBS or MVDDS waveforms to be licensed without further study because they create unknown vulnerability. (3) Satellites not addressed in current report be studied further because DBS receivers operating with new and different satellites could be at risk. (4) Providing protection for only DBS satellites with baseline unavailabilities of 100 hours/year or less when operating without MVDDS interference into DBS antenna with G/T of 11.2 dB/K should be protected. DBS receivers operating with satellites outside those criteria shouldn’t be protected. (5) MVDDS service providers’ opting to mitigate interference with use of different antenna should use replacement antenna with G/T at least as great as original antenna. (6) Considering other sources of outages. (7) Looking for MVDDS backlobes that also could cause interference. Since Mitre believes DBS customers may not know what is causing particular outage, or reason for its duration, mitigation should be done proactively by MVDDS operators and mitigation should be done before license is granted.

Northpoint’s Collier said Mitre report was “significant” because it recommended process for licensing, admitted spectrum sharing was “feasible” and said systems that didn’t use mitigation techniques as Northpoint did were likely to cause interference. “We support the recommendations of the Mitre report,” Collier said: “Mitre correctly concluded that satellite-terrestrial sharing requires specialized technology like Northpoint in order to be effective -- and without a system such as Northpoint, sharing cannot work. We don’t know why the DBS industry is blaring the trumpet. This is not good news for them.”

Collier also said Northpoint was “flattered” by Mitre’s praise of work by Northpoint engineers to “predict and prevent interference.” She said report was “fatal” to companies seeking license without providing technology and to “proponents of auction.” Northpoint agreed with DBS industry in opposing Mitre suggestion of changing dishes to mitigate interference. “It’s not our favorite solution.” Northpoint Vp Toni Bush told us report “verified everything we have said” in filings at FCC. “We never envisioned doing anything without using mitigation techniques. It has been all a part of our plan from the very beginning.”

Satellite Bcstg. & Communications Assn. (SBCA) hailed Mitre report as conclusive evidence that “confirms results” of tests conducted by EchoStar and DirecTV. SBCA Pres. Charles Hewitt said Mitre tests “have unequivocally validated our conclusion” that proposed Northpoint system would cause harmful interference to DBS customers. “The consumer mitigation techniques suggested in the Mitre report are egregious and far too burdensome” for DBS consumers. “Spectrum sharing should not occur simply for the sake of sharing, especially if consumers and competition are forced to pay the ultimate price.” DBS industry will “welcome competition” with Northpoint if it moves back to terrestrial spectrum where it belongs, Hewitt said. “This dispute is about interference, not competition.” SBCA spokesman said “writing is on the wall” for Northpoint. If FCC allows terrestrial sharing, 40 million DBS users will be “impacted.”