Terrestrial wireless and satellite entities disagree on rules the FCC should adopt for bands above 95 gigahertz, setting up a spectrum fight similar to the one that was seen in the agency’s spectrum frontiers proceeding for millimeter-wave frequencies above 24 GHz.
At issue in the new spectrum horizons proceeding is how much spectrum to make available for fixed and mobile terrestrial operations, including on a shared basis, and whether any should be reserved for satellite use only.
Meanwhile, unlicensed spectrum advocates want more spectrum to be set aside for those uses and users of spectrum for scientific purposes warned about the potential for interference from unlicensed operations.
In a notice of proposed rulemaking adopted in February in ET docket 18-21, the FCC sought comments on rules to make spectrum available on a licensed, unlicensed, and greater experimental basis (TR Daily, Feb. 22). Currently, the FCC only has rules allowing the spectrum to be used by amateur operators and experimental licensees.
“Specifically, the item seeks comment on making a total of 102.2 gigahertz of spectrum available for licensed point-to-point services,” a news release on the item noted. “These bands would be licensed on a nationwide, non-exclusive basis and individual point-to-point links would be registered with a database manager. Because of the vast amount of spectrum potentially available, the point-to-point links hold the capability to transmit at much higher data rates than systems in lower frequency bands.”
The rules for the 102.2 GHz of spectrum would be based on the FCC’s existing rules for the 70/80/90 GHz band.
“The item also seeks comment on making a total of 15.2 gigahertz of spectrum available for use by unlicensed devices. The high atmospheric absorption of radio waves in these bands will limit the potential for interference and permit large numbers of unlicensed devices to share the spectrum,” the news release added. The rules for the 15.2 GHz of spectrum would be based on the agency’s rules for unlicensed devices in the 57-71 GHz band.
The NPRM also “seeks comment on creating a new category of experimental licenses available in spectrum between 95 gigahertz and 3 terahertz. These licenses will give innovators more flexibility, compared to the existing experimental licensing rules, by including a longer license term and license transferability to encourage investment and allowing the sale of equipment during market trials.”
“At this point in technology development, the wireless industry believes that spectrum above 95 GHz will be very useful for fixed microwave and wireless backhaul purposes, especially for small cells. This will be especially true in areas where fiber is not feasible or available and would be highly beneficial to enable further small cell deployments for both 4G and 5G mobile broadband services. However, given the nascent nature of technology for the spectrum bands above 95 GHz, the Commission should adopt flexible licensing and technical rules that will further U.S. leadership in the wireless marketplace,” CTIA suggested in its comments.
“Similarly, any sharing requirements for these spectrum bands should prioritize terrestrial fixed and mobile services while providing adequate interference protections to current and future uses. To that end, CTIA generally agrees with the approach outlined in the Spectrum Horizons NPRM and encourages the Commission to utilize database managers to mitigate sharing and interference issues among the various users above 95 GHz,” the trade group added. “Finally, CTIA generally supports the Commission’s proposal to set aside spectrum above 95 GHz for both licensed and unlicensed use, and to make certain bands available under the existing Part 15 rules for unlicensed millimeter wave spectrum bands.”
“Adoption of rules governing terrestrial operations in the spectrum above 95 GHz will facilitate use of the bands for mobile wireless broadband backhaul,” T-Mobile US, Inc., said.
The carrier said the Commission should consider several factors when it adopts rules for the spectrum.
It said that (1) “[t]he rules should contemplate a path to potential mobile use of the spectrum above 95 GHz”; (2) “[w]hile the regulations governing the 70/80/90 GHz bands are generally appropriate for the spectrum above 95 GHz, the Commission should modify the rules applicable to antennas operating above 95 GHz; the 70/80/90 GHz bit rate requirement should be relaxed as proposed; and performance reporting requirements should be imposed”; (3) the “[r]adio astronomy service (‘RAS’) and earth exploration satellite service (‘EESS’) can be protected by terrestrial operations in the spectrum above 95 GHz”; and (4) the FCC “should not reflexively extend satellite access to the bands in which it proposed to adopt terrestrial service rules.”
T-Mobile noted that the FCC “seeks comment on extending the 70/80/90 GHz bands proposal to the bands above 95 GHz that have shared allocations with FSS or Mobile Satellite Service (`MSS’) operations. The Commission believes that sharing here would be similar to the proposed sharing arrangements between Upper Microwave Flexible Use Service and FSS in the 27.5-28.35 GHz band and 37.5-40 GHz band. The Commission should not adopt this proposal for several reasons. First, as T-Mobile and others have demonstrated in the Spectrum Frontiers proceeding, any proposed FSS use of spectrum designated for terrestrial operations will necessarily limit terrestrial providers’ ability to deploy the spectrum. Second, and more fundamentally, the Commission’s continued attempts to create additional capacity for satellite operations is simply misguided – particularly when it requires limitation of other services. There has been no demonstrated requirement for use of this spectrum by satellite providers, unlike the need for terrestrial use, where backhaul requirements are demonstrable. Therefore, the Commission should not adopt service rules at this time for satellite use of the spectrum. If there is a demonstrated requirement in the future, the Commission can revisit the issue then. By that time, there may be more information on the use cases for terrestrial operations and therefore more information on how terrestrial operations can be protected.”
“Given that the technology for practical RF communications above 95 GHz is currently at a ‘very nascent stage’ and presents challenges and opportunities that differ from other bands, we support the Commission’s proposal to develop a new experimental radio license for these bands,” said the Telecommunications Industry Association. “Regarding licensing, the Commission should open at least some bands for mobile allocations to encourage the development of new technologies, while avoiding band fragmentation.”
Regarding the proposed new experimental license, TIA said that “[e]xpanding eligibility for a new research-program-type license beyond manufacturers, universities, etc. to encompass all ‘qualified persons’ may carry some risk of harmful interference from persons not truly ‘qualified.’ However, the Commission’s proposal to require a narrative statement with technical details would likely address most of that risk.”
TIA also said that the FCC is “wise to recognize that permitting limited market trials will help to establish the commercial viability of services in these newly-opened bands. Procedurally, allowing the Commission to approve any licensee’s market experiment, including the number of devices, on a case-by-case basis seems like a cautious but sensible path for the Commission to follow as the agency experiments with allowing expanded pre-authorization market sales.” It also expressed support for “allowing a 10-year initial experimental license period with 5-year interim reporting requirement – as opposed to the 2-year or 5-year periods applicable to all other classes of ERS [experimental radio service] licenses …”
“As the Commission proceeds with its examination of these bands, CTA submits these comments to update the Commission on the efforts of the consumer technology industry to explore the use of spectrum above 95 GHz, to suggest a set of basic principles that should guide the Commission’s consideration of this spectrum as technology utilizing these bands develops, and to respond to certain issues raised by the Commission in the NPRM,” said the Consumer Technology Association. “With respect to issues raised in the NPRM, CTA (1) agrees that the four bands proposed for unlicensed use are well-suited for such operations, (2) requests that the Commission maximize sharing with federal users where appropriate, and (3) urges the Commission to continue to prioritize sound engineering, such as the agency recently did through the creation of an honors engineering program.”
Ericsson said it “supports the Commission’s proposal to set aside portions of the 95-275 GHz band for licensed, fixed point-to-point service. The Commission also should harmonize its 95-275 GHz band plan with those under consideration in Europe, so the U.S. marketplace can benefit from the economies of scale essential for global, cost-efficient products. In addition, Ericsson agrees that the Commission should use the 70/80/90 GHz ‘lite licensing’/link registration model for authorizing facilities at 95-275 GHz.
“Subject to certain exceptions, Ericsson believes that the Commission’s proposed technical rules for the 95-275 GHz spectrum – based largely on the 70/80/90 GHz model – are appropriate. But the Commission should refrain from specifying transmitter power above 95 GHz in terms of maximum EIRP density, and instead apply the current 70/80/90 GHz power limit,” the filing added. “Also, the Commission should not apply a minimum antenna gain of 50 dBi or, alternatively, 43 dBi, to above 95 GHz antennas. Antennas installed on lampposts, light poles, traffic signal masts or similar supporting structures must contend with the phenomenon of ‘mast sway,’ which can cause an antenna to move out of alignment with the antenna transmitting to it, thereby interrupting the link. An antenna with even a 43 dBi gain increases the likelihood that mast sway will lead to link disruption. Optimally, this problem can be solved simply by eliminating any minimum antenna gain requirement for above 95 GHz transmitters. If the Commission nonetheless believes that some type of minimum antenna gain is necessary, it should be no higher than 35 dBi.”
Ericsson also urged the FCC “to consider making spectrum above 275 GHz available for fixed point-to-point service. The issue is already set for review at WRC-19, and, although several frequency bands in the 275-1000 GHz range have been identified for passive services, this does not preclude their use for active services. Lastly, the Commission’s Suppliers Declaration of Conformity (‘SDoC’) procedure, not certification, should be used to authorize transmitter equipment in the above 95 GHz spectrum.”
The mmWave Coalition, whose members include Nokia, urged the FCC to “consider developing rules that would accommodate both point-to-point and point-to-multipoint systems that would allow for innovative and affordable broadband service. While the licensing provisions for fixed point-to-point operations outlined in the Notice of Proposed Rulemaking (‘NPRM’) is one possibility, mmWC encourages the Commission also to explore other options that would allow licensees to register operations in an area around a fixed location instead of requiring registration of individual links as required by the existing 70/80/90 GHz rules.”
The coalition also urged “the Commission to allow fixed operations in a large contiguous block of spectrum (on the order of a tens of GHz or more blocks) and to use this proceeding to establish performance-based criteria that would protect vital incumbent and future passive users of the spectrum while allowing responsible spectrum sharing. By creating such a large contiguous block of spectrum, as opposed to the highly balkanized bands proposed in the NPRM, the Commission can unleash the full potential of the above-95 GHz spectrum while still protecting the present passive allocations.”
The coalition added, “While there may be little present interest in using the above-95 GHz spectrum for mobile services, mmWC urges the Commission to make clear that the Part 101 or the proposed Part 5 rules for above-95 GHz fixed services do not preclude the eventual use of these spectrum bands for shared fixed and mobile use under appropriate service rules for responsible sharing among all existing allocations.”
The coalition also (1) “supports the relaxation of certain requirements in the proposed ‘Spectrum Horizons Experimental Radio Licenses’ rules such as loosening the restrictions on marketing equipment, allowing experimental licenses across the entire 95 GHz-3 THz range, allowing a broad scope for experimental licenses, and the proposed ten-year license term”; (2) “urges the Commission to extend existing RF safety limits on an interim basis, which are currently specified up to 100 GHz, to frequencies above 100 GHz (up to the highest frequency authorized) — even if such limits are later modified in a separate proceeding”; and (3) “urges the Commission to establish regulatory certainty for ISM operations in the above-95 GHz frequencies to encourage capital formation for both developers of new innovative ISM equipment and manufacturers who use the technology in their manufacturing processes. The current approach of OET evaluating equipment that uses the above-95 GHz frequencies on a case-by-case basis does not provide the regulatory certainty needed for investment in the development of new ISM technologies such as Terahertz Spectroscopy.”
Qualcomm, Inc., asked the Commission to “authorize both fixed and mobile operations in these bands using both licensed and unlicensed regulatory paradigms, as explained herein. … Qualcomm requests that the FCC adopt flexible use rules so that both fixed and mobile deployments will be allowed in the spectrum horizons’ bands below 160 GHz.”
Among other things, Qualcomm said it “supports the FCC authorizing 15.2 GHz for unlicensed use within the four bands proposed in the NPRM: 122-123 GHz, 174.8-182 GHz, 185-190 GHz and 244-246 GHz. At this early stage of deployments in the spectrum horizons’ bands, Qualcomm recommends that the Commission apply the rules in Section 15.255 governing unlicensed operations in the 57-71 GHz band; however, the agency should remain open to modifying the Section 15.255 rules for some or all of the spectrum horizons’ bands if certain rule changes can improve spectral efficiency and service to end users.”
The Wi-Fi Alliance said it “appreciates the Commission’s efforts to keep pace with technology by considering how this spectrum can be used and by suggesting that some of it be dedicated for unlicensed operations. However, the marketplace should have the opportunity to dictate the highest and best uses of these frequencies. The Commission should therefore make limited, if any[,] allocation of this spectrum now. Any allocations it makes should allow the necessary flexibility to permit not only Wi-Fi and other existing unlicensed technologies, but also future not-yet envisioned unlicensed uses. Any rules adopted today should not inadvertently preclude future technologies. Further, while the use of the Spectrum Horizon bands will be essential for future unlicensed applications and data demands, the current demand for additional unlicensed spectrum must be met with lower-band frequencies (e.g., mid-band spectrum).”
“We support the Commission’s proposal to make 15.2 gigahertz of spectrum available on an unlicensed basis under Part 15 of the Commission’s rules, and encourage the Commission to also make the 116-122 GHz band available for unlicensed operations,” said Starry, Inc. “The Commission has long recognized the benefit of making spectrum available under Part 15 for unlicensed operations, and the significant technological development that can occur as a result of an unlicensed regime. Most recently, the expansion of unlicensed in the full 57-71 GHz band is a new breeding ground for innovation in low cost mmW technologies for relatively short range, high throughput communication.” The company also supports the creation of a new experimental license.
Facebook, Inc., said it “fully supports the Commission’s efforts to make available more spectrum above 95 GHz for commercial use. With policies in place that promote flexible use, balance unlicensed, lightly licensed, and licensed spectrum, and manage spectrum fairly and efficiently, this spectrum could become the bedrock for a range of new technologies that will expand and enhance connectivity around the world.”
Facebook noted that “the Commission’s proposal makes just 15.2 gigahertz of (noncontiguous) spectrum available for unlicensed use and 102.2 gigahertz of spectrum available under a lightly licensed framework. Instead, the Commission should reconsider its proposed balance between unlicensed and lightly licensed spectrum and shift the balance towards equal allocations among unlicensed, lightly licensed, and exclusively licensed frameworks within this spectrum to better support both access and backhaul use of this spectrum. The Commission should also make the available spectrum blocks larger and less fragmented. Alternatively, rather than dividing this spectrum into separate unlicensed and licensed bands, the Commission should consider licensing rules tailored to use cases that allow for coexistence across bands. Spectrum rules could be based on factors such as: indoor/outdoor use; terrestrial/space use; or power level based distinctions. For example, spectrum could be allocated for unlicensed use indoors and lightly licensed use outdoors within the same band.”
Apple, Inc., said it “supports the Commission’s efforts to open a large amount of underexplored spectrum in a way that promotes innovation and leaves room for future uses. Especially on unknown horizons such as these, the Commission is right to trust in emergent market forces over rules based on government predictions about the future of technology. But even high-level allocation decisions can undermine this goal. The small amount of spectrum proposed for unlicensed use, the narrowness of those bands, and their distribution between licensed bands will combine to disadvantage unlicensed technologies and impede further innovation. As Chairman [Ajit] Pai recently remarked, ‘instead of having regulators decide which frequencies are useful, we should put spectrum out there as a testbed and leave it to the innovators to figure out how to use it.’ In moving forward with this NPRM, the Commission should seek ways to adjust its proposal to better support the innovators who will make these bands successful.”
“The Commission should wait to adopt service rules for bands above 95 GHz until it has access to sufficient technical and market data to avoid miscalculations that limit development of other systems and services that better meet consumer and business needs,” argued Google LLC. “Optimizing the Spectrum Horizons experimental radio license rules to provide flexibility and regulatory assurance to innovators and investors interested in frequencies above 95 GHz would not only advance innovation, but also allow experimental licensees to generate the data requisite to establishing optimal service rules in the future.”
“The Commission is on the right track in this proceeding,” said Robert Bosch LLC. “Clearly, opening the millimeter wave bands to expanded unlicensed operation, at least for radiodetermination applications, is timely and useful. Some of the bands above 95 GHz should be immediately removed from the Part 15 restricted band list in Section 15.205(a) of the Commission’s rules. The technical rules governing such unlicensed operation, especially those related to use of the 122-123 GHz and 244-246 GHz bands (which are of great interest to the international manufacturing community), should be harmonized to the greatest extent possible with those in place in Europe at the moment and going forward. Widening of these two bands, and creating more flexible UWB rules so as to permit UWB applications in the bands around 122 GHz and 245 GHz will permit a large number of new, innovative products for consumers and for industry in the United States.”
The Satellite Industry Association expressed concern about fixed service operators sharing spectrum with satellite entities and the group said some frequencies should be reserved for satellite use.
“The frequency bands above 95 GHz present significant opportunities for future innovation, growth and development for broadband communications and for other important RF-dependent applications. The Commission should therefore exercise caution and seek to achieve an appropriate balance in making spectrum available for communications services above 95 GHz, while protecting critically important passive and satellite services that already operate in portions of this spectrum, and also conserving large portions of this spectrum for the introduction of new services in the future that have not yet been identified,” SIA said.
SIA added that it “does not object to making up to 36 GHz of spectrum available for fixed services (‘FS’) in the bands that are not shared with satellite communications services. The 36 GHz of spectrum identified in the NPRM will be sufficient to provide adequate capacity for the future growth of FS in a wide range of relatively higher and lower frequency bands above 95 GHz. The Commission could also base its rules for FS above 95 GHz on its rules for the 70 and 80 GHz bands.
“Given the substantial opportunities that would be available for FS in this initial 36 GHz of spectrum, no reason exists to adopt service rules or introduce FS in the 66.2 GHz of spectrum above 95 GHz that is shared between FS and either the fixed satellite service (‘FSS’) or the mobile satellite service (‘MSS’). FS operators clearly do not require access to these frequency resources and considerations for sharing this spectrum should be addressed at a later date,” SIA suggested.
“It would also be inappropriate to introduce mobile services into any portion of the frequency bands above 95 GHz, particularly in those bands that have shared allocations to support satellite communications services or other important satellite applications used for Earth sensing and other purposes,” SIA said. “Consistent with this, it would be entirely inappropriate to inject into the bands above 95 GHz the Commission’s highly restrictive rules for the placement of individually-licensed satellite earth stations operating in the 28 and 37/39 GHz bands. The bands above 95 GHz are unlikely to be used for wide-area mobile networks, which is what the Commission sought to protect in the 28 and 37/39 GHz bands. Further, the Commission does not need to impose burdensome restrictions on the placement of individually-licensed earth stations to protect FS, which successfully employs site-by-site coordination with satellite services in other frequency bands.”
SIA said that the FCC “should also identify frequency bands above 95 GHz that will be made primarily available to support ubiquitously deployed satellite end user terminals. Satellite networks operating above 95 GHz will be able to ensure that whatever new communications services are developed in these much higher frequency bands can be made available to all people regardless of where they are located, including in rural and remote areas that are largely unserved by terrestrial broadband networks. For example, the Commission should identify at least seven gigahertz of spectrum (possibly within the range of 209-226 GHz) that would be suitable for Earth-to-space uplink communications from satellite end user terminals on a paired basis with the existing primary downlink allocation for FSS and MSS in the 123-130 GHz band, which is not shared with the FS or MS services. Such an allocation would ensure the continued growth and development of new satellite services for consumers without impeding the future spectrum requirements of other communications services.”
The Boeing Company said, “In seeking to promote innovation, development and commercial spectrum use in the bands above 95 GHz, the Commission should remain focused on two important considerations. First, some of these frequency bands are already used to support critically-important satellite sensing and passive monitoring services, much of the data from which is necessary to ensure the accuracy of inclement weather forecast models used by aviation, industry, and multiple levels of government for logistics and public safety. The Notice of Proposed Rulemaking (‘NPRM’) correctly acknowledges that these essential spectrum uses must be fully protected. Second, the bands between 95 and 275 GHz likely present the last remaining green field opportunities for at least a generation of researchers and technologies involved in wireless innovation and development. Therefore, although the Commission should make significant portions of the bands above 95 GHz available for the expansion of existing communications services, the Commission should preserve even larger portions of this spectrum to ensure its future availability for wireless applications and services that are beyond our current expectations.”
Boeing added that it “generally supports the Commission’s proposal to make available for fixed services (`FS’) up to 36 GHz of spectrum that is not shared with satellite communications services. The service rules for FS in this 36 GHz of spectrum could be based on the FS rules for the 70 and 80 GHz bands as long as they adequately protect co-frequency passive and satellite sensing services. No reason exists, however, to introduce FS into any portion of the 66.2 GHz of spectrum above 95 GHz that is shared with the service or feeder links for satellite communications services. FS operators already have significant spectrum capacity available to them in the 70 and 80 GHz bands and, with the addition of up to 36 GHz of spectrum above 95 GHz, will have sufficient opportunities for growth and development for the foreseeable future.”
“It would be inappropriate for the Commission to authorize mobile services in any portion of the bands above 95 GHz, particularly those that are shared with satellite communications services. The FCC just concluded in its Spectrum Frontiers proceeding that mobile services do not need access (and may be unable to share with FS) in the 70 and 80 GHz bands. These same conclusions apply with even greater weight in the bands above 95 GHz,” Boeing argued.
In addition, the FCC “should refrain from imposing in the bands above 95 GHz its satellite earth station siting restrictions that were adopted in the Spectrum Frontiers proceeding for the 28 and 37/39 GHz bands,” Boeing said. “These burdensome restrictions on individually-licensed earth stations were expressly rationalized on an assumption that protection would be needed for wide area mobile networks that might use these frequency bands. In contrast, the Commission’s NPRM acknowledges that the bands above 95 GHz can only support very short range communications involving relatively controlled operating conditions, making earth station siting restrictions unnecessary. Such siting restrictions are also unnecessary to protect FS links in shared bands, which have long used site-by-site coordination to share spectrum with satellite services. Although the Commission should refrain from imposing burdensome rules on individually-licensed satellite earth stations, the Commission should also set aside large portions of spectrum above 95 GHz for the operation of ubiquitously deployed satellite end user terminals.”
“The 90 GHz band is uniquely well suited for short range radar systems that can penetrate degraded visual environments,” said Sierra Nevada Corp. “Industry chip and parts manufacturers have coalesced design of their technologies centered around 92-96 GHz, almost all using a center frequency of 94 GHz. Given the state of this available equipment and technology, as well as SNC’s requested rule change, the FCC should assure that deployment of EFVS radionavigation in 95-95.5 GHz may occur in conjunction with any new fixed or mobile services allowed within this frequency range.”
“Overall, the Commission is on the right track in this proceeding,” said the American Radio Relay League. “Opening the millimeter wave bands to expanded unlicensed operation is not unreasonable. Some, but not all of the bands above 95 GHz (including the 122.5-123 GHz, the 136-141 GHz and the 241-248 GHz bands) can be removed from the Part 15 restricted band list in Section 15.205(a) of the Commission’s rules without significant concern. However, the Amateur Radio primary allocations at 134-136 GHz and 248-250 GHz which are shared with radioastronomy should be unavailable for either Part 15 operation or for other commercial development. There should be two specific obligations that each Spectrum Horizons experimental applicant should have to satisfy: (1) it should demonstrate convincingly that there are no other allocations that would be suitable for the specific experiment in lieu of the bands 134-136 GHz and/or 248-250 GHz; and (2) it should coordinate its operation with ARRL at the time of filing the application, to ensure that there is no conflict with ongoing or planned Amateur Radio or Amateur-Satellite operation. All non-Amateur operation in the secondary Amateur Radio allocations should be subject to a prior coordination requirement.”
The IEEE 802 LAN/MAN Standards Committee expressed support for extending the FCC’s unlicensed rules to the additional spectrum above 95 GHz and updating its experimental licensing rules.
The National Academy of Sciences’ Committee on Radio Frequencies (COR) said it “appreciates that the NPRM was drafted with detailed attention to the need to protect important scientific observations in bands above 95 GHz. Such protections serve the public interest. CORF generally supports the sharing of frequency allocations, where practical, but protection of passive scientific observations, as discussed herein, must be addressed.”
CORF added that it “does not oppose fixed terrestrial use of the proposed bands, subject to implementation and use of effective frequency coordination. There are a limited number of major RAS [radio astronomy service] facilities that observe in these bands in the United States, and those facilities can be identified with relative ease. While CORF does not have direct experience with the existing coordination system for the 70/80/90 GHz bands, it is logical that a similar system of geographic coordination through the National Telecommunications and Information Administration (NTIA) be applied to these bands.”
The National Radio Astronomy Observatory said, “The Commission is proposing that licenses be granted to experimental devices that transmit in spectrum bands protected by US 246 and RR. No. 5.340 (the so-called passive bands, see ¶75), that such devices be allowed to be marketed (¶70-73), and that they be allowed to operate without divulging the details of their operations (¶67). NRAO opposes such use of bands protected by US246 and RR No 5.340, opposes the marketing of experimental devices except under conditions not considered in the NPRM and Order, and opposes operation under a too-strict cloak of secrecy.”
The IEEE Geosience and Remote Sensing Society (GRSS) Technical Committee on Frequency Allocations in Remote Sensing (FARS-TC) also expressed concern with proposals in the NPRM, including with unlicensed operations in the 122-123 GHz, 174.8-182 GHz, 185-190 GHz and 244-246 GHz bands. It said that “some of these bands are currently employed by EESS [earth-exploration satellite service] sensors and will continue to be used by future EESS sensors. Also, some of these bands correspond to or include allocations to passive science services. Passive services are especially sensitive to artificial transmission and, even at the current power level limits, if a large number of unlicensed operators were transmitting at the same time, the aggregate interference could potentially disrupt EESS operations. Given the current trend in growth of wireless commercial services, the number of emitters will likely reach large numbers. Therefore, we recommend that the permitted power levels in those bands not be increased. It should also be noted that EESS sensors operating in this region of the spectrum are both ground-based and space-based. Unlike operations in the 57-71 GHz bands, atmospheric attenuation in the above-mentioned bands is highly variable due to water vapor content. An important consideration is that unlicensed operations in these bands are to be considered in terms of maximum aggregate level of emissions within EESS bands. We urge consideration to maintain spectral segments that are free from emissions or ‘excluded regions’ in order to avoid potential impact to EESS observations from aggregate effects of unlicensed emitters such as the segments noted in this paragraph that are highly utilized within EESS.”
Daniel Mittleman, an engineering professor at Brown University, noted that for more than 20 years, his “area of specialization has been the science and technology of sub-millimeter and terahertz waves and their uses in spectroscopy, imaging, and sensing. I feel very strongly that this region of the spectrum is poised to have an enormous economic impact. There has been rapid technological progress in the field, along with an astounding acceleration in recent interest on the part of many companies, both in the United States and abroad. Use of frequencies above 95 GHz is no longer just a hope for the future. Moreover, my experimental work has shown that some commonly-held beliefs about limited propagation characteristics are invalid. It is time now for the FCC to take the lead in opening the doors to the benefits of the new technology.”
He added that “(1) high data rates can realistically be achieved over reasonable distances, both indoor and outdoor; and (2) the US is rapidly falling behind the rest of the world. With respect to this latter problem, it is not much of a stretch to suggest that a lack of leadership from the federal agencies who are responsible for fostering innovation in wireless technology is a contributing factor.” For example, he said, “the EU has had RF safety limits in place for frequencies up to 300 GHz since 1999, whereas FCC has yet to even offer a proposal for above 100 GHz.”- Paul Kirby, email@example.com
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