In the last few weeks, the future prospects of small cell antennas got brighter and shrank at the same time. AT&T and T-Mobile both filed comments with the Federal Communications Commission (FCC) in support of an industry-wide waiver of rules against flat-panel antennas for backhaul radios in the 70-80GHz bands. Currently, out-of-date FCC regulations about antenna radiation patterns hold back development and deployment of this type of equipment that urban dwellers will find acceptable in big city cores.
The current rules effectively call for the use of parabolic antennas that will be unsightly and would violate the aesthetics considerations and zoning regulations in many city core locations—precisely the type of environment that 70-80GHz radios exist to service. While the FCC regulations seem to necessitate parabolic antennas to keep radio beams focused and from interfering with equipment in the vicinity that uses the same wavelengths, mobile subscribers prefer more visually friendly solutions.
How to get from here to there
For the last few years, Aviat Networks has been working with the Fixed Wireless Communications Coalition and others to get the FCC to update its regulations in the 70-80GHz bands. The problem: when the FCC promulgated these rules, the idea had never occurred to anyone that these bands would ever service small cell applications. And the applications that the FCC’s 70-80GHz rules were designed to support never materialized, with only 5,500 links registered in this spectrum since 2005, according to T-Mobile.
However, with this breakthrough in support from Tier 1 operators like AT&T and T-Mobile, the FCC should feel reassured that granting the waiver to the antenna rules for 70-80GHz bands is in the best interest of all the wireless industry service providers. And with OEMs in addition to Aviat asking for the waiver, no specific vendor will be favored. We urge other wireless service providers, communications equipment OEMs, subscribers and anyone else interested in moving forward as fast as the technology can go to also contact the FCC about granting this industry-wide waiver.
In the meantime, to learn more about urbanized small cell backhaul in the 70-80GHz bands, download this white paper.Read More
Back in April the telecom experts over at CommLawBlog weighed in on a simmering issue in the 70-80GHz radio space. Since October 2012, the Federal Communications Commission (FCC) has mulled over a motion by the Fixed Wireless Communications Coalition (FWCC) to relax rules for flat panel antennas as well as a 2013 waiver to the existing rules while it considers a new rulemaking.
Lack of taking any action on any of these filings has left the backhaul industry in a quandary. With viable radio solutions ready to deploy in the 70-80 GHz frequency ranges, the only holdup has been a technical requirement that FCC rules place on the radiation pattern of the very thinnest of flat panel antennas. These rules were originally formulated for an era where microwave radios were used for links that spanned 1 to 5 kilometers.
In the new urban reality for small cells, the distances between mobile base stations will be measured in hundreds of meters. At these lengths, the radiation patterns of flat panel antennas will not materially increase interference, to paraphrase language the FCC itself has used previously when approving use of smaller antennas in the 6, 18 and 23 GHz bands, circa 2012.
With small cell wireless in close-in city settings, both mobile and non-mobile subscribers have a heightened sense of awareness, and they will take extra notice of backhaul radios with prominent parabolic dishes that stick out like sore thumbs. With their figurative and literal low profiles, flat panel antennas provide the critical missing link in ameliorating the aesthetics concerns that many feel toward old, bulky microwave installs. While these hulking communications devices were fine on towers at long haul sites way out by the interstate freeway or high atop skyscrapers in the heart of the business district, when they are situated on the side of a residential building the modern-day urbanite will not tolerate these telecom equipment eyesores.
In reality, there is very little for the FCC to decide upon. While the telecom regulator here in the United States has its own rules, regulators in much of the rest of the world use the ETSI standards. Actually, the standard in effect is of little consequence. The point of fact is that the flat panel antennas in question before the FCC have been approved for use in all these ETSI countries without any significant drawbacks being reported in nearly three years of use. Even the FCC’s companion agency to the north, Industry Canada, has given tentative go-ahead to flat panel antennas for use with 70-80GHz backhaul radios, with the implicit understanding that they will receive formal approval if no unforeseen snags occur in final rule drafting.
So while the rest of the small cell community enjoys a flat panel world, the U.S. is walking a tightrope of red tape in hopes that some decision is made—soon.
Full disclosure: Aviat Networks is the filer of the 2013 waiver request and is a member of the Fixed Wireless Communications Coalition. Aviat Networks is legally represented by Fletcher, Heald & Hildreth, PLC, the host of CommLawBlog.Read More
The last time we were together, we discussed the prospects for urban backhaul in 2014. True, it will be a very exciting time in the 70 GHz and 80 GHz E-band frequencies. The promise of small cells is finally coming to fruition after the hype cycle had all but chewed and spit them out. Remember when you first heard of DSL and cable modem? By the time you could get one, the media had stopped talking about them for at least two years. But we’re digressing.
The point is that with cellular network subscribers actually able to connect to these microcell base stations, the need for a viable backhaul solution has come to a head. E-band to the rescue! And the need is not just with the established players to extend their mobile networks into the city cores backed by radio backhaul. By opening up the 70 and 80GHz frequencies to commercial backhaul applications, regulators have created an opportunity for new market entrants to move under the radar and grab share from the legacy carriers, who had previously discounted this spectrum.
With very aggressive pricing and novel tariffs that offer a bare minimum of 50 MB for data downloads and two hours of airtime for the equivalent of less than 3 dollars/month, as an example from Aviat research, a provider of mobile services such as these would need to be very creative capitalizing its backhaul requirements. As it turns out, on a per-link basis, an 80GHz nationwide backhaul license can be had for less than if the operator bought individual licenses everywhere it provides coverage—in one nation, in any event. At least, it would be true once a provider’s backhaul sites pass into four-figures territory.
Nonetheless, it’s a remarkable development made possible by the world shrinking figuratively and people living in closer quarters as never before. Brought to you by (the letter) E-band backhaul!
For years and years, microwave and millimeterwave radio technologies have coexisted without very much overlap in either their markets or applications. Microwave radio served telephone company needs (e.g., long distance backhaul, mobile access aggregation) for the bulk of its implementations with some vertical deployments for oil and gas, public safety and utilities organizations. Typically, licensed bands in service ranged from 6GHz to 42GHz—with 11GHz and under popular for long haul; 18-38GHz trendy for short urban hops. Generally, millimeterwave radio is considered to be between the 60GHz and 80GHz bands and found its applications confined to those for intra-campus communication from building to building for universities, civic centers, other government conglomerations and large, spread-out (i.e., 1 to 5 miles) corporate facilities.
More recently, E-band has seen its profile rise, as mobile operators have had to “densify” their networks to service the more tightly packed populations moving into larger and larger cities around the world. This is due to at least two factors: the shorter distances between wireless sites in urban locations and the lack of available spectrum in the traditional microwave bands. E-band radios are now starting to be deployed to aggregate traffic from macro cell base stations in the Gotham-esque landscapes of the 21st century and the new small cell transceivers that venture where no full-size mobile base station can tread.
So into this brave new world of urban backhaul, next-wave E-band radios have been thrust. But small form-factors and spectrum availability are not going to be enough to ensure the success of this new generation of millimeterwave equipment. Additional features will be necessary. They will need capabilities such as:
It is an exciting time in the E-band space in early 2014. We will share more as the year progresses. Check back regularly to stay apprised of developments.