In PART 1 of this blog, we provided an analysis of utility applications and expected capacity demands. Applications, especially security and surveillance, are rapidly increasing capacity requirements for utility networks. In this blog, we will outline an approach for performing capacity planning for a sample utility network in light of the applications traffic requirements.Read More
The tragedy of the commons happens when people sharing a common resource are inclined to overuse it, degrading it so much that becomes useless. An example is a field open to all in which cattle, have grazed for generations. At some point, a cattleman increases the number of animals of his herd to maximize profit.Read More
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 Currently, out-of-date FCC regulations about antenna radiation patterns hold back development and deployment of this type of equipment that urban dwellers will find acceptable in big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, please contact us.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.Read More
On Dec. 16 2013, Ofcom—the UK telecom regulator—announced a new approach for the use of E-band wireless communications in the United Kingdom. This new approach results from an earlier Ofcom consultation exercise in which Aviat Networks participated.Read More
The Case for Small Cell Backhaul
As the search for frequency bands with suitable capacity for small-cell backhaul continues, frequency bands above 50GHz start to appear attractive because they offer both high-bandwidth availability and short range owing to their inherent propagation characteristics. The white paper available at the bottom of this blog examines spectrum in the 57-64GHz range to see whether it can be of use for small cell backhaul.
In many countries, the frequency range 57-66GHz is split into a number of discrete bands with differing requirements and conditions of use and/or licensing. These differences will be highlighted where applicable.
From a global point of view, the use of this spectrum by Fixed Services (FS) is being addressed by the ITU-R in its draft report on Fixed Service use trends in WP5C, which is currently under development and states:
57 GHz to 64 GHz
The radio-frequency channel and block arrangements of these bands for FS are defined in Recommendation ITU-R F.1497.
In 2011, around 700 links were in use in this band in a few administrations. The majority of the links are used for fixed and mobile infrastructure.
The air absorption around 60 GHz is over 10 dB/km. This condition restricts the hop length; on the other hand, the spectrum reuse efficiency is high. This feature makes the band suitable for small cell mobile backhaul.
Clearly, a global reported usage of 700 links would suggest a great deal of underutilization, although with unlicensed use in many countries it is difficult to know whether these figures are accurate or not. Regardless, there are reasons as to why this could be the case, while noting that the ITU-R believes this band has potential for small cell backhaul.
One factor is that this spectrum is not allocated solely to the Fixed Service. In fact, in many countries the Fixed Services have no access to this spectrum at all. A more detailed country-by-country breakdown follows. Please sign up below to receive the entire white paper.[contact-form-7 404 "Not Found"]
Typically, low-latency microwave is used to “replace” traditional-fiber based networks linking financial centers. The business driver for microwave-instead-of-fiber in low latency is the time it takes to transmit trading instructions. With microwave, latency is reduced by a few milliseconds as compared to fiber. Nevertheless, those few milliseconds can translate into a trading edge over rival investors, which means big bucks. Low latency investors will pay a premium for this edge resulting in increased revenue for low-latency microwave network operators.
However, as with most financial functions, low latency is subject to a set of stringent regulations. The scenario is doubly difficult when low-latency microwave networks transmit across international boundaries. This compares to linking financial centers within a single country, which is relatively straightforward from a regulatory perspective because there is only one set of rules. The fact is when connecting financial centers in different nations and the operator’s network has to traverse other countries’ borders, the process becomes orders of magnitude more complex. Download the complete article for a fuller examination of some of these issues and why there should be widespread support for greater international harmonization of microwave regulation.
In the mobile operator space in many countries, the national regulators are imposing so-called “buildout requirements” as a license condition on many wireless providers. In some countries, these requirements are restricted to licenses awarded by the auction process (e.g., cellular access spectrum) or block allocations while in others these conditions are attached to the majority of licenses.
Where buildout requirements are employed, a license typically has a clause that requires the licensee to build out a network/link or specified portion of a network within a certain period of time, with penalties imposed for failure to do so.
The rationale behind imposing these requirements is to ensure that after spectrum is assigned it is put to its intended use without delay. By doing this, or so the theory goes, bidders are discouraged from acquiring spectrum with the sole intent of blocking competitors’ activities without themselves offering service. Of course, the ultimate goal is the protection of spectrum—a finite and precious resource. There is no reason buildout requirements cannot be attached to any license grant, assuming that the detail of the requirements recognizes any constraints of the application for which the spectrum is sought.
Nevertheless, Aviat Networks is strongly against auctions and block allocations, but where these are a necessity then buildout requirements must be part of any award, with strong enforcement rules. The problem is that with strong enforcement operators and regulators can be at loggerheads and get tied up in court with lawsuits and countersuits for years. For example, in the U.S. you have the case of Fibertower. The FCC claims that Fibertower deliberately underbuilt its network and so moved to revoke its spectrum licenses. With the regulator moving against the operator, it came under insurmountable financial pressure and filed for bankruptcy. But even now, the operator’s creditors are fighting the FCC in order to recoup frequencies valued at more than US$100 million. So it is questionable whether this actually works in practice.
Microwave is the point
Focusing on point-to-point microwave, let’s examine the approach taken in two different countries. In the United States, for traditional link-by-link allocation, the FCC imposes an 18-month deadline by which time the link in question needs to be in service. However, in the United Kingdom, Ofcom imposes no such deadline. For certain applications, certain routes and sites are critical and can quickly become “full.” If these key locations are being filled by license applications that are not being translated into operational services, then this spectrum is effectively wasted as no one else can use it, nor is there any service being offered. Spectrum wasted in this manner reduces overall spectrum efficiency, and all spectrum authorities are motivated to ensure that spectrum is used in the most efficient way possible.
Of course having these rules is fine, but what happens when the rules are breached? In some cases, an operator will apply for an extension prior to the expiration of the original deadline; this may or may not be granted. However, the real test is what happens when the deadline passes. Ideally, what should happen is that the license(s) in question would be revoked and the associated spectrum made available for reallocation. Furthermore, if the spectrum in question was originally made available by block allocation or auction, then again, ideally, this spectrum should be returned to the pool of spectrum available for link-by-link licensing.
Additionally in shared bands, i.e., spectrum shared by the Fixed Service (FS) and the Fixed Satellite Service (FSS) should be governed by the same requirements in this instance. Therefore, unused/defunct FSS allocations/licenses should also be revoked with the spectrum being made available for reuse. In the case of FSS locations, this can have a significant effect owing to the geographic full-arc protection area that is usually associated with earth stations.
The alternative viewpoint is that the current buildout requirements are counterproductive, in their aim to foster efficient use of spectrum. One reason cited for this view is that it takes time for an equipment supply ecosystem to develop, which will serve the spectrum users. However, when we examine this claim more carefully, it seems that this is often used where the spectrum has been awarded to a single user either by block allocation or by auction. We have written before about how auctions and block allocations are unsuitable for point-to-point microwave, and the claim above is a direct result of this process, which negatively impacts the number of operators. In turn, that reduces the ranks of equipment vendors, leading to thinner competition and, therefore, decreased incentive for innovation. This situation is made worse if the operator in question chooses a band plan that is nonstandard in terms of either existing U.S. or international arrangements.
In the final analysis, it does not serve any stakeholders’ goals to have valuable spectrum allocated but unutilized. Thus, having buildout requirements would appear to be a good idea. But along with that, an effective mechanism for reclaiming and making available to others spectrum that runs afoul of these rules is paramount to making the process work for the Greater Good. In Aviat’s view, buildout requirements are a valuable tool in ensuring spectrum efficiency and as such, their use should be seriously considered in all countries.