Monday, February 20, 2012

Why Is The US Strip Mining Radio Spectrum? Hear No RF Evil - See No RF Evil

Why Is The US Strip Mining Radio Spectrum? Hear No RF Evil - See No RF Evil

Link to Hear No RF Evil - See No RF Evil

Why Is The US Strip Mining Radio Spectrum?

Posted: 20 Feb 2012 12:39 PM PST

For many months, now stretching into years, the Curmudgeon has been searching for logical explanations to a bedrock fundamental question, the very one which underlies almost all of his recent blog postings:

Why is the United States (and, to a somewhat lesser extent, the rest of the First World) consuming, burning up, pillaging the finite amount of radiofrequency spectrum at a rapid, accelerating, and unsupportable rate?

Why are we (in this North American society) in effect "strip mining" this gift, this natural resource, primarily just for short term financial gain and/or transient pleasure?  What will we do after the entire available spectrum is consumed and the demand for still more spectrum continues unabated, after all the "administrative fixes" and other sleight-of-hand spectrum management tricks have been applied and still there is not enough?  When, as a result of ever increasing spectrum loading, ambient noise levels continue to rise and coverage areas continue to shrink?

 

 

What will we do when we find ourselves as a society and an economy trying to shovel six new pounds of puppy poop into our sole remaining one pound bag?

From much pondering and thinking about the problem a tentative "first cut" at a general explanation did finally emerge, and it is presented here for discussion, along with a proposed approach for a solution.

The Curmudgeon has used the following list of observations, all from his personal experience, as part of the work toward a first tentative answer.

1.  A young saleslady at an electronics store operated by a well-known nationwide chain cannot answer the question "can this TV set (which I am considering buying) receive over-the-air television broadcasting?," a medium of which she has no knowledge.

2.  A middle-level IT manager, needing to transfer one of his wire line digital networks onto a public wireless platform, cannot understand that wireless networks do not have the inherent transmission reliability of an Ethernet system, and that different wireless carriers have different service area coverage maps.

3.  Cellular telephone base station technicians have never heard of the equivalent private land mobile radio networks, and in any case have no interest in learning anything new beyond the details of their own field of employment.

4.  Employees in an IT department in a large corporation sit at their desks making cell phone calls (on company-funded commercial mobile carrier accounts) while their desk telephones are at easy arms' reach.

5.  Many, probably a majority, of Amateur radio operators have no idea at all what kinds of radio services co-share the spectrum, even one kilohertz outside the edges of their own ham bands.

6.  Computer owners reflexively install "wireless routers" in their homes and apartments and accept potential security problems and range-reduction from RF congestion, rather than to do a one-time installation of Ethernet cable.

7.  AM radio broadcasters complain about "excessive ambient radio noise" and reduction of their coverage contours in the urban areas that they serve, leading to increasing inability of their audience to receive usable service from the broadcasters.

In the Curmudgeon's judgment all of these situations largely, but certainly not uniquely, point toward a common source, one basic origin:

The citizens of the United State, in overwhelming numbers, do not understand at a conscious level that the radiofrequency spectrum exists as a physical medium, that it is a finite resource which they themselves own, and that it is in some respects a "fragile" structure requiring attention. 

 

Little Public Spectrum Education Is Offered in The US.

 

The average, even the well-educated, citizen of the United State is clueless about this.  Few know of the existence of electromagnetic fields, and even fewer are conversant with how the fields lay out and are used for practical needs.  No individual outside of the wireless industries could begin to place even a rough economic value on this unique natural resource, and in today's economy it is the "cost" of something which determines how it is treated.  "Free goods," which are not subject to "full-cost accounting" and thus whose prices do not include their real environmental costs, are almost always squandered, and today the use of the radiofrequency spectrum is, for consumers, a free good.  (Cellular telephone carriers and broadcasters, of course, have a radically different view of this!)

Is it therefore surprising that consumers are smitten by the idea of doing all their communications (in the general sense of the term) and their entertainment "wirelessly," and that many manufacturers of consumer goods look at no-cost use of the radiofrequency spectrum as a quick, cheap, and easy way to increase their sales?

What practical need does the public have for understanding the existence, limitations, and liabilities of the spectrum?  Why shouldn't they just continue to "flow their individual lives onto the spectrum" and never think twice about what they are doing?  For them, generally, there has always been "sufficient spectrum" into which to expand their needs and, to be accurate about this problem, most areas of the country and most radio services didn't begin to experience serious spectrum shortages until perhaps the beginning of the 1990s.  It's a fairly new problem, but one that is growing in seriousness and urgency.

The place to have once learned something about the spectrum is in the elementary and secondary schools, but elementary school teachers generally are not well-conversant and comfortable with science (and math) and in secondary schools only a tiny percentage of U.S. students (i.e., the "nerds") study physics.

Even in the small number of surviving high school physics classes, the curriculum unit on the EM spectrum flashes rapidly by, with just a mention that "radio lies between this frequency point and that point, while above it…….."  Even five minutes in a physics class spent discussing the basic structure of radio applications (transmission, wave propagation, and reception) and mentioning some of the services which occupy the spectrum would be a "great leap forward" in public understanding.

In engineering schools the EM spectrum often gets short-shrift.  ME, CE, BioE., and Comp.E students will get very little exposure to it, and even within the EE field "electromagnetics" isn't a high priority subject area when compared to DSP, digital circuit design, solid-state devices, etc.  Consequently many engineers themselves aren't able to discuss the topic knowledgeably with their non-engineering friends.

If the electromagnetic spectrum could at least be recognized by the general population as a publicly-owned natural resource that needs to be kept sustainable, there would be some basis for hope.  Proposals, for instance, to massively log and clear-cut Yellowstone National Park would almost certainly be met with strong opposition from a public that is knowledgeable about the damages that would result from this action.  They would raise considerations about long-term resource sustainability versus short term profit.  The same kind and degree of response should result from proposals to strip-mine the radiofrequency spectrum.

But there is precedent for public action on radiofrequency conservation from other independent efforts already occurring in a different part of the electromagnetic spectrum.  Terrestrial astronomers have had some success in dealing with "light pollution," created by the existence of indiscriminate outdoor illumination within large cities during the hours of darkness.  The increased city light fluxes, when scattered by atmospheric particles (thus producing, i.e., "noise" in our working vocabulary), diminish the astronomers' ability to receive very small numbers of photons from distant stars and galaxies.  So the astronomers have begun working with local governments to institute more efficient (and controlled) nighttime lighting and thus to lower their local background noise levels.  And they have had reasonable successes with their efforts.

If one technical field has shown the path, why cannot we, the (relatively low frequency) occupants of the same spectrum, follow their lead?

A tentative list of the goals for a program of going to the public with a campaign for education and spectrum cleansing would include:

1.  Bringing to general public awareness the existence, function, ownership, uses, and need for sustainability of the radiofrequency spectrum.

2.  Making the public aware of the economic value of the spectrum as a limited natural resource.

3.  In view of the natural scarcity of spectrum, leading a new public discussion of a prioritization of uses for the spectrum.

4.  Sponsoring a campaign for reclamation, abatement, and clean-up of human-caused radio noise pollution, including non-radio electrical noise generators.  This would include pressing for both "efficiency" in individual applications (i.e., the "most bang per input watt" and the least perturbation of the general radio noise level for each proposed RF application).  This is in line with other conservation campaigns, both for increased energy efficiency and for reduction of pollution from various kinds of sources.

 

The IEEE Has resources to Lead Spectrum Education

 

Finally, there is the question as to who should be the "point man" to conduct the campaign.

The Curmudgeon has an initial recommendation.  It should be the IEEE, the largest professional organization which deals with "matters electrique."  They have both the stature and the experience to conduct this campaign, which might well begin with increasing their own members' understanding of the spectrum.  The IEEE has already published some articles dealing with radiofrequency spectrum matters in their general interest engineering magazine Spectrum and thus has an existing understanding of the problems.

The very notion that the citizens of the United State could actually understand this matter of great natural and economic importance and could participate in gaining effective control of the existing problems is astounding!  But the Curmudgeon has faith that it could be done.  Wouldn't this be a fine time to get it started?

What do you think?

"Let's save the universe for RF!"

The Old RF Curmudgeon
(A conservative conservationist)

Since 1963, LBA has been providing RF equipment and engineering consulting services for radio and television broadcast and wireless communications.

 

How to Get a Hydrogen Fix for Cell Site Utility Bills

Posted: 20 Feb 2012 07:45 AM PST

Using hydrogen fuel cells as backup power units for telecommunication sites, particularly remote ones, is a common practice. More fully incorporating the units into a provider's overall managed power strategy makes economic sense, too. A WCAI-members only webinar—"Smart Energy Solutions Using Fuel Cells"—will explore the option Thursday, Feb. 23.

Chris Horne, the chief technical officer of LBA Group Inc., will host and moderate the webinar's Q&A period following a presentation by Joe Blanchard, chief operating officer of Spokane, Wash.-based ReliOn. The company is a global leader in development of modular, fault-tolerant, proton exchange membrane fuel cell technology.

 

ReliOn fuel cell for remote site power

 

An estimated 1,300 fuel cell systems are situated at cellular and telecommunication sites in North America as backup units during periods of interrupted power service. The hydrogen fuel cells have several advantages over the more traditional diesel power units, including being quieter, longer-lasting, and more easily and less frequently fueled.

Integrating the units into a wireless provider's energy management plan can have significant bottom line consequences. Utility rates can be reduced and credits earned for a company that has reduced its peak power demand. The webinar will offer examples of how to optimize energy usage.

Blanchard joined ReliOn in 2005, coming there after 18 years in management at Texas-based Fujitsu Network Communications, an innovator in connection-oriented Ethernet and optical transport technologies. In all, Blanchard has been working for more than a quarter century in design, development and support of products spanning DLC/DSLAMs and FTTx systems, telecom cabinets and power systems, optical transport, DWDM systems, Class 5 switching and PBX systems.

Horne is a professional registered engineer with a doctorate in electrical engineering. He is a board member of WCAI, the trade organization for the wireless broadband industry with a mission of advancing opportunities for the industry. The organization's several hundred members include such heavyweights as AT&T, Sprint and Clearwire.

The hour-long WCAI webinar begins at 4 p.m. eastern standard time.  Member sign-up details here.

Since 1963, LBA has been providing RF equipment and engineering consulting services for radio and television broadcast and wireless communications.

Thursday, February 9, 2012

LBA’s Chris Horne Moderates 4GWE Panel on Spectrum Issues Hear No RF Evil - See No RF Evil

LBA’s Chris Horne Moderates 4GWE Panel on Spectrum Issues Hear No RF Evil - See No RF Evil

Link to Hear No RF Evil - See No RF Evil

LBA’s Chris Horne Moderates 4GWE Panel on Spectrum Issues

Posted: 09 Feb 2012 07:13 AM PST

Chris Horne, chief technical officer of LBA Group, moderated an expert panel discussion earlier this month on the conundrum of squeezing more serviceable networking capacity from finite, congested spectrum. The discussion occurred at the 4G Wireless Evolution conference Feb. 1-3 in the Miami Convention Center.

Members of the three-person panel were Thomas Knippen, who is vice president and general manager at Benton Ridge Telephone Company and W.A.T.C.H. TV; Greg Williams, senior VP for corporate and business development at BelAir Networks; and Jeff Kohler, co-founder of JAB Wireless, Inc. and responsible for merger, acquisition and corporate development activities.

A technical examination of licensed and unlicensed spectrum was carried out before an audience of about 40 wireless operators, venture capitalists and technologists. The panelists weighed in on two corollary questions: how can wireless congestion be mitigated, and is the better answer in parsing available spectrum or creating new technology?

Their conclusion: a combination of technology and spectrum management is necessary.

"There was a consensus that unlicensed spectrum is here to stay," Horne says. "Both WiFi hotspots and small and large companies who deploy unlicensed networks will be a part of planning to improve the wireless experience."

One panelist observed that for a company to utilize "WiFi" does not always mean deploying it. Rather, a company might use unlicensed frequency bands for distributing and backhauling traffic for experimental work or partner with carriers to offload cell traffic.

The industry fully recognizes that wireless network congestion is a genuine problem to be addressed by development of new equipment and technology. To get by at the moment, AT&T is using carrier WiFi to offload traffic in the unlicensed spectrum. Heterogeneous Networks—HetNets—have a crucial role in enhancing capacity. Some fixed wireless operators are partnering with mobile wireless carriers to offer complementary off-loading and backhauling of internet traffic.

All internet service providers are reeling from the data explosion. Consequently, unlicensed ISPs and licensed ones are eying one another to meet their disparate needs. The time may be ripe for partnerships.

Management of the radio spectrum was viewed by panelists as two forces at play: regulation of spectrum versus the "market." It was noted that cloud services like Apple iCloud and Google music require even more bandwidth and high throughput. That led to the suggestion that a combination of regulated "white spaces" and unlicensed offload might be the best way to mitigate the capacity issue

Panelists also weighed in on the use and practicality of TV white spaces in rural areas where unlicensed space is not congested. Rural areas have better propagation conditions, one panelist noted, but the technology right now does not have any special performance incentives. Panelists talked of the various tradeoffs involved and concluded TV white spaces are an option but not a preeminent one.

Some current WiFi developments were touched on by the panel. It was noted that chip maker Broadcom announced plans for "gigabit WiFi" device, two and three times faster for the 5 GHz band. Unconfirmed reports surfaced about mobile equipment and services supplier Ericsson purchasing BelAir Networks, which provides strand-mounted picocell devices for the unlicensed bands for carrier offload. The Japanese operator KDDI claimed that its new free WiFi network with Android smartphones reaches 10,000 locations and will scale to 100,000 locations by March.

A specialist in wireless system engineering, Horne is a veteran of such discussions as this one. He was a panelist last fall at a 4G World conference in Chicago where splitting and rebranding spectrum was dissected for conference attendees.  Horne is leading another conference presentation in April at a Minnesota State Wireless Association event entitled "The Future of Wireless."

Panelists (from left) were Chris Horne, Tom Knippen, Greg Williams, and Jeff Kohler

Wednesday, February 1, 2012

Microwave Path Study Sells Tower Approval Hear No RF Evil - See No RF Evil

Microwave Path Study Sells Tower Approval Hear No RF Evil - See No RF Evil

Link to Hear No RF Evil - See No RF Evil

Microwave Path Study Sells Tower Approval

Posted: 01 Feb 2012 08:55 AM PST

(What’s all this Fresnel Zone Stuff, Anyway?)

As wireless cell towers and antennas flourish, towns, cites and municipalities are challenged to adopt ordinances that let citizens receive the best telecommunications services available. Regulatory legislation hasn't helped. The Telecommunications Act of 1996 was over 500 pages long; during debate, most legislators considered it to only be about deregulation. But buried inside the Act, in Section 704, lay a crafty clause about the siting of cell-phone towers that trips up planning and zoning groups.

For this and other reasons, zoning boards are challenged to approve high-quality wireless services. It doesn't help when they don't understand microwave propagation.

An appreciation of microwave propagation comes into play when carriers and network operators are faced with securing wireless transmission media (often a microwave link "backhaul") that relay the wireless traffic to the landline network or between towers. As more educational institutions offer additional classrooms in distance education and remote video conferencing, their needs also increase for wireless systems and backhaul.

 

Collocation Tower with Cellular and Backhaul Antennas

 

As a case in point, a town in Illinois accepted an application from SBA Towers to replace an aging tower on a college campus with a taller monopole structure to allow better backhaul of college networks and to support more wireless tenants. The existing short tower was structurally limited but was situated in adequate campus space to meet setback and other pertinent city requirements. The application was presented to the town by wireless zoning attorney Richard Connor Riley, supported by expert testimony from LBA's Chris Horne. Chris' work included a microwave path study of the existing and proposed college backhaul link.

This is where it gets interesting.

The study was performed for a proposed new digital transmission system serving four video conference classrooms and also transporting all internet traffic between the college and a remote teaching facility. The included digital microwave link would be a backup to an existing fiber network between the two campuses.

Controversy arose centered on a proposed antenna dish that was needed to support the data requirements of four video conference classrooms. It would replace an existing microwave dish that served only one classroom and was an outmoded analog link with limited performance and capacity compared to the proposed digital replacement.

When LBA evaluated the microwave installation, it confirmed that greater height was needed for the new dish to support the required performance of the system. It had not been obvious to zoning authorities that such an increase was necessary; the devil was in an "invisible" gremlin!

A close evaluation of the microwave path between the campus and a far terminal revealed that a tall hotel building under construction several miles away was rising exactly in the path of the beam. At its final height, the building would penetrate the microwave Fresnel zone and block the microwave signal. Based upon LBA's engineering evaluation, the town zoning board was persuaded to approve the SBA tower application, and clear the way for the higher microwave dish. The university learning network was saved!

So – just what is this mysterious microwave path Fresnel zone?

In order for radio waves emitted from a transmitting antenna to reach a receiver without attenuation of power, a certain amount of 3-dimensional space is required. The radio wave energy cannot reach the receiver via one straight line in space. Think of a hole the size of a needle in a concrete wall. If you shout across a pond to the wall, do you think all the sound penetrates only the hole?

The Fresnel zone or First Fresnel zone (0.6) is a three-dimensional elliptical space surrounding the line of sight path from the transmitter to the receiver. If a reflective object is placed anywhere on the edge of the ellipse, it will cause a reflected signal that, due to propagation delay, is delayed 180 degrees ("carrier phase shift") with the line of sight signal at the receiving antenna. Digital radio equipment is typically robust in the presence of propagation fades and other noise. However, if there is an obstruction between the antennas (ground, buildings, natural objects, etc.), the radio waves will be reflected, resulting in multipath interference and unacceptable bit error rates–think old TV "snowy pictures.

 

Depiction of a Fresnel Zone in urban environment

 

A 0.6 Fresnel zone clearance is normally desired for microwave paths. While "line of sight" (LOS) is important, it obviously is not always adequate. Even though the path may have clear LOS, when obstructions penetrate the Fresnel zone, unwanted signal attenuation results.

This is precisely what happened in this case; a building encroached upon the 0.6 Fresnel zone of the proposed college microwave link. Such obstacles can wreak havoc on wireless backhaul including transmission errors and signal reception issues.

The take away here is that next time you plan a microwave backhaul link, be sure to consider the Fresnel zone, LOS obstructions, and other antenna placement factors. Consider every detail of the traversed terrain, including vegetation, existing, and planned construction. A detailed path study will provide valuable input results for an efficient tower placement scheme that meets both coverage and transmission quality metrics. A not unimportant byproduct is that it also provides the basis for a credible defense of a tower proposal in an increasingly contentious zoning environment.

LBA can help with all of the above. LBA also offers RF Engineering services including expert testimony and system design. We offer extensive zoning technical support here. Other capabilities include microwave system design, path study, and RF engineering services here.

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