Public Safety Advocate: Spectrum, Licensed and Unlicensed, Who Wins, Who Loses

Article after article has been written to make a case that broadband in the United States should be available to all regardless of where they are located or their ability to pay for the service. While “broadband for all” has been a goal for the wireless/fixed communications industry a long time now, progress has been slow.

Now Congress has allocated $65B toward closing the “digital divide” and the FCC and others continue to fund various aspects of deploying broadband systems. If I were to grade the United States on two properties of broadband deployments, I would give us an “A” for the number of broadband technology options for fixed and wireless communications deployments and a “D” for actually extending broadband to rural America and to those who cannot afford it.

There are many models for how broadband can be extended and, at the same time, deployment and operational costs can be reduced. However, it appears as though the federal government plans to turn all available funds over to the states. States would then be responsible for management of their spectrum, coming up with their own plans, and hiring contractor(s) to build out their rural areas. 

I am afraid vendors have already convinced states to use fiber. If they do, far too much fiber will be buried in the ground at great expense. Today, each mile of buried fiber costs between $20,000 per mile up to about $27,000 per mile. Fiber can also be run above ground, usually lashed to existing telco or TV cables already on the poles. The average cost of lashing fiber to existing wiring runs about $3.80 per foot, which means lashing costs about $20,000 per mile. This might make sense in populated areas where a single fiber run can connect many houses and businesses and where there is also wireless broadband. Running fiber to one farm ten miles outside a community makes no economic sense and it does not provide farmers with what they really want: broadband in their fields. 

There are, of course, ways to use farmhouses as hubs and then wireless to extend broadband to the farmers’ fields. However, that cost would be on the farmer and not part of any funding distribution grant. 

There are already a number of wireless providers covering portions of rural America, so one option is for a state to partner with one or more of the wireless broadband providers and possibly design a system that will extend the wireless broadband footprint and use fiber where makes the most sense.

The reason there is a digital divide in the first place is that while telephone companies were required by law to provide phone service, there is no such mandate for data services associated with available or even new sources of broadband. Before funds of this magnitude were available from the federal government and some states, rural areas were ignored. Building out broadband for a small number of people even in a community does not make financial sense when the typical cost of a cell site is $250,000 and there has to be a connection to either fiber, microwave, or perhaps satellite backhaul. 

Today there are many more technologies to choose from and anyone residing in a rural community has a choice of technologies and a range of cost per square mile.

Rural Broadband

If I were in a position to mandate broadband where there none today, I would make sure any fiber-only (to the premise) deployment would include working with existing wireless broadband providers.

I would also strongly suggest that each state have a deployment plan and, where possible, has engaged with at least one non-broadband company that is already serving the area. Ideally, these partners would already be part of the community, have trucks and people already in the community, and, if at all possible, need broadband for their own use and/or to sell to their existing customer base. 

For example, states can partner with existing wireless broadband providers. Sometimes theses network operators are difficult to work with but partnerships can and do develop with time. The list would include the top three wireless broadband networks (FirstNet/AT&T, Verizon, T-Mobile) plus all of the members of the Competitive Carriers Association (CCA) and other carriers serving rural areas. 

Other choices would include co-op power companies. These are non-profit companies that already provide power to rural customers in forty-nine states. They have rights of way access, they need broadband for their own power grid control, and they have a built-in customer base. Additional potential partners include colleges and universities, schools, libraries, medical facilities, and many more. 

With all these potential partners out there, it is difficult to understand why more states are not taking advantage of them. Of course, the most obvious partner would be FirstNet (Built with AT&T). The reason I suggest FirstNet as a perfect rural broadband deployment partner is that FirstNet is required to build out a sizable amount of rural America as part of its contract with the FirstNet Authority and as specified by Congress.

Changing Gears (or perhaps wireless devices)

As those charged with solving digital divide issues are working on solutions, people who live in suburbia and metro America will become overrun with broadband choices. 

Using Phoenix as an example, until about a year ago, we had two terrestrial broadband choices: our telephone company and our cable provider. We also have the usual big-three wireless providers and Mobile Virtual Network Operators (MVNOs). However, for the most part, neither businesses nor residential customers use the current wireless LTE broadband providers since they already have access to wireless broadband almost everywhere they travel within their area and across the United States. 

In the past year, however, we have been told to expect fiber to the home from at least one provider, 5G millimeter wave designed to replace your existing Internet provider from at least two of the big three, and I am sure others will follow—and don’t forget about the thousands of Low Earth Orbiting satellites (LEOs) being put into orbit. Now it seems that, according to a new set of ads running on TV, we are entering an era of 5G for data speeds. According to one ad, Wi-Fi “will be coming to a telephone pole near you!” 

Yes, some Internet providers are regressing back to the last decade when muni-Wi-Fi was the solution that would be deployed by cities and counties to provide free Wi-Fi both outdoors and indoors. All one needs to do to be reminded of that era in Phoenix is to look up at the many streetlight poles where Metricom’s very early Wi-Fi transmitters remain. Metricom explained that these systems started out using pre-Wi-Fi in the 900-MHz unlicensed band. True Wi-Fi was later added to its systems. In its heyday, many muni-Wi-Fi systems were built by many Wi-Fi vendors and cities. Only a handful have survived and none provide the type of broadband coverage that is needed today. 

As I started looking at this “new and improved” Wi-Fi I had some questions. For example, what is Wi-Fi 6 or 6E? What is Wi-Fi 7? Can my home or business Wi-Fi take advantage of these new technologies and if not, why? Before we go further into Wi-Fi, I am sure you have noticed that the press is full of “XYZ broke this speed barrier using Technology A” while another beat a record using “Technology B.” None of this matters. Tests in labs and even real-world tests before a network goes commercial are meaningless for users, so be wary of speed and capacity claims as you shop for wired and wireless products.

Wi-Fi

Most technologies have or had a driving force behind them. In this case, it is the Wi-Fi Alliance. Chart 1 below, its new chart for Wi-Fi versions, implies that all of us who are using earlier versions of Wi-Fi are way out of date.

Chart 1, Wi-Fi Generations, courtesy of the Wi-Fi Alliance

Keeping my previous comments in mind, you will see “official” peak data speeds in the next graph. According to this website, which is a good source of information, today’s average home Wi-Fi typically provides speeds of about 45 Mbps. 

Chart 2 below, is courtesy of Minnim, and its website, as well as the Wi-Fi Alliance website, which are great sources for additional Wi-Fi information.

Chart 2, Standard Wi-Fi throughput speeds, courtesy of Minim

The bottom line for Wi-Fi is that there are new versions that will run on new portions of the radio spectrum so most of us will have to update our Wi-Fi devices in the office, at home and also our mobile devices if we want to take advantage of the new speeds being promised. 

We are all accustomed to Wi-Fi in the 2.4-GHz band (along with Bluetooth and microwave ovens) and the 5.8-GHz band where everyone fled as 2.4 GHz became overcrowded. Remember that Wi-Fi operates on licensed spectrum or, as the FCC recently decided, underneath already-licensed users of the allotted portion of the spectrum. 

Most of today’s Wi-Fi access points and routers work on both 2.4- and 5-GHz Wi-Fi bands but it is not yet clear if new routers and access points will include all of the Wi-Fi bands. I recently saw a Samsung phone that included 6-GHz Wi-Fi. But a word of caution here. The FCC says Wi-Fi 6, or rather 6E, will be permitted to run underneath existing 6-GHz licensed microwave users. The Wi-Fi community is thrilled, but the licensed microwave users, not so much. So far, in a number of tests, Wi-Fi 6, which the FCC claims will not interfere with licensed users, have proven otherwise in a number of field tests. 

Unlicensed means you have no recourse if your system or devices are interfered with, and if your system causes interference to licensed users there is currently no real way for a licensed operator to be able to find an interfering Wi-Fi system. Even if the interfering Wi-Fi device is found, there is no legal right to have the device turned off. Only the FCC has that power and that means one of a very few field engineers has to find and then fix the interference problem. Good luck with that since the FCC’s field force has been gutted over the past few years.

Chart 3, shows how Wi-Fi will fit into which portions of the spectrum

This chart is fairly up to date but subject to change if new bands are made available. Since there is a limited amount of spectrum available for the many different types of communications systems, my question has to be if John Q. Public (including myself) really needs to have this much unlicensed spectrum when critical-communications services including public safety, utilities, and others, are often unable to gain access to additional spectrum. 

Public Safety Spectrum

Today, almost all of the radio spectrum being used for Land Mobile Radio (LMR) communications (narrow band, primarily voice) is in lower portions of the radio spectrum that are not conducive to broadband services and, therefore, not appropriate for unlicensed use. Still, we must be aware of the direction being taken by some who believe LMR should be eliminated and broadband is and will be the only answer going forward. 

One of the most significant advantages to FirstNet is that even though much of the public-safety broadband traffic is running over AT&T’s commercial LTE/5G spectrum, the 20 MHz of 700-MHz spectrum licensed to the FirstNet Authority and used by FirstNet (Built with AT&T) seems to be secure so far. However, the FCC is still considering how to handle the 50 MHz of 4.9-GHz spectrum. From 2002 until last year, this spectrum was designated for public-safety use until it was taken back by the previous FCC. Now it appears this spectrum will be returned to public safety. We need to make sure that when it comes to spectrum sharing on this band, only licensed, identifiable users are permitted to share the spectrum, on a secondary basis, with public safety, which needs to have full priority and pre-emption just as it does on FirstNet.

Spectrum issues are complex because different technologies can cause different types of interference that are difficult to find and eliminate, especially when unlicensed users are sharing spectrum with licensed users. 

Increased noise on any portion of spectrum can wreak havoc with those trying to use that particular spectrum. In some cases, this could have an impact on first responders who are having to contend with radio interference while they are heading for an incident, which is a complication they certainly don’t need.

Over the past few years, we have seen how inference can create issues for licensed users. The case of Nextel interfering with public safety in the 800-MHz band comes to mind. The number of interference issues have been increasing and it is expected that this will continue to cause problems. Thus, we all need to be aware of what causes interference and how it can be mitigated. 

When people ask me about receiver sensitivity, which describes a receiver’s ability to hear an incoming signal clearly, I tell them receiver sensitivity can be compared to a grain of sand. A single grain between two of your fingers does not feel like much. However, if you put that same grain of sand in your eye, it feels like a boulder because the eye is more sensitive than fingers. If the eye is already seeing “noise,” it may not be able see clearly beyond the boulder (interference).  

Radio spectrum and who is permitted to use it will become more and more difficult to manage as demands for more speed and more capacity become the norm. Perhaps it is time to restrict the radio highway. In this example, traffic stays in its own lane between the lines AND there are speed limits. Perhaps it is time to consider imposing speed limits on some types of radio communications to make room for more radio traffic while engineers search for ways to free up more spectrum and/or use it more efficiently.  Spectrum is a finite resource and there is still only so much available to us. The challenge that remains is how to ensure spectrum is available to those who need it, when it is needed.

Want to hear what our spectrum could be like if we don’t pay attention? Go to your garage, dust off your old CB radio, and listen to the CB band. Years ago, the FCC required a license to operate on the CB band and power was limited to 5 watts. Then the FCC simply walked away from the band and now it is full of noise and 500-watt or more power transmitters. Today, the CB band is basically useless. 

Winding Down

Radio spectrum is a precious resource that must be carefully managed to prevent networks from clashing with each other or mobile units. In this case, mobile units will not be able to communicate with each other or even their dispatch center. 

The by-products of over-population of a segment of spectrum can be observed with 2.4-GHz Wi-Fi, which is losing both distance signals can travel and the amount of data that can be sent. This is primarily due to overcrowding of the band. As the number of devices on a band at one time increases, the “noise” level increases accordingly and noise is the arch enemy of radio systems. Interference can also be generated in different bands using different technologies and “spill over” to other spectrum.

A Mission-Critical Network?

The goal of everyone who builds networks is to make a mission-critical network, which means it stays up and usable 99.999-percent of the time. However, we know from many years of experience that 5-9s reliability is not actually achievable. 

Some providers understand that. For example, our local cable vendor states that its network is 90.9-percent reliable, leaving it to the public to figure out what that really means.

Land Mobile Radio systems, FirstNet, and other networks are being upgraded to provide more reliable service. However, instead of “Mission-Critical” reliability they are striving for “public-safety grade,” which is more appropriate and achievable. If they end up building a network that meets or exceeds the published standards for public-safety grade, as opposed to “best effort,” your engineers and others might celebrate. This achievement would truly be something to cheer about. 

Unfortunately, the day after you declared your network to be public-safety grade, out of the blue you begin experiencing interference that is affecting your network and your customers or users. 

You did everything correctly and built the best network you possibly could. Then an outside source of interference was turned on and your network no longer worked as it should in some areas. 

There are many examples of the effects of interference with CB, W-Fi, and fairly recently, near the U.S./Mexican border. The U.S. network had been performing well for a long time when a company on the other side of the border turned on its network and created a high level of interference to both networks. That was resolved between the two countries, but it can happen between states, cities, counties, and basically anywhere a new user is licensed or where unlicensed radio spectrum becomes available. 

Even a secure, closed network is susceptible to interference. 

All of the above are reasons I believe in both FirstNet and Land Mobile Radio systems not only co-existing, but being interoperable at least for voice. 

Until next week…

Andrew M. Seybold
©2022, Andrew Seybold, Inc.

print

Be the first to comment on "Public Safety Advocate: Spectrum, Licensed and Unlicensed, Who Wins, Who Loses"

Leave a comment

Your email address will not be published.


*