I have been commenting about the FCC chairman seeming to feel many segments of our spectrum resources need to be opened up for access to yet more WiFi services. Perhaps there is a need for more WiFi, but to the detriment of the many existing services? This Advocate was prompted by the announcement that FCC Commissioners plan to vote on April 23, 2020, to open up the 6-GHz band of spectrum, which is heavily used by thousands of critical microwave point-to-point systems in use by state and local governments, many industries including water, gas, and electric utilities, and a huge number of critical public-safety microwave links.
It appears from conversations with others that the chairman was criticized for holding too many auctions too close together so now he has done a one-eighty and appears to be trying to share any possible spectrum with WiFi systems. In the meantime, you may have noticed there are still a number of significant spectrum issues on hold. Seemingly, when the FCC cannot decide how to handle an issue, it simply “freezes” the spectrum in question so no one can make changes to what it is being used for and more users are blocked from access to the spectrum.
Back to 6 GHz. The chairman wants the commissioners to approve opening all 1200 MHz of the 6-GHz spectrum to WiFi, specifically WiFi 6, the newer, higher-speed WiFi. Many comments opposing this move have been filed by 6-GHz users over the course of this debate, and during our recent Government Wireless Technology and Communications Association (GWTCA) board meeting, the issue of interference to critical microwave links in this band was raised. With mixed licensed and unlicensed use, licensed microwave users will have a difficult time identifying sources of interference and the equipment owners. When one licensed user interferes with another licensed user, it is fairly easy to determine who is responsible for the interference and to work with them to resolve the issue. Not so with unlicensed use.
When it comes to unlicensed WiFi, computer analyses will be used to assign a portion of 6-GHz spectrum to a specific WiFi system. This technique is not foolproof, as we have seen with TV white space assigned by a clearinghouse. Further, if there is interference once the clearinghouse has approved spectrum for a specific use, who will be held accountable, the clearinghouse or the user? If it is the user, how will users identify the offending equipment so it can be taken off the air or the interference can be mitigated in some other way, and who pays for the detective work?
Now it appears this situation might become worse since Verizon, it is reported, is in talks with the FCC to license a portion of the 6-GHz band for 5G mid-band services. The microwave systems currently in this spectrum are, in reality, part of the critical public-safety infrastructure and as such they should be protected with 100% assurance they will remain interference-free. Since the FCC has an agreement to share spectrum with the National Telecommunications Information Association (NTIA, the agency that controls federal spectrum) I question why the FCC has not targeted the 7-GHz spectrum used by federal government agencies. Are state and local systems including public safety and major utility companies not as important as the federal systems occupying the 7-GHz band? If the FCC is so sure 6-GHz band sharing will do no harm to existing and licensed users, it should feel the same about the 7-GHz spectrum assets controlled by the NTIA.
If the FCC approves use of the 6-GHz band for WiFi 6, in order to reach the 2-Gbps speeds promised by WiFi 6, the bandwidth for each channel will have to be much greater than standard WiFi bandwidths in the 2.4- and 5-GHz WiFi bands. This, in itself, could create inference with point-to-point microwave systems. The FCC’s plan appears to be to allocate 850 MHz for “standard-power” WiFi and indoor “low-power” WiFi 6 over the entire 1200 MHz unless Verizon can convince the commissioners to carve out some of this spectrum for licensed use. While this might not be a good idea, if users are licensed it will be easier to identify offending sources of interference. If the 6-GHz band remains all WiFi 6, it will probably be managed by an Automated Frequency Coordination (AFC) system which, we are told, would prevent standard-power access points from operating where they could cause interference to incumbent (microwave) services.
How can licensed users who experience interference issues access the AFC and identify offending units? Since this is an automated system, how long does anyone think it will be before hackers find a way to use the spectrum without paying the AFC system? I don’t think the FCC chairman has a firm understanding of the implications of plunking down unlicensed users on top of critical infrastructure. I believe he will live to regret this and at the end of his term he will walk out the door never to return, leaving the critical communications users to address the problems he left behind.
What Comes after 6 GHz?
The answer appears to be 5.9-GHz spectrum. This time, at least thirty-eight members of the House Committee on Transportation and Infrastructure are complaining to the FCC about its desire to allocate more than half of the 5.9-GHz band for guess what? Unlicensed WiFi. Since 1999, this spectrum has been allocated for Dedicated Short-Range Communications (DSRC) systems for transportation. Those promoting the idea of converting half of this spectrum to WiFi include Google, Microsoft, Boingo, Wireless Internet Service Providers (WISPA), Comcast, and Public Knowledge, all of which claim the band is lightly used and the lower 45 MHz of the band is already allocated for unlicensed use. After the proposed allocation, only 20 MHz would be left for Cellular Vehicle to Everything (C-V2X) and 10 MHz for existing DSRC systems. Not only are members of Congress upset with this plan, the FCC is also at odds with the U.S. Department of Transportation. During a discussion of this issue, a public-safety professional who also understands DSRC commented that limiting the amount of spectrum available to DSRC is like trying to operate a P25-trunked radio system with a control channel but no channels for moving traffic off the control channel.
To be clear, when 5.9-GHz spectrum was allocated for DSRC use in 1999, it took a long time to harness the technologies to create the service. Today, many roadway intersections in the United States are equipped with this technology and many more are in the planning stages. However, as mentioned above, when the FCC is undecided about what to do with spectrum it “freezes” it, in this case essentially stopping all DSRC deployments until it makes a decision. If the 6-GHZ band is, indeed, opened up and 1200 MHz of spectrum becomes available for WiFi 6, why would the FCC want a paltry additional 45 MHz of spectrum? Exactly how much spectrum does the FCC want to allocate to WiFi 6, which is a low-power broadband technology designed for local use, both indoor and, unfortunately, outdoor. Like 2.4-GHz and 5-GHz WiFi, WiFi 6 is reusable over a short distance from an access point, so why does the FCC need 1200 MHz of already-encumbered spectrum? It does not make any sense to keep cobbling up our spectrum without regard for current and future needs of existing users.
Which Brings Me to 4.9 GHz
At least 50 MHz of the 4.9-GHz spectrum was originally allocated to public safety in 2002. Now the FCC says it is too lightly used and therefore it needs to be reallocated. The FCC’s sixth notice of proposed rulemaking includes the following statements about usage of this spectrum:
“The Commission has allocated and designated 50 megahertz of spectrum in the 4.9 GHz band (4940-4990 MHz) to public safety. Although nearly 90,000 public safety entities are eligible under our rules to obtain licenses in the band, there were only 2,442 licenses in use in 2012 and only 3,174 licenses in use nearly six years later in 2018. With no more than 3.5% of potential licensees using the band, we remain concerned that, as the Commission stated in 2012, the band has “fallen short of its potential.”
This statement is erroneous for a very simple reason. When the band was first made available, licensing was by geographic area. Typically, licensing has been based on the number of devices in use. The rules were later amended to require point-to-point systems to be licensed separately. Today there are many devices and users for temporary and fixed use that do not show up in the FCC’s data simply because they are licensed by areas, not systems or number of devices.
Next, the 4.9-GHz band, like the 5.9-MHz band, was slow to be populated because the technology had not caught up with the band’s capabilities. Further, it was allocated to public safety long before FirstNet was created. I believe that since FirstNet became available, the number of public-safety users that want and need access to this spectrum has increased dramatically. For the past year or more I have been working with agencies that need fixed HD camera surveillance for a specific event, a short period of time, or sometimes for longer periods of time.
Many of these agencies had tried using commercial broadband companies for this purpose, only to find that after a while they were being throttled by LTE providers. Cellular broadband systems were not designed to handle fixed HD cameras with data rates of 5 Mbps or more. Cellular systems are based on the premise that, for the most part, devices and people move in and out of one cell or cell sector into another. A lot of math goes into handling this traffic, and each cell is designed to have headroom to accommodate users entering the cell. Without this headroom, the call or data session would drop.
Adding stationary cameras to a cell sector means that while that these cameras are sending a continuous data stream, that cell sector cannot handle as much mobile traffic as it normally would. The solution for many departments is to move their camera activities to 4.9 GHz. While there is a mis-understanding that distances between fixed devices are rather limited at 4.9GHz, I can say from experience that in Santa Barbara, Calif. where we were using 4.9 GHz for links to a VHF simulcast system, we were able to achieve solid, point-to-point distances of more than twenty to thirty miles in some cases.
Point-to-point links are needed but these links should not be on FirstNet or other cellular networks. Now, more than ever, there is a need to replace T-1 copper lines, which are either no longer available or will not be available much longer. Many of these connections need to be replaced with wireless connections and 4.9 GHz is ideal for these T-1 replacements. FirstNet has not yet taken advantage of 4.9 GHz, but in addition to communicating with FirstNet, today’s vehicular routers can also establish a WiFi bubble around a vehicle for use by those in range. As the demand for FirstNet grows and the need for short-range communications at a scene increases, I can see a use case for 4.9-GHz spectrum in lieu of commercial WiFi.
This FCC is not looking toward the future, it is only looking at the past when it comes to 4.9 GHz and other spectrum. How are we to keep up with the increasing need for public safety and other critical communications when the FCC seems to be hell-bent on converting what we have to unlicensed WiFi to appease big business that wants to sell more access points and other devices? I always thought one of the FCC’s jobs was to plan for future growth, not only for unlicensed users but for all users including those with critical communications needs.
Speaking of other spectrum, the FCC freeze on T-Band spectrum is preventing growth for public-safety T-Band users. One bright spot here is that Chairman Pai has publicly stated he is in favor of allowing public safety to remain on the T-Band, but he says it is up to Congress to act and he is correct. Having said that, the FCC is authorizing new TV stations (mostly low power) during the TV repacking, and some are causing interference to public-safety systems in Los Angeles and other T-Band cities. When the T-Band repeal bill is passed, this interference could continue to be an issue and it needs to be addressed now rather than later.
Other freezes were placed on some 800-MHz spectrum after the Nextel/Sprint rebanding, and on some Land Mobile Radio (LMR) spectrum in the 900-MHz band. It appears that the FCC is finally moving to “unfreeze” the 900-MHz band, but we are still awaiting action on the 800-MHz band, which is needed by the public-safety community.
One way to look at the FCC chairman’s role is that he is a father bird, flying back to a nest full of babies, trying to make sure each one has something to eat. At least that is the way I would like to believe the FCC works. Instead, this FCC seems to listen to those who speak loudest or have the most powerful lobbyists and act without the stringent technical assessments that played a vital role in FCC actions in the past. Juggling in an effort to please everyone is a thankless job. In this case, the business world that wants more spectrum so it can sell more widgets is receiving most of the attention to the detriment of critical communications. This is not what I would expect from a federal agency charged with protecting a rare and precious resource. Spectrum is critical to the performance of our public-safety agencies and other users for their own critical communications needs.
Public-Safety Agencies Plan Ahead
San Bernardino County is a huge county on the California-Arizona border and in total there are eighteen local fire departments including the County Fire Department. During wildfire threats, these departments band together to form a regional management team to ensure a unified response. Another regional management team has been formed so all eighteen departments can cooperate with the San Bernardino County Fire District incident management team. According to the Sunnewspaper, the team was formed on March 6 “to manage exposed and/or sick members of its agency, to ensure responders have necessary personal protective equipment, and to maintain consistent communication with its cooperators.”
Those agencies “are now united to ensure consistent service regardless of jurisdiction. As the virus establishes itself within our county, citizens may see fire apparatus from other departments responding in their communities and even firefighters from different agencies on the same engine company,” the association said.” This is looking ahead to ensure the safety of the county’s citizens as well as the first-responder community.
The next example came from a really good article in FireEngineering entitled, “Fire Department EMS: Thinking Outside the Box for COVID-19.” This article is filled with great advice for responders. In the section entitled, “Alternate Transport Dispositions,” it says, in part, “In the early days of EMS, it was society’s unwritten rule that ambulances should only be used for life threats, not for all threats. That has changed and many EMS systems transport nearly all persons requesting service. This must be modified by EMS medical command and protocols prepared for EMS providers to determine the need for ambulance transport instead of the patient or family deciding the need.
EMS is in the direct path of the COVID-19 pandemic, requiring leaders to think outside the box. Adequately trained EMS personnel with proper medical control protocols should be able to defer stable patients to alternate transport modes and facilities. An EMT or firefighter driving a modified police transport van or squad car with plastic seats can safely deliver stable ambulatory patients to the ER without an attending EMT. Police vehicles typically provide a robust barrier to the driver and their plastic or metal seating is much easier to decontaminate than an ambulance patient compartment. Cities like Denver have been using similar alternative transport guidelines for decades to transport inebriated patients to detox units via specialty vans. This same practice could be applied to COVID response.”
I think both these articles deserve review by those who respond to medical emergencies. I also read about a state where they started sending an “EMS SWAT team,” for want of a better term, without an ambulance. The purpose of these teams is to assess patients and if they are not showing virus symptoms, try to find a way the patient can continue care at home and not be transported to a hospital. Unfortunately, I have not been able to find that article again, but I am counting on at least one reader to find it and forward it to me.
FirstNet (Built with AT&T) made several product and service announcements last week. The first was about two approved High-Power User Equipment (HPUE) devices made by Assured Wireless that will provide much higher transmit power from field devices (mobile routers and devices capable of USB connections) back to cell sites equipped with Public-Safety Band 14, the only cellular band that permits high-power operation. Both the 3GPP standards body and the FCC have approved use of up to 1.25 watts of power in this band, as opposed to the 0.25-watt systems used on other LTE bands and Band 14. A few weeks ago, AllThingsFirstNet.com ran a first of its kind session on Facebook where HPUE devices and uses were discussed conversation-style along with some Q and A among three of us involved with the website. If you are interested in finding out more about HPUE devices, you might want to listen to it.
Next was the introduction of FirstNet Push-to-Talk. This PTT meets the MCPTT standards developed by the 3GPP standards body. I understand the term “mission-critical” will be used by FirstNet only to indicate that this PTT service meets the standards but it will be promoted as “FirstNet PTT.” I will be writing more about this service once more details and a full set of features and functions have been released. As you know, PTT is the voice lifeline of the public-safety community and we are hopefully heading for a set of products and services that will provide interoperability between LMR and FirstNet PTT as well as between various PTT products and services that are and will become available on FirstNet.
Stay safe, protect yourselves and your loved ones. We will get through this and move on.
Until next week…
Andrew M. Seybold
©2020, Andrew Seybold, Inc.
Hi Andy, very interesting! I definitely agree that the alarm needs to be sounded, though I fear for some spectrum it’s already too late. Some thoughts:
Only Wi-Fi 6E can use 6 GHz. Wi-Fi 6 can’t, and this is an important distinction. Another point (pedantic but interesting): DSRC spectrum was dedicated to Wi-Fi technology to begin with: DSRC is based off of 802.11p, so the conversion of spectrum to unlicensed isn’t that large a leap. I do think the amount of bandwidth being assigned to Wi-Fi is a bit excessive. There will be a potential unexpected benefit in that the 2.4 GHz might be more free for Bluetooth devices, but I think 2.4 GHz Wi-Fi will remain for some time for legacy and coverage purposes.
There’s been issues in 5 GHz when licensed and unlicensed mixed as well, such as in Puerto Rico: https://docs.fcc.gov/public/attachments/DA-20-194A1.pdf and https://docs.fcc.gov/public/attachments/DA-20-195A1.pdf . These may predict issues, especially if the users can disable the interference mitigation.
As for 4.9 GHz, it’s been especially hamstrung by the lack of devices available in the band; it’s hard to adopt spectrum when there’s no devices available. There are other issues that occur behind the scenes, as well. Back in 2018, I presented at the Bluetooth SIG conference for using 4.9 GHz for public safety Bluetooth devices, but nothing developed from it. Should there be interest in attempting that again, I’ll certainly assist.
As for HPUE, BC14 technically isn’t the only band or even the first. That title actually goes to Sprint at 2.5 GHz back in 2017: https://newsroom.sprint.com/1-2-3-hpue.htm
The HPUE devices will most likely never be in a portable device, and we have the additional issue of SAR restrictions (Specific Absorption Rate). There’s a real opportunity for allowing SAR waivers for public safety mobile devices, but I’m unsure who would have to do the lobbying. As it stands, the mobile device’s power is reduced when it’s close to the body.