Public Safety Advocate: Spectrum, Spectrum, and PTT Interoperability

Welcome to October! This has been a tough year for everyone, especially for the public-safety community. However, there continues to be good news on the communications front along with, of course, some bad news. On the plus side, after a very strong bi-partisan vote, the House of Representatives passed H.R. 451, the repeal the T-Band giveback. Currently, the FCC is faced with having to auction the T-Band spectrum (470-512 MHz) that is designated for use by the public-safety community in eleven major metropolitan cities and their surrounding suburbs.  

It is hoped that the Senate will also pass a bill to repeal the T-Band giveback (currently S.2748) and it is quickly signed into law. The situation today is that there is no other spectrum available to relocate all of the public-safety agencies that use the T-Band every day, funds for relocation are not available, and licensed business users in the T-Band are not required to vacate the spectrum. 

Since many network operators and other potential bidders have stated they have no interest in this spectrum, there will be few if any bidders even if the FCC is forced to auction it. Thus, there will be little if any interest in bidding on the FCC’s reserve prices for each segment of spectrum in each of the eleven metro areas. As you can see from the FCC chart below, each metro area uses different portions of the T-Band and no one area uses all of the spectrum. In fact, the Channel 14 block is the only swath of 6-MHz spectrum shared by most cities and that spectrum is designated for public-safety use in six of the eleven metro areas. The other 6-MHz blocks are used by three or fewer cities.

Chart from the FCC Notice of Proposed Rulemaking PS Docket No. 13-42

Many TV stations are using these frequencies outside of the 80-mile radius around the eleven metro areas where T-Band spectrum is used by public safety to protect life and property. For example, Channel 20 is used by only public safety in LA and Philadelphia, but it supports TV stations in surrounding areas. It’s hard to believe that 6 MHz of spectrum would be of any real value for any other use beyond this 80-mile radius. To say the FCC is being unrealistic about the chances of T-Band spectrum being sold at auction is an understatement. In fact, Chairman Pai has indicated several times to Congress that he supports leaving the spectrum in the hands of the public-safety community. 

Again referring to the FCC chart, a bidder interested in Channel 14 (6 MHz available in six metro areas) that wanted to add a second swath of 6 MHz in these six metros areas would have to pair with Channel 16 in Boston, LA, and NY/NE New Jersey. In Chicago and NY and NE New Jersey, they would have to purchase Channel 15. The only spectrum available in three metro areas is the spectrum for NY/and NE New Jersey where it is being used for TV Channels 14, 15, and 16, and the spectrum from these channels is heavily used in the entire area for public-safety communications.  

The bottom line is that the “repeal the T-Band bill” has been passed by the House by a hugely bi-partisan vote (410-5), the FCC knows putting this spectrum out to bid will not result in a windfall for the feds, the FCC Chairman has stated he believes the current public-safety use should continue, and the GAO report on the T-Band concurs. It appears the stars and planets are lined up in favor of the repeal but the Senate has not taken the logical next step to ensure public safety continues to have access to this critical spectrum. 

4.9-GHz Public Safety Spectrum

Depending on to whom you listen, the action taken by the FCC Commissioners during its September 30, 2020 meeting was a disaster for the public-safety community or it is an opportunity. Their rulemaking gives the spectrum to the states to lease out as they see fit. The states will have the option of “leasing” 50 MHz of 4.9-GHz spectrum that has been used by public safety since it was authorized by a previous board of FCC Commissioners. Despite heroic efforts by the Public Safety Spectrum Alliance (PSSA) and the current U.S. President basing his campaign in large part on “law and order,” the Commissioners ignored the pleas of the public-safety community and continued in its intent to add spectrum for those who want it for their own profit. 

As quoted on the website, “The report and order adopts a voluntary leasing framework for the 50 megahertz of spectrum in the band in an attempt to increase use of the band. Under the proposal, eligible states would have the opportunity to lease some or all of their spectrum to commercial or critical infrastructure entities.

Each state that chooses to lease spectrum will designate a single statewide 4.9 GHz licensee as the state lessor. The state lessor would then have the ability to lease the spectrum to entities for non-public-safety operations. The proposal grandfathers existing public-safety licensees into the band, but those licensees cannot modify their licenses if it would expand their operations.

The report and order limits the issuance of new 4.9 GHz licenses to state entities and states without an existing statewide license. The version the FCC considered at the meeting also included a provision that would make states that divert 9-1-1 fees to non-9-1-1 purposes ineligible to take part in the leasing process.”

The vote was along party lines with all three majority party Commissioners voting for the measure. Their rationale is that the public-safety community is making light use of the spectrum, but there is no way to prove or disprove that claim since most licenses for 4.9 GHz were based on geographic areas rather than the number of base stations and mobile units. 

For the most part, those effected have been using this spectrum for point-to-point links including cameras. Cities with extensive deployments include Portland, Chicago, New York City, and others. If states move to lease this spectrum, even with supposed priority and pre-emption for public-safety user protection, the band could turn into a free-for-all. Radio waves don’t stop at state borders and different technologies mingled together in a single band is a recipe for disaster. However, since all three of these Commissioners will most likely be moving on regardless of the outcome of the election, they won’t be around to see the results of what I think will be detrimental not only to the public-safety community but to those who lease the spectrum from the states. Many states probably won’t even carve out a portion of the spectrum for pubic safety since their motive will be to maximize the spectrum’s lease value within their state. 

The PSSA and its supporters put up a good fight, but it appears that while many outside the Commission (and perhaps the minority Commissioners) realized this ruling would be a grave mistake on the part of the FCC. However, this did not matter since the three majority Commissioners had already made up their minds. I can only hope that the next set of FCC Commissioners will be more inclined to listen to those who actually use the spectrum and not exclusively to those who make money from the spectrum. 

But wait! There’s more! The FCC also previously ruled to permit the 6-GHz critical-microwave band to be used for unlicensed WiFi 6 systems, and to allow Ligado to build out a 5G Internet of Things (IoT) network that may, in fact, impact our ability to use the Global Positioning System (GPS) for location determination. In my opinion, the current majority Commissioners have done nothing to protect existing spectrum users and are responsible for a series of potentially disastrous spectrum allocations.

Push-To-Talk Interoperability

Response to my September 10, 2020 Advocate, “Why Are We Waiting for a Push-To-Talk (PTT) Interoperability Solution?” brought both positive and negative comments. As expected, negative comments asked what is wrong with waiting for the 3GPP Internetworking Function (IWF) that will be designed to work best when marrying LTE Mission-Critical Push-To-Talk (MCPTT) to digital LMR PTT networks. Positive comments included some interesting notes from companies working on the issue of interoperability for PTT with LMR-to-LTE and as well as for LTE-to-LTE. Both efforts are important. The majority of the comments from within the public-safety community were in favor of solving the interoperability issues sooner rather than later. Some indicated they felt FirstNet, which is intended to be a fully-interoperable nationwide broadband network, is very close where the network is concerned but far from where it needs to be with PTT and common applications.

Some information I have received (much under non-disclosure) indicates that a number of companies are either working toward a full-interoperability LMR/LTE or LTE/LTE PTT solution. Some companies have pieces and parts of what could be crafted into a solution when augmented by other vendors’ offerings, and one vendor has chosen a unique way to provide interoperability by making use of text messaging for first responders. I plan to write about this last one in more detail in a future Advocate to discuss the concept and some successes that have resulted from this application being used during a number of real-world incidents. 

Several working on interoperability solutions will be employing cloud-based services to provide full interoperability and two companies working on their own solutions are presently using the Internet with Virtual Private Network (VPN) connectivity to provide proof-of-concept. I hope when and if these offerings are made available to the first-responder community, they use non-Internet connectivity. Ideally, both a text-based solution and a full-interoperability solution would be hosted in or near the FirstNet core to provide the same level of security FirstNet provides today.

Having been given a glimpse into these efforts, I believe text interoperability that gives public-safety professionals their own text-based system and does not mingle their texts with any personal or business text messages is a significant advancement, and I can envision a future PTT interoperability solution integrated with a text-based system. I would expect such a combination to be an instant success in the public-safety world. However, for now we need to focus on PTT interoperability. 

Whatever solution the United States settles on, there may be different solutions for other parts of the world even though the requirements are the same: sharing voice PTT at an incident so everyone, regardless of how far they have traveled, is able to participate in on-the-scene PTT voice services. For those who believe the end-game is to wait for IWF/ISSI to be available and integrated, I would like to suggest that while that solution may work for many departments and agencies in the United States, it will not support many other agencies including federal, state, and local fire services, particularly those that use Analog, P25 conventional, or even Digital Mobile Radio (DMR) or NXDN (yet another digital standard based on Frequency Division Multiple Access (FDMA) technology that is available from JVC/Kenwood). 

In other words, a solution for departments large enough to warrant P25 trunked systems and have the money it takes to include Inter-RF Subsystem Interface (ISSI) from some (but not all) vendors means smaller, less well-funded agencies will not necessarily have the same interoperability capabilities. Yet during wildland fires, hurricanes, tornadoes, and other disasters they are just as likely to need assistance from other agencies or to be called to assist others. I am hopeful that what I have seen so far and some things that have been alluded to mean many highly knowledgeable people are working on taking interoperability into the field in the next one or two years instead of another five or six years.

Winding Down

Rural Broadband

The Department of Commerce has indicated that in FY2020, FirstNet added coverage for 8.9 million more people in rural America. The goal now is for FirstNet to reach 55-percent of the total rural population by the end of September 2021. In other words, FirstNet has exceeded all its goals for rural build-out. 

However, other Federal Government agencies including the Department of Agriculture (USDA), the National Telecommunications and Information Association (NTIA) Broadband America committee, and the FCC continue to work independently. As a result, the expansion of rural America broadband coverage is taking far too long. Some agencies are focused on fiber to the exclusion of wireless. Other agencies provide grants and loans for build-outs but not for ongoing operational costs. As with deployment of any new network, it takes time for users to sign up, go online, and begin paying for the service. There is also the reality that many in rural America cannot afford broadband charges that are imposed in metro and suburban areas. The primary reason rural areas do not already have broadband access is that the economics simply don’t work for most rural areas.

Fiber is not the most cost-effective way to extend broadband into rural areas and Little Leo satellites are not yet available. Further, we don’t know what satellite access will cost, nor do we know the cost of the equipment it will take to receive signals inside businesses and homes. As I have pointed out before, running fiber fifteen miles to a single farmhouse is not a great way to provide Internet access. Fiber is far too expensive and furthermore, what farmers really want is broadband in their fields so they can use all the new farm technologies that are becoming available. Fiber to a hub, followed by various wireless configurations for the last mile, makes more sense. 

I again assert that the smartest way to cover more of rural America with broadband is to team with FirstNet. You will need to meet with FirstNet personnel, learn about their plans, and explore ways in which other federal, state, or county agencies can expand on FirstNet’s plans for the area and help with funds to add more sites to increase coverage for both first responders and area citizens. This makes the most sense, but so far I have not seen any indication anyone is working on collaborations with FirstNet. 

Until next week…

Andrew M. Seybold
©2020, Andrew Seybold, Inc.


2 Comments on "Public Safety Advocate: Spectrum, Spectrum, and PTT Interoperability"

  1. Peter Moncure | October 1, 2020 at 3:24 pm | Reply

    Anyone with the telephone number of their Senator would do Public Safety a great favor by calling about S.2748, it’s a noncontroversial sleeper. Also, Andy, note that the LA Sheriff also has the use of T-Band TV channel 15 with nearly 28 thousand base records on file. Thanks SO much for shining another light on this fiasco.

  2. Peter thanks the bill was brought to the floor of the Senate shortly after the Advocate was published, it was set to pass by unanimous vote–BUT Senator Barrasso of Wyoming objected for Senator Cruz who wanted to have the have an amendment added which I am told states” The Ensuring Public Safety’s Access to Airwaves Act of 2020 would also require the National Telecommunications and Information Administration to identify by Dec. 31, 2020, at least 42 megahertz of federal spectrum below the 10.5 gigahertz band to be reallocated for commercial mobile and fixed broadband access” I don’t know why a Senator from Texas where Houston makes use of T-Band spectrum has to muck around with this bill which as you stated is noncontroversial and will not cost the government one red cent but the spectrum is very badly needed by the Public Safety Community. Thanks Peter

Leave a comment

Your email address will not be published.