Public Safety Advocate: The 5G Wedding Cake, More Networks/Less Interoperability, Open Standards

I recently commented here about T-Mobile and others confusing both the public-safety community and the citizens of the United States with its lack of specifics about 5G data rates and latency issues. It seems no one wants to speak about actual 5G data speeds. Surfing the Internet does not provide much in the way of data-speed or latency information. The closest I have found concerning the speed question is a statement that it will range from, “~50Mbit/s to over 2 gigabits at the start, and is expected to grow to even 100Gbit/s, 100x faster than 4g. The fastest 5g, known as mm Wave, delivers speeds of up to and over 2Gbit/s.”

Several companies including T-Mobile refer to the 5G “Wedding Cake” model to explain huge differences in 5G speeds. How they depict a wedding cake does not resemble any wedding cake I have ever seen. The bottom layer of the cake denotes 5G coverage using low-band spectrum (600-800 MHz) which is shown as being nationwide. (The best way to describe this coverage is about the same as today’s LTE with perhaps some better latency and supposedly more network capacity.) Today, LTE or 4G aggregate (use of multiple LTE network segments) can provide better data speeds and perhaps more capacity than low-band 5G. 

T-Mobile identifies the next layer of the cake as good for metro areas because it uses mid-band portions of the 5G spectrum and includes the upcoming “C”-band spectrum auctions (3.7 to 4.2-GHz band). However, some of this spectrum will continue to be used for satellite communications. T-Mobile will be in a great spectrum position with the T-Mobile/Sprint merger due to the amount of 2.5-GHz spectrum Sprint has licensed and leased from universities and colleges.  

The final layer of this three-layer cake is designated as the “mmWave” bands. In the United States today, this includes spectrum between 24 and 100 GHz. The FCC has already auctioned spectrum in 24-GHz and 28-GHz segments and more auctions are on the books for 37 and 39 GHz, with the 46-GHz auction recently completed. These include very wide swaths of spectrum so data speeds are being predicted for 1 Gigabyte and above. However, the distance covered by each mmWave cell will not be measured in miles, or even half-miles, but more likely as less than one-quarter mile. These mmWave systems will only become available in high-density urban areas with use of light poles and other right-of-way poles that are very close together. Some network operators also plan to use mmWave 5G for into-the-home, fiber-like data speeds instead of running fiber to each home or business.

The final layer of this three-layer cake is designated as the “mmWave” bands. In the United States today, this includes spectrum between 24 and 100 GHz. The FCC has already auctioned spectrum in 24-GHz and 28-GHz segments and more auctions are on the books for 37 and 39 GHz, with the 46-GHz auction recently completed. These include very wide swaths of spectrum so data speeds are being predicted for 1 Gigabyte and above. However, the distance covered by each mmWave cell will not be measured in miles, or even half-miles, but more likely as less than one-quarter mile. These mmWave systems will only become available in high-density urban areas with use of light poles and other right-of-way poles that are very close together. Some network operators also plan to use mmWave 5G for into-the-home, fiber-like data speeds instead of running fiber to each home or business.

Later on, we will see 6G technologies rolling out using spectrum above 100 GHz with even less range but more speed and probably lower latency. 

When mobile or residing or working in a high-density urban area, users will probably have gigabit speeds quickly falling to high-megabit speeds and falling still further in suburban and rural areas to about the same as today’s LTE speeds but with the promise of becoming faster over time. 

Using LTE as a benchmark for broadband data speeds, we find that speeds have increased over the last ten years. This trend is expected to hold true with 5G speeds as well. One advantage to 5G is higher capacity per cell site that has been reported but not yet definitively measured. FirstNet states its subscribers will have access to all AT&T 5G low-band, mid-band, and mmWave bands. They will also have full pre-emption and priority so I am not sure the issue of 5G cell capacity makes a difference for FirstNet users. 

We have three different types of 5G with speeds about the same as today’s LTE (low-band) to speeds that should be about double today’s LTE or a little better than LTE aggregate and, finally, within blocks of a mmWave microcell, users may come to expect gigabit and higher data speeds. These speeds are so fast because large amounts of spectrum are available in the mmWave band. 

The formulas for data speeds for LTE and 5G are based on the same premise. The more spectrum used by a network for a specific technology, the faster its broadband service will be. If an LTE system has only 10 MHz of spectrum available (5X5) and is competing with an LTE network with 20 MHz (10X10) available, the network with the largest portion of spectrum devoted to LTE will have the best data speeds and capacity. 5G could provide more capacity for the same amount of spectrum but don’t expect to see gigabit data speeds for 5G unless you are very close to an mmWave microcell. 

You may recall that I came down hard on the FCC’s rural broadband phase II fund because it has been cast as a 5G-only rural broadband fund. No LTE, no other types of fixed wireless, only 5G. The way wireless technology has progressed in the United States is that network operators choose the technology they prefer and add speed and capacity as the technology is upgraded. Today there is a cost differential between LTE and 5G and since rural 5G is the lowest layer of the wedding cake carrying the lowest 5G speeds, I don’t understand why it is the only wireless technology being funded by the FCC. It makes no sense. 

We have all lived through a number of “next big thing” technologies. Some have proven to be as promised, many took longer than the pundits and engineers predicted, and others simply collapsed under their own weight. It makes more sense to continue moving forward with LTE and add 5G as its performance improves and its cost to deploy comes down. The 5G future looks bright, but how many new devices will each of us feel compelled to purchase, over what short period of time, as 5G is updated and matures? I would like to see us move a little slower into the unknown and learn what 5G can actually do for us and how to best make use of the 5G technology. 

Those enamored with more and more speed and perhaps Artificial Intelligence (AI) capabilities tend to lose site of the fact that our first responders have tasks they need to complete on an ongoing basis. We are still learning how to apply FirstNet and we do not yet have Next-Generation 9-1-1 (NG911) up and running in most of the United States. I believe NG911 and the capabilities it brings will be the pathway to FirstNet for sending text, images, or video to a NG911 Emergency Communications Center (ECC) and it will be a true launching point for today’s FirstNet and tomorrow’s 5G FirstNet. Even so, we are not ready to be pushed into 5G before we are comfortable with FirstNet as it is today.

More Commercial Networks, Less Interoperability

Prelude: I opened last week’s Advocate with the following:

” There is only one vetted and approved FirstNet public-safety broadband network and it was created as a private/public partnership by Congress. It is NOT a commercial broadband network even though it is being built by a commercial network provider (AT&T) after winning the contract. FirstNet is managed and run by The FirstNet Authority, an independent authority created by Congress and signed into law by the then President and placed under the National Telecommunications Information Administration (NTIA) within the Department of Commerce.

I am repeating this because more commercial networks are offering or about to begin offering public-safety communication services. Both The FirstNet Authority and the FCC need to make clear that the bill that created FirstNet and was passed into law was for the ultimate goal of a SINGLE nationwide public-safety broadband network. We have already seen one major commercial network operator try to duplicate FirstNet but it is missing a whole lot including the use of Band 14, the ONLY public-safety broadband spectrum, in addition to all other LTE spectrum serviced by AT&T. 

Both Sprint and T-Mobile have some public-safety customers, many of which have or are in the process of leaving these two carriers for FirstNet. According to the November 8, 2019 issue of Urgent Communications, T-Mobile’s answer was to make what appears to be a political statement that if the merger between T-Mobile and Sprint was approved (it has been) the new T-Mobile will offer public safety the following:

“Public-safety agencies and their personnel would have access to free, unlimited talk, text and smartphone data at 5G speeds for 10 years via a Connecting Heroes initiative announced yesterday by “New T-Mobile,” but the offering will become a reality only if T-Mobile’s proposed merger with Sprint is closed, according to T-Mobile officials.” 

I will be surprised if this turns out to be a serious proposal and I am totally against this idea. Why? Because it is free? No, I am against the involvement of commercial broadband networks where management only has to please its board of directors and investors as opposed to a public-safety network that happens to be built and maintained by AT&T but is THE public-safety network that is overseen by The FirstNet Authority, not stockholders.

After 9/11, Katerina, and Sandy, the issue of interoperability for public-safety communications was finally recognized even though the public-safety community has struggled with the problem for more than thirty years. Land Mobile Radio (LMR) systems continue to operate without being nationwide even though two or more agencies often must work together but cannot communicate using LMR. However, if they are part of the FirstNet public-safety system they can interoperate seamlessly with each other. 

Since FirstNet (Built with AT&T) has also stated it is making all its 5G build available to public safety under the same rules for public safety using Band 14 and AT&T LTE spectrum, I do not see why yet another commercial network should be allowed to buy its way into and disrupt what FirstNet is already doing to meet the goals as established by law.

Now that the merger is official, if the new T-Mobile decides to target the public-safety community, I would like someone at T-Mobile to answer the following questions:

  1. Can a public-safety agency receive free services from any commercial vendor? Is it permitted under city and county charters? 
  2. Is the free service only available if you throw away your FirstNet phone and purchase a new T-Mobile 5G phone?
  3. Does the service include true pre-emption, true priority? 
  4. Is T-Mobile offering a public-safety-grade private public-safety core or will the public-safety community share the commercial core?
  5. What data rates will be provided to public safety? Will it be publicly assured that there will never be a data slowdown for public-safety users?
  6. How long will it take T-Mobile and Sprint to join their two networks with diverse technologies into on cohesive network, and what happens to public-safety users in the meantime?
  7. If there are places where the new T-Mobile 5G signal is not available, will T-Mobile provide 4G fallback for no additional charge?

One of the more interesting quotes from the Urgent Communications post is a statement by T-Mobile’s President and COO Mike Sievert. During a T-Mobile conference call announcing the proposals, Sievert stated, “It’s [T-Mobile] not a FirstNet competitor; it’s an AT&T competitor” and “We applaud FirstNet and the initiative behind it, but the bottom line is that AT&T won that bid, and they’re planning to monetize our first-responder community by overcharging them.”

Well, paper does not refuse ink. AT&T is planning to monetize the FirstNet network as provided for in the terms of both the law and The FirstNet Authority RFP. AT&T will spend more than an estimated $30 Billion in building out a truly robust FirstNet network. Both the law and The FirstNet Authority RFP recognized that any bidder would need a way to recoup costs over the course of the 25-year contract. There are only two ways to do this. First, the public-safety community would pay a monthly per-unit fee for FirstNet service and some of this money would be returned to The FirstNet Authority to be used for network and service enhancements. Second, when not needed by public safety, AT&T is permitted to add commercial subscribers to Band 14, but when public safety needs access, these commercial users are returned to AT&T’s bought-at-auction LTE and 5G spectrum.  

It would be a good practice to fact-check statements before they show up in print. AT&T is NOT FirstNet, and AT&T’s commercial business is fair game for other vendors, just as it is fair for ATT to go after other vendors’ commercial business. However, the Nationwide Public-Safety Broadband Network (NPSBN) is not fair game and service is not to be spread out among three or more network operators, especially when the U.S. Government has authorized only one network to build, maintain, and expand the network. The quest to add other networks appears to be a vendor-to-vendor play to gain more public-safety subscribers or win back subscribers that may have moved to FirstNet.  

While this may seem to be in the best interest of commercial networks, it is too late. The contract is well underway, FirstNet subscriber numbers keep growing, more device vendors are including Band 14 in their devices, and FirstNet is a secure and private network for public-safety agencies that enables inter- and intra- agency sharing of voice, data, text, and video services. This push by commercial wireless providers to participate in public-safety communications is not what is best for the public-safety community. Perhaps it is time for these vendors that are already making bags of money to back off and let FirstNet become the network public safety wants and needs. 

I believe most wireless communications vendors are still in the “we need to make a huge profit” mode rather than wanting to do the right thing to assist our first responders. Should they persist no matter what as long as they make money, or should they be better citizens and do what is best for public safety? I want to emphasize that I would be making these same statements regardless of which company became the FirstNet vendor by winning the FirstNet RFP award. This is not about T-Mobile versus Verizon versus FirstNet. It is about what is best for the public safety-community, as it should be. 

Winding Down

Last week I received the latest version of the L3Harris LMR/FirstNet Xl-200 portable. I activated a SIM so I am on the LTE network and in the process of setting up the LMR sections. Since I only recently finished updating an APX8000 using the Motorola computer interface, I had to unlearn Motorola and re-learn L3Harris speak, which is quite different. I need to contact NPSTC about the work it did on a spreadsheet designed to move channel information from one vendor’s radio to another, but at the moment I am remembering the differences. I like having one device that clips to my belt and gives me VHF, UHF, and 700/800-MHz LMR as well as full access to FirstNet LTE. However, I will readily admit we need LTE-only, LMR-only, LMR/LTE devices, and more.  

It was pointed out to me that there is a bump at the top rear of the radio. This bump contains the LTE antennas I suggested to be located away from the other antennas. Harris agreed and the radio’s LTE operation out-performs the cell phone I am wearing. Looks to me like a home run for L3Harris.

Finally, I want to discuss my belief that one company will finally win the Push-To-Talk (PTT) battle and it won’t be one of the companies waiting for the 3GPP to pass a PTT interoperability “standard.” It will be a company that makes it happen instead of waiting around. At that point, one or more approved FirstNet PTT vendor will balk at providing true PTT interoperability with all other FirstNet-approved PTT vendors. If I was in charge, I would give all of them ninety days to make it happen and then disqualify any vendor that refuses to support FirstNet interoperability. 

The same tactic should be applied for LMR/FirstNet PTT interoperability. The difference is that with LMR-to-FirstNet PTT interoperability, there are so many committees, standards bodies, and others working on options that no one will get it right. 

We need an organization such as NPSTC to put together a group that includes all the existing committees from PSTA, NPTSC, TIA, and others. By bringing everyone together, I believe a consensus could be reached quickly. The caveat here is that everyone on the committee must leave their desire for patents, etc. at the door and devote their time to agreeing on a set of open standards that can be implemented by any vendor that desires to take part in the FirstNet network and can pass its acceptance tests for devices, applications, or other elements required to provide cost-effective interoperability solutions.

Until next week…

Andrew M. Seybold
©2020 Andrew Seybold, Inc.

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1 Comment on "Public Safety Advocate: The 5G Wedding Cake, More Networks/Less Interoperability, Open Standards"

  1. Andy,
    Sorry to hear you are flummoxed over the new software (L3-Harris) learning curve. Doesn’t the pope speak 5 languages?
    It appears that you are traveling to the land of wind power with the rant over carriers. AT&T has the franchise with high-power Band 14. Carriers can market all they want. As AT&T’s coverage grows and technology advances, the other carriers will need to pay public safety to use their systems. Or, perhaps carrier aggregation will take a new turn! It will all work out . . .
    Finally, LTE is a modulation scheme. 5G is not that different than 4G. It leverages higher (microwave) frequencies to improve bandwidth by both increasing the frequency and the amount of band spectrum. 5G can work in tandem with 4G at current 600MHz-2GHz+ spectrum with moderately improved coverage (MIMO leverage) and throughput.
    The estimated year of 4G build-out is 2024, which will release the digital radio spectrum along with 3G. That gives ‘plenty of’ time to upgrade subscriber units to 5G and coming 6G capability.
    You are on the money with ENode-B distance capabilities in the higher microwave spectrum. Looks like the carriers that bought Huawei parts and pieces are going to get reimbursed. Rural public safety will forever be bandwidth limited by the formulaic distance between cell sites and the need to use lower frequencies based on site economics. Until I perfect my anti-gravity drive for satellites, its all in what’s the going rate of the monthly fee!
    Hope to see you in LV!

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