Public Safety Advocate: 3GPP Mission-Critical Working Group, MCPTT Standards, T-Band

This week we begin with comments about The FirstNet Authority blog concerning 3GPP and my comments on the 3GPP MCPTT standard and devices in the market today. Next up is the delay in the Senate’s passing of the repeal of the T-Band giveback due to one Senator and hopes for new Majority FCC Commissioners who truly care about how spectrum is used and who needs it instead of doling it out to commercial interests to the detriment of critical-communications systems. 

3GPP Mission-Critical Update

People who, like me, are interested in the mission-critical segment of the 3GPP standards for both 4G (LTE) and 5G networks commented on last week’s Advocate and agreed that sifting through the 3GPP website is quite difficult. Several people pointed out that The FirstNet Authority with FirstNet (Built with AT&T) is the only United States network participating in development of 3GPP’s mission-critical standards. According to multiple sources, while Verizon, T-Mobile, and the Competitive Carriers Association (CCA) support 3GPP, they have not taken an active role in the development of solutions for mission-critical issues that impact the public-safety community and others whose communications needs are critical.

The 3GPP established the SA6 (Mission-Critical) group in 2015 based on work done by the Public Safety (PSCR) and FirstNet. I have been unable to find a complete list of participating companies, but this link shows which companies have been directly involved. While Verizon recently announced its Mission-Critical Push-To-Talk (MCPTT) offering from Ericsson, it apparently had no interest in working with the 3GPP group that crafted the standard it is now promoting. T-Mobile already has a robust push-to-talk offering and I cannot find any reference to T-Mobile plans to implement MCPTT. Further, you might recall that prior to FirstNet, T-Mobile and Sprint were fighting public safety and asking Congress to auction the “D Block,” which has become a vital part of the success of FirstNet Band14.

It continues to amaze me that networks including Verizon and T-Mobile that did not bid on the FirstNet RFP to build and operate the FirstNet network are now trying to win over (or back) public-safety users. Once it became evident that public-safety agencies were joining FirstNet (Built with AT&T) in large numbers, they suddenly came alive. Now they are attempting to compete with FirstNet by implementing a Push-To-Talk (PTT) standard they had nothing to do with.  

Mission-Critical Push-To-Talk

My comments last week about the MCPTT standard not being “ready for prime time” drew a number of responses. One person who posted in the “comment” section below my column on said, “You think MCPTT standards are taking a long time? You are aware the P25 standards are still being amended with new functionality (example – patch and simulselect, a basic function used by all agencies is still not supported across the ISSI). It’s been close to 20 years so don’t expect miracles with MCPTT. AT&T is supporting MCPTT as are other carriers and we all hope they work together to make sure users can roam between them in MCPTT mode”

I fully understand his comments and have lived through what has been about twenty-five years of P25 progress and yes, there are still issues to be addressed. However, even from the beginning when vendors were building non-standard P25 systems so their competitors could not bid on add-on equipment, the systems could communicate with any and all devices on the network. While P25 was slow to evolve, there is a huge difference between a standard that can be used on any Land Mobile Radio (LMR) band assigned to public safety and a standard that works on a nationwide network. 

P25 networks are local, regional, and statewide. Within each system, the radios operate together and can communicate with each other. Today, after all this time, there is true interoperability between vendors’ products, which is as it should be, and there are still things that need to be addressed. However, with MCPTT on a nationwide public-safety broadband network, half of the devices on the network (iOS) cannot communicate with other devices (Android) on the network. If P25 was designed to operate on a nationwide network from day one, it would be about the same as MCPTT with its multiple interoperability issues. My issue is that we have seven or more PTT systems approved on FirstNet, including MCPTT. All of the other PTT applications serve all the different makes and models of both iOS and Android devices.

The FirstNet network is designed to provide a consistent nationwide broadband network dedicated to the public-safety community that can be accessed wherever services are needed. The physical network is mostly in place as are the devices. However, we are not finished with the rest of what is needed in the way of PTT and common sharable applications to provide a fully-interoperable public-safety network. We will get there, but sometimes when too many groups and organizations that mean well attempt to solve the same problem, it does not result in a timely solution. To support public safety, we have to provide the tools they need when they are needed.


The U.S. Congress will soon be a lame-duck Congress as is normal after an election. Regardless of who wins what, those who currently hold seats in the Senate will be Senators through the end of the year. Meanwhile, as required by law, the FCC is working toward auctioning spectrum that is of critical importance to eleven metro areas and their surrounding suburbs. The House has passed the “Repeal the T-Band Giveback Bill (H.R. 451) but a single Texas senator who wants an amendment to the Senate version of the bill prevented it from reaching a vote on the floor. 

I have to wonder what is to come. Our current President is running on “law and order” and has been endorsed by many public-safety organizations and unions. Yet, for whatever reason, a single Senator of the same party has decided to place millions of lives at risk. If these eleven metro areas lose this spectrum there will be neither money nor spectrum to move them off the T-Band. What I find most annoying is that this Senator represents a state that is home to one of the cities that will lose use of this spectrum. 

The sitting FCC has already jeopardized critical-communications capabilities on the 6-GHz microwave band by permitting unlicensed WiFi 6 to be used throughout the band. Further, it has decided the public-safety community can do without another 50 MHz of spectrum in the 4.9-GHz band. As a result, the three majority Commissioners, in their wisdom, ruled that this spectrum will be allocated to each state so the states can lease it out, perhaps with protections for existing public-safety users. Finally, the FCC moved to permit Ligado to build a 5G Internet of Things (IoT) terrestrial network in spectrum reserved for satellite communications that is much too close to Global Positioning System (GPS) spectrum. Many federal, state, and local agencies voiced opposition to Ligado’s proposed network but they were ignored.

It is time to replace today’s three majority Commissioners with three new ones who will take time to investigate how spectrum allocations will impact users today and into the future. The two minority Commissioners seem to fully understand this. 

Let’s push the Senate to pass a simple bill with no associated costs before the end of the year to ensure that our public-safety agencies can remain on the T-Band and further expand their radio systems.

[NOTE: I just received word that there may be light in the Senate chambers but more needs to be determined. It appears the rogue Senator from Texas who held up the plan to repeal the T-Band bill is now agreeable to re-engaging with consideration of the “Frontier Bill,” which would also either include or preclude (not clear) the Department of Defense (DOD) building its own 5G nationwide network. I will stay on top of this ever-changing situation as it unfolds.] 

Winding Down

As mentioned in a previous Advocate, it appears part or all of the current Administration is still putting forward the idea of a federalized 5G network that would be built and run by the feds, perhaps the DOD, and leased out to other carriers, businesses, or whatever. Meanwhile, the U.S. Army’s Installation Management Command (IMCOM) recently inked a deal with FirstNet (Built with AT&T) to support seventy-two installations.

It looks like the Army understands better than the DOD that FirstNet was created for federal organizations including the U.S. Coast Guard and the U.S. Army as well as local and state first responders. One quote from the announcement attributed to a U.S. Army spokesperson sums it up this way:   

“Just like your local municipalities, the Army installations around the country have police, fire, EMS and other emergency services,” Singer said: “They will be able to leverage FirstNet, so that they can improve the safety of the people and the workforce they have on the post.

Just as important, it allows them to have interoperability with the local municipalities that are outside the base. Often, an event that happens on the base or near the base is jointly responded to by the base personnel, as well as local communities’ first responders. There are no alternatives available to the federal government that comply with all (not some) of the capabilities that are provided in the public-safety broadband network known as FirstNet,” according to a September 2018 document justifying the contract.”

According to the article, this contract will provide 3,200 FirstNet connections, more than 3,000 devices, and 700 signal boosters to enhance connection inside the facilities. I hope this type of contract with FirstNet will put an end to the idea of the federal government building a nationwide 5G network. The main reason FirstNet has been successful in providing services and devices for state, local, and federal agencies is that while being overseen by an “Independent Authority” (The FirstNet Authority) that reports to the National Telecommunications and Information Administration (NTIA), FirstNet has its own board of directors, staff, and funding. I cannot imagine what FirstNet would be today if the federal government had decided to undertake the task of building out the network and securing users. 

A common issue with direct federal involvement has always been the disruption that occurs every four years after a Presidential election. Even if the same party remains in power, there is a huge turnover in personnel who tend to move back into the private sector being replaced with people who might see things differently—but may not understand the history of why networks are better off being built by private enterprise (among other things). 

A look back at the cellular industry proves this point. Many countries including Japan, France, the U.K., and others started out with government-owned cellular networks. This seemed to work well since they usually did not have to bother with the red tape involved in permitting sites and other necessities. However, it became clear early on that a single network run by the government was not the way to lower the cost of the network or cost to users. After only a few years, these networks were privatized and other private network operators were permitted to compete for the business. The nations’ businesses and citizens were the winners. 

Looking back at history can sometimes keep us from making mistakes a second or even third time! 

Until next week…

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


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