Public Safety Advocate: Interference at the Southern Border

In opening, I would like to welcome our new subscribers. The topics we cover relate to wireless communications, especially as used by public safety, and vary from week to week according to developments as they happen, and suggestions for future columns are welcome. This week we examine interference problems along our border with Mexico.

On August 31, 2019, Politico Pro Technology was first to post an article about a new source of radio interference at our southern border. Issues between the United States and Mexico concerning radio spectrum have been well known and worked out over a long period of time. The two nations are entitled to the same spectrum according to the International Telecommunications Union (ITU) which attempts to harmonize spectrum use around the world. 

However, each nation has its own rules, its own version of our Federal Communications Commission (FCC), and its own ways of making that spectrum available to the various groups that want and need it, including public safety. In the United States, the National Telecommunications and Information Agency (NTIA) is a second “keeper of the spectrum” and is responsible for all spectrum used by the federal government. The Mexico equivalent is its Instituto Federal de Telecomunicaciones (IFT). Theoretically, there are Mutual Recognition Agreements (MRAs) between the United States and Mexico that address issues of interference along with more detailed agreements.

Over the years, there have been many issues with spectrum that is used on both sides of the border. Unlike border entry points, radio waves do not stop at the border. They often spill into the other country causing interference to radio systems that operate in the other country. In earlier days, the City of San Diego, for example, had to delay moving to a new portion of radio spectrum as required by the FCC because of interference coming from Mexico. While this situation was resolved, there have always been problems for states on the border with Mexico.

Interference problems were usually confined to a few LMR channels being used by a department and did not bring down an entire network. This time things are different. The introduction to the Politico article sums up what appears to be an ongoing problem that needs immediate attention from our federal agencies, perhaps Congress, the IFT, and others within Mexico. This time, interference is affecting the Nationwide Public Safety Nationwide Broadband Network (NPSBN) known as FirstNet. When there is interference to this network, it affects all aspects of voice, data, and video.

The article begins this way, “Two days after El Paso’s Aug. 3 mass shooting that left 22 dead and even more wounded, first responders and medical professionals in the Texas city saw their wireless equipment start to glitch.

Certain critical communications went dark for El Paso firefighters and police patrol cars. In-ambulance hardware, including network-connected defibrillators, lost their links to hospitals. The University Medical Center, where more than ten people injured in the shooting were still being treated, experienced a near-total wireless network blackout. The cause: interference from wireless testing in Mexico. U.S. government leaders fear the issue could soon become far worse.

The testing was conducted by Mexican wireless firm Altán Redes, which the country’s government tapped in 2016 to build a nationwide wholesale network. U.S. officials caution that if the company decides to light up its network along the southern border, U.S. public safety across the entire border territory could suffer. Fearing the network launch is beginning, multiple U.S. wireless heavyweights are sounding the alarm about interference. 

“I’d be concerned too. The interference is real,” telecom analyst Roger Entner told POLITICO. “The two sides need to coordinate and compromise.”

According to another article in Mission Critical Communications, a Radio Resource International publication, this apparent activation plan, according to Chair Pai of the Federal Communications Commission (FCC), reverses what the U.S. government had deemed good progress toward ensuring there would be no disruption in this key swath of airwaves in the 700-MHz band, home to many existing wireless services. “Once we learned of this, we immediately contacted and shared the limited information we had with all domestic carriers potentially affected by Altán’s initiation of service, as well as the State Department,” Pai added.”

Further on, Chair Pai was also quoted in a letter he wrote in response to the letter from Senator Ted Cruz. Pai said he spoke “Aug. 19 to his counterpart in Mexico, Chairman Gabriel Contreras Saldívar of the IFT, about the issue and explained that even limited operations by Altán to date had caused interference, including to public-safety communications.” Pai added that he had spoken to another Mexican office, and his staff also worked on the issue. Since Mexico chose to implement an incompatible 700-MHz band plan, the FCC has been engaged, in coordination with the State Department and IFT, in crafting a revised protocol to govern use of the 700-MHz band across the border.

I find this to be an interesting set of comments coming from the FCC. Since FirstNet was created in 2012, we have received updates from the Public Safety and Homeland Security Bureau of the FCC at every public -safety conference and the Bureau has assured us that talks were well underway. I thought for certain we (the government) knew what was happening on our border with Mexico like we do on our northern border with Canada (Canada’s spectrum, including its public-safety broadband spectrum, appears to be identical to ours). However, it now appears as though the build-out of this Mexican network-for-hire was a total surprise to some in the U.S. government. Until Senator Cruz and others raised the issue, there had been no awareness of the problem and now it is bordering on an emergency situation not only along the Texas section of the border but along the entire border with Mexico if Altan’s network is allowed to be turned up and provide services so close to the border.

Communications is needed on both sides of the border; it is useful for the United States to have some coverage along the border into Mexico and vice versa. To me, this is a different situation in that it concerns a “for-hire” network for Mexico’s general public and a dedicated public-safety network in the United States. Reading further in both the Politico Pro and Mission Critical articles, it was noted that there appears to be a stalemate as this is seen as part of a broader set of border issues and trade agreements between the two countries.

It seems to me that those working for the federal governments on both sides have enough issues to argue about and work out without endangering the lives of United States and perhaps Mexican citizens by allowing a for-hire network to be turned on near the U.S./Mexico border. Most communications professionals in the United States agree that doing so would cause heavy interference to our public-safety broadband network. 

The only way to solve this problem is for the two countries to address this issue apart from any of the many other issues that have already proven to be contentious. They need to hammer out a solution to this interference issue to ensure both our public-safety broadband network and commercial networks on this side of the border do not face man-made, preventable interference. 

This is one more item to add to the list of what the FCC, NTIA, and/or Congress needs to address quickly before any civilian or first-responder lives are lost. I will be providing updates on this situation in future editions of the Advocate.

Winding Down

I am taking a break from naming people I believe belong in a public-safety wireless hall of fame as I both hope and encourage an organization or group of organizations to take on this project. In some ways, it is disappointing that the existing Wireless Hall of Fame seems to be restricted to those who have contributed to the cellular side of the wireless industry. This is especially galling since it was Land Mobile Radio (LMR) and advancements to LMR that helped propel the cellular market into what it is today. 

The history of land mobile radio and wireless voice-and-data solutions employed by public safety reveals that the development of LMR from analog to digital, simplex to repeater to simulcast, and then to trunked radio systems all came before the first cellular systems were installed in the United States. Public safety adopted slow-speed wireless data services from RAM, ARDIS, CDPD and Motorola’s DataTac as they were developed. This push to add data services to public-safety voice services was a precursor to today’s cellular data systems, and I firmly believe cellular systems were designed by people familiar with what was happening in the LMR and slow-speed-data world who found ways to turn that into cellular systems. By the way, the concept of cellular communications was floated by the then Bell Labs in the 1947, but the first cellular system did not go live in the United States until 1971.

Before cellular, we had paging, one-way alerting, and then one-way text developing into two-way services. We had nationwide data networks that provided from 8KB up to 19KB-per-second data and our LMR voice was undergoing many transitions. I am not trying to say cellular and cellular text, video, and data would not have happened had it not been for LMR and the early data providers. However, I do believe the concept of wireless communications for the general public, public safety, and business came before cellular. Based on this, I feel a wireless hall of fame should be all-encompassing but the Wireless History Foundation has chosen a different path.

Public-safety communications experts watched the development of cellular with interest. In some cases, they tried it in the early days and found that cellular was too expensive and coverage was not good enough. Nextel was the first cellular system to include push-to-talk. Its spectrum came from buying LMR 800-MHz operators and to keep this customer base, PTT became a standard offering from Nextel. Over the years, more public-safety agencies began to use the Nextel network, especially for plain-clothes personnel since a Nextel phone did not signal their occupation as quickly as a PTT handheld radio.

My point in all this is to show that LMR, paging, and slow-speed wireless-data networks were the standard until cellular technology advanced enough to be able to provide most of these services, its coverage was good, and the cost of the service became reasonable. I am still a believer that in the world of public safety we need to continue LMR systems, upgrade them, convert them to IP-based back-ends so they can work in concert with FirstNet (Built with AT&T), and NG911 nationwide, when implemented, to provide an almost-total range of communications tools for public safety. I believe Datacasting using the Public Broadcast TV Network is one more piece of the puzzle. All it would take on the device side would be to embed a chip to provide real-time video delivery to most of the United States without burdening the FirstNet Network. I will discuss this in more detail next week.

Andrew M. Seybold
©2019, Andrew Seybold, Inc.


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