TSA's Radio Infrastructure

As I mentioned in one of my earlier posts, I work for TSA, the Transportation Security Administration, the federal agency charged with protecting the nations transportation systems. Today, I'm going to give you a little overview of the agency's two-way radio systems.

Sensitive Security Information

Before I begin though, I must go over Sensitive Security Information or SSI. SSI is a designation used by TSA which is coded in federal regulation that states that SSI "is information that, if publicly released, would be detrimental to transportation security."

SSI is essentially sensitive but unclassified information. As I work for TSA, I am automatically a "covered person" who is required to protect such information. Therefore, I am limited in what I can I use and say on anything that is considered SSI.

However, most of the sources I'm using for this blog post are publicly available third-party sources which are not SSI or if it is a TSA source, was not marked SSI.

History of TSA

TSA was founded in the aftermath of the destructive September 11th terrorist attacks which showed how weak and complacent the aviation security industry had become in the United States. I say industry because it was a literal sub-industry of security companies usually subcontracted by the airlines to provide screening services with weak oversight by the Federal Aviation Administration and it's sub-office, the Office of Civil Aviation Security.

As a result of 9/11, Congress decided, after a long debate, to federalize/nationalize the aviation security industry via the Aviation and Transportation Security Act or ATSA, which was signed into law by President George W. Bush at a ceremony at Washington Reagan National Airport on November 19, 2001.

For the first couple of months, TSA was nothing more than a dozen people in a small basement office at the Department of Transportation (DOT) headquarters until February 2002 when TSA more or less absorbed the FAA's Office of Civil Aviation Security and continued until November 19, 2002, the one year deadline imposed by Congress to have all aviation security activities overseen by TSA.

TSA Field Operations

Before I begin describing radio infrastructure, I should probably give you an overview of how TSA's field operations work. TSA oversees about approximately 460 airports, the number fluctuates because many of the smaller airports are seasonal or see irregular air service that comes and goes based on the airline.

Airports are divided in 5 categories of security, at the top end is Category X, these are your major international airports in major metropolitan areas, below that are Category I airports, these are airports in say smaller cities or secondary commercial airports in a major metropolitan area say like Dallas Love Field (DAL), Houston Hobby (HOU) or Chicago Midway (MDW). At the other end of the spectrum are Category IV airports; these airports are essentially your small Podunk general aviation airport that has commercial service through say the Essential Air Service.

Just like the airlines, TSA field operations are based on a hub-spoke model. Most Category X and I airports have Category II, III and IV spokes. For example, here in Massachusetts, my airport, Boston Logan International (BOS) is the hub for the rest of the state such Worcester Regional (ORH), Hanscom Field (BED), Westover Metropolitan (CEF) and the airports on the Cape and Island (ACK, HYA, MVY and PVC), and since 2014 also oversees Maine's airports.

At these hub airports, there is a small operations center known as the Coordination Center, which is essentially the clearing house for all information in the area of responsibility. If an incident happens at a checkpoint or a baggage area, the TSA officers (TSOs) will call it in and the Coordination Center will make the proper notifications to local or state law enforcement, our explosives specialists or our regulatory inspectors if needed.

The TSOC Watch Floor
These Coordination Centers in turn report to TSA's national operations center, the Transportation Security Operations Center or TSOC. TSOC is essentially the national clearinghouse, all incidents reported go to TSOC. Unlike the Coordination Centers which are just staffed by TSA employees, TSOC has TSA employees along with employees from various other government agencies, such as other DHS agencies, the FAA and FBI serving as liaisons.

TSA's Frequencies and Radios


Since TSA and the FAA were essentially under the same department at the beginning, that being the Department of Transportation. The FAA gave away a chunk of their land-mobile VHF frequencies to TSA, so it could set up it's land mobile network. It should be noted, that even though the frequencies maybe the same at many airports, each airport land mobile radio system is an independent system, they are not interlinked into a national network or even regional networks.

The large airports will have repeaters, but smaller airports might not need one and just run simplex.


(Note: I started at TSA in 2008, so what they used for radios prior to me starting is hazy and I can't find much on the Internet, unless the radios we were using in 2008, were there since day one.)

The first radios used were Motorola XTS5000 P25 radios in Model I and Model III versions, along with XTL5000 consolette base stations and Motorola Quantar repeaters.

In 2009, as part of a major TSA project known as "Checkpoint Evolution", one of the sub-projects was introducing "Whisper Radios" to "quiet" the checkpoint. These "Whisper radios" were analog Icom F50V radios using voice inversion scrambling in an attempt to mask the communications.

In 2015, TSA completed a contract with RELM Wireless (now BK Technologies) to purchase their KNG series of P25 radios to replace both the Motorolas and the Icom "Whisper" radios. This acquisition only affected the portables and repeaters, which also came from RELM/BK. The Motorola consolettes remain, although most have been replaced by ones from Motorola's APX series of radios.

TSA communications are required to be encrypted per DHS Policy Directive 4300A.

Ultra High Future?

In 2018, TSA posted a request for information on FedBizOpps looking to once again upgrade their LMR infrastructure. However, there was something different about this solicitation, instead of once again requesting VHF radios, the TSA was requesting UHF radios instead. 

It seems that TSA is going to give up the VHF frequencies for UHF frequencies, returning them to the FAA or having the National Telecommunications and Information Administration (NTIA) reassign them.

700/800 MHz Bands

I have seen occasional references on FedBizOpps to TSA acquiring radios that can be used in the 700 & 800 MHz public safety bands.

My scientific wild-ass guess is that it has to do with radio interoperability purposes allowing TSA and requisite airport and public safety authorities to communicate if need be.

TSA on Shortwave

Unlike many other government agencies, like some of the those in DHS, such as U.S. Customs and Border Protection (CBP), the Federal Emergency Management Administration (FEMA) or the U.S. Coast Guard, TSA never had the need for high frequency spectrum.

For example, CBP has COTHEN, the Customs Over The Horizon Enforcement Network, mostly for air and marine assets under CBP's Air and Marine Operations division. The Coast Guard has plenty of HF spectrum from being a military service. FEMA has the FEMA National Radio System (FNARS) and DHS' new Cybersecurity and Infrastructure Security Agency (CISA) runs the SHARES (SHAred RESources) HF network.

However, that all changed with Hurricane Katrina, TSA had communication problems with getting information between headquarters and Louis Armstrong New Orleans International Airport (MSY). Landline, mobile and even satellite phone service was impacted, according to former TSA Administrator Kip Hawley's book, Permanent Emergency.

As a result, in 2006, TSA and the US Army's Network Enterprise Technology Command signed an agreement for TSA to use the Army branch of the Military Auxiliary Radio System (MARS) [At the time, MARS was known as the Military Affiliate Radio System.]

In fact, TSA has three specialist positions dedicated solely to emergency communications for this purpose located strategically across the country, along with hundreds of other employees who possess an amateur radio licence and MARS training to operate the equipment TSA uses to participate in MARS.

Private Radios for Private Companies

When TSA was established, that previously mentioned sub-industry of aviation security companies didn't disappear. A pilot program was established that took five airports of the five security categories and had private security companies provide the screening personnel with TSA oversight. That pilot program evolved into the Screening Partnership Program or SPP.

As there are various private screening companies (and one airport itself handling screening, that being Jackson Hole Airport [JAC] in Wyoming) under contract and those contracts change every few years with new bids (or in one case revocation for performance), it's hard to keep track of what the private companies use for radios. Being that they want to keep things cheap, I'm assuming they use cheaper radios and from what I've heard, it's mostly been of the Digital Mobile Radio (DMR) variety.


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