Improving the Reach, Resiliency and Relevancy of Link 16: Sponsored Content

As military operations become more dependent on networked sensors and shooters seamlessly working together, there is a greater need for sharing critical information in real time to meet today’s and tomorrow’s challenges.

Resilient waveforms such as the Link 16 tactical data link will be key components in the U.S. Department of Defense’s (DoD’s) approach to networked warfare. Introduced 40 years ago to coordinate NATO air defenses during the Cold War, Link 16 communications continue to evolve into smaller and more diverse form factors, going from theater commands to individual warfighters.

Before the development of Link 16, many platforms essentially used their own proprietary data links. However, one of the goals of Link 16 was to provide a common data link that every service could use that matched or exceeded the bespoke equipment they were using, says Jamie King, a systems engineer with Viasat.

The effect on air defense operations was revolutionary. Before Link 16, typical command and control (C2) for air defense consisted of a command center vectoring in aircraft to coordinates provided by a ground-based radar, explains Pete Camana, Viasat’s business development director of Tactical Data Links. With Link 16, information about incoming threats was distributed across communication networks to the units best able to counter it and information such as radar and sensor tracks could be shared between aircraft within that unit.

“You get a common operational picture that everyone sees, and that makes a real difference,” Camana says.

Another example of this change is how air and ground coordination for close air support is now handled. Traditionally, ground controllers guided attack aircraft using voice. Once the ground controller gives those commands, the pilot has to read the sequence back to verify that they got it correctly, notes Camana.

Link 16 changed this because it allows the ground controller to share information directly from their user device directly to the aircraft’s computer in the same way the data link allows aircraft to share radar track data to intercept enemy planes, says Camana.

Changing with the times

Although Link 16 became the waveform of choice for warfighters, the U.S. military and its allies were limited by the necessity of large radios that usually were operated from aircraft and ground based (C2), King explains.  With that limitation of Link 16 employment throughout the entire fighting forces, there has been a requirement for data link gateways to translate the data to other waveforms, which can introduce the potential for latency and errors. 

With Link 16 on more tactical platforms, the services are doing more to get the waveform out to warfighters while reducing the need for data translation and potential for errors. This expansion, however, requires evolving the network design, with Information Exchange Requirements (IERs) being built in to help warfighters at the tip of the spear, King says.

Besides getting information to units at the tactical edge, Link 16 also lets commanders receive information, greatly enhancing their situational awareness to rapidly changing conditions on the ground, he added.

The introduction of small form factor Link 16 terminals has also led to an explosion of Link-16 capable platforms at the tactical level, says Nigel Nurse, Viasat’s vice president and business area director for Next Generation Tactical Data Links.

“Now we have the ability to give every soldier in a battalion, every solider in a company, a Link 16 handheld radio. However, even with the nature of warfare evolving, we’re still using the outlines of the networks that were designed 10, 15, 20 years ago. That’s where the network has to evolve.” Nurse explains.

Challenges and considerations

The U.S. military faces several communications-related challenges when training in the continental United States (CONUS). This is because parts of the spectrum the military can use overseas aren’t available at home (inside CONUS), as these parts are either reserved for civilian use or used by other US government agencies such as the Federal Aviation Administration (FAA), said Camana.

Because Link 16 radios operate on the same band as radar beacon transponders used by FAA flight controllers, techniques such as frequency remapping (FR) will now allow Link 16 network operation in the United States. FR can help move Link 16 into communications bands that the FAA isn’t using but this is not expected to be available until after 2025, Nurse explains.

Another potential step might involve redesigning communications network architectures to allow for more varied use of Link 16 radios in the U.S. This evolution involves the FAA and other federal agencies not cataloging every Link 16 radio as a large 200-watt terminal, King says. He adds that this is important because the military is considering equipping most individual soldiers in frontline units with small 8-watt handheld Battlefield and Awareness Targeting System–Dismounted (BATS-D) radios that are Link 16 capable.

“There’s an opportunity for having scaled-down network files for those platforms, just to make sure that they’re receiving exactly what they need, and also to be cognizant of the time slot duty factor (TSDF) that the FAA is concerned about,” King said.

Another challenge is scaling as the DoD considers deploying up to 15,000 new Link 16 capable radios. These radios are different from the military’s standard Multifunctional Information Distribution System (MIDS) Low Volume Terminal (LVT) or Joint Tactical Radio System (JTRS) radios. King notes that an important issue is helping the military better understand how it can accommodate using these newer radios in the U.S. while meeting FAA protocols.

From the network planning perspective, they must meet the radio user’s needs and FAA expectations, so more information about the training and operational environments is better. For instance, “If I tell you that for a training evolution, we can only put 10 BATS-D radios in the field in a 2-mile radius to meet the FAA requirements, but in a combat situation there will be many more, that could create some problems for training-like-you-fight scenarios. Making training and operational network scenarios as close as possible is critical,” King said.  

However, if more details are provided, such as having 10 BATS-D radios all connected to a tactical gateway such as a Move Out/Jump Off (MOJO) radio that connects to a larger network via Link 16 Enhanced Throughput messaging, this would help alleviate TSDF concerns in both training and combat scenarios, King adds.

Navigating commercial aviation frequency requirements through techniques such as frequency remapping and more efficient network design will continue to be a major concern for any peacetime military training activities in the U.S.

An increase in improvements

With a variety of Link 16 compatible radios and waveforms appearing in recent years, there has also been an increase in technical improvements. One example is the Link 16 Enhanced Throughput or LET messaging (packing more data in a timeslot), as well as other advanced capabilities such as Concurrent Multi-Netting (CMN) and Concurrent Contention Receive (CCR), which allow radios to receive much more information in one time slot, King explains.

Where older terminals could only receive a single message in a time slot, newer MIDS and small form factor radios are capable of receiving up to four transmissions in one time slot or receive on four different hopping patterns.

“That allows these radios to consume more data and realize more information exchanges from whoever is providing the data to them,” King says.

Another Link 16 application is the Amalgamated Remote Management System (ARMS), which is a Joint Interface Control Officer (JICO)-level network management tool designed to provide users with accurate information about what is happening on their Link 16 networks and flags any user who is not operating per the network load.

This is important for planning operations in the U.S. because it helps JICOs better understand the rules and regulations to ensure TSDF limits in certain geographic areas meet FAA regulations, King adds. ARMS helps users understand how much TSDF is occurring in a given geographic area and by extension, it can help communicate to the FAA about how much bandwidth is being used.

ARMS also permits users to manage their networks in an administrative role. For example, if there is a problem with a radio (or radios), ARMS can disable, turn off or activate a relay.

“It gives you an active means of network management to make sure that you’re abiding by all the TSDF rules,” King says.

ARMS also provides a level of network transparency, allowing network designers and technical operators in the field to manage their systems.

Another tool is a network management system called Terminal Operational Environment Simulator (TOES). This allows network designers to create virtual radios in a computer environment to plan out a network and ensure that all the radios on the system work as intended and comply with spectrum allocation rules and regulations, King says.

The goal is not just to improve the reach, resiliency and relevancy of Link 16, but also to make the entire Link 16 ecosystem more efficient. This includes the evolving concept of operations (CONOPS), information exchange requirements (IER), software tools such as ARMS and TOES, and support equipment such as tactical gateways, as well as comprehensive training.

For more information, go to https://www.viasat.com