Insight | L-TAC: Tactical Beyond Line of Sight communications for military users


L-TAC: Tactical Beyond Line of Sight communications for military users


Steve Gizinski, Inmarsat Vice-President Special Programs for U.S. Government, details how users benefit from greater connectivity, mobility and capability using our L-TAC service.

Reliable command and control of units that are often widely dispersed and in tough environments is essential to mission success.

Deploying and protecting terrestrial communication infrastructure is not generally a practical or cost effective solution, so military forces have tended to rely on Ultra High Frequency (UHF) tactical satellite (TACSAT) communications.

But a limited supply of UHF TACSAT channels means there is a need for a new solution. With our manufacturing partner, Spectra Group, we have developed L-TAC (L-band Tactical Satellite) – a highly resilient communication capability that provides robust, low-cost, beyond-line-of-sight (BLOS) mobile communication in the L-band using in-service UHF and Very High Frequency (VHF) tactical radios.

L-TAC enables BLOS communications on the move (COTM), voice and data connectivity for military UHF and VHF Push-to-Talk users without the cost of additional terrestrial infrastructure. Using in-service tactical radios and the field-proven SlingShot solution from Spectra Group, rapid deployment and operation of user networks are supported.

Operations on Inmarsat-4 satellite narrow beams and synthesized beams are made possible with a kit that includes omni-directional antennas. Solutions are provided for aviation, vehicle, maritime or dismounted users.

L-TAC uses the same tactical radios as UHF SATCOM, but instead of connecting these radios to a UHF antenna, they are connected to an L-band antenna through a small frequency converter unit.

This allows the user to operate security-accredited equipment over L-band using the same interoperable waveforms as a UHF or VHF.  Because SlingShot has solutions for VHF military and commercial frequencies, the TACSAT net can be extended to include forces not equipped with UHF.

The system is typically used to support ‘Push-to-Talk’ voice networks in a military theatre of operations, where users spread across the coverage area share access to transmit a signal that can be heard by others in the network (similar to a telephone conference call). The service may also be used for point-to-point data communications between terminals in theater.

In addition, the L-TAC/SlingShot combination enables users to transition from larger UHF/VHF antennas to smaller, discreet omni-directional ones, which can be placed on a vehicle, a helicopter or the backpacks of soldiers on the move.

This is a transformative capability for agencies requiring fast-reaction deployment worldwide with optimal portability and security. Users obtain a superior level of secured satellite throughput with small, lightweight antennas supporting highly mobile asymmetric missions, such as patrols from Forward Operating Bases and Airborne Intelligence, and Surveillance and Reconnaissance (AISR).

The L-TAC service is currently in active operations for several nations’ armed forces across the world, and a civilian variant has been launched for police and emergency services.


About the author

Steve is the Vice President of Special Programs of the U.S. Government Business Unit, providing focused support to the Special Operations, Intelligence and aero/UAV Customer communities.

Steve brings to this role 30 years of in-depth experience overseeing mission-critical technology efforts for commercial, intelligence, and U.S. Department of Defense customers. Prior to joining Inmarsat, Steve was the President and CEO of CVG, Inc., a SATCOM start-up and before that held a variety of management positions at Northrop Grumman, Hughes Space and Communications and Lockheed Martin