L-Band TACSAT Capability to Complement Existing UHF and VHF channels

Many MOD users rely on secure UHF TACSAT and VHF radios to provide all-informed communications for command, control and coordination of widely dispersed forces in austere environments without the delay of deploying terrestrial infrastructures or the operational burden of protecting and sustaining them. TACSAT is in very high demand by government users as it easily and reliably extends tactical Push-to-Talk radio networks to wide area Beyond Line of Sight (BLOS) communications where existing networks are over utilized. However, UHF TACSAT channels are in short supply and expensive.

Inmarsat’s global L-TAC service complements the scarce UHF TACSAT satellite capacity with a single-hop, low-latency voice and data service, providing additional reliable capacity when UHF TACSAT channels are inaccessible. Available on a global, seamless basis, L-TAC enables existing in-service tactical radios to access BLOS without the need to modify the radio hardware or the cryptos.

The L-TAC service utilizes the ability of Inmarsat-4 satellite fleet to connect L-band transponders on the satellite to provide a single-hop relay in space through existing UHF and VHF tactical radios. This is accomplished using a small external frequency adaptor on the existing military radio, which converts between the UHF/VHF and L-band, and connects to one of a range of directional or omni-directional L-band antennas substituted for the existing UHF/VHF antenna.  This approach enables L-band to augment UHF TACSAT capacity resources, offering service throughout the global footprint of the Inmarsat-4 constellation. The small hardware package that will include the L to UHF/VHF frequency convertor, an integrated power supply and omni-directional antenna which will support both fixed and on-the move applications. Versions that are available include: manpack, marine, and vehicle.

Inmarsat’s L-TAC service is fully flexible and designed to meet government security and reliability requirements cost-effectively. It is quick to set up, providing a fully-configured solution which needs minimal user intervention before deployment. Once deployed, remote management and support is provided through a 24/7 network operation center.

Inmarsat’s L-TAC communication-on-the-move service is available for vessels, vehicles and dismounted warfighters, providing a combination of reliable voice and data connectivity that is available globally, independent of local infrastructure. The L-TAC service is easy to acquire, available via flexible bandwidth leasing options for coverage and duration.


  • Uses existing VHF and UHF radio hardware and cryptos
  • Very small form factor, lightweight and low power consumption
  • Global access with strategic backhaul
  • Narrow, Regional and Customised Beam footprints available
  • Beyond Line of Sight Communications without additional infrastructure             
  • Easy to use
  • Netted voice and data for all informed network
  • On the move, on the pause or at the halt
  • Channel lease options from one month

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