Software Defined Modem Powers Resilient Battlefield Links
Sep 14, 2025
Comtech Telecommunications has achieved a major milestone in the satellite communications industry with the certification of its defense-grade SLM-5650B modem to operate with SES O3b mPOWER Medium-Earth Orbit (MEO) constellation. The release on September 10, 2025, prepares the way for hybrid communications services that will support the U.S. Department of Defense (DoD) and allied partners. Under this certification, Comtech will be the first company to receive Government Terminal Certification of a sovereign-certified modem to work on the O3b mPOWER network. This certification is almost a year after SES first ordered these next-generation modems, highlighting the progress made since the contract was signed toward achieving operational capability.
Comtech SLM-5650B Satellite Modem. Credit: Comtech
The SLM-5650B’s technical capabilities highlight its adaptability to the needs of today’s defense communications. This software-defined modem is already certified for the DoD’s Wideband Global Satcom (WGS) system and accommodates multiple Department of Defense and NATO waveforms. Supported protocols include STANAG 4486 Ed3, Direct Sequence Spread Spectrum, and DVB-S2X, with additional waveforms available as required. Its software-defined architecture provides upgrade flexibility, ensuring that the modem can evolve alongside emerging military communications requirements. This future-proof design allows defense customers to adapt rapidly to new mission demands without replacing hardware.
During October 2024, Comtech and SES Space & Defense entered into a partnership agreement, as SES contracted a major deal on special modem technology to be developed to integrate seamlessly with the O3b mPOWER satellite network. This was a procurement of Comtech software-defined SLM-5650B modem and other state-of-the-art communication systems, and the delivery schedules would go all the way to the next twelve months. Although particular contract prices were not disclosed, the time-scale was in tandem with an expediency in market demands of advanced satellite communications potentials, both in defense and commercial sectors. The two organizational leaders emphasized the strategic value of the partnership. Daniel Gizinski of Comtech’s Satellite and Space Communications division said more than 10,000 defense-grade modems produced by his company today provide crucial connectivity infrastructure for Department of Defense and other military operations in the field, such as for the North Atlantic Treaty Organization (NATO), worldwide. He relayed excitement about collaborating with SES to improve the capabilities of warfighters and sustain information superiority over many different theaters of operations. In the same way, David Fields of SES Space & Defense emphasized that the achievements of the missions are the primary focus of their strategic choices, and thus the SLM modem portfolio became a necessary component to fulfill the needs of the customers on a mission.
Market dynamics in government satellite communications show a high upward movement, which is good for SES’s strategic positioning. Throughout the first six months of 2025, SES has seen an impressive 17% year-over-year revenue growth within its Government division. SES leadership has attributed this to growing demand across American and European defense sectors. Overall corporate revenues stood at €978 million over this period, which is a consistent level with the performance of previous years, with the Government segment having a disproportionate impact on growth. This governmental expansion of the market is a direct validation of the strategic importance of Comtech’s modem certification initiative and is in support of SES’s broader operational objectives. The technological base of this success is the O3b mPOWER constellation that is a groundbreaking creation in satellite communications with its Medium-Earth Orbit design. This orbiting system offers better geographical coverage and significantly lower signal latency in comparison to traditional Geostationary Orbit systems. SES has been progressively moving customers off of traditional GEO services to the advanced O3b mPOWER platform with a milestone recorded with its largest maritime customer migration of cruise ship operators over the course of the recent operations. Dependence of the constellation on DVB-S2X protocols—technology that is inherently supported by the SLM-5650B modem of Comtech—ensures that there is easy integration and maximum operational efficiency of the constellation depending on various mission requirements.
