Solution Review: A New Approach to Low Probability of Intercept/Detect (LPD/LPI) Satellite Communications (SATCOM)
Wednesday, August 21, 2019: 8:40 AM - 8:55 AM
The Warfighter demand for LPI/LPD/Anti-Jam (AJ) communications against increasingly sophisticated adversaries mimics the historical contest between armor and artillery. The traditional communications approach to counter the threat uses expensive, hard-to-use, nuclear-hardened communications systems or direct-sequence waveforms to protect low capacity data links by spending large amounts of bandwidth. Viasat's approach is to arm our warfighters with affordable, resilient, high-capacity, easy to use, rapid deploy SATCOM systems that have inherent LPI/LPD/AJ protection. This requires our adversaries to bring their most exquisite and expensive systems to the field, to invest considerable resources, and yet fail against our flexible, affordable systems. Our approach is based on a whole-system perspective, and Viasat's High-Capacity Ka (HC-Ka) satellite communications solutions show that Industry can provide high information rates while addressing the need for SATCOM systems to be LPD/LPI/AJ. In addition to LPI/LPD/AJ attributes, warfighters also require LPA/LPG (attribution, geo-location) properties to provide essential communications with minimum emissions-based risk. A whole-system approach integrates all elements: orbit, frequency-band, satellite, waveform and terminal, optimizing end-to-end performance to achieve unprecedented capacity and resilience for millions of users. This approach stands in contrast to the traditional SATCOM design approach where operators piece together a system from a variety of components, including the modem (and waveform), terminal, and satellite. The traditional, lowest-common-denominator approach is sub-optimal, and the warfighter bears the brunt of the shortfall. A SATCOM network that can support a million legitimate users can also tolerate high levels of interference (AJ), while the scale of the network improves LPD/LPA/LPG properties. SATCOM networks that support 100s of Gbps of capacity are designed to work with small, low power, Ka-band user terminals that are more LPD than large, high powered terminals. HC-Ka networks support more spreading and better automated network authentication than traditional DoD resilient waveforms: higher capacity and less detectable. With 250-500 MHz carriers and 100s of Gbps of capacity, Viasat and other HC-Ka providers can support advanced LPD SATCOM waveforms. GEO and MEO HC-Ka systems force the adversary to use his most sensitive detectors at close range and bring his largest ECM assets to bear to jam the system: tipping the armor-artillery scale in our favor. Viasat has incorporated its HC-Ka technology in its currently fielded terminals, such as the AN/TSC-241 MMT. Small, light, and battery-operated, MMT delivers 18/5 Mbps capacity (typical): much more than typically provisioned for traditional Ku-band trailer-mount terminals designed for operation in worst-case conditions on poor-performing satellites and constrained bandwidth. On Viasat and other HC-Ka satellites, there is no worst caseunprecedented performance is achieved anywhere within the HC-Ka footprint. Viasat's HC-Ka technology can be retrofitted to traditional military SATCOM terminals, increasing data rates while reducing electromagnetic footprint: when only 75 cm of 2.4m aperture is illuminated, the rest acts as a shield to reduce sidelobes and detection. Demonstrations of the MMT on HC-Ka in northern Norway provided the same service capacity as demonstrations in Eastern Europe or in Germany.