Wolf was associated with the installation and preliminary commissioning of the MBTT in 2017. He then led the MBTT through a rigorous certification process with the U.S. Army Space and Missile Defense Command, finished in 2019, demonstrating that the get and transmit efficiency of the antenna was enough for it to run on the Wideband Global SATCOM (WGS) system.
A constellation of 10 satellites owned and operated by the U.S. Department of Defense, WGS provides high-data-rate connectivity in between numerous points on Earth. Since 2019, Wolf has actually acted as primary private investigator on a job that owns the MBTT, supporting the development of the U.S. Space Forces Protected Anti-Jam Tactical SATCOM (PATS) abilities.
” PATS is developing the capability to provide protected tactical waveform, or PTW, services over WGS, along with over commercial transponder satellites and brand-new DoD satellites with dedicated onboard PTW processing,” says Wolf.
The Multi-Band Test Protected and terminal Anti-Jam Tactical satellite communications development team collects inside a radome at MIT Lincoln Laboratory. Credit: Glen Cooper
As Wolf describes, a waveform is the signal transmitted between two modems when they are communicating, and PTW is an unique kind of waveform created to provide extremely protected, jamming-resistant communications. Lincoln Laboratory started establishing PTW in 2011, contributing to the initial design and system architecture.
” Our prototype PTW modems have been fielded to industry sites all over the nation so suppliers can test versus them as they develop PTW systems that will be deployed in the real world,” states Wolf. The preliminary operating capability for PTW services over WGS is anticipated for 2024.
Personnel originally conceived the MBTT as a test asset for PTW. Directly below the MBTT is a PTW advancement lab, where scientists can run connections straight to the antenna to carry out PTW testing.
Lincoln Laboratory specialist John Boughner (foreground) helps 2 General Dynamics engineers in installing a new antenna feed throughout the initial MBTT setup. Credit: Glen Cooper
One of the style goals for PTW is the flexibility to run on a large range of RF bands relevant to satellite communications. That indicates researchers need a way to evaluate PTW on these bands. The MBTT was designed to support 4 frequently used bands for SATCOM that span frequencies from 7 GHz to 46 GHz: X, Ku, Ka, and Q. However, the MBTT can be adapted in the future to support other bands through the design of additional antenna feeds, the devices linking the antenna to the RF transmitter and receiver.
To switch between the various supported RF bands, the MBTT needs to be reconfigured with a new antenna feed, which discharges signals onto and collects signals from the antenna dish, and RF processing parts. When not in use, antenna feeds and other RF parts are kept in the MBTT command center, situated below the main platform of the antenna. The feeds be available in a variety of sizes, with the biggest signing up 6 feet in length and weighing nearly 200 pounds.
To swap out one feed for another, a crane inside the radome is used to lift up, unbolt, and get rid of the old feed; a 2nd crane then lifts the new feed up into location. Not only does the feed upon the front of the antenna need to be replaced, but all of the RF processing parts on the back of the antenna– such as the high-power amplifier for enhancing satellite signals and the downconverter for converting RF signals to a lower frequency more suitable for digital processing– likewise require to be changed. A team of proficient technicians can complete this procedure in four to 6 hours. Prior to researchers can run any tests, the specialists must adjust the brand-new feed to ensure it is operating properly. Usually, they point the antenna onto a satellite understood to relay at a specific frequency and collect get measurements, and point the antenna directly into free space to gather transmission measurements.
Considering that its setup, the MBTT has actually supported a vast array of tests and experiments involving PTW. Throughout the Protected Tactical Service Field Demonstration, a PTW modem prototyping effort from 2015 to 2020, the laboratory performed tests over a number of satellites, consisting of the EchoStar 9 commercial satellite (which provides broadband SATCOM services, including satellite TV, across the country) and DoD-operated WGS satellites.
In 2021, the lab used its PTW modem model as the terminal modem to carry out an over-the-air test of the Protected Tactical Enterprise Service– a ground-based PTW processing platform Boeing is developing under the PATS program– with the Inmarsat-5 satellite. The lab again used Inmarsat-5 to check a model enterprise management and control system for allowing resistant, uninterrupted SATCOM. In these tests, the PTW modem prototype, flying onboard a 737 aircraft, interacted through Inmarsat-5 back to the MBTT.
” Inmarsat-5 supplies a military Ka-band transponded service ideal for PTW, along with a business Ka-band service called Global Xpress,” explains Wolf. “Through the flight tests, we had the ability to demonstrate resistant end-to-end network connections across several SATCOM paths, consisting of PTW on military Ka-band and a commercial SATCOM service. By doing this, if one satellite interactions link is not working well– perhaps its congested with too many users and bandwidth isnt enough, or somebody is trying to interfere with it– you can switch to the backup secondary link.”.
In another 2021 demonstration, the laboratory used the MBTT as a source of designed disturbance to test PTW over O3b, a medium-Earth-orbit satellite constellation owned by the company SES. As Wolf explains, SES supplied much of their own terminal antenna devices, so, in this case, the MBTT was helpful as a test instrument to simulate different kinds of disturbance. These disturbances ranged from misconfigured users transmitting at the incorrect frequencies to simulation of sophisticated jamming strategies that might be deployed by other nation-states.
The MBTT is also supporting worldwide outreach efforts led by Space Systems Command, part of the U.S. Space Force, to extend the PATS ability to international partners. In 2020, the laboratory used the MBTT to demonstrate PTW at X-band over SkyNet 5C, a military communications satellite providing services to the British Armed Forces and union North Atlantic Treaty Organization forces.
” Our role comes in when an international partner states, PTW is fantastic, but will it deal with my satellite or on my terminal antenna?” explains Wolf. “The SkyNet test was our very first utilizing PTW over X-band.”.
Connected through fiber-optic links to research study facilities across Lincoln Laboratory, the MBTT has likewise supported non-PTW screening. Personnel have actually tested brand-new signal processing innovation to reduce or get rid of interference from jammers, brand-new techniques for signal detection and geolocation, and new methods of connecting PTW users to other Department of Defense systems.
In the years ahead, the lab anticipates carrying out more screening with more user neighborhoods in the Department of Defense. As PTW reaches functional maturity, the MBTT, as a referral terminal, might support screening of vendors systems. And as PTS satellites with onboard PTW processing reach orbit, the MBTT could add to early on-orbit checkout, measurement, and characterization.
” Its an amazing time to be included in this effort, as suppliers are establishing genuine SATCOM systems based on the principles, models, and architectures weve established,” says Wolf.
The radome securing the Multi-Band Test Terminal– a big antenna on an MIT Lincoln Laboratory structure roof– is shown illuminated during the night. Credit: Glen Cooper
Reconfigurable antenna can transfer and receive signals over multiple radio-frequency bands appropriate to industrial and military applications.
Called the Multi-Band Test Terminal (MBTT), the antenna can turn 15 degrees per 2nd, completing a single transformation in 24 seconds. At this speed, the MBTT can discover and track satellites in medium and low Earth orbit (medium and low refer to the elevation at which the satellites orbit the Earth).
Prior to the setup of the MBTT in 2017, the lab relied on a variety of smaller sized antennas for SATCOM screening, consisting of OTAKaTT, the Over-the-Air Ka-band Test Terminal. The MBTT is seven times more delicate compared to the nearly eight-foot size OTAKaTT antenna. And unlike its predecessor, the MBTT, as its name suggests, is developed to be easily reconfigured to support numerous radio frequency (RF) bands utilized for military and business satellite SATCOM systems.
The MBTT was designed to support 4 frequently used bands for SATCOM that cover frequencies from 7 GHz to 46 GHz: X, Ku, Ka, and Q. However, the MBTT can be adjusted in the future to support other bands through the style of additional antenna feeds, the devices connecting the antenna to the RF transmitter and receiver.
In 2021, the laboratory utilized its PTW modem model as the terminal modem to perform an over-the-air test of the Protected Tactical Enterprise Service– a ground-based PTW processing platform Boeing is establishing under the PATS program– with the Inmarsat-5 satellite. In these tests, the PTW modem prototype, flying onboard a 737 airplane, interacted through Inmarsat-5 back to the MBTT.
In another 2021 demonstration, the laboratory used the MBTT as a source of designed interference to test PTW over O3b, a medium-Earth-orbit satellite constellation owned by the company SES. And as PTS satellites with onboard PTW processing reach orbit, the MBTT might contribute to early on-orbit checkout, measurement, and characterization.
” As a much larger, more powerful, and more flexible test possession than OTAKaTT, the MBTT is a game-changer for making it possible for the advancement of sophisticated SATCOM innovation,” says Brian Wolf. He is a technical staff member in Lincoln Laboratorys Advanced Satcom Systems and Operations Group.
