Software-defined radio (SDR) tech drives military communications today
In this Q&A with Mike Jones, Vice President and General Manager of the Rockwell Collins Communication and Navigation business in Cedar Rapids, Iowa, he discusses how software-defined radio (SDR) technology has changed military communications over the last 25 years, how it is being integrated to today, and future communications innovations such as cognitive radio. Edited excerpts follow.
MCHALE REPORT: Please provide a brief description of your responsibility within Rockwell Collins and your group’s role within the company.
JONES: I am Vice President and General Manager of the Rockwell Collins Communication and Navigation business, which reports in through Rockwell Collins Government Systems. My business focuses on the military market where we provide communication products serving air, ground, and naval domains domestically and around the globe. My business also provides navigation products and is involved with the development of GPS and GNSS equipment and technology.
MCHALE REPORT: Can you please give a history of SDR technology, including how it was a key component of the now defunct Joint Tactical Radio System (JTRS) program, of which Rockwell Collins was a part of?
JONES: SDR communication systems meet a need for enhanced mission effectiveness through shared situational awareness and improved information sharing and collaboration, as well as synchronizing ground and airborne radios into robust networks. This need - articulated by the DoD and ministries of defense around the world since the mid 1990s – was the driving force behind the DoD’s JTRS program. While the large JTRS program is now defunct, a number of variants survived and are moving into full rate production and competition today such as the HMS Manpack and the Rifleman Radio. On the datalink side the MIDS J still exists as it enabled Link 16 capability for collaboration between air and ground forces.
The Software Communications Architecture (SCA) standard was what made these variants work by enabling the creation of many types of waveforms such as the Wideband Network Waveform (WNW) and the Soldier Radio Waveform (SRW). More waveforms have since been added and are available in a software repository and all compliant with the SCA standard. The success of JTRS was in the waveforms and the SCA.
The original program struggled with the hardware side of the equation, which substantiated the need for greater processing power. But, now processing technology has caught up and what has developed today is the availability of system-on-ship (SoC) hardware. This SoC capability is being brought to market in the HMS Manpack, Rifleman Radio, and MIDS J family of programs.
MCHALE REPORT: Many say SDR is now “a solved problem,” and that today it is all about how to integrate the technology. Do you agree with that statement and how do you see SDR technology being used today in defense programs?
JONES: When I look at the big picture regarding SDR I think the industry must deliver technology that meets the concept of operations goals and objectives.
SDR enables the ability to pick a waveform and a set of functions to create an ability to switch around multiple channels, thus bringing situational awareness and enabling voice and data to move across an ad hoc network. The real challenge is to bring simplicity to SDRs in order to make them easier to operate.
The challenge will be around continued improvement in SWaP, range, and cost. So while it’s fair to say SDR is mature, the technology is being pushed into smaller form factors and there is still a lot of engineering to be done year after year to keep up with that trend.
MCHALE REPORT: Many say that SDRs will evolve to enable smartphone-like multi-functionality in the near future. What are some new functionalities and capabilities that we may see in future programs?
JONES: There is a current waveform that does much of this and it is called the Mobile User Objective System (MUOS). The MUOS program – for which Lockheed Martin is the prime contractor – brings cell phone like capability to a tactical radio. The MUOS waveform is Internet Protocol (IP)-based and enables users to run apps over a satellite communications (SATCOM) network. The Rockwell Collins ARC-210, which currently has Demand Assigned Multiple Access (DAMA) and Integrated Waveform (IW) satellite communications capabilities, will add the MUOS waveform.
Will there someday be additional cell phone to cell phone networks? That could happen but there are security challenges that need to be overcome first.
The key capability in my opinion is SDR’s ability to host modern waveforms over the network. It all starts with fielded and soon to be fielded software-defined tactical radios that can form ad hoc networks, with commanders choosing what to put out over the network such as video intelligence and surveillance. This type of radio is being deployed and fielded more and more with combat brigades and should continue to be deployed over the next three to five years.
MCHALE REPORT: How are reduced size, weight, and power (SWaP) requirements impacting SDR designs? What are the tradeoffs with smaller tech?
JONES: Regarding SWaP the first part that needs to be dealt with every time is power management. Savings in weight and heat comes from power management. The first step in designing any SDR is power management, which can be accomplished via waveform optimization, sleep modes, and other methods.
Once you get power management figured out then you can look at reducing size and modern signal processing technology has greatly enabled such reductions. Faster processors in smaller chip sizes have created order of magnitude performance increases in the same or smaller footprints. As embedded processing continues to enable this capability it will allow SDR designers to keep up with SWaP requirements.
MCHALE REPORT: The DoD’s FY 2016 budget request, released earlier this year, had an increase in overall funding, almost a reverse trend from the last few years. How do you see the funding outlook for SDR in DoD programs?
JONES: There are large programs of record entering into competition now and over the next 18 months some will start full rate production. However, I can’t be more specific at this time.
Budgets are trending in the right direction, but the big concern right now is uncertainty. Sequestration has made it difficult to forecast and to find programs of record with steady purchasing power and the continuing appropriation resolutions prohibit new starts. It is difficult to plan and close a business case when you are uncertain of funding priorities and the timing of new starts. If you could move the sequestor and continuing resolutions out of the viewfinder then the base demand for SDR technology is there and will increase as the network benefit it brings the military cannot be ignored.
Which brings me to the trend toward commonality and how that coincides with the benefits of SDR technology. As SDR has matured with advanced waveforms facilitating air-ground connectivity and vice versa as well as connectivity amongst the troops, it has been supported by common technology and common waveforms. This is why Rockwell Collins developed our TrueNet family of SDRs, specifically achieving air to ground connectivity by leveraging common waveforms and software and hardware standards so the radios can be used in multiple applications. All the technical parts of the TruNet network run the exact same waveforms and capabilities and have the potential to support Joint Services and Coalition forces, enabling them to plug and play and work seamlessly together.
MCHALE REPORT: Many say the next radio tech evolution after SDR will be cognitive radio. What are the benefits of cognitive radio and the challenges that still remain in enabling the technology?
JONES: The next layer is cognitive radio. Once you have a SDR with a RF front end and an embedded system that is programmable, the next step is to add sensing. The sensing will enable the radio to change programming by enabling ad hoc networks providing information when it is being jammed or has frequency interference. A cognitive radio will make these changes real time to deal with multiple spectrum environments. We are about five to seven years from seeing a true cognitive radio fielded.
MCHALE REPORT: Outside of defense what areas has SDR technology impacted?
JONES: SDR technology brings the same benefit to law enforcement and paramilitary that it brings to military applications by enabling multiple waveforms in one device through software and embedded processing technology. The transition has been mostly determining which waveforms you port to the non-military devices such as the APCO 25 waveform used by public safety operators.
MCHALE REPORT: Looking forward, what disruptive technology/innovation will be a game changer in the SDR world? Predict the future.
JONES: I will answer that by saying there are three key problems to solve in the near future – the next five to 10 years. The first is network simplicity and the second is spectrum management and solving spectrum management will require some element of network simplicity.
The third is the ability to operate in an anti-access/area denial (A2/AD) environment. There clearly is a tie between spectrum management and A2/AD environment and it will bring additional complexity as well as additional capability. The key for solving this complexity will be through intensive signal processing and spectrum sensing, with software to tie them together to make a whole system.