'I think, therefore I am': Cognitive Radio Leads War Fighters Into the Breach

Contributor:  Robert Densmore
Posted:  12/22/2010  12:00:00 AM EST
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In this interview, Defence IQ Editor Rob Densmore speaks with Dr Al Emondi, Chief Technology Officer for SPAWAR – US Space and Naval Warfare Systems Command-Atlantic in Charleston, South Carolina.

R Densmore: Can you give us some background on your areas of expertise and how you came to be involved with SPAWAR?
Dr Emondi: I have worked in the area of software defined radio for most of my career.  In 1988, I worked at the [US] Air Force Research Laboratory where we were just starting to perform research on programmable modem technology and wideband RF capabilities.  We considered these the two most challenging areas that must be understood before a programmable radio could be realised. 
About a year later, I started the Tactical Anti-Jam Signal Processor program.  We were able to incorporate additional requirements from other services. Once the joint requirements were captured, we added more funding to the effort and as a result we created the Speakeasy program.  While I managed the first phase of the Speakeasy program there was a significant need to work with international partners in this technology area. 
After about a year of exploratory meetings with Germany, France, and the United Kingdom, we created the FM3TR program which jointly developed a programmable waveform that was used to demonstrate that software radios developed by various international vendors could communicate using a single software defined radio waveform.  That same international group went on to develop a waveform development tool.
While going back to school for my graduate degree, I transferred to the Space and Naval Warfare (SPAWAR) Systems Center, where I continued to work with the international community and the JTRS program.  I worked on the BOWMAN, TETRA waveform development efforts.  I also worked with Japan on a series of waveform projects.
In my relatively new role as the Chief Technology Officer for SPAWAR Systems Center (SSC) Atlantic, I have been interested in researching new capabilities and possibilities that are emerging as a result of the proliferation of SDR technologies.  I have funded a series of research efforts relating to portability, network modelling and other SDR hosted applications.

R Densmore: To many, software defined radio sounds like a field that is both technologically niche and with limited application. Yet, the truth is, the US DOD has already spent millions of dollars on research and development. If you could highlight 3 major benefits of what SDR could do for future war fighters, what might those be?
Dr Emondi: To put this question in context, let’s look at the 2010 Quadrennial Defense Review.  In that document a series of goals and objectives were laid out.  I would argue that SDR makes a significant contribution toward the realisation of these objectives.  For example, the need for Enhanced Robustness of C4ISR Capabilities can be greatly advanced by realizing SDR technology in the military inventory. 
The ability to perform software updates, add new waveforms after the system is fielded, and create new applications to address requirements that emerge after the fielding of SDR systems are some examples of how SDR addresses this requirements.  Similarly, extended lifecycles and expanded functionality objectives are called out in the QDR and are also supported by software radio technologies. 
Recently I have funded research in the Center to explore other applications that can be hosted in a SDR platform and used during the dwell times when the radio is not fully using the computational resources resident on these capable new systems. 
Enhanced Partnerships with Other Nations is also a goal stated in the QDR, and one that we have achieved already in varying degrees through a series of international efforts such as the BOWMAN and TETRA joint efforts.  At last count I believe over 19 European countries use the TETRA waveform. 
If we jointly host the TETRA waveform on our systems, we can be immediately interoperable with a system that can be widely used for peace keeping missions.

R Densmore: Let’s talk radio waveforms – this is a major element of the JTRS project you used to be involved with and a key feature of what makes SDR special in combat operations. Can you describe how SDR handles waveforms differently from legacy radios and why this is important?
Dr Emondi: Radios in the past were largely developed with an architecture that was streamlined for a single waveform.  This allows very specific tradeoffs to maximise efficiency, power, and weight among other aspects of system design.  We could argue that SDR is considered more generalised rather than specialised. 
The RF front ends are much broader in frequency capability while paying a price in sensitivity, and the modems are programmable and flexible while paying a price in size, heat and power.  While these tradeoffs may on the surface seem costly and inefficient, what you gain in flexibility, reconfigurability and upgradability are considered worth it. 
The RF capability of a multiband SDR can be quite beneficial when operating across multiple geographic locations that have differing RF radiation regulations.  Additionally, SDR requirements in the military, compared to commercial use, are quite different and more challenging than modes used in the civilian sector.
For example, some unique aspects which are not widely found in commercial systems are Dynamic Reconfigurability. Broad Spectrum, Low Probability of Intercept (LPI) and Adoption of Open-Systems Architectures.

R Densmore: As DOD set about to research and develop SDR, an interesting business model evolved to carry this process. We now see the private sector heavily involved in making SDR a reality. What are the drawbacks to doing this?
Dr Emondi: SDR is here today, it is in our everyday systems, such as cell phones, and it will be here tomorrow.  There really are only a few drawbacks - which are quite tolerable.  This acceptance is proven by the widespread adoption of SDR in the commercial markets - particularly as evidenced in cell phones. 
A downside is the increased power consumption as compared to ASIC [Application Specific Integrated Circuits] architectures.  Even then, efforts by FPGA [Field Programmable Gate Array] and DSP [Digital Signal Processing] vendors have been continually addressing power and efficiency.  
From a DoD standpoint, the military demand typically dwarfs a commercially adopted technology.  The regular transfer of commercial technologies into the military is proof of this point.  Therefore, the broader the adoption of SDR in the commercial world, the more benefits in advances of SDR-related technologies the DoD can realise.

R Densmore: One aspect that is so appealing about SDR is its potential universality and versatility. In your current role at SPAWAR, what do you see that excites you about future applications of SDR platforms?
Dr Emondi: In the near term I am excited about the new capabilities we are seeing in networking and assured communications through some of the advanced waveforms we are studying.  As these research efforts are realised, we will have a clear transition capability to host these new improved communication waveform designs into a fielded system. 
The potential realised cost savings by simply performing a software upgrade, rather than performing a complete radio replacement programme, is enormous and very timely.  I believe the research in these new communications capabilities has a promising future - and that excites me.

R Densmore: Computer processor functionality is perhaps an ancillary benefit of SDR development – we are now at the point where we can consider other applications for that processor inside a manpack or a handheld radio or in an airborne radio comms system. What do you think some of these possible applications might be in the future battlefield?
Dr Emondi: Having been involved in SDR for most of my career - typically on the R&D side of things - I have been intrigued by new concepts and new capabilities that emerge as a result of this new technology.  Now many vendors throughout the world have SDR communications capabilities and we are moving into a more mature understanding of SDR.  
My role as a CTO requires me to look to the future where SDR may be and what capabilities will be available.  Cognitive radio in the nearer term with geo-sensing capability can lead to smarter frequency allocation.  But looking further out we will have a tremendous computational capability embedded in our communications systems which didn't exist previously. 
I am intrigued about what those new capabilities afford us.  We have a research group at SPAWAR that specializes in understanding the loading of the processing units in the SDR and how those processors could be used for other purposes other than radio communication - such as sensors, data collection, fusion, pre-processing and data reduction.
R Densmore: Is cognitive radio a possibility for frontline use - where are the issues here?
Dr Emondi: Cognitive radio is a possibility - but keep in mind, cognitive radio is an SDR with "smarts" built in.  Many of the cognitive radio concepts are more readily enabled and modified through a programmable architecture.  A near term capability that has been largely discussed is the ability to sense the RF spectrum coupled with a system that is geographically aware. 
This can allow the system to choose the appropriate frequency spectrum based on known licenses that protect frequency use over a particular geographical area.  So, yes, cognitive radio technologies do have their place in the future systems but we need to get the current SDR systems fielded first before we can add on additional capability. 
One concern with cognitive systems is behaviour that is reproducible.  For example, if a SDR system makes a cognitive decision based on a certain set of data, will the system make the same decision at other times? 
If there is unpredictability, how does this affect the security and recurrent operations such that an acceptable level of assurance can be achieved?  In my opinion, these are issues that must be fully understood before we will implement this functionality in military critical systems.

R Densmore: We’ve seen much said about defence spending on both sides of the pond – certainly President Obama’s National Security Strategy and the Quadrennial Defense Review discussion have put some pressure on high price projects like SDR. How do you see this impacting the future of SDR technology and applications?
Dr Emondi: A repeated theme throughout the 2010 QDR is the need to field systems that are well understood and well tested.  When faced with long acquisition timelines, engineers tend to integrate the latest available technology since that system will likely be in the field for quite awhile. 
However, the "latest" technology is often "hyped" beyond what the technology can truly offer, or has an expected availability sooner than what is realistic.  Based on this guidance I would anticipate that future systems will be fielded with technology which is not at the "bleeding edge" and the testing requirements of these systems will be specific and thorough. 
One thing we have learned with SDR as a military critical system is that security aspects need to be considered throughout the system design.  As changes are made, or new software is added, the security implications must also be considered.  This can add significant time to the insertion of new capabilities to be sure that the integrity of the system remains intact. 
I would expect, as systems are fielded and become operational, research in the area of security assurance in the midst of new software proliferation could help alleviate these stresses in the certification process - and eventually lead to quicker technical insertion.
R Densmore: Dr Emondi, thank you for your time today.
Dr Emondi: Thanks Rob, it’s a pleasure.

Robert Densmore Contributor:   Robert Densmore

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