The Stack Archive

Hardware-agnostic military comms system is an intriguing prospect for the private sector

Tue 4 Nov 2014

Though it boasts one of the most opaque and uninformative of acronyms, Software Reprogrammable Payload (SRP) is among the most ambitious and unsung technologies to filter down from space research into military usage – and to offer potential in the private sector down the line.


SRP is designed to facilitate continuous communication across a range of partly or entirely incompatible voice and data systems. Though frequently associated with the Shadow 200 Tactical Unmanned Aircraft System drone, SRP effectively facilitates a node-based mesh network, via hub drones or mobile placements, where none of the devices are from the same manufacturer or even, literally, on the same frequency.

Chris Huffine of the Naval Research Laboratory (NRL) leads SRP development and testing at the Naval Research Laboratory in Washington, which will be shipping 100 SRP units to USMC Aviation from 2016.

“We’re not trying to replace the standard military green radio that industry already builds,” he explains. “We’re trying to provide that server or that nexus that allows you to tie all those different radios together.”srp-table

SRP also handles data over a number of frequencies, enabling disparate display technologies and other forms and protocols of communication to be transmitted and shared among personnel.

The system, co-developed between the Office of Naval Research and the NSA, is already included as a functioning, battle-ready technology [PDF] in the Marine Air-Ground Task Force Electronic Warfare scenario. The core runs on Linux and utilises the NSA’s Redhawk framework. The viability of the project, which is itself an ambitious attempt to redefine interoperability, depends on a friendly IDE.


Huffine explains: “Just like Apple doesn’t create all the applications for that phone, we can give out that software development kit and we can engage academia, FFRDCs [federally funded research and development centres], and industry to help us.”

The mesh-network aspect of SRP, even only as a rough analogy for a system intended to unite disparate systems, is an obvious advantage in military operations, where units might be cut off from command centre infrastructure but still retain access to one node that is not.

“The digital interoperability idea is to get as many Marine Corps aircraft capable of being those nodes in that ‘string of pearls,’ as they sometimes call them—in addition to Navy, Air Force, whatever types of aircraft are available. So maybe you have a KC-130 tanker that’s up there, you know, keeping those MV-22s filled up with gas: it might be a key node in the string of pearls.”srp-layout

Beyond the support function, using SRP as a method of interception or jamming, which it is capable of, is more problematic. SRP takes in so many spectrum capabilities that it may well end up attempting operations which are legal on others but not on the frequency or protocol being used. Listening and jamming signals are also currently regulated by different sections of U.S. law, and overseen by different agencies.

The technology is developed by the Space Systems Development Department of NRL, and the next iteration of SRPs, known as Spiral 2, will include Tactical Targeting Network Technology – capable of accelerating the kill chain – and the military tactical data exchange system Link16.

SRP in the private sector

In a public and private environment which is plagued by interoperability issues and rapidly abandoning proprietary lock-in in favour of cooperative open-source infrastructure, SRP-style transliteration offers new possibilities to Communication as a Service (CaaS).

But ironically SRP seems to be emerging not just from the inter-system problems that have always plagued military technology between generations and departments, but from the same pressure on budgets that is seeing the private sector looking to abandon hardware development in favour of software systems that can redefine the available hardware.

The NRL already admits that depending on advanced systems that redefine legacy systems could erode command and control information sharing processes. In the private sector, the prospect of enabling inter-systems communication as an on-going and evolutionary software development process could shift economic attention almost entirely away from hardware.


feature military research
Send us a correction about this article Send us a news tip