For as long as there has been warfare, military field commanders have tried to extend their range of vision, gather and interpret critical intelligence, and gain strategic and tactical advantages through real-time, uncompromised communications.

The modern (and future) battlespace is a complex, interconnected, multivariable, real-time labyrinth of data acquisition, interpretation, digestion, and distribution in spectrum-based operations – all aimed at instant decision-making for the soldier.

Military systems directed at sensing and information processing for exploitation by tactical commanders must confront significant bandwidth and size, weight, and power (SWaP) constraints. Bandwidth is a particularly consternating battlefield problem; varied platforms require interoperability and backward compatibility between new and legacy platforms, between services and agencies, and networked in real-time between the space layer, the aerial layers, the ground layer, and even to the sub-surface layer.

Soldier as a System

For example, at the ground layer, the ‘Soldier as a System,’ as defined by the U.S. Army, is the idea of networking soldiers and integrating network nodes not typically accessed by soldiers. Variables on the battlefield such as incoming fire, possible points of attack, topography, size, location, and lethality of an enemy, air and surface fires alternatives, all conspire to demand new information and facilitate real-time decisions. Some decisions, such as which weapons to use and where to use them to counter the threat, are literally life or death.

This challenge requires an electronic architecture connecting sensor systems designed to collect, detect, process, and respond to radiation signatures spread over a wide area of the electromagnetic spectrum. On-platform (or on-soldier) sensors include hyperspectral imagers, laser warning sensors and spectral tagging, tracking, surveillance sensors, helmet-mounted ultra-low-light sensors, weapon sights, wearable computers, and handheld devices with interactive digital maps. When presented in an actionable format, this data allows new intelligence and Optics and real-time decision-making for the soldier.

The Connected Battlespace will provide warfighters with a wide variety of wireless sensors that allow instant access to information otherwise delayed or denied by legacy interoperability problems.

One layer higher, the ‘network of networks’ that govern the integrated battlespace and attach to the military’s Global Information Grid (GIG) require high-performance computing and communications in the terascale – and soon the exascale – ranges.

The Connected Battlespace concept enables decisive action using a global network that connects command and control (C2) nodes, analysts, and warfighters with a wide variety of wireless sensors that allow instant access to information otherwise delayed or denied by legacy interoperability problems. Access to bandwidth has been a critical limiting factor when it comes to informing soldiers operating in roles of command and control. The bandwidth bottleneck is a growing obstacle as not only the quantity of data increases, but the number of ways the data is being evaluated and used is also increasing.

Artificial Intelligence (A.I.) is one such tool that is highly valuable, but it requires bandwidth. A.I. is increasingly being used to evaluate data and create instant information-sharing between soldiers, commanders, and remote assets to provide tactical and strategic advantages for individual soldiers and vastly improve their prospects for survival.

In a recent article by Kris Osborn in her online publication Warrior Maven, Dr. Bruce Jette, Assistant Secretary of Army, Acquisition, Logistics and Technology, articulated the bandwidth problem this way:

“I have eight targets and four enemy vehicles. Which ones are the best ones to shoot? Or does everyone have to decide on their own? Or could I have an A.I. program that is looking at all eight vehicles seen and decide how I would distribute fire most effectively? It would be an A.I. program on top of an A.I. program.”

A.I., and the hardware needed to operate it, requires significant increases in bandwidth to accommodate data densities, signal speeds, and the need for unassailable data distribution, anywhere, on-demand, in real-time. In a separate article by Lauren C. Williams in FCW: The Business of Federal Technology, Steve Tourangeau, VP for electronic warfare strategy at Warrior Support Solutions, a research and analysis consulting firm, saw the bandwidth problem this way:

“We didn’t talk across the services and talk across industry. So, what we ended up doing is putting in the field these jammers that stopped the bombs from going off, but they also prevented us from communicating because they were all working within the same frequency… how do we both operate within the same portion of the spectrum without interfering with each other?

“This question is something that we’re going to have to figure out in the not-too-distant future because there just isn’t that much of the spectrum available, and the more and more people that jump in on it, the more congested it is, and the more difficult it is to work within it. We all end up interfering with each other.”

What Does This Mean for the Electronics Manufacturing Industry?

The ever-scaling need to drive faster signals from the chip through the carrier, the printed circuit board, the assembled module, and out to the infinite users requires solutions to the contributing signal loss factor at every level of the electro-metallic pathway. Otherwise, signal loss will ultimately impede the required system-level performance. With growing limitations in electrical chip-to-chip communications at the board level, emerging technologies portend mitigating these issues.

Carbon nanotubes are now emerging for high-speed electron transport and can achieve ultra-high-frequency transistor technology compatible with Complementary Metal Oxide Semiconductor (CMOS) technology. For electronics manufacturing, that demands a decided shift toward far smaller packages akin to multi-chip modules (MCM’s) and system-in-package (SiP) solutions, rather than the ubiquitous printed circuit board (PCB) footprints that typical assembly lines were designed to accommodate. Electronics manufacturers need to invest in technologies that enable production of these micro-scale modules now to make the promise of the Connected Battlespace a reality.

Photonic Interconnects May Drive the Most Significant Efficiencies

A high-level illustration of elements in the connected battlespace.

The concept here is to allow chip-to-chip communications to occur at on-chip speeds and scale the intra-chip densities by orders of magnitude. Using metal, the physical limitations of the materials in which the electrons are managed create a myriad of ‘crossed wire’ problems. Using photonics, greater densities of signals can be generated even if they cross over one another in operation.

On-platform sensors and off-platform communications systems are crucial for establishing situational awareness in the battlespace and managing ultrahigh data rates in the networked battlefield. On-platform systems include the ability to create, distribute, and digest data running between sensors, radars, storage, and processor configurations. The signal paths between these elements need to operate with extremely high demands for speed and integrity, then be transmitted off the platform to facilitate real-time decision making. Metallic interconnect in this realm is self-limiting due to the physical limitations of wires and pitch.

Photonics Offer an Alternative for Next-Generation Military Platforms.

Imagine a next-generation, semiautonomous UAV platform with a flat hyperspectral imaging sensor and a suite of other surveillance devices, all interlinked using silicon photonic processors that generate light beams encoded with harvested imagery. The processors are attached to flex and rigid printed circuits containing planar polymer waveguides to carry the light signal toward optical storage units. A modulator encodes the sensor data. On-demand, a ground-based laser is aimed at a corner-cube mirror mounted on the UAV and retrieves the data in real-time from that element.

The power required for the UAV is minimal because the ground-based laser is supplying much of the energy. The mirror is very small and light, employing micro-electro-mechanical systems (MEMS) in conjunction with the processors along the signal path. The photonic system’s weight can be measured in grams, reducing the overall platform weight and allowing the UAV to gain economies in loitering time, scope of intelligence gathering, and fuel costs.

That example, along with the promise of carbon nanotube technology and an ever-shrinking electronic package, models where the next military systems are going. Developing a complete manufacturing infrastructure beyond metallic interconnect won’t happen overnight. But with the right investment, these technologies usher in the ability to facilitate a new era of strategic and tactical advantages in the Connected Battlespace unlike any the world has seen before.

This article was written by Steve DeWaters, Application Development Manager, Benchmark (Tempe, AZ) For more information, visit here .

Aerospace & Defense Technology Magazine

This article first appeared in the June, 2021 issue of Aerospace & Defense Technology Magazine.

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