The next conflict will be fought in the dark. Electromagnetic (EM) spectrum and satellite communications capabilities are likely to be neutralized or denied early in any future conflict. China and Russia each have demonstrated the capability to destroy communication and GPS satellites and a willingness to breach U.S. cyber networks. Even disregarding hostile acts, the EM spectrum is congested, and with the advent of 5G, it is likely to become only more so. The future will require fast, secure communication capabilities to maintain an advantage over adversaries. The solution lies in one specific band of the EM spectrum: visible light. “Light fidelity” (Li-Fi) was introduced in 2011 and has since had limited research and development in the field for US military and governmental capabilities.
Light fidelity uses modulated light-emitting diode (LED) bulbs to transfer data through light rather than radio waves. An on-off keying modulation is set up by computer. The flickering properties of LEDs allow the diodes to act as binary signals that a receiver can translate using the same principles fiberoptic cables use. Its primary disadvantages are short range and the necessity of a line-of-sight connection between transmitter and receiver.
Li-Fi has been reported to operate at speeds upward of 224 gigabits per second (Gb/s), 11 times faster than peak speeds for 5G technology. Typical household wi-fi speed is approximately 150 megabits per second (Mb/s); with Li-Fi, data connections would be approximately 1,500 times faster than current wi-fi, and in practice, real-time accessibility could be several thousands of times faster than current capabilities. Communications and data transfer speeds would be virtually instantaneous. With the data needs of the navy growing alongside UAVs, UUVs, and other computer-based systems being fielded. High-speed data communication is becoming a vital strategic necessity.
Li-Fi for Better Security
Radio- and microwave-frequency EM-spectrum-based data networks are difficult to shield from attack. The nature of EM-spectrum technology dictates that signals propagate in every direction, giving actors with nefarious intentions ample opportunity to hijack these signals and gain entry to networks.[1] Li-Fi can be an effective solution to this vulnerability for several critical reasons.
Light is easily shielded from diffusion outside of secured areas, making it more difficult for adversaries to gain access to networks housing sensitive information. Individual LED bulbs can serve as their own network, controlling and tracking any connection. In addition, because an individual LED can serve as its own network, the transfer of classified material can remain on a secured network within a room and never propagate its contents outside of the light’s limit. Secure networks in the Pentagon or the Office of Naval Intelligence, for example, could guarantee containment to individual rooms unless interdicted by an actual physical intrusion. Guaranteeing the light-shielding properties of each router or room will increase the preventability of a data breech.
Despite the disadvantage of line-of-sight requirements, they offer a great deal of security as well. Present adversaries have the technology neither to intercept nor decrypt messages transmitted through light. Light-based data transfer can be used for effective, mobile, long-range data sharing that could be intercepted only with a line-of-sight interruption.
Li-fi as a Communication Tool
At present, in the event of a “dark” battlespace, the Navy will have to operate similarly to the ships of sail. Communication between fleet commander to ship captains or fleet commander and the U.S. mainland will no longer be a viable option. Understanding the consequences of command in a strategic setting must be mitigated by executing a well-formulated commander’s intent. Li-Fi can allow fleet commanders to retain control to accomplish strategic goals.
With U.S. fleet logistics and tactical systems heavily reliant on space-based assets, the United States is very vulnerable to a space-denial attack, whether from cyber or kinetic strikes on satellites and communication assets. Even if a U.S. response leaves adversaries equally blind, the red team will have the advantage of operating in its own backyard. To offset this advantage and maintain tactical parity, the Navy could rely on faster, modern Aldis lamp-like light-based communication assets. This would allow ships to continue operating with all the necessary data transfer uninterrupted by a space attack. Light-based communication and data transfer between ships in close formation could be augmented with unmanned aerial vehicles, buoys, and even other ships to dramatically increase the geographic size of the network.
Even without losing space-based assets, light-based communications still have tactical advantages over other EM-band communications. Light cannot be jammed by adversarial EM warfare assets, nor does it suffer from the cluttering issues that result from proliferation of internet- and satellite-connected devices. With Li-Fi, ships can more choose the precision with which they directionally send information, which can streamline everything from ship-to-ship comms, to Aegis-style targeting coordination in the most intense environments. An entire fleet has the option to eliminate its long-range emissions signature but maintain instant communication across the horizon with friendly assets.
Although Li-Fi does not provide any direct offensive capabilities, it can augment or replace the range projection advantage provided by satellites to our long-range weapons systems. As ships “go dark,” adversaries will lose the ability to intercept communications, facilitating a reduced signature and availability to operate passively, similar to submarines.
For all its advantages, Li-Fi is not a panacea for every potential threat the Navy faces in space and in cyberspace. Research and development will be expensive, as Li-Fi is an emerging technology. Furthermore, the line-of-sight nature of its operation limits Li-Fi and requires highly coordinated assets to work together for it to be tactically effective. The potential capabilities for the Navy are significant, but unproven.
Strategic Necessity
Both Russia and China have made great strides in developing their cyber warfare capabilities, as well as abilities to deny the United States use of its space infrastructure. In both areas, the U.S. Navy is at serious risk of being unable to maintain tactical parity, unless it looks to emerging technologies to supplement the force’s tactical capabilities to execute strategic objectives on the high seas.
Li-Fi stands as a viable option to help secure cyber networks from intrusion, as well as augment the Navy’s data infrastructure to facilitate continued operation in the case of a space denial attack. In Li-Fi exists the potential to achieve and maintain battlefield superiority, not by weapons, but by uninterrupted communications. Li-Fi is by no means the only solution to the dwindling technological gap currently maintained by the U.S. Navy, but its potential is an untapped resource that can enhance a fleet’s tactical effectiveness.
[1] Kevin Beaver and Peter T. Davis. Hacking Wireless Networks for Dummies, (New York: Wiley, 2005), pp. 9–10. See also, Bryan Burns et al., Security Power Tools, (Boston: O'Reilly Media, 2007), pp. 32–33.