N251-007 TITLE: Alternative Wireless Technologies for the Aircraft Carrier Flight Deck

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Integrated Network Systems-of-Systems

OBJECTIVE: Develop a wireless communication method that functions inside shipboard radio frequency (RF) limited environments to accommodate data links between mobile devices and computer systems.

DESCRIPTION: The aircraft carrier flight deck is not only a physically hazardous environment, but a highly contested electromagnetic environment. Allowing wireless communication between computers and mobile devices on a flight deck is a challenging problem. Various systems such as radar interfere with bands in the electromagnetic spectrum, ruling out technologies such as commercial Wi-Fi as a solution. The importance of managing Electromagnetic Interference (EMI) is especially important in the presence of ordnance where technologies must be tested under Hazard of Electromagnetic Radiation to Ordnance (HERO). Most importantly, there are RF restrictions due to Emissions Control (EMCON) during operations. Wireless communication on the flight deck is an enabler to many key technologies. This includes mobile devices used for providing naval aviation information to flight deck Sailors, audio communication devices, and autonomous systems relying on wireless links. Creating a flight deck compatible wireless solution would improve many aspects of Sailors’ jobs during operations.

There have been many advancements in wireless links using technologies outside of the RF spectrum. Technologies based on free space optics use both the visible and nonvisible spectrum to transfer data. For example, Light Fidelity (LiFi) technologies have been created to provide a WiFi alternative in indoor environments. Ceiling mounted lights can be used to transfer data to receivers on laptop computers. Long distance data transfer has also been demonstrated to be able to send data in outdoor environments when directionality and power are adjusted. However, there are disadvantages in the light spectrum due to the need for direct line of sight and loss of effectiveness in degraded weather conditions. Alternatively, the sound spectrum outside of human audible frequencies can be used as a medium but has disadvantages in range and interference. There are difficulties in both mediums when implementing within a wireless network with multiple devices.

The U.S. Navy is seeking a solution to prototype a wireless communication network that is capable of being used in RF limited environments. It must provide bi-directional connectivity between mobile devices across the entirety of the aircraft carrier flight deck. While examples were given above with solutions outside of the RF spectrum, methods that make use of RF with low probability of intercept and detection is also acceptable. The proposed solution should include hardware designs for networking devices such as access points and peripherals to enable mobile device connectivity. A plan on how to implement connectivity across an area as large as a carrier flight deck should be included. The solution should accommodate data throughput of at least 100 kbit/s from device to device on a single channel to accommodate voice and intermittent data transfer. Technologies will be judged based on reliability, compatibility with shipboard emissions requirements, and anticipated data rates.

PHASE I: Define and develop a concept for wireless connectivity within an air capable shipboard environment that eliminates or reduces radio frequency emissions. Perform an initial assessment of the technology through modeling and simulation or in a lab setting where data is sent between a minimum of two devices using the wireless medium. Provide a plan to expand the technology to a local area network. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Develop a prototype wireless network of devices using a wireless medium that eliminates or reduces radio frequency emissions. Produce prototype network hardware such as transceivers and access points. Demonstrate the technology in an outdoor environment at ranges experienced on aircraft carriers. Provide an assessment of probability of detection, as well as test results for latency, data rates, and reliability. Provide documentation on hardware architecture and device drivers.

PHASE III DUAL USE APPLICATIONS: Integrate the wireless network developed in Phase II into an air capable ship flight deck and validate system functionality. Test its compatibility within the environment (EMI and HERO requirements) and determine if the system has a low probability of detection.

The project has significant implications to the telecommunications industry. Wireless transmission outside of commonly used RF bands are vital to future generations of wireless networks (i.e., 6G) to use in conjunction with RF. It increases overall bandwidth by offloading data sent through RF bandwidth to other mediums. The technology can be used indoors within local area networks and outdoors through cell phone towers.

Technology developed in this effort can be implemented in locations where traditional RF or WiFi cannot be used. It has implications within areas where there is equipment sensitive to RF such as medical devices. It can be used in undersea communications systems where traditional WiFi will not work.

REFERENCES:

1. Haas, H.; Yin, L.; Chen, C.; Videv, S.; Parol, D.; Poves, E.; Alshaer, H. and Islim, M. S. "Introduction to indoor networking concepts and challenges in LiFi." Journal of Optical Communications and Networking, 12(2), 2020, pp. A190-A203. https://opg.optica.org/jocn/fulltext.cfm?uri=jocn-12-2-A190&id=424075

2. Sugumaran, S.; Sampath, G;, Deivasikamani, G.; Maurya, N. K. and Srinivas, C. V. "FSO (free space optics) application for various weather conditions and wavelengths." 2022 IEEE 2nd Mysore Sub Section International Conference (MysuruCon), October 2022, pp. 1-6. https://doi.org/10.1109/MysuruCon55714.2022.9972385

3. Jiang, W. and Wright, W. M. "Multichannel ultrasonic data communications in air using range-dependent modulation schemes." IEEE transactions on ultrasonics, ferroelectrics, and frequency control, 63(1), 2015, pp. 147-155. https://ieeexplore.ieee.org/abstract/document/7321037

KEYWORDS: Wireless Network; Radio Frequency; WiFi; Optical Communication; Local Area Network; Emissions Control

---