TECHNOLOGY AREA(S): Info Systems OBJECTIVE: Free Space Optical (FSO) communications are rapidly maturing in both military and commercial sectors. The objective of this SBIR topic is to leverage these technologies to develop a multi-beam, airborne FSO terminal. The fleet typically operates in widely dispersed formations that are not within line-of-sight (LOS) of each other. Introducing an airborne component greatly expands FSO networks currently under development by the Navy through the addition of beyond-line-of-sight (BLOS) and over-the-horizon (OTH) range extension. DESCRIPTION: FSO communications provide fiber-optic-like data rates in low Size-Weight-and-Power-Cost (SWAP-C) terminals. Their extremely narrow beamwidths, directionality, and operation in the invisible near infrared (IR) region (optical C-band) facilitate naval military communications in contested warfighting environments. The proposed SBIR topic serves as a logical follow-on implementation by introducing a multi-beam, airborne-layer FSO component to expand potential Navy FSO implementations to include cooperating Carrier Strike Groups (CSGs). The SBIR topic expects to tackle the very difficult and unique challenges of developing a modular, integrated airborne multi-beam FSO relay node, capable of multiple, simultaneous beams in one or multiple optical apertures that can provide robust connectivity to ships. Although modem development is not the objective of this SBIR topic, the optical head is expected to interface to a commercial off-the-shelf (COTS) or government off-the-shelf (GOTS) modem to test the functionality of the FSO relay node developed under this SBIR topic. PHASE I: Develop a viable conceptual design for a modular multi-beam, airborne FSO relay node that satisfies Naval air-to-surface communications needs, such as range, atmospherics and weather, aero-optics tolerance, field-of-view (FOV), Pointing Acquisition and Tracking (PAT), and link availability. The concept for the airborne FSO relay node must address how the fully stabilized multi-beam (minimum 3 beams full-duplex) optical head provides 360 degrees azimuth and 105 degrees elevation coverage on manned and unmanned aerial platforms. Single or multiple aperture systems may be considered, with special emphasis on minimizing beam blockage while steering and inter-beam handoffs. Both pod and conformal implementations should be assessed with environmental factors/impacts considered (nominal platform speeds up to 400 mph). The Phase I option period, if exercised, may include an initial system design of a given technology selection, and prototyping of key technology enablers germane to air-to-surface node discovery, beam steering, dynamic PAT, link adaptation and (beam-to-beam) handoff. Modular designs with standard interfaces are encouraged. Include lab measurements and/or analysis of key subsystems to support link margin determinations for relevant link ranges, atmospheric conditions, and aero-optical impacts. Develop a Phase II plan. PHASE II: Develop and prototype a small number of multi-beam airborne FSO relay nodes that must be integrated with a COTS or GOTS FSO modem to support both laboratory testing as well as a field demonstration involving networked operation with air-to-ground relay, ground-to-air, and ground-to-ground nodes. A Phase II option period, if exercised, may consider FSO topology formation and discovery having strong connectivity in a decentralized quasi-mesh configuration. This would combat signal fading and range limitations while offering link options to ensure quality-of-service (QoS) objectives can be met, especially low latency, low packet error rates, and reduced network congestion. PHASE III: Establish a final system design along with a detailed cost assessment to support a low rate initial production (LRIP) estimate. Phase III may include additional technology insertions and an open architecture system to accommodate various optical modems, software algorithm updates, tech refresh opportunities, and platform integration requirements. It is possible that the Phase III effort could involve reasonable low maneuver or level flight, air-to-air links, and/or manned-to-unmanned aerial vehicle (UAV) FSO link establishment. Eye-safe, high data-rate, airborne FSO communication links also have notable dual use commercial applicability. FSO systems can flexibly operate in closer proximity and exploit longer periods of time to close links, thereby allowing near all-weather operation. Increasing use of UAVs in commercial markets may result in RF spectrum allocation conflicts and the need for ubiquitous low-cost, communications-on-demand. Other options may support scientific community whereby extremely large data exchanges can be achieved without having to run fiber. Additional applications may evolve into a high-altitude, balloon-to-balloon relay with hybrid optical-RF cellular networks. The FSO market as of 2015 was $120M and expects to reach $1B by 2020. REFERENCES: 1: Thomas, L. and Moore, C. "TALON Robust Tactical Optical Communications." CHIPS Magazine, Oct. Dec. 201 http://www.doncio.navy.mil/CHIPS/ArticleDetails.aspx?id=55502: Son, I. K. and Moa, S. "A Survey of Free Space Optical Networks." Digital Communications and Networks, Elsevier Vol 3, Issue 2, May 2017, pp. 66-7 http://www.sciencedirect.com/science/article/pii/S23528648163005423: Demers, F., Yanikomeroglu, H., and St-Hiliare, M. "A Survey of Opportunities for Free Space Optics in Next Generation Cellular Networks." IEEE Computer Society, 2011 Ninth Annual Communication Networks and Services Research Conference. http://ieeexplore.ieee.org/document/5771213/4: Mansour, A., Mesleh, R., and Abaza, M. "New Challenges in Wireless and Free Space Optical Communications." Optics and Lasers in Engineering, Vol 89, Feb 2017, pp. 95-10 https://ac.els-cdn.com/S0143816616300252/1-s0-S0143816616300252-main.pdf?_tid=799adf1e-e402-11e7-8c3c-00000aab0f6c&acdnat=1513608674_bfe340439f7c0484bd1f5eb9496c7880KEYWORDS: Laser; Optical; Communications; Free-space; Multiple Beam; Multiple Access CONTACT(S): Santanu Das (703) 588-1036 santanu.das@navy.mil Linda Thomas (202) 404-2062
