N241-020 TITLE: High-Speed Wavelength Division Multiplexing (WDM) Optical Backplane for Avionics Applications

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

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop and package a high-speed (100–400 Gbps) optical backplane based on Wavelength division multiplexing (WDM) for onboard avionics applications.

DESCRIPTION: Current airborne military (mil-aero) core avionics, electro-optic, communications, and electronic warfare systems require ever-increasing bandwidths while simultaneously demanding reductions in Size, Weight, and Power (SWaP). The effectiveness of these systems hinges on (1) optical communication, computation, and networking components that realize high connectivity and throughput, (2) reconfigurability, (3) modularity (plug and play), (4) low-latency, (5) large link budget, and (6) compatibility with the harsh avionic environment. The traditional use of copper traces to support board-to-board communications in sensor and mission computing applications requires hundreds upon hundreds of electrical pins and a spider web of connecting copper traces. For example, the latest embedded system backplane standard, VITA 65 – OpenVPX, has connectors with 728 pins on a 6U size card and 280 pins on a 3U card, and still does not provide enough bandwidth for current or future generation systems. This situation complicates the integration of processing cards within mission computers, sensors, and imaging systems. The saturation of high-speed traces throughout the backplane can generate electrical impedance problems, creating bandwidth limitation problems [Ref 16].

In the commercial data center sector, the bandwidth capacity needs to increase along with reduced power consumption, which has increased the demand for efficient interconnects. These functions are not available with traditional interconnects, which are copper-based, thus further enhancing the utility, and in turn the need, for an optical interconnect technology refresh. Moreover, companies are innovating new solutions with multiple variants of 100 to 400 Gbps+ optical transceiver modules. Although these solutions are designed to enable network operators to address increasing bandwidth demand through simplified network architecture, these solutions are not directly compatible with the complexity of modern digital avionics networks [Ref 1]. Traditional optical implementations based on single-wavelength fiber optic transceivers operating at up to 28 Gbps per lane, 100 Gig Ethernet switches, along with the OpenVPX and Sensor Open Systems Architecture (SOSA™) standards, is testing the boundaries of optical connectors and backplanes in avionics [Ref 2–5].

Future avionics signal transmission rates are expected to increase to 100 Gbps per lane and higher over 50 µ OM4/OM5 fiber. The use of high-speed digital fiber optics and wavelength division multiplexing in avionics backplanes can enable a significant increase in aggregate bandwidths beyond traditional electrical and optical networking implementation limitations. A 100 Gbps (scalable) and WDM-based optical backplane with OpenVPX capability and SOSA™ compatibility will be required for future data transmission and networking in avionics [Ref 6]. As such, a high-speed WDM optical backplane for onboard avionic networking that extends beyond the current state-of-the-art technologies is desired [Ref 7–14].

The proposed WDM optical backplane should minimally meet the SOSA™ roadmap expectations. The proposed high-speed WDM optical backplane must operate across a -40º-+95ºC temperature range and maintain performance upon exposure to typical naval air platform vibration, humidity, temperature, altitude, thermal shock, mechanical shock, and temperature cycling environments [Ref 15]. The proposed approach should incorporate a quick routing capability to overcome latency and connectivity limitations and enable future avionics network architectures.

PHASE I: Develop a WDM optical backplane hardware engineering design with OpenVPX capability and SOSA™ compatibility. Demonstrate the feasibility of the optical backplane design and packaging. The Phase I effort will include prototype plans to be developed in Phase II.

PHASE II: Optimize the backplane design for future avionics networking and sensors. Build and test the optical backplane in a simulated avionics environment that is compatible with OpenVPX and SOSA™. Deliver one optical backplane—including active and passive components—for future WDM avionics application.

PHASE III DUAL USE APPLICATIONS: Support transition of the technology being developed to military aircraft platforms, commercial data center and defense avionics industries.

Commercial sector telecommunication systems, fiber-optic networks, and data centers will benefit from the development of the WDM-based optical backplane such as mitigating the bandwidth limitations. These applications will be able to drive more data input at a higher speed.

REFERENCES:

1. Kultur, O. R., & Bilge, H. S. (2021, July). Comparative analysis of next generation aircraft data networks. In IEEE EUROCON 2021-19th International Conference on Smart Technologies (pp. 317-320). IEEE. https://doi.org/10.1109/EUROCON52738.2021.9535577
2. Standards Organization. (2019). ANSI/VITA 46.0-2019: VPX: Baseline. VMEBUS International Trade Association (VITA). https://www.vita.com/Standards
3. VITA Standards Organization. (2019). ANSI/VITA 65.0-2021: OpenVPX system. VMEBUS International Trade Association (VITA). https://www.vita.com/Standards
4. VITA Standards Organization. (2019). ANSI/VITA 66.0-2016: VPX: Optical interconnect on VPX - base standard. VMEBUS International Trade Association (VITA). https://www.vita.com/Standards
5. VITA Standards Organization. (2019). ANSI/VITA 67.0-2019: VPX: Coaxial interconnect - base standard. VMEBUS International Trade Association (VITA). https://www.vita.com/Standards
6. Sensor Open Systems Architecture. (n.d.). What is the SOSA™ consortium? SOSA. Retrieved March 15, 2022, from https://www.opengroup.org/sosa/trifold
7. SAE Technical Standards Board. (2018). AS5659 WDM LAN standard. SAE. https://www.sae.org/standards/content/as5659
8. Ma, J., Leong, K.-W., Park, L., Huang Y., & Ho, S.-T. (2008, November 9–13). Wide temperature tunable laser packaging for avionic WDM LAN applications [Paper presentation]. 21st Annual Meeting of the IEEE Lasers and Electro-Optics Society (LEOS 2008), Acapulco, Mexico. https://doi.org/10.1109/leos.2008.4688788
9. Whaley, G. J., & Karnopp, R. J. (2010, April). Air Force highly integrated photonics program: Development and demonstration of an optically transparent fiber optic network for avionics applications. In Enabling Photonics Technologies for Defense, Security, and Aerospace Applications VI (Vol. 7700, p. 77000A). International Society for Optics and Photonics. https://doi.org/10.1117/12.852445
10. Peterson, N., Beranek, M., & Heard, E. (2014, November 11–13). Avionic WDM LAN node utilizing wavelength conversion. 2014 IEEE Avionics, Fiber-Optics and Photonics Technology Conference (AVFOP), Atlanta, GA, United States. https://doi.10.1109/AVFOP.2014.6999425
11. Kebort, D. J., Morrison, G. B., Garrett, H., Campbell, J. N., Estrella, S. B., Banholzer, R. H., Sherman, J. B., Johansson, L. A., Renner, D., & Mashanovitch, M. L. (2017). Monolithic four-channel (QUAD) integrated widely tunable transmitter in indium phosphide. IEEE Journal of Selected Topics in Quantum Electronics, 24(1), 1-7. https://doi.org/10.1109/JSTQE.2017.2774205
12. Petrilla, J., Cole, C., King, J., Lewis, D., Hiramoto, K., & Tsumura, E. (2014). 100G CWDM4 MSA technical specifications: 2km optical specifications. CWDM4 MSA. http://www.cwdm4-msa.org/files/CWDM4_MSA_Technical_Spec_1p0.pdf
13. Kolesar, P., King, J., Peng, W., Zhang, H., Maki, J., Lewis, D., Lingle, R., & Adrian, A. (2017). 100G SWDM4 MSA technical specifications: Optical specifications. SWDM. http://www.swdm.org/wp-content/uploads/2017/11/100G-SWDM4-MSA-Technical-Spec-1-0-1.pdf
14. Bechtolsheim, A., & Paniccia, M. (2014). 100G CLR4 industry alliance. Intel. https://www.intel.com/content/dam/www/public/us/en/documents/presentation/clr4-press-deck.pdf
15. Department of Defense. (2019, January 31). MIL-STD-810H: Department of Defense test method standard: Environmental engineering considerations and laboratory tests. http://everyspec.com/MIL-STD/MIL-STD-0800-0899/MIL-STD-810H_55998/
16. Blumenthal, D. J. (2011, October). Terabit optical Ethernet for avionics. 2011 IEEE Avionics, Fiber- Optics and Photonics Technology Conference, San Diego, CA, USA. IEEE. https://ieeexplore.ieee.org/document/6082127

KEYWORDS: OpenVPX; SOSA; Wavelength Division Multiplexing; optical backplane; multimode fiber optic; higher bandwidth

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