17 December 2024

Sumitomo Electric Industries, Ltd. led the ISO document development initiative for publishing an international standard for automotive optical harnesses. This effort was part of the International Standardization of Automotive Ethernet System Integrity Project (FY2020 to FY2022), under the Project for the Acquisition and Promotion of International Standards on Energy Conservation, etc. commissioned by Japan’s Ministry of Economy, Trade and Industry. As a result, ISO 24581:2024*1 (hereafter “ISO 24581”) was officially published on September 24, 2024.

The automotive industry is entering a once-in-a-century period of transformation due to the rapid advancement of CASE*2 and the influx of new players from diverse industries. Automated driving requires data communication from high-precision sensors, leading to a significant increase in communication capacity both inside and outside the vehicle. Conventional automotive electrical harnesses using copper or aluminum materials are not expected to meet the required transmission speeds.

The use of optical fiber is attracting attention as a countermeasure against this problem. The recently published international standard ISO 24581 specifies standards and tests (vibration test, bending test, high/low temperature test, etc.) for optical harness components (multimode glass optical fiber cables, optical connectors, etc.) using optical fiber to maintain stable, ultra-high-speed communications even in harsh environments.

As a result, the adoption of optical harnesses allows for the design of new automotive communication systems that are independent of existing communication standards required for automotive Ethernet communication and image transmission for automated driving. This expands the options for development, accelerates the development of automotive communications components, and contributes to the overall advancement of the automotive industry.  

* LVDS
　An acronym for low voltage differential signaling.

* SerDes
　An abbreviation derived from Serializer/Deserializer, which refers to converting signals between parallel and serial formats (Serializer: converting signals from a parallel bus into a single transmission line, and Deserializer: converting serial signals received via a single transmission line back into parallel signals).

* MIPI
　An acronym for Mobile Industry Processor Interface, a high-speed interface standard primarily used in products related to cameras, such as smartphones, industrial equipment, and automotive applications.

Adopting optical harnesses enables ultra-high-speed communications of up to 100 Gb/s and application to long vehicles such as articulated buses and trailers. Features such as low loss, high noise resistance, long communication distance, thin and lightweight design, and easy cable routing allow for system construction without constraints on the placement of electronic control units (ECUs).  

* ECU
　An acronym for electronic control unit. ECUs are widely installed in vehicles and controls various functions electronically.

* SW
　An acronym for switching unit. SWs optimize the automotive network by appropriately switching the necessary information when many ECUs communicate in bi-directional or uni-directional communications individually. SWs are placed in the areas where ECUs are concentrated.

Sumitomo Electric is a leading company in the automotive wire harness industry and also engages in businesses that support information and communications infrastructure through optical fibers and cables, and related technologies. The achievements in this instance are the result of collaboration between these two business areas.
Moving forward, Sumitomo Electric will continue to maximize synergies between different business sectors, develop automotive optical harnesses based on ISO 24581 standards, realize the application of optical communications to vehicles, and further contribute to the advancement of the future CASE society.

*1 ISO 24581:2024
Road vehicles - General requirements and test methods of in-vehicle optical harnesses for up to 100Gbit/s communication
https://www.iso.org/standard/78993.html

*2 CASE
The term describes trends in the automotive industry and is an acronym for Connected, Autonomous, Shared & Services, and Electric.

(Reference)
May 11, 2023 press release: "Sumitomo Electric Accelerates the Development of Automotive Optical Harnesses for Practical Use in 2026”
https://sumitomoelectric.com/press/2023/05/prs023