OIF Publishes Implementation Agreement for 112 Gb/s Retimed Transmitter Linear Receiver (RTLR) Electrical and Optical Interface Advancing Energy Efficiency

IA connects electrical and optical design to meet rising datacenter and AI bandwidth demands with greater interoperability and power savings

FREMONT, Calif.--(BUSINESS WIRE)--OIF, where the optical networking industry’s interoperability work gets done, today announced the publication of a new Implementation Agreement (IA) — OIF-EEI-112G-RTLR (Retimed Transmitter Linear Receiver).

The new IA defines a high-speed, energy-efficient 112 Gb/s chip-to-module electrical interface that connects retimed optical transmitters with linear optical receivers, sometimes referred to as ‘half retimed optical links.’ It supports Ethernet C2M 100 Gb/s and OIF CEI-112G-VSR-PAM4 16 dB channels, operating in the 36-56 GSym/s range for full Ethernet compatibility. By eliminating the need for a receive DSP in the optical module and leveraging signal processing already available in the host device, the IA helps reduce power, cost and design complexity while maintaining interoperability and performance across vendors — a critical need in AI architectures.

“Across the ecosystem, OIF heard a clear message — the industry needs robust lower power links that are IEEE compliant,” said Jeff Hutchins, OIF Physical and Link Layer (PLL) Working Group Energy Efficient Interfaces (EEI) Vice Chair (Ranovus). “This IA reflects that input, advancing energy efficiency without sacrificing link quality or compatibility. It reinforces that OIF is where collaboration and technical leadership deliver the interoperability specifications needed for AI-driven, high-performance networks.”

Recently at ECOC 2025, more than 30 OIF member companies participated in a comprehensive, multi-vendor interoperability demonstration showcasing technologies spanning 400ZR, 800ZR, Multi-span Optics, Common Electrical I/O (CEI) — including CEI-448G and CEI-224G — Co-Packaging, CMIS and Energy Efficient Interfaces (EEI). Within this broad ecosystem demonstration, RTLR technology was featured as part of OIF’s EEI track, illustrating how retimed, half-retimed and unretimed pluggable optics interoperate across vendors. The RTLR portion specifically highlighted how OIF’s work bridges electrical and optical design to enable lower power, reduced complexity and real-world, multi-vendor interoperability — validating the framework defined in this new IA.

The EEI-112G-RTLR IA builds on OIF’s CEI-112G-PAM4 foundation and aligns fully with relevant IEEE 802.3 standards. The specification details general requirements, electrical and optical specifications, test methodologies and parameter definitions.

About OIF

OIF is where the optical networking industry’s interoperability work gets done. With more than 25 years of effecting forward change in the industry, OIF represents the dynamic ecosystem of 160+ industry leading network operators, system vendors, component vendors and test equipment vendors collaborating to develop interoperable electrical, optical and control solutions that directly impact the industry’s ecosystem and facilitate global connectivity in the open network world. Connect with OIF on LinkedIn, on X, on Bluesky and at https://www.oiforum.com/.