OIF released a new Implementation Agreement (IA) defining a 112 Gb/s Retimed Transmitter Linear Receiver (RTLR) electrical interface, advancing energy-efficient optical module design for AI and hyperscale datacenters. The OIF-EEI-112G-RTLR specification supports Ethernet C2M 100 Gb/s and CEI-112G-VSR-PAM4 16 dB channels while operating across 36–56 GSym/s, enabling compatibility with IEEE 802.3 standards and existing Ethernet ecosystems. By removing the need for a receive-side DSP in optical modules and shifting signal processing to the host device, the IA reduces power, cost, and design complexity at a time when operators face rising bandwidth requirements and tightening energy constraints.
The new framework defines how retimed optical transmitters pair with linear optical receivers—often described as “half-retimed links”—to bridge electrical and optical design boundaries with consistent performance across vendors. At ECOC 2025, more than 30 OIF member companies demonstrated interoperability across 400ZR/800ZR, CEI-224G/448G, multi-span optics, CPO, CMIS, and Energy Efficient Interfaces (EEI). The RTLR portion showed retimed, half-retimed, and unretimed optics working together in multi-vendor environments, validating the approach captured in the IA.
The OIF-EEI-112G-RTLR IA extends the CEI-112G-PAM4 family and provides detailed electrical/optical requirements, parameter definitions, and test methodologies. Operators and module vendors can now rely on a standardized blueprint for lower-power pluggable optics aligned with AI-era network scaling demands. “Across the ecosystem, OIF heard a clear message — the industry needs robust lower power links that are IEEE compliant,” said Jeff Hutchins, OIF PLL Working Group EEI Vice Chair (Ranovus).
• Defines a 112 Gb/s chip-to-module RTLR interface for energy-efficient optical modules
• Supports Ethernet C2M 100 Gb/s and CEI-112G-VSR-PAM4 16 dB channels
• Operates in the 36–56 GSym/s range for full Ethernet compatibility
• Eliminates receive DSP in modules, reducing power and complexity
• Demonstrated at ECOC 2025 as part of OIF’s Energy Efficient Interfaces track
• Fully aligned with IEEE 802.3 standards
🌐 Analysis: OIF continues to expand its Energy Efficient Interfaces portfolio, complementing earlier CEI-112G and emerging CEI-224G/448G efforts as hyperscalers seek lower-power optical paths for AI clusters. This IA arrives as vendors increasingly explore LPO-style architectures, half-retimed designs, and host-based DSP consolidation to contain power budgets across 800G and 1.6T optics. The RTLR specification positions OIF as a central coordination point between IEEE, Ethernet implementers, and the growing AI-optics ecosystem.
🌐 We’re tracking the latest developments in networking silicon. Follow our ongoing coverage at: https://convergedigest.com/category/semiconductors/
