XGS-PON & GPON Combo OLT SFP-DD Transceiver | Class B+ | Industrial Temp (-40°C to +85°C)

Overview

The XGS-PON & GPON Combo OLT SFP-DD Transceiver (Class B+) is a robust Multi-Protocol Module (MPM) designed to facilitate the smooth migration from GPON to XGS-PON in outdoor and harsh industrial environments. Utilizing the advanced SFP-DD (Small Form-factor Pluggable Double Density) interface, this module leverages two distinct electrical lanes to transmit 10G XGS-PON and 2.5G GPON data streams independently, ensuring zero bandwidth contention between services.

This model features a Class B+ optical power budget, making it a cost-effective solution for standard network architectures with split ratios up to 1:64 and distances up to 20km. Rated for Industrial Temperatures (-40°C to +85°C), it is specifically engineered for deployment in non-temperature-controlled environments such as street cabinets, Remote OLTs (R-OLT), and mobile backhaul nodes.

Key Features

• SFP-DD Form Factor (Dual-Lane): Features a double-row electrical connector compliant with MSA standards. Lane 1 handles high-speed XGS-PON traffic, while Lane 2 handles legacy GPON traffic, simplifying OLT MAC processing.
• Class B+ Optical Budget: Provides standard optical performance (typically ~28-29dB budget), ideal for typical urban and suburban fiber deployments with 1:64 split ratios.
• Industrial Temperature Rated: Hardened components allow continuous operation in extreme heat and freezing cold (-40°C to +85°C), eliminating the need for expensive air conditioning in remote nodes.
• Single Fiber Coexistence: Integrates WDM filters to multiplex four wavelengths onto a single fiber, allowing XGS and GPON services to coexist on the same ODN without interference.
• Standard Compliance: Fully compliant with ITU-T G.9807.1 (XGS-PON) and ITU-T G.984.2 (GPON) standards.
• DDM/DOM Support: Built-in digital diagnostics provide real-time monitoring of Tx power, Rx power, temperature, and voltage via the I2C interface.

Applications

• Outdoor Cabinet Deployments: The industrial temperature rating makes this module perfect for Fiber-to-the-Curb (FTTC) or Fiber-to-the-Building (FTTB) setups where equipment is exposed to ambient weather conditions.
• Cost-Efficient Network Upgrades: Allows ISPs to upgrade OLTs to support 10G services without over-specifying the optical budget, offering a lower cost per port compared to Class C+ modules for standard reach networks.
• Hybrid Fiber Access: Supports a mix of legacy GPON residential users and premium XGS-PON business users on the same PON tree.
• SFP-DD Enabled OLTs: Designed for next-generation OLT line cards (e.g., from Nokia, Calix, Adtran) that utilize SFP-DD ports for high-density Combo PON delivery.

Specifications

SFP-DD vs. SFP+ Combo Modules

While both form factors look similar, the SFP-DD interface represents a significant architectural improvement for Combo PON:

• SFP+ Combo: Uses a single electrical lane (10G). The OLT must multiplex GPON and XGS-PON data into one stream before sending it to the module, or use non-standard overclocking. This can add latency and complexity.
• SFP-DD Combo: Uses two electrical lanes. The module connects directly to the OLT’s XGS MAC and GPON MAC separately. This “hard-wired” separation ensures that the 10G service always has full bandwidth availability, regardless of GPON traffic load.

Compatibility

This transceiver is MSA compliant and compatible with major OLT vendors supporting the SFP-DD ecosystem for PON:

• Nokia: ISAM FX and FWLT-C series (Functionally equivalent to Nokia B+ MPM SFP-DD modules).
• Calix: E7-2 Intelligent Access Systems with SFP-DD support.
• Generic: Whitebox OLTs supporting the SFP-DD MSA and ITU-T PON standards.

FAQ (Technical Questions)

1. What is the difference between Class B+ and Class C+?

The primary difference is the Optical Power Budget. Class B+ typically offers a budget of around 28-29dB, suitable for split ratios up to 1:64 and distances of 20km. Class C+ offers a higher budget (>32dB), allowing for higher splits (1:128) or longer reaches. Choose Class B+ for standard deployments to optimize costs.

2. Will this module fit in a standard SFP+ port?

It will mechanically fit, but it will not function correctly as a Combo module. Standard SFP+ ports lack the second row of contacts required to drive the GPON lane of this SFP-DD module. It must be used in an SFP-DD compatible OLT port.

3. Can I use this for indoor Central Offices?

Yes. While it is rated for Industrial Temp (-40°C to +85°C), it works perfectly in temperature-controlled Central Offices (CO). Using I-Temp modules in a CO adds an extra layer of thermal reliability and lifespan, though it is often chosen specifically for unconditioned environments.

4. Does this module support Digital Diagnostics (DOM)?

Yes, it supports the SFF-8472 standard for Digital Optical Monitoring. Operators can remotely view parameters like optical output power, receiver input power, temperature, and laser bias current via the OLT command line.

5. Do I need separate fibers for XGS and GPON?

No. The module contains an internal WDM combiner. You connect a single Single Mode Fiber (SMF) patch cord to the SC/UPC port, and the module handles the bi-directional transmission of all four wavelengths.