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

Overview

The XGS-PON & GPON Combo OLT SFP-DD Transceiver is an advanced Multi-Protocol Module (MPM) designed for next-generation fiber access networks. Engineered with the SFP-DD (Small Form-factor Pluggable Double Density) form factor, this module features a unique dual-lane electrical interface that enables the simultaneous, independent transmission of 10G XGS-PON and 2.5G GPON services over a single fiber strand.

This specific model offers a Class C+ optical power budget, providing higher transmit power and receiver sensitivity than standard Class B+ modules. This makes it the ideal solution for networks requiring extended reach or support for high split ratios (up to 1:128). Built to withstand extreme environments, the module is rated for Industrial Temperatures (-40°C to +85°C), ensuring unwavering reliability in unconditioned outdoor cabinets, Remote OLTs (R-OLT), and harsh field deployments.

Key Features

• Dual-Lane SFP-DD Interface: Utilizes a double-density electrical connector to provide two dedicated data lanes (Lane 1 for XGS-PON, Lane 2 for GPON), eliminating the bandwidth bottlenecks common in legacy SFP+ combo modules.
• Class C+ High Power Budget: Delivers superior optical performance (typically >32dB budget), enabling deployment across longer distances or passive optical networks with higher split ratios (e.g., 1:128).
• Industrial Temperature Hardening: Fully tested and certified for operation in a wide temperature range of -40°C to +85°C.
• Four-Wavelength Operation:
  • Downstream: 1577nm (XGS-PON) & 1490nm (GPON)
  • Upstream: 1270nm (XGS-PON) & 1310nm (GPON)
• Integrated Coexistence: Built-in WDM filters combine XGS and GPON signals internally, allowing both services to share the same Optical Distribution Network (ODN).
• Digital Diagnostics: Supports real-time SFF-8472 DDM/DOM monitoring for temperature, voltage, laser bias, and optical power.

Applications

• High-Density Rural Broadband: The Class C+ budget allows service providers to reach subscribers in rural areas where longer fiber runs and multiple splitters attenuate the signal.
• Outdoor Network Nodes: Perfect for deployment in street cabinets and remote nodes where active cooling is unavailable and temperatures fluctuate wildly.
• Seamless Service Migration: Enables ISPs to introduce high-speed 10G XGS-PON packages to premium customers while maintaining existing GPON services for others on the same PON tree.
• SFP-DD Capable OLTs: Specifically designed for modern OLT line cards (such as Nokia ISAM or Calix E7) that utilize SFP-DD ports for high-density Combo PON delivery.

Specifications

Cross-Platform Compatibility

This SFP-DD Combo OLT transceiver follows open standard MSA protocols, ensuring interoperability with major OLT platforms that support the SFP-DD form factor for PON applications. It is engineered to function as a direct equivalent to OEM modules used in high-performance access nodes.

Advantages

The transition to SFP-DD represents a significant leap in OLT architecture. While traditional SFP+ ports have a single row of electrical pins (limiting them to one data stream or requiring complex serialization), the SFP-DD interface adds a second row of contacts. This allows the Combo Class C+ module to interface directly with the OLT’s switch fabric using two separate lanes—one for the 10G XGS-PON traffic and one for the GPON traffic. This architecture reduces latency, simplifies MAC-layer processing, and ensures that the 10G service is not throttled by sharing a lane with legacy traffic.

Furthermore, the Industrial Temperature rating combined with the Class C+ power budget ensures this module can be deployed anywhere—from a climate-controlled central office to a freezing roadside cabinet—without sacrificing signal reach or subscriber density.

FAQ (Technical & Product Questions)

1. What is the main benefit of Class C+ over Class B+ in Combo PON?

Class C+ offers a higher optical power budget (typically exceeding 32dB) compared to Class B+ (approx. 28dB). This extra “headroom” allows operators to use higher split ratios (like 1:128) or transmit signals over longer distances (up to 40km in some valid configurations), providing greater network flexibility.

2. Can I use this SFP-DD module in a standard SFP+ OLT port?

Physical insertion is possible, but full functionality is unlikely. A standard SFP+ port only connects to the first row of pins (Legacy Lane). Since this SFP-DD module uses the second row for the additional PON service (typically XGS-PON), a standard port cannot communicate with both MACs simultaneously. You must use an SFP-DD compatible OLT.

3. Why is this module called “Industrial Temp”?

Industrial Temp (I-Temp) indicates the module is built with hardened components to operate in extreme temperature ranges from -40°C to +85°C. This is critical for outdoor deployments, such as in Remote OLTs (R-OLTs) or street cabinets, where commercial-grade modules (0°C to 70°C) would fail.

4. How does the Dual-Lane interface work?

The SFP-DD connector features two rows of electrical contacts. In this Combo application, Lane 1 is typically dedicated to the XGS-PON 10G signal, and Lane 2 is dedicated to the GPON 2.5G signal. This allows the host OLT to treat the module as two logical ports, simplifying bandwidth management.

5. Is this module compatible with Nokia ISAM OLTs?

Yes, this SFP-DD module is designed to be compatible with Nokia ISAM and FWLT-C line cards that utilize SFP-DD ports for Multi-Protocol Modules (MPM), functioning as an equivalent to parts like the 3FE47581AD.

6. Does this module require two fibers?

No, it uses a single strand of Single Mode Fiber (SMF). Inside the module, a high-precision WDM (Wavelength Division Multiplexing) optical engine combines and separates the four distinct wavelengths (1270/1310nm upstream and 1490/1577nm downstream) through a single SC/UPC connector.

7. What split ratios are supported by Class C+?

Class C+ is designed to support split ratios of up to 1:128, whereas Class B+ is typically limited to 1:64. The actual achievable split depends on the total loss of the fiber plant, but Class C+ maximizes the subscriber count per port.

8. Do I need to replace my ONUs when installing this OLT module?

No. One of the primary advantages of Combo PON is coexistence. Legacy GPON ONUs will continue to communicate with the GPON part of the module, while new XGS-PON ONUs will connect to the XGS-PON part. Both services run simultaneously on the same fiber.