GPON SFP VS Regular BiDi SFP, What're the Key Differences?

Comparing GPON SFP (Gigabit Passive Optical Network Small Form-Factor Pluggable) and regular BiDi SFP (Bidirectional Small Form-Factor Pluggable) modules reveals essential differences crucial for network deployment decisions. Despite both being vital components in optical network setups, GPON SFP and regular BiDi SFP modules offer distinct features tailored to specific networking needs. This article aims to uncover these key disparities, aiding in better understanding and decision-making for network infrastructure planning.

Basic Introduction to GPON SFP

The GPON SFP is a powerful bi-directional single-fiber optical transceiver, boasting either an UPC or APC connector. It delivers an impressive bandwidth of 2.5 Gbits/sec and efficiently caters to end-users through its point-to-multipoint service mode. Unlike earlier GPON setups requiring cumbersome external devices, its compact SFP form factor revolutionizes network upgrades with its seamless plug-and-play design, enhancing both cost-effectiveness and efficiency.

The GPON OLT SFP provides the OLT (Optical Line Terminal) in the service provider’s central office with an interface to access the optical fiber network, enabling the transmission and reception of triple-play traffic (data, voice, or video traffic). Simultaneously, it connects to multiple ONTs/ONUs on the subscribers’ side, thereby allowing the OLT GPON SFP to master traffic control both upstream and downstream. The SFP gigabit PON OLT transceivers offer a data rate of 2.5G-TX/1.25G-RX, capable of reaching distances of up to 20km over SMF at 1490nm-TX/1310nm-RX.

The GPON ONU SFP provides ONT/ONU functionality on the client end sides of the interface, facilitating communication with end devices over the optical fiber network. With the ONU GPON modules, triple-play services are delivered to switches, routers, computers, phones, or other end devices for residential or business usage. GPON ONU SFPs offer a plug-and-play solution for ISPs to provide multiple terminals to obtain optical fiber-based services. The GPON ONU stick provides 1.25G upstream and 2.5G downstream, supporting distances of up to 20km over SMF.

Figure1: FS GPON Modules

Basic Introduction to Regular BiDi SFP

The regular BiDi SFP transceiver is a compact optical module that employs WDM (wavelength division multiplexing) technology and adheres to the SFP MSA protocol. Utilizing WDM bi-directional transmission technology, BiDi fiber optic modules employ two distinct wavelengths to carry duplex signals over a single optical fiber separately. They are utilized to achieve high-performance integrated duplex data links over a single optical fiber, particularly in bi-directional communication applications. Unlike traditional SFP transceivers, regular BiDi SFPs are deployed in matched pairs, with each part transmitting at different wavelengths. One part handles upstream ("U") transmission while the other manages downstream ("D") transmission.

Figure2: Difference Between SFP Port and BiDi Port

GPON SFP VS Regular BiDi SFP, What're the Key Differences?

Though the GPON SFP module belongs to bi-directional SFP. However, GPON SFP differs significantly from standard BiDi SFP transceivers.

Connectors

In the market, GPON modules are typically equipped with SC connectors, ensuring compatibility with the prevailing infrastructure standards. However, BiDi SFP transceivers are available with LC or SC connectors, offering flexibility to suit different network configurations.

Wavelength and Duplexing

GPON SFP modules leverage distinct wavelengths to facilitate bidirectional data flow over a single fiber, typically employing 1490 nm for downstream and 1310 nm for upstream traffic. This wavelength arrangement enables efficient communication in GPON. Conversely, regular BiDi SFP modules also operate over a single fiber but adopt different wavelengths for transmission and reception, commonly employing 1310 nm for transmission and 1550 nm for receive (or vice versa). This wavelength configuration ensures bidirectional communication in various networking applications, such as data centers and enterprise networks, optimizing signal integrity and network performance.

Transmission Distance

GPON SFP transceivers are generally recommended for shorter distances, typically up to 20km, using 1490nm-Tx/1310nm-Rx wavelengths. It's worth noting that maximum transmission distances may vary among vendors, with some claiming extended reach. Conversely, standard BiDi SFP transceivers can achieve transmission distances of up to 160km, utilizing wavelengths of 1490nm-Tx/1550nm-Rx and 1550nm-Tx/1490nm-Rx over single-mode fiber with LC simplex connectors.

Topology

GPON modules are primarily designed for point-to-multiple-point applications. In this setup, an OLT equipped with an OLT GPON SFP is connected to a fiber optic splitter via a single fiber in the central office. The optical splitter then distributes the signal to multiple ONUs located at the subscribers' premises, enabling efficient network connectivity for multiple users. On the other hand, traditional BiDi SFP transceivers operate in a point-to-point signal transmission mode, wherein pairs of BiDi SFPs with opposite TX and RX wavelengths are symmetrically deployed at both ends of the link.

Technology and Application

GPON SFP modules are tailored for GPON, chiefly deployed in FTTH setups. Their design focuses on efficient bidirectional data transmission over optical fibers, particularly suited for residential and small business connectivity. In contrast, regular BiDi SFP modules find utility in a wide array of networking environments necessitating bidirectional communication over a single fiber, spanning data centers, enterprise networks, and telecommunications infrastructure, providing versatile solutions for point-to-point links and network interconnections.

Cost and Availability

GPON SFP modules, owing to their specialized design for GPON and specific applications in FTTH deployments, often carry a distinct cost profile and availability compared to more generic networking modules. Conversely, regular BiDi SFP modules are readily accessible from numerous vendors and boast compatibility with a diverse range of networking equipment. This broader availability, coupled with their versatility in addressing bidirectional communication needs across various networking environments, positions regular BiDi SFP modules as cost-effective solutions catering to a wide array of networking requirements, from data centers to enterprise networks.

Power Budget and Sensitivity

GPON SFP modules are meticulously crafted with precise power budgets and sensitivity specifications to suit the unique demands of GPON deployments, taking into account the passive nature of the optical network. In contrast, regular BiDi SFP modules are engineered with a more expansive power budget and sensitivity range, accommodating diverse network architectures and deployment scenarios beyond the constraints of GPON environments. This broader design scope ensures compatibility and optimal performance across a wide array of networking setups, ranging from data centers to enterprise networks, where bidirectional communication over a single fiber is essential.

Conclusion

In conclusion, GPON SFP and regular BiDi SFP modules offer distinct advantages suited to specific networking needs. GPON SFP excels in point-to-multipoint setups with its SC connectors and tailored wavelength arrangement, while regular BiDi SFP, with flexible connectors and versatile wavelengths, serves diverse networking environments. Each module type balances cost, performance, and compatibility to meet varying deployment requirements effectively. FS provides a comprehensive selection of top-tier GPON SFP modules and BiDi SFP modules to cater to diverse networking requirements. With GPON SFP modules, customers have the flexibility to choose based on parameters like wavelength, data rate, connector type, operating temperature, and budget link grade, ensuring complete satisfaction. Similarly, our BiDi SFP modules offer customization options to meet specific needs regarding transmission distance, connector type, data rate, and compatibility with various brands, ensuring optimal performance and compatibility across a wide range of applications.