Home Broadband Spectrum Splitter Light Receiving Standard

Home broadband optical splitters distribute a single fiber signal to multiple homes using standard split ratios, with ONTs requiring sufficient optical power (typically −8 to −28 dBm) to operate reliably.

Optical Splitter Types and Split Ratios

Home broadband networks use passive optical splitters to share a single OLT port among multiple subscribers. The two main types are:

• PLC (Planar Lightwave Circuit) splitters: Highly uniform, ideal for large splits like 1:32 or 1:64, providing consistent signal strength across all outputs .
• FBT (Fused Biconical Taper) splitters: Lower cost, suitable for small splits like 1:2 or 1:4, but less uniform for larger splits . Split ratios define how many outputs a splitter has and how evenly the input power is divided. Common ratios include 1:2, 1:4, 1:8, 1:16, 1:32, and 1:64. Uniform splitters are standard for FTTH, ensuring each subscriber receives similar optical power .

Splitter Architectures

Two primary deployment architectures exist:

• Centralized splitting: Splitters are located in a central office or cabinet, allowing flexible customer assignment via jumpers. This architecture simplifies maintenance and upgrades .
• Distributed splitting: Splitters are placed closer to subscribers in closures or pedestals. Once deployed, customer assignments are fixed, reducing fiber usage on the feeder side but limiting flexibility .

Light Receiving Standards at the ONT

The optical network terminal (ONT) requires a minimum optical power to function correctly. Typical standards for GPON and XGS-PON networks are:

• OLT transmit power: +3 dBm to +5 dBm
• ONT receive sensitivity: −8 dBm to −28 dBm depending on split ratio and network design Each split introduces insertion loss, approximately 3.5 dB per 1:2 split. For example, a 1:32 split can result in ~15–17 dB loss, so the ONT must be capable of receiving signals within the specified range. Proper planning ensures all subscribers receive adequate signal strength without requiring active amplification .

Practical Considerations

• Fiber distance: Centralized home-run architectures can support distances up to ~1 km without significant signal degradation .
• Port isolation: Splitters should maintain >55 dB isolation to prevent crosstalk between outputs .
• Scalability: Adding subscribers is straightforward with centralized splitters, while distributed splitters may require additional fiber runs . By selecting the appropriate splitter type, ratio, and architecture, and ensuring ONTs meet the light receiving standards, home broadband networks can deliver reliable high-speed service to multiple subscribers efficiently.