What is an MST Box?

MST (Multiport Service Terminal) Box is a compact outdoor fiber distribution terminal, typically mounted on poles, walls, or aerial strands. It provides multiple ports for drop cables to connect directly to homes or businesses. Being sealed, pre-terminated, and easy to deploy, MST boxes have become a preferred choice for FTTH rollouts.

What is a Daisy Chain?

A Daisy Chain is a simple yet effective network topology where devices are connected in series, like links of a chain. In optical distribution networks, this means multiple MST Boxes are linked along a single feeder cable. The optical signal enters the first MST and continues downstream through the second, third, and so on, until the end of the chain.

How MST Works in a Daisy Chain

In a fiber network, each MST Box acts as a node along the chain. A single backbone cable runs through multiple MST Boxes, and the optical signal is distributed step by step:

• The backbone cable enters the first MST Box. Some fibers are terminated to serve local users.
• Remaining fibers are passed through—via patching or splicing—to the next MST Box.
• This process repeats along the route, forming a chain-like structure that gradually extends coverage.

Each MST Box includes splitting, connection, and management functions, allowing operators to expand capacity or perform maintenance at a single node without affecting the rest of the network. This approach enables a single feeder cable to serve multiple homes or businesses, making deployment more efficient and cost-effective.

Key Considerations: Link Loss Calculation

When designing a Daisy Chain, the number of MST Boxes is limited by total link loss. Factors to consider include:

• Connector loss (MPO, SC/APC, etc.)
• Splice loss
• Splitter loss (PLC splitter)
• Fiber attenuation

The number of MST Boxes that can be connected in a Daisy Chain is not unlimited, as it is constrained by link loss. Therefore, careful calculation of optical loss is essential.

Advantages

• Cost-Effective: Significantly reduces fiber usage and expensive on-site splicing, lowering overall deployment costs.
• Fast Deployment: With pre-terminated plug-and-play design, installation is faster and easier.
• Reliable: Factory-terminated with high optical performance.
• Flexible: Build as needed, flexible and scalable.

Applications

• Newly built residential areas on city outskirts
• Broadband coverage in rural towns or villages
• Villa clusters along highways
• Large campuses or industrial parks
• FTTH: Linking multiple MST Boxes within a residential community to cover different buildings

Customer Case Study

A customer planned to deploy seven MST Boxes along the route. We proposed a step-down Daisy Chain design using a 24-fiber MPO trunk cable.

At the first MST：

• One branch connects to a 1×4 PLC splitter to serve four homes
• Two branches terminate with SC connectors for two homes
• The remaining 21 fibers continue downstream

Subsequent MSTs follow the same way, erving local users while letting the remaining fibers continue downstream. By the seventh MST, one trunk cable can serve up to 45 homes.

Summary

Daisy Chain design should be driven by actual deployment requirements. It’s crucial to fully understand the area, determine the fiber count and type, calculate optical power and splitting ratios, and consider fiber distances. Proper planning ensures maximum network flexibility and capacity.

At AngNet, we are more than a factory, we aslo provide tailored design solutions for your projects. If you're interested, feel free to reach out us. 📩 [Sales@szangnet.com]