How to Design for FTTx MDU Deployment

FTTx has brought us incredible possibilities and total convenience in delivering high-speed bandwidth, no wonder it gains in popularity around the globe. In accordance with the spread of high-speed FTTx service, the demand of an optical distribution for MDU is increasing rapidly. MDU (Multi Dwelling Unit) plays a huge part in the FTTx network and are growing dramatically since it provides a densely concentrated service area for the service provides. This article will illustrate how to efficiently design for FTTx MDU deployments.

What MDU Stands for?

At the beginning, I’d like to briefly explain the definition of MDUs. Known as multi dwelling unit, MDUs generally refers to places such as apartment buildings, offices, and hotels, etc. MDUs come in all shapes and sizes, ranging from high-rise buildings, small condos, duplex units, or multi-use properties with a combination of business and residential customers. This means the structures and conditions of MDUs can be quite diverse. Let’s see how to classify them.

Multi Dwelling Unit MDU

Common Classifications of MDU

Basically, we can classify MDUs with reference to the construction types, for example: high, medium and low-rise buildings (usually in North America), or just like most of the countries in Europe, simply refer to them as horizontals, verticals, and mixed (hybrid). The details of each will be illustrated in the following pictures.

High, Medium and Low-rise MDU

high-rise,medium-rise and low-rise MDU

Horizontals, Verticals, and Mixed (Hybrid) MDU

Horizontals, Verticals, and Mixed (Hybrid) MDU

Solutions for MDU Deployment with Fiber

Understanding the diverse structures and conditions that may encounter lies the foundation of connecting MDUs into the FTTP network. For different connection scenario, the solution required can be various. For instance, the connection in some cases may be via a feeder fiber directly from the central office / head-end connected to a splitter hub on the premises. While for larger MDU structures, it may involve splitter hubs and subtending riser and drop cable networks with intermediate fiber terminals throughout the building. Since one design doesn’t fit all, the challenge is thus the engineering and design of FTTP network in MDUs.

The following part offers some feasible solutions in regard to the its engineering and designs. Some design scenarios are shown below.

Scenario One: Overhead Pole Feeding

In this scenario, the fiber is designed to deliver from the overhead pole distribution box. Several factors need to be considered in this design:

  • Place the distribution box on the outside power pole
  • Drops placed from the pole DP
  • No permissions required prior to installation
  • ONTs can be inside or outside of the unit

Overhead Pole Feeding

Scenario Two: Underground Feeding from RoW

This design scenario is specifically for high-rise MDU, with fiber serving from underground right of way (RoW) fiber distribution terminal. The design factors include:

  • Fiber terminal will be from underground (pit required)
  • Trench to the property required
  • Pre-place drops or paths creation is required
  • Permissions required prior to installation
  • Additional work required prior to installation

Underground Feeding from RoW

Scenario Three: Multi Floor MDU Design

In this scenario, fiber is designed to serve from an underground fiber distribution hub to each floor with different fiber cables. With a main distribution cable installed to the ground floor distribution point, each dedicated fiber will be installed from the IDP to each floor distribution point. In this way, connectivity can benefit till the end ONT.

  • Fiber terminal will be from underground (pit required)
  • Trench to the property required
  • Pre-place drops or paths creation is required
  • Internal (IFDHs) required
  • Each floor termination boxes required
  • Permissions required prior to installation
  • Additional work for interior is required prior to installation

Multi Floor MDU Design


Effective MDU designs simplify deployment process, ensure simply routing paths and enhance maintenance capabilities. Delivering high speed fiber network to MDU provides rich potential returns and the market is doom to grow in the near future. The design of FTTx MDU is primary yet critical, just take this article as a guide but do remember your choice should better base on the unique requirements of the MDU.

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