Fiber Network Management: Blog and News

FTTH design & engineering standards- what you need to be successful?

Written by 3-GIS Team | Nov 2, 2016 6:47:00 PM

Many of our customers are facing challenges as it relates to documenting specifications, data models and output required to support the end-to-end design and construction process for fiber to the home (FTTH). This is true whether you are considering utilizing conventional CAD based technology or leveraging a geographic information system. 3-GIS has faced these challenges head on with our customers and wanted to pass on some lessons learned for consideration.

FTTH Design Standards Development

 As our customers develop their strategy to facilitate fiber deployment in their market, it has become increasingly evident the resources necessary to plan, budget and design a network are not readily available inside or outside of the organization, especially in smaller providers or municipalities considering making the jump to design, construct and maintain fiber to the home networks.  To this end, 3-GIS works closely with our customers to outline standards for their FTTH deployment which typically consist of the following supporting documents:

  • FTTH Design Specification and Architecture
  • FTTH Geodatabase Model
  • FTTH Construction Typical and Assembly Guide
  • FTTH Style Guide

A description and intent for each of the documents listed above can be found below.

 FTTH Design Specification and Architecture

 If one were to “Google” FTTH Design Specification today, very little in the way of supporting information is available.  One can only speculate as to the reason for this but commonly design specifications are developed for a carrier’s specific network architecture and predetermined hardware components.  Municipalities and utilities often do not posses the experience necessary to develop and implement network architectures and typically rely on equipment manufacturers to facilitate their needs.  While this approach has worked in the past, the direction is often time weighted in favor of the manufacturer as opposed to the long-term plan for the municipality or provider.

To this end, it is necessary to develop a specification that can be shared and implemented by municipalities and providers during their FTTH deployment.  This specification must provide the underlying elements of successful FTTH projects and take into account the reality of smaller target markets.  Specifically, the specification may need to address multiple architectures to account for very dense/large city deployments in addition to smaller/more rural deployments coupled with a blended architecture so as to best serve both dense and less dense populations in the target market. Ultimately the design specification provides the foundation for all FTTH network planning, design and development activities and would consist of accepted architecture, manufactured materials, labor activities and data models. At a minimum the design specification must take into account the following:

  • Network Architecture to include demand profiles, connectivity and construction methods
  • Approved Material and Sizing of network assets
  • Connectivity requirements to include splicing
  • Building and Permitting Constraints as mandated by local, state and federal authorities
  • Existing Conditions such as leased assets and backbone connectivity
  • Existing HUT locations

FTTH Construction Typical and Assembly Guide (Typicals)

The construction typicals provide a foundation for understanding constructible elements of design.  Typicals can be as specific as outlining individual part components of a construction element or broad as an “assembly” of parts.  Assemblies are often referred to as A, B and C level parts.  An A level part consists of a top level component of a network such as a splice enclosure where a B is a subset part of the A level part or in this case a tray inside of the splice enclosure.  C level parts are typically optional and are installed as part of the construction process. An example of a C level part may be as small as a bolt.  Often times networks are modeled to the A level assemblies for general pricing and down to B level assemblies to support construction bid documentation.  Normalizing the existing construction typicals into a generic format with general pricing guidelines is critical to estimating both costs of and materials required for construction.  This will provide municipalities and providers with a method for accurately pricing their network design prior to submitting for financial assistance from investors, bond markets or existing reserves.   To better prepare for the FTTH design and deployment, municipalities and providers should consider documenting the A and B level parts, at a minimum, to be used during construction and aligning them closely to the Design Specification.

 FTTH Geodatabase Model and Style Guide

While the design specification and typicals are critical to planning and designing a network, the geodatabase provides a standard mechanism for storing the data generated during the design.  In addition, a standard geodatabase predicated on the design specification and typicals is critical in accurately portraying the cost of the network through the generation of bill of materials (BOM).  The BOM is a summation of network features at the A and B level assemblies listed in the construction typicals with associated pricing.  By automating the generation of the BOM, municipalities and providers are able to confidently deliver pricing information to their constituents and stakeholders.  The geodatabase model will require strict adherence and alignment with the design specification and typicals to ensure generation of an accurate and reliable BOM.  In addition, elements of the BOM can also inform the construction process by facilitating ordering of materials and preparing subcontracts for labor requirements.  Attributes to collect and populate in support of these activities and the format for which they are inputted must be documented and tested within a sample database design prior to commencing the FTTH design process.

 The style guide is an extension of the data model and design specifications.  It is a visual que to the municipality and guides their users/contractors toward the creation of quality data inside of their designs.  In addition the style guide will act as a foundation element to creation of BOMs as well as a method for assessing the quality of the design.  The deliverable style guide will note snapping expectation of features in addition to expected methodologies for drawing network features.  Examples would include value engineering of underground assets so as to reduce cost by leveraging industry standard E, U, H, J designs.

Summary

While it may seem that many of the documents above both exist and are being maintained by those seeking a FTTH deployment, often times municipalities and providers are often focussed on meeting the urgency of the now in regards to executing their buildout.  This causes an inability to evaluate the existing and future states for the program and its execution.  Arguably, without the documents listed and strict adherence to them amongst the project stakeholders, programs will find themselves in a constant state of change and adjustment which can be avoided with proper planning and adherence to standards and specifications built to meet their program requirements.