From high-level architecture to construction-ready packages — we design fiber-to-the-home networks that get built right the first time. 44,000+ miles of OSP planning behind us. We know what works in the field.
FTTH design engineering services cover the full technical lifecycle from initial network architecture through construction-ready low-level design packages. A complete engagement includes high-level design (HLD), low-level design (LLD), optical budget modeling, fiber count planning, splice diagrams, and AutoCAD construction packages — all delivered in formats your construction crews can use directly.
The FTTH design engineering services we provide span the full technical lifecycle:
Network architecture, splitter placement, fiber allocation, serving area boundaries, feeder/distribution topology, and optical budget validation.
Pole-by-pole or conduit-by-conduit construction documents: strand assignments, splice case locations, reel sizes, attachment heights, and BOM.
1:32 and 1:64 staged split designs, FDH sizing, NAP placement strategies, and cascade configurations optimized for your address density and drop lengths.
Distribution and feeder fiber counts sized for buildout coverage, future scalability, and spare capacity — not just minimum viable pass counts.
GPON and XGS-PON network architecture with optical loss budget modeling, OLT port planning, and ONT placement recommendations.
Full AutoCAD plan sheets, permit drawing sets, splice diagrams, equipment schedules, and installation notes formatted for your construction crews.
The FTTH network design process begins with high-level design (HLD), where network architecture, splitter placement, serving area boundaries, and optical budgets are established before any pole-level design begins. HLD decisions directly determine downstream LLD complexity, make-ready scope, and ultimately construction cost per home passed. Getting HLD right is the single highest-leverage investment on any FTTH build.
High-level design is where the important decisions get made — and also where most projects get into trouble. Understanding FTTH high-level design mistakes early in the project lifecycle can save significant redesign cost. I've seen HLDs come in from other firms where the splitter architecture looked fine on paper but the serving area boundaries were drawn without any real knowledge of the address density or the terrain. Six months later the client is scrambling to redesign half the network because the fiber counts weren't right.
Our HLD process is a lot more grounded than that.
We start with your address layer — parcel data, address points from county GIS, or a combination — and build a demand map before we touch the network design. MDU vs. SFU mix, linear density per mile, projected penetration. This tells us how to carve serving areas before we put a splitter anywhere.
We identify primary fiber corridors using existing aerial and underground plant, road centerlines, and natural barriers. We flag areas where underground bore will be required, creek crossings that need USACE permits, and railroad crossings early — before they become schedule surprises. Our field survey team conducts strand mapping on any existing aerial plant we're overlashing or tying into.
We model splitter locations using address clustering and drop length analysis. In rural BEAD work, we sometimes end up with distributed cabinet FDHs at 1:32 because the address density can't support a centralized 1:64 architecture without excessive drop lengths — 800-foot aerial drops in hill country are a real thing, and they cost as much as the service site itself. The splitter architecture has to match the terrain, not just the theory.
Every HLD deliverable from our team includes an optical power budget table — feeder span length, distribution cable loss, connector counts, splice count, splitter insertion loss — all of it modeled against your OLT's minimum receive power. We've seen too many designs fail optics check at commissioning because the engineer who did the HLD assumed best-case connector performance throughout. We don't do that.
The HLD deliverable includes a materials BOM for major cable runs, FDH/FAT hardware, and splice closure quantities. Not a rough order of magnitude — an actual bill of materials that your procurement team can use to get firm pricing. We build BOM in Excel with unit cost assumptions keyed to current market pricing, not 2019 numbers.
HLD output you can actually use: Our HLD deliverable includes route maps in AutoCAD and ArcGIS formats, a fiber count summary spreadsheet, optical power budget table, serving area topology diagram, and a BOM for major materials. It's not a slide deck — it's an engineering document.
FTTH low-level design (LLD) converts HLD architecture into pole-by-pole construction documents: span tables, reel cut assignments, splice case locations, conduit schedules, and AutoCAD plan sheets formatted for permit submission. Weak LLD means construction crews make expensive decisions in the field. A complete, QC'd LLD package eliminates change orders from design errors and reduces construction cost-per-home-passed significantly.
Low-level design is where FTTH design engineering services either earn their fee or kill the project budget. A weak LLD means your construction crews are making decisions in the field that should have been made at a desk — our guide on FTTH low-level design splice point placement covers the most common placement mistakes — and field-level engineering is expensive engineering. Every reel size wrong by 500 feet means either a waste cut or a mid-route splice. Every splice case put in the wrong location means access issues later during maintenance.
Our LLD packages include:
The LLD doesn't go out the door until it's been through our internal QC process — a second engineer who didn't touch the design reviews it against the HLD to catch fiber count mismatches, missing spans, and optical budget deviations. We catch our own mistakes. It's not glamorous, but it's why our re-design rate is extremely low.
For new deployments, we default to XGS-PON (ITU-T G.9807.1). The incremental cost difference between designing for GPON versus XGS-PON at the fiber plant level is minimal — the ODN architecture is essentially the same — and deploying GPON in 2026 for a new build is setting yourself up for an upgrade project in four years. That said, we design GPON networks too, particularly for brownfield upgrades where existing optical budgets and splitter cascades are already in place.
Our standard design toolset:
We design to NESC (National Electrical Safety Code) for aerial clearances, NEC for any equipment enclosures, and OSHA standards for construction phasing. For BEAD projects, we also follow NTIA's technical specifications for network documentation and the applicable state broadband office's design standards where those exist — they vary quite a bit by state, which is something to account for in project scheduling.
We've written about the most common mistakes engineers make at the HLD stage — if your project is in early design or you're about to hand off to a design firm, this is worth reading: common FTTH HLD design mistakes and how to avoid them. Also worth reviewing: our piece on how GIS fiber network planning reduces construction cost — the data model decisions at design phase have a direct impact on what construction costs per mile.
FTTH design engineering varies significantly by project type. Greenfield builds require clean network architecture from scratch. Brownfield overbuilds require make-ready analysis around existing attachments. Rural BEAD builds demand specialized splitter economics at low address densities of 3–7 homes per route mile. Each project type requires different design assumptions, different schedule allowances, and different risk management.
Not all FTTH design is the same. A greenfield suburban deployment in North Carolina has almost nothing in common with a rural BEAD build in the eastern panhandle of Oklahoma, and both of those are different from a brownfield overbuild where you're designing around an existing cable or DSL plant that you can't move.
Greenfield builds are the cleanest to design — no legacy conflicts, no make-ready complications from existing attachments, and the client usually has reasonable address data. The challenge is speed: greenfield builds often have aggressive schedules driven by investor timelines, and HLD approval needs to happen fast. We've turned around HLDs for 8,000-address greenfield deployments in under three weeks when the project required it.
Brownfield overbuilds are slower because you're dealing with someone else's plant. Make-ready analysis is more complex — you're adding attachments to poles already loaded with the incumbent's cable, and the pole owner's joint use process adds weeks to the schedule. A project we worked on in central Georgia ran into 23 poles that needed full structural replacement before we could attach, which wasn't in anyone's original budget. The pole loading analysis on that job paid for itself many times over.
Rural BEAD builds present a different set of constraints entirely. Address densities of 3–7 per route mile mean long feeder runs with very few taps, and the economics of the drop infrastructure become critical. One project outside of Billings, MT involved serving 41 addresses over 17.3 route miles of aerial plant — 2.37 addresses per route mile. The splitter architecture for something like that is completely different from a 35-address-per-mile suburban density.
MDU design is its own specialty — riser cable routing, IDF/MDF placement, in-unit wiring strategies, and the contractual complications of dealing with building management. We handle MDU design but we're honest with clients that it adds complexity and timeline. If you have a mixed build with significant MDU penetration, plan for it from the start.
This is the thing most clients don't fully appreciate until they've been burned once. The quality of your FTTH design directly determines your construction cost per-home-passed. A design with wrong fiber counts means construction pauses while the engineer redesigns. Wrong reel cut lengths mean field splices that add labor, materials, and optical loss. Splitter locations that don't account for access — a cabinet in a drainage ditch, a FAT on a pole that turns out to be in a private lot — mean schedule delays that cost real money.
We've seen construction costs diverge by $200-$400 per home passed between well-engineered projects and poorly-engineered ones. The design fee is a small number compared to that delta. Paying more for rigorous FTTH design engineering services is almost always the right economic decision.
We also have in-house field survey capability, which matters a lot for design quality. Desktop-only design off satellite imagery and county GIS data will get you in trouble — pole heights are wrong, spans are estimated, underground obstructions aren't in the data. When our field team walks the route and captures real attachment data, the LLD is dramatically more accurate. On projects where we've done both the field survey and the design, change-order rates from field discrepancies are nearly zero.
FTTH high level design is the first engineering phase — it defines the network architecture before any construction documents are created. HLD locks in where the hub or headend goes, how feeder cables route through the serving area, where distribution cables branch, and how the passive optical splitter stages are configured. It sets fiber counts, splitter ratios, and optical budget margins. A solid HLD is the foundation everything else is built on. Skip it or rush it, and you pay for it in redesigns.
HLD defines the architecture — serving area boundaries, splitter locations, fiber allocation, route corridors. LLD is the construction document — pole-by-pole span details, splice case placements, conduit schedules, reel cut lengths, permit drawings. HLD tells you what to build; LLD tells the crew exactly how to build it. You can't have a good LLD without a solid HLD. Trying to jump straight to LLD without proper architecture work is one of the most common ways FTTH projects end up mid-build with fiber count problems.
It depends on project complexity. Aerial builds in flat terrain can run $800–$1,400 per route mile for combined HLD and LLD. Underground urban builds with significant permitting complexity, complex MDU work, or hilly terrain push into the $2,500–$4,500 range per mile. BEAD rural projects are often priced per address rather than per mile due to the low linear density. We scope every project individually and provide fixed-fee quotes — reach out and we can turn around a number quickly.
An OSP engineer translates a business plan into a physical network design. That means site analysis, route selection, pole survey coordination, fiber count calculations, splitter architecture, optical budget modeling, make-ready engineering, permit drawing preparation, and construction package production. A good one also understands NESC clearance rules, can spot a problematic bore crossing before the drill shows up, and has enough field experience to know when a design looks right on paper but won't work in the real world.
We default to XGS-PON (ITU-T G.9807.1) for new greenfield builds — it supports 10 Gbps symmetrical and the ODN architecture is the same as GPON, so the incremental design cost is negligible. We also design GPON networks and handle upgrade paths from existing GPON plants. All designs include optical loss budget modeling with realistic connector and splice loss assumptions — we don't assume best-case performance and leave clients to deal with margin problems at commissioning.
Yes. A substantial portion of our current project portfolio is BEAD-funded rural broadband. We understand the NTIA documentation requirements, state broadband office design standards (which vary significantly by state), and the engineering constraints that come with low-density rural builds. We're also familiar with the cost modeling requirements for subgrantee reporting. Our team has designed BEAD-eligible networks across 22 states — rural builds at 2–8 addresses per route mile are not unusual territory for us.
Whether you're starting from scratch or need an independent review of an existing design, our engineering team is available to talk through the project. We work with ISPs, municipalities, co-ops, and BEAD subgrantees across the country.
Contact Our Engineering TeamOr email us directly at info@draftech.com — we reply within one business day.