Microwave, fibre and transport, worked out in the open

Every formula is visible, every constant is derived rather than remembered, and nothing you enter — coordinates, frequencies, equipment figures — leaves your device. No vendor numbers are supplied, because a link budget built on invented thresholds looks authoritative and is fiction.

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Start here · the whole service in one place

End-to-End Path Designer

Both paths of a service, their latency, their availability and everything they share — in one model rather than four spreadsheets. It catches the protection path that meets its availability target and blows the latency budget the moment it carries traffic, which is the failure nobody sees until the day it happens.

Open the designer
The labs · every stage at once

Four labs that join the calculators up

A single calculator answers one question. These take a whole job end to end and show you which constraint is actually binding — which is rarely the one you were worried about.

Microwave Link LabOne hop through every stage at once — terrain, tower, antennas, budget, availability. Rain and multipath modelled separately, and a Google Earth export with the beam at real altitude. Height bought to clear a hill costs feeder loss; past a certain diameter a bigger dish delivers less.LabFibre Reach LabLoss, OSNR, dispersion and PMD are four independent walls and only one is binding. Which one changes with the bit rate — the same route reaches 88 km at 2.5 Gbit/s and under four at 40.LabTransport Operations LabA year of incidents, turned into what it cost, what really caused it, and which fix returns the most uptime per pound. The element with the most tickets is usually not the problem.LabNetwork Designer LabSeveral services over one network, and the failures that take more than one — including the ones that strip protection from three services at once without raising a single alarm.Lab
Line of sight

Microwave

Air, terrain and the Earth's own curvature

Microwave Link BudgetEIRP, free-space path loss, received level and fade margin, with every line of the budget shown so it can be checked against a rack. Distance entered directly or worked out from coordinates.MicrowavePath Profile & TerrainThe ground along a hop and which obstacle actually controls it — usually not the tallest, because the Fresnel zone and the Earth’s bulge both peak at mid-path. Type, paste or fetch terrain, and export the result to Google Earth.MicrowaveFresnel Zone & ClearanceA path can have perfect line of sight and still not work. Zone radius, Earth bulge at any K factor, and the antenna height that would actually clear an obstacle.dBm, Wavelength & Antenna GainThe conversions done twenty times a day — power units, frequency to wavelength, dish diameter to gain — plus an ordered gain and loss chain.
Glass

Fibre & optical

Four independent walls, and only one of them is binding

Fibre Loss BudgetOptical loss, received power and both margins — above sensitivity and below overload. A short link can fail from too much power, with a 30 dB margin showing.FibreOSNR, Dispersion & PMDHow much signal-to-noise survives a chain of amplifiers, how far a pulse spreads, and why PMD grows as a square root. With the model's limits stated rather than implied.FibreDWDM & CWDM Channel PlannerThe ITU grid at any spacing, anchored in frequency where it belongs, plus a channel check that catches overlapping spectrum on different channel numbers.FibreFibre Colour CodesAny fibre by number or by colour, with a map of the whole cable — and an honest answer when a colour pair stops being an address.Fibre
When it breaks

Operations & assurance

What it costs when it breaks, and what stops it breaking

SLA & Outage AnalyserAvailability from an incident log under both measurement conventions, the service credit next to what the outage actually cost, and MTBF with the confidence interval three failures really deserve.OperationsAvailability & Shared RiskNines turned into hours, and a check on the assumption under every redundancy calculation. Two paths through one duct are not two paths — and the naive answer can be five hundred times optimistic.ResilienceSite Power & BatteriesDC load and the current it really draws, conductors judged on what the equipment sees when the battery is flat, and autonomy corrected for discharge rate rather than read off the label.SitePTP Time Error BudgetHops, holdover, and the error the protocol is structurally unable to detect: one metre of fibre length difference is 2.45 ns, and no better clock will ever find it.Timing

What these do and do not claim

No vendor figures are supplied. Receiver thresholds, radio capacities and antenna patterns come from you or from a datasheet. Inventing them produces a link budget that looks authoritative and is fiction, which is worse than no answer.

Models are named and bounded. A free-space budget is a free-space budget: rain, multipath and terrain diffraction are separate effects and are not in it. Where a figure is a planning convention rather than physics — 60% of the first Fresnel zone, K = 4/3 — it says so.

Nothing here certifies anything. Not structural loading, not electrical code, not frequency coordination, not regulatory compliance. Those need a qualified engineer and a signature, and a web page is not one.

Where the care went

Constants are derived, not remembered. The 32.44 in the free-space expression is 20·log10(4π/c) adjusted for kilometres and megahertz; the 17.32 in the Fresnel radius is the same idea for kilometres and gigahertz. Both are computed from the speed of light when the page loads, so changing the units cannot leave a stale number behind.

Distances are geodesic. Vincenty's method on the WGS-84 ellipsoid, not a spherical approximation — on a 50 km hop those differ by a couple of hundred metres, which is enough to move a path profile when the clearance question is marginal. Checked against Vincenty's own published test pair, where it agrees to a tenth of a millimetre.

Both antenna bearings are given. The back-azimuth is not the forward bearing plus 180 — the meridians converge, and on a long path the two differ by a fraction of a degree. With a narrow beam that is a real pointing error, so both are shown.

Being built, in order
  • Availability and downtime, series and redundant path modelling, and shared-risk analysis — because two logical paths down the same duct are not diverse.
  • Site infrastructure: −48 V loads, battery autonomy, rectifier sizing and heat.
  • Terrain-driven path profiles. The geometry works today from elevations you supply; the question of where elevation data comes from, and what it costs in privacy, is a separate decision worth making deliberately.