Link Engineering

All-Outdoor

An All-Outdoor microwave radio architecture is a modern, highly efficient telecommunications deployment model where the entirety of the active electronics—both the baseband networking modem and the high-frequency RF transceiver—are integrated into a single, hermetically sealed, ultra-ruggedized chassis bolted directly to the back of the parabolic dish antenna at the top of the tower. This architecture was explicitly developed to support high-capacity, high-frequency (E-Band, V-Band) millimeter-wave backhaul links. Because millimeter waves suffer catastrophic attenuation when traveling through standard coaxial cables, the RF generating unit must be physically flush against the antenna feedhorn. By utilizing an All-Outdoor model, the telecom operator completely eliminates the need for expensive, lossy elliptical waveguide runs and eliminates the requirement for an expensive, air-conditioned ground shelter. The system requires only a standard, cheap Cat6e Ethernet cable or fiber-optic strand to carry pure digital data and Power-over-Ethernet (PoE) up the tower.
Category: Link Engineering

Understanding All-Outdoor Microwave Systems

If you look at a modern 5G cell tower, you will not see a massive concrete bunker at the bottom of the tower anymore. Telecommunications companies realized that building and air-conditioning concrete bunkers was too expensive. To cut costs and massively increase performance, they shoved the entire computer system into a small, weatherproof metal box and bolted it directly to the top of the tower. This is the All-Outdoor architecture.

The Death of the Copper Pipe

Historically, radios lived in a bunker, and the radio wave was pumped up a massive copper pipe to the antenna. But modern 5G backhaul links operate at incredibly high frequencies (like 80 GHz). At 80 GHz, a radio wave cannot travel up a 300-foot copper pipe; the pipe will absorb 100% of the energy and kill the signal instantly.

The Zero-Loss Solution

In an All-Outdoor system, there is no pipe.

  • The entire digital modem, the computer processor, and the massive RF amplifier are crammed into a tiny, rock-hard aluminum box.
  • The box is bolted directly, flush against the back of the dish antenna. The radio wave only has to travel 2 inches from the microchip to the antenna, completely eliminating signal loss.
  • To get internet data up to the box, the engineers just run a cheap, lightweight fiber-optic cable or Ethernet wire up the tower. Because fiber optics use light, they have zero RF signal loss.

This allows telecom companies to deploy massive, gigabit-speed 5G backhaul links on a cheap telephone pole without needing to buy land or build a massive concrete bunker.

Key Equations

All-Outdoor:
An All-Outdoor microwave radio architecture is a modern, highly efficient telecommunications deployment model where the entirety of the active electronics—both the baseband networking modem and...

Key specifications:
80 GHz | 100 % | 32.44 dB | 60 km | 99.999 %

Path loss: FSPL = 20log(d)+20log(f)+32.44

Comparison

AspectAll-Outdoor SpecTypical RangeImpactDesign Note
Primary functionThis architecture was explicitly develop...Application-dep.CriticalVerify in sim
Operating rangeBecause millimeter waves suffer catastro...Application-dep.CriticalVerify in sim
PerformanceThe system requires only a standard, che...Application-dep.CriticalVerify in sim
IntegrationUnderstanding All-Outdoor Microwave Syst...Application-dep.CriticalVerify in sim
Trade-offTelecommunications companies realized th...Application-dep.CriticalVerify in sim
Common Questions

Frequently Asked Questions

What is the biggest downside of All-Outdoor?

Maintenance nightmares. Because the entire multi-million dollar computer is bolted 300 feet in the air, you cannot easily fix it. If a single microscopic capacitor blows out on the circuit board, the entire cell tower goes completely offline. The telecom company must hire a highly trained, expensive tower climber to physically scale the tower, unbolt the massive metal box, drop it to the ground, and bolt a brand new one in its place.

How does the All-Outdoor radio get electricity?

Using Power over Ethernet (PoE). Running a heavy, high-voltage electrical cable 300 feet up a tower is a massive fire and lightning hazard. Instead, the engineers use a single, thin Cat6e Ethernet cable. This single cable transmits both the high-speed gigabit internet data and exactly 48 Volts of DC electricity simultaneously, safely powering the massive radio without requiring a certified electrician.

How do they survive lightning?

With massive, heavily engineered grounding systems. Sitting at the top of a steel tower makes the All-Outdoor radio a prime target for a 200,000-Amp lightning strike. The metal chassis is bolted directly to a massive copper grounding wire that runs straight down the tower and is buried deep into the dirt. Furthermore, specialized optical isolators are used so that if lightning hits the radio, the lethal electricity cannot travel down the Ethernet cable and destroy the routers on the ground.

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