# Internet backup for office buildings: what facility managers actually need

Facility managers are not network engineers, but they own the consequence when the internet goes down. Here is what the backup conversation actually involves.

The network outage arrives without warning. It is usually discovered when someone calls the facilities desk to say the phones are not working, the access control system is stuck, or a tenant's VoIP line has gone silent. By that point the damage is already happening.

## The single point of failure most buildings carry

Most office buildings connect to the internet through a single fibre link. That fibre enters the building at one point, runs through the technical room, and feeds everything above it. When it fails, everything fails at once.

The failure modes are varied. Roadworks cut the duct. An operator incident takes down a segment. A water ingress event in the basement technical room damages the patch panel. The common feature is that none of them require a dramatic event. They happen quietly, and the building has no fallback.

In a building with 200 workstations and a handful of networked building systems, a four-hour outage has a real cost, even if no one calculates it afterwards. Downtime attribution is underreported in FM because it tends to be absorbed as overhead rather than logged as an incident.

## What RTO means in practice

Recovery Time Objective is the maximum acceptable time before a critical service is restored. In practice, most FM teams have not defined an RTO for internet connectivity. They should.

A building where the VoIP system cannot function without the internet has a very different RTO profile from one where only tenant laptops are affected. If the building management system sends alerts and commands over the internet, the RTO for connectivity is the same as the RTO for fire safety monitoring. That changes the conversation.

## 4G backup: where it works and where it does not

4G failover is the most common backup approach and the easiest to deploy. A 4G router with a data SIM takes over automatically when the primary link drops. For a small or mid-sized office with modest bandwidth requirements, this works.

The limitations show up at scale. A building with several hundred concurrent users generates bandwidth demand that 4G cannot sustain. 4G cells in urban areas are already loaded during business hours; adding a building's entire traffic at the moment of a local fibre failure compounds that load. In dense business districts, the cell that serves your building also serves the five buildings around it, all of whom may have lost the same duct.

There is also the infrastructure dependency problem. 4G relies on terrestrial towers and ground-level fibre backhaul. If a major civil event causes the original fibre outage, the 4G network in the area may be affected by the same incident.

## What satellite backup adds

A satellite backup path uses a completely different infrastructure. No local towers, no ground-level ducts. The signal path goes to orbit and back. This makes satellite genuinely independent of local terrestrial infrastructure, which is its primary advantage over 4G as a backup option.

Low-earth orbit satellite provides latency that is workable for most business applications. It is not ideal for latency-sensitive real-time applications, but for VoIP fallback, building management alerts, and general internet access during an outage, the performance is adequate.

The bandwidth ceiling is higher than 4G for a building-level deployment. A well-specified satellite terminal can sustain meaningful throughput for a building during an outage period.

## What the hardware means for the roof

A satellite terminal for a commercial building sits on the flat roof. The antenna needs a clear view of the sky with no significant obstruction in the relevant arc. Most flat commercial rooftops have this, though it is worth checking against any planned solar installations or HVAC equipment.

The mounting penetrates nothing if done correctly. A ballasted mount sits on the roof surface and does not touch the waterproofing membrane. On a roof with 40 cm of concrete slab and a bituminous membrane, a ballasted installation adds no risk to the envelope. On a lightweight single-ply membrane, the approach is different and needs to be specified with the roofing contractor.

The cable runs from the antenna to the technical room. One penetration, properly sealed, is all that is required. From the technical room perspective, the satellite hardware connects to the existing multi-WAN router or, if the building does not have one, a new device that manages primary and backup paths automatically.

**Who manages the subscription for the satellite backup link?** TerraLink supplies and installs the hardware. The satellite subscription is handled by the operator or service provider. The two layers stay separate, which means the FM team has one hardware contact and one service contact.
**Is a planning permit required to install satellite hardware on an office roof?** Rules vary by municipality and building classification. In most cases a small satellite terminal on a flat roof does not require a full planning application, but this should be confirmed locally before installation. TerraLink does not provide planning advice.