Guide · point-to-point links
Point-to-point link between buildings: the wireless bridge.
Short version: linking two buildings without trenching a road or paying for a leased line is a wireless bridge job. Two directional antennas, one on each roof, aimed across the car park or the street. In town the distance is short but the challenges differ from the bush: crowded spectrum, glass and parapets in the way, and a landlord to get past. This guide covers what makes an urban link work.
Last updated 3 July 2026 · by Alien IT Solutions
What a building-to-building bridge is
A point-to-point link between two buildings is a pair of directional antennas that carry your network or internet across the gap over the air, instead of through a trench or a carrier's leased line. One end on each building, aimed at each other, and the two sites run as if they were on the same wire, without digging up the road between them. If your two sites are out on rural land, the fundamentals on the outdoor line-of-sight page are the right read; in town it is a different animal.
Short range, crowded air
This is the big one, and it catches people out. Between buildings in town the distance is trivial; the spectrum is not. On rural land the air is clean, but in a suburb or business park every office, cafe and apartment around you is pumping out 2.4 and 5GHz WiFi, and your link has to fight through it.
The bands are full
2.4GHz is a write-off in most built-up areas and 5GHz is filling fast, so we survey what is already on air before choosing a band, not after.
60GHz for dense areas
For a short, busy urban hop, 60GHz is often the right call: huge throughput over a short distance, and almost nobody else uses it, so a congested laneway link gets its own clean lane.
Licensed when it has to work
Where a link cannot afford a bad neighbour next month, a licensed microwave band gives you spectrum that is legally yours. It costs more, but nobody else may sit on it.
Interference you did not cause
On the free bands a link can test perfectly, then degrade months later when a new tenant lights up a competing system, so we design with margin and monitor.
Mounting, glass and the parapet problem
The second in-town difference is where the gear goes. On a commercial building the roofline itself is often the obstacle: a parapet, a plant room or the lip of the roof next door sits right in the path, so the antenna wants mounting high on the roof edge or a short pole to see clean over it. There is still a Fresnel zone to respect around the straight line between the two antennas, and a parapet clipping the bottom of it drags the link down.
And the thing people ask most: no, you cannot point it out through the window. Glass weakens the signal badly, the coated or tinted glazing on modern commercial buildings worse again, and a brick or concrete wall stops it dead. The antennas belong outside with a clear view, cabled down into the building.
What it is actually for
Most building-to-building links come down to a handful of jobs, all the same shape: two sites, one network, no carrier in the middle. The common one is two parts of the one business, an office and a warehouse across a yard, or a shopfront and a storeroom, sharing servers, printers and cameras without a second internet service at the far building. The bridge makes the second building behave like another floor of the first.
The other big one is sharing a single internet feed: rather than order a second connection for building B, you carry the one you already have across the link, the same idea as the shared-connection setup at smaller scale. Campus is the third, buildings a single provider will not neatly cover, tied together with point-to-point hops on infrastructure you own.
Throughput: what to expect
Over a clean, short hop the gear is not the bottleneck. Modern point-to-point radios carry gigabit-class throughput across a hop that short, enough to run a second office or a warehouse full of devices as if they were on the same switch, so the ceiling is your own internet plan, not the bridge. Congestion is what quietly costs you: on a busy 5GHz band hemmed in by neighbours the usable throughput falls well below that headline number. That gap is the argument for surveying the air and moving to 60GHz or a licensed band where it is tight.
Getting permission to build it
This part has nothing to do with radio and still stalls more urban links than any technical problem. If you do not own the buildings, you need sign-off before anything goes on a roof, so start that conversation early because it often takes longer than the install.
Mounting an antenna and running a cable into your suite touches the base building, so the landlord or building manager has to agree, and in a strata building the roof and external walls are common property, which brings in the owners corporation through the strata manager. It is rarely a hard no, but they will want to know exactly what is going up and where, and it helps to sort the cable path to the roof up front. A site and line-of-sight survey settles all of this before any money is spent.
Bridge or leased line?
A bridge is not always the answer, so here is the honest call. A bridge is a one-off build you own afterwards, with no monthly line rental, and it goes in far faster than a carrier can trench fibre. If you want your own bandwidth quickly, without an ongoing charge, and the two roofs can see each other, the bridge usually wins on cost and lead time.
Where it flips is service level and line of sight. A leased line puts a carrier contractually on the hook for uptime, and if the link is critical enough to need that guarantee, it is worth paying for. And if the two buildings genuinely cannot see each other, no bridge makes one work. We will tell you which side of that line you are on first.
How we set it up
We survey both roofs
We check the line of sight and listen to what is already on the air, then pick a band with room in it. If a parapet or a neighbour's building is in the way, you hear about it up front.
We mount and aim both ends
Antennas go up on each building, fixed to the roofline or a short pole with a clear view, aimed precisely and cabled down, so both buildings run as one network.
One network, monitored
The two buildings share the connection, and we monitor the link so a new neighbour is spotted before it becomes your problem, with a real person to call if it drops.
Who builds it
Long Range WiFi is the point-to-point service of Alien IT Solutions, an Australian IT and networks company with more than 18 years building wireless links. Two sites on rural land rather than in town? The outdoor line-of-sight guide is the right read; to cover a whole site rather than link two points, see Paddock Networks.
Questions people ask
Can you link two buildings wirelessly across a car park or street?
Yes. A point-to-point wireless bridge is two directional antennas, one on each building, aimed across the gap, carrying your network between them without trenching a road or paying for a leased line, provided the two mounting points can see each other.
How is a link between city buildings different from a rural one?
In town the distance is short but the air is crowded: neighbouring offices, cafes and apartments flood the 2.4 and 5GHz bands, so a link that is effortless across paddocks has to fight for clean spectrum, and in dense areas we move to 60GHz or a licensed band.
How fast can a wireless bridge between buildings go?
Over a clean, short hop modern gear carries gigabit-class throughput, plenty to run a second office or warehouse as if it were on the same network; on a busy 5GHz band real throughput drops well below that, which is why we survey the spectrum first.
Do I need permission to mount antennas on the roof?
Usually yes: if you lease the space the landlord or building manager signs off on roof access and a cable run, and in a strata building the owners corporation is involved. It is worth sorting early because it can take longer than the install.
When is a wireless bridge better than a leased line or fibre?
When you want your own bandwidth between two buildings quickly and without a monthly line rental; a bridge is a one-off build you own that goes in far faster than a carrier can trench fibre. A leased line still wins on a contracted service level, or where the two buildings cannot see each other.
Will glass or a wall block the link?
Often, yes. Glass, especially the coated or tinted glazing on modern commercial buildings, badly weakens the signal, and a brick or concrete wall stops it dead, so the antennas want mounting outside with a clear view, not firing through the glass.
Link your two buildings.
Tell us where the two buildings are and what sits between them. We will check the line of sight and price the bridge.
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