What line of sight means, and why we check it first

A neighbor may get a strong signal while you get none, and neither of you did anything wrong. Line of sight is why. It is the one requirement that cannot be settled from an office, so it comes before price, plan and install day. This guide explains what is being checked, who checks it, and what you can look at yourself.

What is line of sight for internet?

Imagine a straight line from the antenna on your building to the antenna on the tower. If you could stand on your roof and see the tower with your eyes, you would have line of sight. If a hill, a grove or a building hides the tower, you do not. BroadbandNow's fixed wireless guide states the rule plainly: the antenna at the customer's premises and the provider's ground station must have a direct line of sight, and the signal cannot pass through or around minor barriers.

High Desert says the same thing about its own service. Its Google reviews describe a technician surveying the property and placing the antenna, which is this check in practice.

Do I need to see the tower from my yard?

Not necessarily. You are checking from the spot where the antenna will go, which may be a gable end, a roof edge or a short mast, and that point is higher than eye level in your yard. Towers can also be many miles away and hard to pick out from the ground. Seeing a tower or a mountain with a tower on it from your roof is a good clue. It is not proof, and not seeing one is not a no.

What matters is the stretch of air between the two antennas, not the view from your kitchen window.

What is the Fresnel zone?

The path between two antennas is not a thin line. Radio spreads out in a shape like a stretched football around the straight line, and engineers call it the Fresnel zone. Most of that shape needs to be clear for a good link. A tree that does not touch the straight line can still sit inside the zone and weaken the signal. This is one reason a technician looks at clearance, not just whether a tower is visible. The glossary has a short entry on the Fresnel zone.

Can anyone tell before the install?

Partly. When you send your address, a person at High Desert looks at the route from the nearest tower to your roof. That first look can often show whether the path is promising, doubtful or needs a visit. The final answer comes from a technician at your house, because only the site shows the tree that grew last year or the shop your neighbor built.

That is also why the address check never gives an instant yes or no. It is a request for someone to look. Our page on the address check shows the three outcomes: the path looks clear, it does not, or it needs a closer look.

What can I look at myself first?

Walk around your property and note anything tall that stands between your roof and the nearest high ground in the direction of towns you know have towers: tall evergreens, a ridge, a two-story building on the next lot, a grain bin or a metal barn. Write those down and mention them when you call. Tall trees that are still growing deserve extra attention, since a clear path today can close in a few years.

Please stay on the ground. Never climb to a roof or touch outdoor radio equipment to test a view. A technician has the gear and training for that.

What if the answer is no?

Then you hear it before anything is installed. The path can be blocked at one spot on the roof and open at another, so a technician may try a different mount, or a different tower may see you better. When no mount works, the honest answer is that fixed wireless is not the right fit for that spot, and the guide on options when cable stops at the end of the road covers the alternatives.