Using wireless in brick & cement structures

[mubs]

Any caveats? Does one spec work better than others -- A vs B vs G? It's hard to come by these structures in quake ridden CA, where we live in cardboard shacks . Those of you living in real houses on the Right Coast, please chime in!

 

[Bozo]

We've installed a 'G' system in our plant. Lots of steel walls and equipment. Seems to work pretty good; better than we expected anyway.
Range is about 100' depending on where you are. Connecting vertically seems to be a problem. IE: first floor to third floor through concrete floors.

Bozo :mrgrn:

 

[mubs]

Thanks for the feedback, Bozo. Helps to know 'G' works at least laterally thru steel.

I really wouldn't expect it to work from first floor thru to the third, but how about the first floor to the second?

Thanks!

 

[Mercutio]

Second floor to first works much better in practice.

 

[time]

Connecting vertically seems to be a problem. IE: first floor to third floor through concrete floors.

That's because concrete floors contain lots of steel mesh reinforcement.

Signal definitely won't pass through steel walls but it will probably bounce around a fair bit.

Brick (or concrete block) walls don't use much/any steel and you should be able to go through at least a couple of them (I'm less confident about solid concrete). However, the building code here insists on in-wall insulation for external walls, which typically involves foil.

A big problem is the angle at which your signal has to pass through a wall. The effective thickness increases exponentially as you move away from the perpendicular, i.e. there are more bricks in line of sight.

Don't be like me and wonder why a signal is clobbered by a couple of plaster walls - when in fact a washing machine and refrigerator are on the other side of the wall ...

 

[Bozo]

In our discussions we've decided to put access points in a more-or-less line of sight pattern.

I'm wondering; if you could see the radio waves coming from an access point, would they be like a ball or a plate around the antenna?

Bozo :mrgrn:

 

[Buck]

In our discussions we've decided to put access points in a more-or-less line of sight pattern.

I'm wondering; if you could see the radio waves coming from an access point, would they be like a ball or a plate around the antenna?

That's a good question Bozo. I have experienced that the connectivity within the horizontal 'plate' zone is best. Connectivity above the antenna (e.g. second floor) is good, but not quite as good as the same floor. Whereas signal integrity below the antenna is the worst (e.g. Access Point upstairs). Of course, take any of these arrangements and insert the usual interruptions as have been mentioned (plus flourescent lights and microwaves) and connectivity can become a real gamble. I still favor hard wiring a network if it is possible.

 

[Fushigi]

As time mentioned, the angle between the WAP antenna & the workstation matters. A "300 foot range" (or whatever) is not spherical; really more of a squished sphere or ellipsoid. And the more solid matter, especially metal, it passes through the shorter the range becomes.

If you want a single WAP for a 3 story structure, your best bet will be a WAP on the 2nd floor. Or maybe on the first (or third) floor but with the antennae angled. But WAPs are cheap enough now that a WAP for each floor is easily do-able.

Also, depending on the manufacturer, a singal booster may be available.

 

[time]

What Buck said.

It's also worth trying horizontal antenna orientation (at both ends), or possibly even the compromise oblique orientation. And different channels may give different results.

 

[time]

And what Fushigi said.