Propagating a Signal Through Old Walls?

avjewe asks: "I have a wireless (802.11) network in my 100 year old house. The walls are thick plaster, with enough metal in them to block the signal quite effectively. The floors, however, pass the signal just fine. Does anyone have any experience or suggestions as to how one can propagate a signal through a maze of faraday cages? I recently added an omni-directional antenna which, as one would expect, boosted the signal where I already had one, but didn't help the dead spots."

Comments

Sledgehammer?

[swillden]

I realize it has some downsides from the aesthetic point of view, but, really, what's more important?

Re:Sledgehammer?

[HRbnjR]

As a corollary to this, I would suggest the following:

a) a large drill
b) a large spool of cat 5 cable
c) a crimping tool
d) electrical tape*

* One might incorrectly assume the electrical tape is just for use with the cat 5 cable, when in fact it's primary use is for tying up your wife to keep her from hurting you while you drill cable holes through the living room wall :)

Re:Sledgehammer?

[foidulus]

One might incorrectly assume the electrical tape is just for use with the cat 5 cable, when in fact it's primary use is for tying up your wife to keep her from hurting you while you drill cable holes through the living room wall :)
Make sure to save a little bit for some "fun" with the wife afterwards :P

multiple antennas

[TheSHAD0W]

You might be able to connect multiple transmit and multiple receive antennas to the same access point. I don't know how well it'd work, especially with the receive portion.

Re:multiple antennas

[curious.corn]

that would whack the impedance of the output line. Even if you retuned the line with some passive component you'd end up with nasty losses, reflections on the bifurcations and phase interference between the antennas; this kind of stuff is only worthwhile if you're making a phased array (now that'd be fun: make an access point that tracks your position and target enough power to your receiver. but you're still linited by your laptop antenna range & power).

Attic?

[Omega1045]

Have you tried putting the WAP in the attic? Perhaps there isn't metal in the ceilings?

Re:Attic?

[cybermancer]

That is a good idea. Maybe putting one in the crawl space too.

Another posibility would be to drill small holes in the walls (along the baseboards or close the to ceiling maybe) and run a wire through the wall with an antena attached on both sides. Maybe a powered repeater.

I'd try the attic / crawl space first. Let us know if that works.

Re:Attic?

[GreyWolf3000]

At that point, why not just use Gigabit ethernet?

Instant PowerLine Etherfast 10/100 Bridge

[Razor's Edge]

Anybody have experience with Powerline technology in the home?

http://www.linksys.com/products/product.asp?grid =3 4&scid=33&prid=416

I've heard Siemens also has some good gear. Better than Linksys?

Re:Instant PowerLine Etherfast 10/100 Bridge

[mrscott]

I happen to have experience with many of the various powerline home networking options. Actually, they're VERY cool, and will probably work even on your old cabling. If you're just trying to get one remote system up and running, you'd need two (one for the computer and one to connect to your router - all via Ethernet) and they're around $70 each or so.

They're not speed demons at 4-8Mbps in real life, but still faster than broadband and not a bad choice at all.

use the walls themselves...

[greywire]

I dont know if its possible, but could you actualy use the metal in the walls as an antenna? Just expose a part and attach your AP directly to the metal in the wall?

Re:use the walls themselves...

[j1m 5n0w]

I dont know if its possible, but could you actualy use the metal in the walls as an antenna?

If the antenna isn't properly matched to the radio you can end up with high SWR (standing wave ratio), which could potentially damage the radio. The energy, instead of being transmitted out the antenna, gets reflected back to the transmitter, which can cause it to overheat. That's my understanding, at least. If someone else knows better, feel free to correct me.

-jim

Re:use the walls themselves...

[mokomull]

I happen to be a ham radio operator (so I have to know all about SWR and things...), and I'll say you did a fine job of explaining it... except, at 200mW, high SWR isn't likely to create enough heat to kill it... it may get hot to the touch, but I don't think that any irreversable damage will be done. But, yes, SWR will be a problem with that.

best solution

[JVert]

Do what parent does, if you really need wireless in each room then add an access point at each drop where you have you cabling. Its not that bad really, access points are getting very cheap and you can start with as many or as little as you want.

Re:best solution

[JVert]

Nice, I heard a good rule of thumb for where to put wireless access. When you think of a place where you want wireless, if your not in that place when you think of it, then you dont really need it.

My solution

[teknikl]

My house is old, real old. We have wires running inside old gas light tubes for conduit and lots of knob and tube to mess with signals. The radiators don't seem to be much trouble, unless you're tx/rx ing right in front of one, course they are by the windows so it's never a problem. And yes, we have the old old plaster - very think stuff. Can't even nail in it. Still I managed to find a central location for my little netgear mr814v2 with a stock antenna to do its thing, after some trying. My perfect spot was at the VERY top (9ft up from 1st floor level - we have high ceilings) of the basement steps - attached to the ceiling. From this location it was: a) in the center of the house (very little signal leakage to outside world) b) in between the first and second floors c) hidden away where I could forget it was there and just use it. My advice is - mount it up a wall in the center of your home. Higher the better. For me... this was enough. I still have dead spots where the oversized central 19th century chimney simply refuses to pass a signal. That just means you have to sit on the OTHER sofa to check your email.

Re:My solution

[dchamp]

My house is a 2 story, 3 bedroom built in 1923, and has plaster over wood lath, not wire mesh... so I don't have quite the farraday cage issue.

My WAP (a DI-614+) is in the basement - about 5 feet off the ground on a shelf. It works great in the whole house, using just the stock antennas. Oddly, I get better reception on the 2nd floor than I do in the 1st floor living room right above the WAP.

Even though it's in the basement, I can still pick with netstumbler about 50 yard down the street with the laptop sitting in the front seat of my car. I'm running WEP and not advertising the AP....

Try this

[aminorex]

solder one pole of your antenna cable to one end of
the wire mesh behind the plaster, and solder the
other pole to the other end of the mesh. Voila,
what was previously shielding has become your
antenna.

Short and simple summary and solutions...

[stienman]

Your problem is that you want to get network access to all parts of your home with a minimum of fuss, ideally wireless.

The walls prevent a single wireless access point from working throughout your home.

Your implicit question is: How can I, without investing in more equipment, get wireless throughout the home?

The answer is: You cannot.

Solutions:

1) Place multiple access points throughout the home. Honestly, you can get one for $19 now - why are you so worried about it?

2) Wire passive repeaters throughout the home. Get two 802.11 antennas, put one on each side of the various offending walls, and connect them with their very short cables through the wall. Not great, causes other small problems, but recent radios and APs can sort those out with some loss in quality and speed.

3) Use APs with two antennas, and mount an antenna on each side of one wall. Means you don't have to have an AP for each section, one AP can serve two sections.

4) Use wireless bridges and repeaters - again, one antenna on each side of a wall.

5) Use an amplifier with your AP. DLink, Linksys, etc - they all have amps. Mount the AP and both antennas in the attic. Spread the antennas out, 20-30 feet apart to get the largest cover area.

6) Use a powerline to wireless adaptor, and place them all over the place. Should be able to buy these very cheaply online now.

There are many other solutions, but these are the ones that come to mind readily and should be easily implementable by even the most technophobic individual.

Hopefully you know how to repair cracks and holes in plaster.

-Adam

You already HAVE the wiring!

[Jeremiah Cornelius]

You need a home powerline network!

The MacWireless Powerline Network Adapter allows you to route your network through the electrical lines in your home or office. With speeds up to 10 times faster than DSL, this is a great way to get your ethernet network to other floors or rooms in your building, without the need to run wires. Powerline Network Adapters are particularly useful when concrete, metal, or other obstructions in the walls of your home or office block your wireless signals.

100 year old plaster?

[millia]

don't worry, you're living on borrowed time. that plaster's about reached the end of its lifespan, and when you have to put up sheetrock, problem solved!

but seriously...
i have a similar situation, and i solved it by using my cellar to poke up cat5 and repeaters. (i've got a 65 year old house, but it's plaster *on* sheetrock- best of both worlds) my faraday cage used to drive me nuts- move 6 inches over, lose a signal. i just hid the repeaters behind furniture. *note* - i am a bachelor.

somebody needs to make a repeater/access point that fits in an electrical outlet wall-box, btw. what with schools wanting wireless everywhere, that would make it easy to do. i digress, however.

now, if you need to run cable, the trick some people do in old houses- take off the- aw dang it, words fail me. the boards around the periphery of the room, on the wall? take those off, and then raise em up about half an inch- run the cable there, and put quarter round molding in front to hide the gap and wire.

similarly, you can hide wire behind a picture rail. drilling a hole through plaster is always fin, though, as you know. (i always start a hole with, like, a 1/16th inch bit, then after i've drilled through, go back with the size i really need.)

if you try any of the verious antenna repeaters, let me know. i'd like to get a signal outside in the backyard...

Re:Sir

[Jeremiah Cornelius]

Yeah - but we arene't sending 10+ MBPS 802.3 signal, either.

Powerline networking is using live, unshielded, untwisted electric wiring as a collision-tolerant physical medium to trancieve the equivalent of 802.11 datagrams...

It's "wired" wireless - for the scenario in question.

(Thinks me, to myself: "Was that a subtle troll?")

electrical tape-- or--

[way2trivial]

I convinced my wife (easily) we needed crown molding in the babies room.. (it's between my office and the master bedroom) she readily agreed to add it to the list of renovations for that room, (she was 'nesting' dontcha know)

then she agreed to the cables run behind the molding...
3 strands of cat 5, and 5 rca lines... wheee!