My apartment is bisected by a ~8" thick concrete wall, through the center of which is a doorway.

My ethernet (provided by the building) jack emanates from one face of this partitioning wall. My office is, unfortunately, on the other side.

Is it better to place the wireless router flush with the wall and try to "blast through" or across from the doorway and try to bounce through and into the adjoining room?

Current setup with poor signal reception:

|        ||        |    || = concrete wall
|        || office |    PC = desktop
|        ||     PC |    wr = wireless router
|        ||        |     e = ethernet jack
|        ||        |
|        ||   +----+
|        ||   |    |
|              bath|
|wr      ||   |    |
|        ||   |    |
|        ||   +----+
|       e||        |
|        ||        |
|        || bedroom|
|        ||        |
|        ||        |
|        ||        |
|        ||        |

Currently I'm running CAT-5 from the jack along the baseboards to the router, which is located there because there is no outlet near the doorway/hall. The CAT-5 is hidden nicely behind furniture and such, which keeps the wife happy... but the signal in the office sucks.

What solutions exist to me? Can the antenna or location of the router be manipulated in some way to provide a better signal quality on the other side of the wall? Is there some other technology available that could solve the problem?

  • 1
    Does that mean you'd have to run power from the outlet round to the concrete wall in order to mount the wr on the wall? If I were you I'd just try it, get an extension cable and see where you get the best signal. The antennas should be perpendicular to the direction you want reception. Ie, pointing up rather than at the PC. – Paul Nov 10 '11 at 2:13
  • suspend it (or its antenna only) in the doorway at the opening in the concrete wall :-) thats what I would/have done. then eventually I would get ticked off and run a real wire. – Psycogeek Nov 10 '11 at 3:59
  • 2
    Have you thought about a powerline kit? It's a plug that goes into the wall with an ethernet jack and uses the mains instead of having to run cable. – tombull89 Nov 10 '11 at 9:51
  • I've used homeplug powerline kits for years, although my situation was worse than this due to multiple floors. They are a bit pricey. – Amicable May 25 '12 at 12:55

I have one word for you; Homeplug! It is a standardised form of Powerline Communication used as a bearer for Ethernet connections.

They allow you to use your home wiring as an extension of your network, currently you can get up to ~500Mbps kits - although this is a bit of a lie, since its usually 500Mbps half-duplex, but its still higher than most every residential internet connection. They are very simple to set-up and don't do any routing or packet manipulation and are invisible to your computer, it will simply think it is plugged directly into the router and will be addressed as such.

They are usually advertised to work within any given ring of a building, however from experience I've found they will work pretty well anywhere on you're side of the fuse box.

The downside is that currently they can be a bit pricey (and they REALLY anger amateur radio folk), you'll be looking at something like £60 for a pair right now.

In you're use case you have two option, the most likely I would say it to just get a pair of them and run a wireless repeater/switch on the other side of the wall so that you don't have to worry about transmitting through it. The other option is to get a single plug for each device, which can be significantly more expensive - however it would give a better connection.


Bounce it through the doorway. The frequency that Wireless operates at is highly reflective off the right surfaces. It also is absorbed by porous concrete (cinder block). Poured concrete with an appropriate surface will reflect the signal, but you aren't going to blast through it at the Part 15 power levels available in most APs. A corner reflector could be built with tinfoil coated fiberboard to direct the signal through the doorway and in the general direction of the office. Place the AP in front of the reflector and turn it for maximum strength at the other end.

I use the microwave absorbtion/reflection properties quite effectively to divide our place of business into two separate wireless networks.

The warehouse is cinder block wall with a metal roof. The general use AP for the office area (for sales reps and employees lunchtime use) is on the other side of the wall and the metal roof of this area waveguides the signal all the way to the front lunchroom where you get nearly full strength at 60 feet and around a 90 degree corner. Each network is totally isolated from each other except at the warehouse door where the thick oak swing door and metal interlaced safety glass do a pretty good job of keeping the two broadcast regions isolated except when someone blocks the door open.

The standard answer for business radio is VHF bounces off mountains, UHF bounces off walls. You use VHF radio out in the field and UHF in city building work where it will go through windows and bounce around inside as long as it has openings to waveguide through. Wireless networking frequencies are even higher yet and so you're not going to blast through any concrete walls with it.


First answer is correct, but it sounds like someone who is not facing the same wifi boundary conditions. Yes, you need to use the door to get through, but no, you're not going to be using foil covered fiberboard.

First thing I would do is assess the concrete. If the concrete wall behind the router is actual poured concrete or brick, that's great. It reflects well off of it. Cinderblock sucks, it just absorbs it. Metal and metalized surface are fantastic, as is. . . metalized GLASS, i.e., a mirror. Step one is to adjust the placement along the present wall for the router probably a bit downward in your diagram. You are multipathing the crap out of your signal to get through the door if it really is concrete, and you want to get the best bang out of each bounce.

If the center wall is cinderblock and the bath wall is just drywall over timberframe, then pull the router about even with the jack (except still on this wall). That gives you a line of sight through to the office PC, except perhaps having to blow through the very corner of the bathroom wall (which it will do happily).

If the center wall is poured concrete, and the bath wall is something bouncy like brick, then you have to be more creative about your multipathing, since you won't go through the corner of the bathroom. You may have to do the same positioning I recommend above, except position an attractive wife-approved large mirror in your hallway between the doorway and your office on the center wall. This may be needed to give you extra bounce.

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