Improving signal in a wi-fi jungle?
October 22, 2011 10:24 PM   Subscribe

Is there anything I can do to improve wi-fi connectivity in a small area (three rooms) when dealing with a large number of other signals? I'm in a high-rise apartment building in a city; after letting inSSIDer run for a while, it shows that I'm competing with 125 other access points. My signal is okay in the first room, fair in the second room, and unusable in the third room. I'm using DD-WRT -- are there any settings I can tweak that might help?

This building has Cat5e wires to each room, but the network patch panel only lets you connect one location to a live signal. Sadly, the patch panel does not have access to power, or I'd put a spare router there to wire all the rooms together. The wireless router has to be in the first room because there are several devices wired into it there.
posted by stopgap to Computers & Internet (14 answers total) 4 users marked this as a favorite
I assume you've already tried changing the channel number your access point uses, to a less popular one?
posted by Joh at 10:39 PM on October 22, 2011

You can't use PoE to power a closet router? You could stick something like this into your closet to act as your wireless AP and provide a Cat-5 switch, and use a PoE injector to power it from another room.
posted by rodgerd at 10:46 PM on October 22, 2011

(Or you can use a straight PoE powered switch like this.
posted by rodgerd at 10:47 PM on October 22, 2011

Yes, you can tweak the output power in DD-WRT, but it's a generally not the best idea. The extra heat will often cook the router and you're really just starting an arms race. A better way to achieve the same end result while still staying within the law (which due to some regulatory oddness, regulates transmit power and not EIRP in the wifi band) is to stick on an external antenna. Something with a little bit of directional gain (which you point at the distant room) might do just the trick. This also avoids starting an arms race because little of your power will be radiated at your neighbors... assuming most of them aren't in a line with your rooms.

As mentioned above, it's a very good idea to put a hub (PoE or otherwise) at the patch panel and run wired for anything you can. But you'll still need wireless for phones, etc., so check out other wireless solutions.
posted by introp at 10:53 PM on October 22, 2011 [1 favorite]

Sounds like you're talking about 2.4 GHz. Is there any chance of upgrading all your equipment to use the 5 GHz band? that's a lot less common and it might work better for you.
posted by Chocolate Pickle at 10:58 PM on October 22, 2011 [1 favorite]

As Chocolate Pickle suggests, you want to get a "WiFi" router which meets the IEEE 802.11n standard. 802.11n operates on 2,4GHz and 5Ghz. The 5GHz band is much less crowded.
posted by three blind mice at 2:13 AM on October 23, 2011 [2 favorites]

I had a little bit of luck extending the signal (well, focusing it actually) with an aluminum foil baking dish. It worked pretty well, too, and the price was right. In the end, I put in a second unit in bridge mode in the low-signal area as a permanent fix but you might give the foil thing a try.
posted by jquinby at 3:34 AM on October 23, 2011

I don't really understand what's up with your ethernet wiring - you're saying it's not possible to have a wired device in each room and have them all networked together? That seems fairly useless.

You could use powerline networking from the first room to the third room, where you'd need an additional AP, but for that amount of money (~$100) you could get dual band router.
posted by unmake at 6:53 AM on October 23, 2011

Okay, thanks for the suggestions. I've tried several channels, but with so many other APs in the area there really isn't anything free. I've had the best luck when I go off the standard channels (1, 6, 11) though it makes me guilty to do that since it's just making the situation worse for neighbors.

I have a dual-band router, but I'm running the 802.11n on 2.4GHz because some of my Wireless-N clients don't support 5GHz. Either way, I have a few BG-only devices that still need a good signal on 2.4GHZ. I'm not looking to upgrade my hardware all at once here.

Yeah, the patch panel situation is weird, but I didn't design it that way. It's in a closet with no access to power, and that's the only access I have to the building's supplied incoming internet connection. I've been looking into the PoE options but it's tough since I don't have a way to inject power on the incoming line. I found a passive PoE injector with a plug size that matches a spare router, so I'm hoping I can use that on an unused ethernet port in another room to send power to my patch panel and set the router up there as a switch so every room can be wired.

If that fails, then I'll start looking at antenna/foil-baking-dish options.
posted by stopgap at 7:32 AM on October 23, 2011

antenna/foil-baking-dish options.

Well, if you're gonna go the antenna route, go and get yourself an old-fashioned TV antenna. The standard design is called a Yagi-Uda and it offers extremely good directivity. Make sure to get one that covers the UHF band (up to 3Ghz). Gain is not an issue for you; it's rejecting unwanted signals on the same frequency so directivity is the goal. You can build one yourself pretty easily - it's a very forgiving design - but even if you're way off, it'll still work good enough.

Even a loop antenna will work better than a pie dish.

The TV band suffers (or benefits from depending on your point-of-view) from multi-path (signal reflections arriving from different angles) so these antennas are very good at rejecting signals coming from directions other than where the antenna is pointed.
posted by three blind mice at 10:56 AM on October 23, 2011

Does the closet have a light in it?
posted by unmake at 3:53 PM on October 23, 2011

I got a wifi repeater when I had a similar layout to yours and had a problem with a chimney blocking my signal: it worked perfectly. Put the repeater in the middle room, that way you'll get reception in the far room.
posted by clone boulevard at 10:13 PM on October 23, 2011

I don't have a perfect understanding of your setup, but two things you may want to consider are getting a wireless router that has an external antenna connector and mounting the router in the first room and the antenna in the second. (This is based on your statement that the wired devices are all in the first room.) This would involve wiring, of course, but just the antenna wire.

Second, I use an Apple Airport Extreme and an Airport Express to implement a WDS extension of my wireless. Not sure it would work, but it may. You can set your client (pc) to ignore all the other networks and ONLY connect to yours and perhaps it would work better. It involves some reduction in performance, but if you are web surfing or emailing in the bedroom, you don't really need N-adapter performance, right?

Just a thought.

Personally, I am not afraid of drill bits and know how to repair walls, so I'd just pick the configuration I wanted and put it in place. Before moving out, I'd patch the holes.

Sometimes, you just need to get things working right and then move on to more worthy projects. You've got a communal pool of wireless channels there, and the pool is kind of full. What you fix today might not work tomorrow. How long do you want to do this? Wired connections are kind of bulletproof and they are 100Gbits. Even N looks slow by comparison.

Good luck!
posted by FauxScot at 9:12 AM on October 24, 2011

To follow up, the passive PoE injector worked like a charm to send power back to my patch panel. Now every room has live ethernet ports and the wifi signal blankets everything!

I had tried WDS here in the past, but the interference was too bad so the signal would drop intermittently, making streaming audio or video impossible. That's actually what led to my wire-everything-up-in-one-room solution. And this is a rented condo unit so I wasn't going to drill holes for wires or pay to have an electrician add an outlet to the patch panel (there's even a cut-out for one and it would have been so easy before the drywall went up!)

Thanks, all — the hivemind comes through again!
posted by stopgap at 2:52 PM on October 25, 2011 [1 favorite]

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