The present situation in my flat is a classic failure of coordination. There are so many (encrypted) wireless networks operating that interference seems to have become a major issue. Internet access has become slow and unreliable. Of the eleven channels in the 802.11b/g standard, only three (1, 6, and 11) are fully non-overlapping. The individual wireless access points are all interfering with one another, as well as with everything else that operates in the same part of the radio spectrum: microwaves, 2.4 GHz cordless phones, security cameras, Bluetooth devices, baby monitors, wireless video game controllers, fluorescent lights, etc, etc. Indeed, a new phone somewhere in my vicinity may well have been the straw that broke the camel’s back, as far as the 2.401 MHz to 2.473 MHz range goes.
Everyone would have faster and more reliable internet access if we could shut down all but a couple of the access points. Unfortunately, there is no way to coordinate such an action. Furthermore, anyone who actually ran one of the reduced number of access points, if such an agreement could be reached, would be faced with the same kind of illicit usage that forced me to shut down my open network.
One option is to seek a technological fix, in the form of 802.11a or 802.11n equipment that is less likely to be interfered with by existing devices. Of course, given enough time, those devices are likely to face similar hurdles.
Aristole’s tragedy of the commons rearing its ugly head again…
A/N work on the 5GHz band using only 20Mhz chunks per channel (N allows bonding of 2 20MHz chunks so a possible 40Mhz), so the number of available channels is much greater than the 11 available on b/g in NA, of which only 1, 6, and 11 which don’t overlap. Much less possibility of interferance.
Regarding that, run a wireless network sniffer (kismet or netstumber), and determine what channels networks in your arrea are using (most default to 6) then run yours on either 1 or 11 depending on where the least amount networks are.
if you run a G router with open source firmware (ie. tomato, openwrt, etc), you can usually select channel 12, 13 or even 14 (which was only ever allowed by Japan for use with b networks…) Most European contries allowed channels 12 and 13 with g… Less interference in those channels here in NA…, thouh 10 and 11 interfere with 12 and 13… Just make sure your wireless NICs can also use those channels and you are set… Note that 2.4GHz cordless phones call also use channels 12 and 13 in NA so ymmv with those channels.
I don’t really want to switch to A or N. For one thing, my iBook only works with G. It would be annoying to need to buy and use a USB dongle. For another, the speed limitation on the network arises mostly from the DSL line, so using A or N won’t speed up surfing (though it might foil interference for a while).
Most of the other networks are on 6. A few are on 11. Mine is one of the only two on 1.
Regarding channels 12-14, will the Airport Extreme cards built into G4 iBooks work with it? There is also the matter of Emily’s computer, my DS, etc…
What is Interference Robustness?
Arbi Karamians
Monday, September 10, 2007
There are few forces more powerful
than geeks desperately trying to get
internet in a new apartment.
How Best To Deal With WiFi Interference?
By Soulskill on all-it-takes-is-one-EMP
marciot writes “I live in a condominium where I get interference from my neighbors’ WiFi. I understand that 1, 6 and 11 are the only non-overlapping WiFi channels, but how does this translate into real-life best practices? When you must overlap, is there a ‘good’ way to do it? With nine access points, for example, is it better to have three APs each on 1, 6 and 11, so that each completely overlaps with only two others? Or is it best to distribute those APs across nine channels such that they only partially overlap others (but potentially overlap more APs in total)? Do use patterns affect interference? For example, is it best to overlap a channel with multiple APs that rarely transfers data, or to share a channel with one person who downloads torrents 24/7? Does maximum data rate affect interference or robustness to interference? I found out by accident that setting my access point to ‘802.11b only’ mode appeared to give me a vastly more reliable connection that leaving it in ‘mixed 802.11b/g.’ Is this a fluke? Or does transmitting at 10 Mbps when everyone else is using 54 Mbps (for their 3 Mbps DSL pipes!) give you a true advantage?”
How-to: set up dual-band WiFi (and juice your downloads)
By Nilay Patel on WirelessNetworking
Let’s come right out with it — you should be running a dual-band 2.4 and 5GHz WiFi network. Why? Because the 2.4GHz spectrum is cluttered with everything from other networks to Bluetooth to cordless phones and microwaves, and all that RF interference slows everything down, making file transfers interminable and HD streaming nearly impossible. On the other hand, 5GHz 802.11n is clean and incredibly fast — we’re talking almost hardwire fast. But you can’t just move up to 5GHz without leaving your phones and other legacy devices behind, so you’ve got to keep 2.4 around as well — which is really easy if you’ve got a simultaneous dual-band router like Apple’s new Airport Extreme or something like the D-Link DIR-825, and only slightly harder if you don’t. And, as luck would have it, Apple just sent us a new AEBS to play with, so we thought we’d show you how to configure both kinds of setups. We promise you’ll thank us.
BuddyRich mentioned this as a possibility, but I’d like to endorse it fully:
Run a router with open source Firmware.
I’m running a WRT54G (that I got on Craigslist for $20) with Tomato firmware, and I couldn’t be happier with it. Allow me to explain how you might benefit: It does wireless surveys right from the router to allow you to see the least crowded channel, it allows you to use the usually inaccessible 12-14 channels (which I’ve personally found don’t work with a lot of devices) and best of all it allows you to boost your antenna gain which is great. You want your router to be ‘louder’ than the others, don’t you?
I’ve also experimented with DD-WRT which has a better interface. I’ve found Tomato to be more stable with QOS that works very well if you spend the time setting it up correctly. Both offer great features, though, like static DHCP assigned IPs (useful for keeping ports forwarded to the right computer) and bandwidth graphs. Again, I very highly recommend using a router with open source firmware.
Baby Monitors Killing Urban Wi-Fi
“Baby monitors and wireless TV transmitters are responsible for slowing down Wi-Fi connections in built-up areas, according to a report commissioned by British telecoms regulator Ofcom. The research smashes the myth that overlapping Wi-Fi networks in heavily congested towns and cities are to blame for faltering connection speeds. Instead it claims that unlicensed devices operating in the 2.4GHz band are dragging down signals. “It only requires a single device, such as an analogue video sender, to severely affect Wi-Fi services within a short range, such that a single large building or cluster of houses can experience difficulties with using a single Wi-Fi channel,” the report claims.”
I suppose it was just a matter of time.
Now, enough of my neighbours have locked 802.11n routers for there to be significant interference on those frequencies now. My internet connection is back to an awkward stuttering mode of operation.
There’s always good, old fashioned ethernet cable…
Yeah, but it would mean a cable across half my apartment. Still, this laggy wireless network is really annoying.
Yeah, but it would mean a cable across half my apartment. Are you using your iBook for wireless or your iMac? Or both?
My iBook is dead, as the battery is kaput.
I am using WiFi with my iMac.
“PC Pro has taken an in-depth look at Wi-Fi and the factors that can cause connections to crumble. It dispels some common myths about Wi-Fi problems — such as that neighboring Wi-Fi hotspots are the most common cause of problems, instead of other RF interference from devices such as analogue video senders, microwave ovens and even fish tanks. The feature also highlights free and paid-for tools that can diagnose Wi-Fi issues, such as inSSIDer and Heatmapper, the latter of which maps provides a heatmap of Wi-Fi hotspots in your home or office.”
I’m in the exact same situation again: embedded in about three dozen overlapping wireless networks.
It’s less of a problem now, though. I am using a simultaneous dual-band 2.4GHz and 5GHz wireless router.
It would still be better if people could coordinate, especially since I use only a fraction of the bandwidth I pay for. At least interference is less of a problem than back in 2008.