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Wireless Networking

What's Killing Your Wi-Fi? 248

Posted by samzenpus
from the jamming-the-signal dept.
Barence writes "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."
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What's Killing Your Wi-Fi?

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  • Horrible link... (Score:4, Informative)

    by Azmodan (572615) on Monday May 30, 2011 @04:27PM (#36290366)
    Billions of ads + need to check 15 pages to RTFA... and the article is actually a little shallow...
    • by Threni (635302)

      Pc pro is a shit mag; what would you expect? I grew up on mags like pcw - they had assembly columns and maths sections etc. Now it's all recycled press releases and mp3 player reviews. No wonder they're dying.

      • by Jezza (39441)

        But worse, the "web IT press" is actually worse... I miss PCW and Byte. Mind you, I miss the Amiga as well.

        Anyway - I'm a "desktop" person, so I tend to just use an ethernet cable... I know, but I'm not carrying these monitors into the lounge, so why does it matter?

        • by AVryhof (142320)

          I second the vote for old PCW and Byte. I miss the codes you could type into debug on DOS, and things like Byte's CD full of compilers.... the stuff that inspired you to try some new programming language because you want to do something neat. Some of these old mags also developed some cool tools like notepad alternatives, disk format utilities, and things you might not always care about, but are useful.

    • by Stumbles (602007)
      Worse than shallow; it was a scam article just to push a couple of apps.
  • by cerberusss (660701) on Monday May 30, 2011 @04:40PM (#36290468) Homepage Journal

    Both InSIDDer and Heatmapper are Windows-only, AFAIK. For Linux, there's the awesome Kismet [kismetwireless.net] and its cousin for OS X, KisMAC [kismac-ng.org].

    • by Cwix (1671282)

      There is an InSSIDer for linux in alpha.

      It does seem to work in Linux at least for me, it is alpha so YMMV.

      http://www.metageek.net/products/inssider/linux/ [metageek.net]

    • by Rigrig (922033)
      There's inSSIDer for Linux [metageek.net], although Kismet is nice, it doesn't output pretty pictures :p (Seriously though, the graphical overview of networks is a nice addition to just a textual list of networks and their strengths for each channel, especially for seeing the overlap if they're using something besides the three standard channels)
  • by Master Moose (1243274) on Monday May 30, 2011 @04:47PM (#36290534) Homepage

    My wifi was going great... until the neighbours decided to secure their network

  • and even fishtanks

    I knew that goldfish was up to something!

  • Microwave at 50m (Score:5, Interesting)

    by thegarbz (1787294) on Monday May 30, 2011 @05:01PM (#36290654)

    Research from the Farpoint Group suggests that data throughput can fall by 64% within 25ft of a microwave, and Farpoint analyst Craig Mathias said the firm had even “seen problems at 50m”.

    I'm sorry but if this is the case you have far bigger problems with your microwave then simply WiFi interference.

    RUN!

    • by Mashiki (184564)

      I guess it depends on how old the microwave is. Some really old microwaves really kicked out EM fields.

      • My parents have a working microwave from the early 80. It will kill any kind of transmission in the house but my parent wont replace it as any replacement they had was not as fast as this 2500W monster.... My current 1100W microwave kill the signal only if my laptop is resting at about 6 inch of it....

        • It will kill any kind of transmission in the house but my parent wont replace it as any replacement they had was not as fast as this 2500W monster....

          Because heaven forbid they wait an extra 20 seconds...

          • Because heaven forbid they wait an extra 20 seconds...

            It's a microwave man; the whole point is speed. If you're going to suffer eating nuked food, you better damn well at least get a speed advantage out of it.

    • by AmiMoJo (196126)

      Not really. WiFi signals are very weak so it doesn't take much interference to degrade throughput.

    • Re:Microwave at 50m (Score:4, Interesting)

      by the_raptor (652941) on Monday May 30, 2011 @06:06PM (#36291178)

      I thought most Slashdotters had a basic understanding of science? Non-ionising radiation is basically all the same. It doesn't matter if it comes from the magnetron in a microwave oven or your Wi-Fi AP. The only issue as to whether it will cook you is the power you absorb. Microwave ovens tend to run in the range of 500-1000+ watts of power, your AP probably puts out below 5 watts. It doesn't take much to figure out that minor and completely safe levels of leakage from the microwave will heavily interfere with Wi-Fi.

      Of course I have actually had RF burns from playing with radios so I am not terrified of non-ionising radiation like luddites are.

      • Re:Microwave at 50m (Score:4, Interesting)

        by Solandri (704621) on Tuesday May 31, 2011 @02:28AM (#36293808)
        I'm surprised this hasn't been modded up. The FCC limit on omnidirectional broadcasts in the 2.4 GHz band is 1 Watt. Most wireless routers I've seen are 500-750 mW max. They actually self-regulate their power output to use the weakest possible signal and still maintain good throughput. Most microwaves are actually around 1500 Watts. So even if the shielding is 99.9% effective, it's still putting out at least 2-3x more "signal" than your router, probably a lot more. It's simple enough to demonstrate. Start copying a large file over wireless with something like Teracopy (which gives instantaneous MB/sec). Then turn on your microwave. Throughput will plummet.
    • Some urban legend is circulating that this will work for radiation, but it will definitely work for WiFi interference: Set a bag of microwave popcorn out on the counter. If it starts popping, you've probably got WiFi interference problems.

  • affinity for lathe and plaster.

  • by hackus (159037) on Monday May 30, 2011 @05:02PM (#36290670) Homepage

    Crap firmware and products.

    That is what is killing my wifi.

    I would also like to add:

    1) Wall Street fascist pig CEO types who need that 5th mansion and stupid Board directors and shareholders who let him get away with it while the companies network infrastructure rots to hell.

    That doesn't help my wifi either.

    2) Closed proprietary crap hardware primarily by CISCO that makes it impossible to produce decent firmware via a 3rd party even after you bought the damn thing.

    Apparently in a fascist system you really don't get to own anything you buy and can go to jail if you try and figure out how it works or make your own improvements.

    Poor WRT guys, how they must suffer. Even though they work really hard, their firmware still sucks because the binary blobs they get with the radios suck it and my Wireless N router (WRT600N) still, has to auto reboot every 24 hours or it just plain stops working.

    3) Finally I would like to thank all of the fascist members in Congress for creating laws that pretty much guarantees our wifi will suck.on a country wide basis, insuring intellectual property nonsense will continue to make wifi blow.

    -Hack

    • by labnet (457441)

      While I agree with your ranting, I have a more productive solution.

      For years I put up with crap box all in one WiFi/Routers that would fall over almost daily (in multiple locations as we had moved house) (the reboot walk).
      My solution:
      Cable Modem -> Crap Box AllInOne (But only for the NAT function) -> Dedicated Cheap Gigabit Ethernet Switch -> POE Ubiquti UniFi AP
      My printer (Ethernet) and NAS (Synology DS211J) plug direct into the Ethernet Switch.

      Finally a setup that is cheap and doesn't crash. Been

    • by drinkypoo (153816)

      Poor WRT guys, how they must suffer. Even though they work really hard, their firmware still sucks because the binary blobs they get with the radios suck it and my Wireless N router (WRT600N) still, has to auto reboot every 24 hours or it just plain stops working.

      I have used OpenWRT and was impressed but not happy.
      Then I used DD-WRT and I was happy but not ecstatic.
      Since my hardware happens to be compatible I was able to switch to Tomato, and now I am at least very happy, if not... well you get the idea. WDS is finally working for me, for example. So this might not help you, but some might be pleased. I try to wire any bandwidth hog...

  • by cerberusss (660701) on Monday May 30, 2011 @05:06PM (#36290712) Homepage Journal

    What's killing your Wi-Fi? Or rather, who? *maniacal laughter*

    Mini Portable Signal Jammer (Wi-Fi/GPS) [dealextreme.com]

  • by lobiusmoop (305328) on Monday May 30, 2011 @05:13PM (#36290788) Homepage

    Nachos [xkcd.com]

  • 5GHz, or wired (Score:4, Informative)

    by sillivalley (411349) <sillivalley@com[ ]t.net ['cas' in gap]> on Monday May 30, 2011 @05:22PM (#36290870)
    Go 5GHz with WPA2 and 802.11n -- you'll have great performance until all your neighbours do the same.

    Go wired (gigabit) when you can -- that's faster and more secure.

    If you're forced to run on 2.4, don't expect great things in crowded (spectrum) areas. Do spectrum scans, and if you can't work with one of the non-overlapping 2.4GHz channels (1,6,11), and can't use a directional antenna (you can build your own corner reflector or parabolic reflector for under $1) try 3 or 8 and don't worry about HT (high throughput) datarates.

    Take up arc welding as a hobby.
    • by cbeaudry (706335)

      5ghz wont do you any good if you have lots of walls, as it just bounces off them.

      I tried, it doesnt work unless you are trying to saturate a large open area.

  • My 8 year old Airport base station dying, that's what killed it.

  • Not mentioned in this article was the problem of people operating poor quality routers. Ironically enough that they quoted a rep from Belkin in the article, cheap $30 routers from the likes of Belkin, D-Link and such from the local Wal-Mart electronic section tend to have a bad habit of "dropping out", or freezing traffic to the point to where the only solution is to power off and power on the router. On some bad quality routers this happens nearly 100% of the time under heavy traffic loads (2 or more com

  • by TAZ6416 (584004) <mccormackj@rocketma i l . c om> on Monday May 30, 2011 @06:10PM (#36291214) Homepage
    Once my daughter goes to sleep and my wife turns this bad boy on, my wireless network totally falls apart.

    http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110693416818&clk_rvr_id=236365054762 [ebay.co.uk]

    Seems quite common, I work in IT and now and again I get asked do you know why my wiresless network is so crap and a lot of the times they've just had a baby.
    • by green1 (322787) on Monday May 30, 2011 @06:45PM (#36291464)

      I work as a service tech for a local telco, I frequently go out to fix people's wireless when they can't figure out what's wrong, baby monitors and other people's wifi do kill the signal, but usually not badly enough to be a major problem, simply changing the channel on the AP or moving the equipment a few feet usually solves it.
      Microwave ovens are a big deal, but usually only in close proximity to them, or if it is directly between the computer and the AP.

      What has always amazed me more is how badly various other household appliances can affect networks, and I'm not just talking wireless either, I've had cases where a hand mixer in the next room was able to make streaming video unwatchable on an ethernet cabled computer. And a customer who watched streaming video while on the treadmill required a lot of creative work to get a signal through even on ethernet. (turns out the problem was actually interference on the power line side of things, a UPS on the computer and moving the treadmill to a circuit on the other half of the electrical panel eventually solved it)

      Basically, consumer gear is garbage, everything from hand mixers and treadmills to computers and routers. sometimes you can work around it, sometimes you just can't.

  • Gold Dust! (Score:5, Funny)

    by failedlogic (627314) on Monday May 30, 2011 @06:21PM (#36291280)

    In my carefully controlled laboratory (the basement of my parent's house), I decided to try things that would enhance the wireless connectivity. "Scientists" tend to only focus on the negative. Who wants to read something that very craftily calls us idiots? Summary of article the article I didn't read: "Want better wireless? Get rid of the microwave, dumb ass!"

    I'm going to write a paper. But my parents want me to clean up the basement first. I don't feel like it ...... so its going to take a while. :)

    In writing this more positive paper, I felt gold dust would be the best stuff to sprinkle in the air to enhance wireless signals. After all, this stuff works *MIRACLES* for stereo cables and computer cables. Why not wireless signals?

    So I installed some fans in the basement to blow the gold dust around while testing my wireless network. I tried 3 different gold samples. 1) Gold bought from Dollar Store. 2) Gold bought from Pawn Shop. 3) Gold extracted from Monster Cables.

    Total cost of materials (gold): $2000*. Acquiring gold from the first two sources was much cheaper than the 3rd (see Marketing Materials as reference).

    I'm not going to bore you with the methodology. "What was the purity of the samples?", you might ask. I trust I'm getting 100% Gold from all my sources. They told me it is.

    Suffice it to say, my paper will conclude (I'm not done looking at most if of the results just yet and don't think I need to) that sprinkling gold dust in the air boosted wireless signals up to 2 x 10 ^ 3 % (this is a scientific study so I must use scientific notation!). I'll leave the reader to conclude which of the 3 sources resulted in the best results. Frankly, I lost track.

  • xbox 360 controllers.
    ps3 controllers.
    bluetooth.
    electrical motors for ceiling fans.
    cordless phones in the 2.4Ghz range.
    cheap RC cars/planes/helicopters.
    Your paper shredder, while it's running.
    your 5 neighbors' wifis all on channel 6.
    CFL bulbs. (They tend to absorb radio signals.)

    All of these will interfere with wifi. Perhaps you should switch to 5Ghz 802.11N

  • Network Down (Score:4, Interesting)

    by rmccoy (318169) on Monday May 30, 2011 @06:53PM (#36291510)

    Back in the day...

    When WiFi was just starting to get rolled out in most businesses, I had set up a multi access-point wireless network that had worked really well for about five months. Then, with no known changes, it started dying across the entire building almost every afternoon about the same time.

    I worked with the building maintenance staff to try to find any electrical gear that might be starting up about that time with no luck. Finally, because the executives loved their wireless, I had to buy a spectrum analyser to try to track down the problem. I kept it on my desk until the next time we had an outage and started following the high amplitude broadband noise that had suddenly appeared.

    The directional antenna led me straight to the kid that worked in the mailroom who had his feed up on the desk talking into a wireless phone. I pulled the plug on it and the noise stopped, the network reappeared. He'd brought in a consumer wireless phone so he could talk to his girlfriend while he moved around the mailroom sorting mail. I'm surprised his hair wasn't smoking with the signal the thing was emitting.

    I took it away from him and everyone, except maybe his girlfriend, was happy. :)

  • by FudRucker (866063) on Monday May 30, 2011 @07:24PM (#36291658)
    even people can block wifi, my router is next to a desktop in the office at the front of the house, normally i get about 75% signal strength, when someone is sitting at that desk it drops down to about 55% to 60% and i notice the slowdown...

    this router has a rubber ducky antenna so while searching for a way to improve my signal quality i found this and it really does work, now when someone is sitting at the office desk near the router it does not weaken the signal and the overall signal averages about 85% solid without problems

    build one of these out of heavy paper like card stock or similar (cereal box cardboard) and aluminum foil http://www.freeantennas.com/projects/template2/ [freeantennas.com]
  • by nazsco (695026) on Tuesday May 31, 2011 @03:58AM (#36294194) Journal

    have one with 2 wireless speakers for the back channels.... I loved it while i was oblivious to the fact that it kill wifi in a 3ft radius!
     
    ...until i tried to play online on the wii.

    Now i have to choose if I want 5.1 audio or multiplayer.

  • by Bones3D_mac (324952) on Tuesday May 31, 2011 @05:21AM (#36294526)

    ... mismatched devices!

    You would not believe how many people "upgrade" their broadband to 20+ Mbit/sec service and then complain that their computer is still only getting 1-3Mbit/sec speeds. A lot of them don't realize that the older 802.11 devices can significant reduce the performance of a modern wireless network.

    Most 802.11b devices (which are still in use today) usually top out at around 10-11Mbit/sec, and that's under perfect conditions. If you start adding multiple users, competing networks and outside interference, things get out of hand pretty quick.

    Here's a list of things to look for in examining your wireless network for performance issues:

    - Replace the router.

    If you're router is over 3 years old, it might be time to replace it. Especially if it's an older 802.11a/b model. The really old 802.11 devices, like Apple's original AirPort base station, have a lot of problems working correctly when they encounter other networks within their own service range. This can result in dropped or spotty connections and overall losses in bandwidth. Many of these first generation wireless network devices barely worked, but they worked well enough for the few people that could afford them. Most of these devices have since been trashed for more recent models either because they started failing under the weight of other networks or simply died from various flaws or age.

    - Update the firmware.

    Many wireless devices have firmware chips on them that can be upgraded through software. This can help weed out networking issues that might be caused by buggy firmware, or may add enhanced features that can help your device work better under heavier loads from competing networks, interference, multiple users and various security issues.

    - upgrade all client-end networking hardware at the same time.

    When putting a wireless network together, or upgrading an existing one, make sure your client devices use similar configurations. (Or identical, if possible...) A single, poorly configured client device can significantly impact your wireless network's performance. By making the network devices functionally similar to each other, the simpler it will be to put together an efficient network setup. For example, if you have a network consisting of only 802.11g devices and set up a router to only accept 802.11g connections, it'll run at around 54Mbit/sec. But, if you have a network consisting of random 802.11 devices and a router that will support several protocols going back to 802.11b, the network will default to using the slowest, most common protocol available (802.11b) and will force all connected clients to run at that speed (11Mbit/sec), regardless of each client's individual configuration. That bandwidth is then divided by every connection, making then network seem much slower than it is. By keeping the client and router hardware similarly configured, the network speeds are less likely to suffer. Your maximum network performance is limited only by the hardware you use to build it.

    - Secure your network.

    Make sure your network hardware is secure on both the router and client end. Set up your router to use the most powerful encryption protocols it supports and utilize MAC address detection to identify each piece of hardware on the network, so you can ensure no one outside of your client list can access your network. Also, don't use DHCP to assign IP addresses. Manually configure each client, so they have a static IP. Finally, disable SSID broadcasting. This will reduce the likelihood of a war-driver finding your network and tagging it for others to find.

    - Use the latest available network protocols.

    Using protocols like 802.11g or 802.11n may help to significantly improve your network speeds over older ones, but may also offer some added flexibility. Unlike the older 802.11b/a protocols, some of the newer protocols aren't limited to one broadcast frequency (2.4GHz). While the broadcast frequency of your wireless hardware has relatively little to do with your netw

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