Curing unexplained Wi-Fi interruptions

Discussion created by beachb on May 9, 2014
Latest reply on Apr 8, 2015 by morrisb.mvhqhs

The following article is from the Windows Secrets Newsletter, posted here by permission of the newsletter's associate editor. I am a long time subscriber to the newsletter.

Since Wi-Fi is such an important issue for Republic Wireless subscribers, particularly those who conscientiously offload traffic to wi-fi whenever they can, I thought this article could be an excellent reference to help troubleshoot some of the wi-fi issues we sometimes face. So, I asked for and received permission to re post the article here, for Republic Wireless members. I hope you find it useful and informative.


Curing unexplained Wi-Fi interruptions

(By Fred Langa)

It's extremely frustrating when your Wi-Fi connection suffers periodic slowdowns and dropouts.

The causes might be mysterious, but a little sleuthing with some free tools can usually get things working properly.


Why does his Wi-Fi randomly disconnect?

Reader Roland Pokorny's Wi-Fi setup briefly stops working for no apparent reason. He's not alone: Wi-Fi interruptions, slowdowns, dropouts, and other problems are extremely common.

For that reason, I've devoted most of this column to covering the most likely causes — and solutions!

Here's Roland's note:

  • "I recently purchased a new laptop. It works great, but it won't stay connected to my wireless router. In some instances, it drops the connection as often as every half hour; in others, it disconnects after several hours. (The laptop connects fine when connected via Ethernet.)  "I've searched the Internet and tried everything. I took the laptop in for servicing and the techs did a firmware upgrade. But that didn't solve the problem. I also tried relocating the laptop next to the router, but it still dropped the connection.  "I can reconnect immediately, but it's annoying with a new system. I'm at a loss as to how to fix this. Any advice or help would be appreciated."

Because you're running into trouble with only the Wi-Fi connection, I'll rule out fundamental issues with the router or the laptop. I suspect something in the vicinity of the router or laptop is causing interference with the Wi-Fi signal.

Some Wi-Fi setups, especially older routers, are vulnerable to signal interference from many sources. They could include Bluetooth devices, garage-door openers, baby monitors, microwave ovens, portable phones, and amateur radio activity. Sometimes, Wi-Fi trouble can even be caused by nearby utility and emergency vehicles that are equipped with powerful two-way radios. Also, people living near major airports might experience problems from nearby radar installations.

Part of finding the source of the Wi-Fi interference is to simply review what's in the environment around you. If you can associate some external event with the Wi-Fi interruptions, you can then begin to put in place a cure — such as moving, reorienting, or replacing the offending device, if possible. You also could try upgrading to a new router, which would be more resistant to interference. Or perhaps the cure is to select Wi-Fi hardware that uses a different radio bandwidth. (More on this below.)

There's another kind of problem — Wi-Fi overcrowding or pollution — that can crop up in apartment buildings, condos, neighborhoods of houses clustered together, office buildings, dorms, and other places where there are numerous Wi-Fi devices in close proximity.

Standard 802.11b/g/n Wi-Fi routers have up to 14 separate channels (radio frequencies). But channel use is regulated by country; not all countries are allowed to use all channels. In most of the world, routers automatically select one of three channels: 1, 11, and (most often) 6. That should provide good signal separation between Wi-Fi devices within range of each other.

Modern Wi-Fi routers are also designed to share channels. It's perfectly fine for multiple, nearby, Wi-Fi devices to use the same channel at the same time. If any one channel gets overcrowded, most routers should switch automatically to a less-busy channel. But in my experience, few actually do so on their own.

In densely populated locations, there can be numerous Wi-Fi networks (and their associated wireless devices) piling up on channels 1, 6, and 11. With too many Wi-Fi devices competing for a portion of the same limited, local, Wi-Fi frequency, you're very likely to end up with interference, slow transmission speeds, and signal dropouts.

A good tool for detecting Wi-Fi overcrowding is Wi-Fi analysis software. The software can easily show all Wi-Fi routers in an area and what channels they're using. If the software shows that too many routers are occupying one or more specific channels, you manually set your router to a channel that's less used.

There are many free and commercial Wi-Fi analysis tools available for Windows, iOS, and Android; I list some below. Surprisingly, some of the best and simplest tools are on Android!

Here's a personal example: The Wi-Fi in my apartment was annoyingly erratic. I installed FarProc's Wifi Analyzer (free; site) on my Android phone to find out what was going on.

The analysis software showed 40 to 50 other routers operating within range of my router! Include the PCs, notebooks, smartphones, tablets, TVs, set-top boxes, gaming consoles, and other Wi-Fi-enabled devices communicating with those routers, and there might be several hundred Wi-Fi devices all crowding onto the same airwaves.

Without exception, all my neighbors' devices were set to channels 1, 6, and 11. So potentially hundreds of devices were sharing just three channels. No wonder my Wi-Fi performance was poor!

To minimize interference from my neighbors' setups, I manually set my router to the relatively open channel 3. Figure 1 shows the result, as graphed by the FarProc software. (Note: This view displays only the strongest signals; not all of the 40-50 active routers are shown.)

Wi-Fi analysis

Figure 1. To reduce interference from the crowds camped on channels 1, 6, and 11, I moved my Wi-Fi network (Holodeck) to channel 3.

Although channel 3's signal overlaps those of channels 1 and 6, the clear center portion of channel 3's bandwidth reduced the interference on my wireless network — and my Wi-Fi performance improved dramatically.

If you suspect Wi-Fi pollution is causing problems for your setup, experiment with different channel assignments. It's easy to change a router's channel setting via its setup software. The exact process will depend on your brand and model of router. Basic Cisco routers, for example, have a simple pull-down menu to manually set the channel, as shown in Figure 2.

Wi-Fi channel setting

Figure 2. Most routers provide an easy means to manually assign the Wi-Fi channel of your choice. This example is a Cisco router.

Again, not all channels may be available, and not all channels will improve performance. You have to experiment to find the setup that yields the best performance (least interference) for you and others sharing the Wi-Fi airwaves.

There are many other Wi-Fi analyzers available; here are a few:

  • NetSurveyor — 802.11 Network Discovery/WiFi Scanner for Windows (free; site)
  • Xirrus Wi-Fi Inspector for Windows (free with sign up; site)
  • Webprovider Wifi Analyzer for Android (free; site)
  • Martin Hloušek's WiFi Analyzer Lite for Android (free; site)
  • MetaGeek inSSIDer for Android (U.S. $10; site) and for Windows and Mac ($20; site)

If none of the above helps, then you should consider changing your Wi-Fi gear. A newer Wi-Fi router is usually better at resisting interference than is older hardware; it might also let you use a different, less-crowded bandwidth — for example, 5GHz 802.11a — instead of the more common 2.4GHz 802.11b/g/n.

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