Why is my wireless network so slow?

Struggling to figure out why your WiFi connection feels sluggish compared to your hard-wired devices? Perhaps its not the fault of the technology, but an issue with configuration and utilization.

Perfect World, Worst Case

With wireless technology, every device operating in the same frequency shares the bandwidth available.  This includes not only the devices connected to your network,but ANY wireless devices operating in the same frequency range as yours, such as your neighbors’ WiFi.  Additionally, the rated speed of your wireless access point is not per-device, but a total shared rating. In a simplified perfect-world model, a WiFi router with ten devices utilizing their connection to capacity (worst case) is only capable of providing one tenth that speed per device. Remember those “walkie-talkies” you played with as a kid?  Only one of you could transmit your voice at a time.  The same concept applies here, which is why the bandwidth is shared.

Real World Problems

In the real world, given the situation above, your connection speed would be much less when taking into account the additional network traffic associated with maintaining the connection and correcting for errors in transmission. Errors are introduced when some bit of information that is sent doesn’t make it to its intended destination or is unreadable, either due to the distance involved or radio interference (noise) that may be interfering with the signal.  That microwave oven in the break room next to your office?  It operates in the same frequency range as your WiFi connection, making it a direct source of radio frequency (RF) interference.  Cordless phones within your business environment?  If they are of the 2.4GHz variety, they can be an additional source of noise.

So how you do fix it?

You can reduce interference by relocating things such as microwaves and cordless phones, or simply operate on a frequency with less wireless traffic.  The wireless frequency range used by WiFi is split up into channels, which are smaller divisions of the total frequency range.  You may have seen the channel setting in your wireless access point and left it set to “auto” or some other default channel value.  Each channel uses a particular part of the wireless spectrum, and if you can select the channel with the least noise and least amount of utilization, you should be able to maximize the use of your wireless bandwidth.  Software exists that allow you to take an accounting of the wireless networks in your area and provide some easy to read visuals, letting you know which channel would be most advantageous for your network.

Screenshot of inSSIDer, a tool used for analyzing wireless networks.  Note lots of overlap in the graph at the bottom, giving us a quick visualization of wireless network channel allocations.

Screenshot of inSSIDer for Home, one tool used for analyzing wireless networks. Note lots of overlap in the graph at the bottom, giving us a quick visualization of wireless network channel allocations and channels to avoid.

Once you’ve determined which channel is most appropriate, you can reconfigure your access point to use that channel.  While the “auto” setting on most routers purports to do this, it is typically inadequate for high traffic areas or anything more critical than home usage, and manually setting the channel is preferred.  In the screenshot above, you can see that there are lots of networks overlapping in the middle of the 2.4GHz band.  It is also important to note that while 2.4GHz is the most widely used frequency, equipment can also be purchased that operates in the 5GHz range with reduced interference.  However, this frequency is not without drawbacks, most notably reduced operating range and increased cost.  As such, 2.4GHz is usually the better choice overall.


Besides the unrealistic expectations of relocating all your office microwaves to the farthest end of the hall or forcing your company president to stop using the cordless phone in his office suite (both of which will not help your reputation), channel selection is the best option for maximizing wireless bandwidth availability.  It is one of the easiest fixes to make, but also one of the easiest to get wrong if ignored. Don’t forget, however, that a hardwired Ethernet connection will always win out in speed and security (which we’ll cover in a future post), and wireless connections should only be used if absolutely necessary.