Why Your Wi-Fi is Slow (And How You Can Fix It)
5. Varying CPU frequencies and their effect on wireless signals
Your computer's motherboard is also working in the "Gigahertz" spectrum. That "noise" is being picked up by your built-in Wi-Fi transmitter. Unfortunately, the higher that noise is, the more likely it is for your wireless adapter to lower bandwidth automatically (by lowering the link-rate and avoiding frequency interferences). As CPUs these days clock dynamically, the Wi-Fi adapter needs to constantly adapt the link rate which not only causes a variation in Mbps but may also be the cause for dropped connections. Especially on laptops, the Wi-Fi adapter is often built close to the memory and CPU bus, which is a major source for problems.
Of course, this all depends on the design of your Wi-Fi adapter, but if these symptoms sound familiar you might solve this issue by getting an external adapter. Some of these adapters, such as my Linksys adapter, even have a little stand that's connected via a long USB cable. Putting that kind of space between the Wi-Fi adapter and your CPUs noise is likely to help a lot. Of course, that's not too handy when you're traveling, but at home it's a viable option. Typical Wi-Fi adapters such as the Linksys AE2500 (802.11n dualband) or the MSI US310EX will set you back between $20 and $40 and they're worth every penny.
6. Firmware or driver issues
An easy, yet often forgotten piece of advice: Make sure that your router's firmware is up-to-date -- especially if you've purchased a new one. Expect bandwidth, feature set and resiliency to signals to increase with the first few firmware updates. (My Linksys router could only deliver full bandwidth to my living room after the upgrade.)
Also make sure that the Wi-Fi adapter (either external or built-in) is always up-to-date. Dropouts, standby issues, low performance may be gone in the next 0.1 release of your adapter's drivers. Although the frequent driver delivery via Windows Update has gotten better in recent years, it rarely fetches you the latest and the greatest drivers. Instead, do this...
The first place to hit for updates is the manufacturer's support pages. But if their driver area is not well maintained, you can go the chipset maker's website. It's not uncommon that the chipset of each Wi-Fi adapter was just bought and rebranded. For example, my external Linksys WUSB 600N adapter houses the popular RT2870 chipset manufactured by Taiwanese manufacturer Ralink. It's a perfect example for why going straight to the chipset maker is always a smart move.
Just head over to their Support/Download pages, enter your e-mail address and get the drivers.
To figure out which chipset you've got, it's a good idea to check the specification sheet of your Wi-Fi adapter. The Debian Wiki sports a list of well-known Wi-Fi chipsets.
7. Choose the right channel
The day your router is set up, it automatically detects the least crowded channel and makes that its default. However, with the arrival of new neighbors or offices nearby, the situation may change quickly: All of a sudden, one channel may be used by a handful of routers while others are deserted. InSSIDer is your little helper: The tool analyzes the entire Wi-Fi spectrum and gives you details about your home network as well as channel usage.
I was surprised to see that I was sharing channel 1 with four other routers. Not the most ideal situation. As channel 9 has not been used, so far, I decided to jump on this one and was able to improve latency as well as throughput noticeably.
8. Use your router's 5GHz network
The 2.4GHz frequency is crowded. Not just with neighbors using the same frequency, but also baby monitors, cordless phones, microwave ovens and more. Modern 802.11n routers offer "dualband", which means they're sending two network signals: One at 2.4GHz, and one at 5GHz, which is far less crowded and offers more channels. So why not make the jump to 5GHz and enjoy a less crowded Wi-Fi frequency at higher speeds? Well, unfortunately, many device makers thought it was a good idea to save some pennies on the Wi-Fi chip and go only with the 2.4 GHz receiver. This includes all portable gaming consoles and also a slew of Android phones, all Apple iOS devices and Windows Phone. Here's my advice: Activate both networks and connect the mobile devices to the 2.4 GHz network. Just enable the 5GHz network for your laptops and desktops.
9. Limit your router's frequency band
Sometimes you can't have the luxury of choosing the 5GHz frequency band or selecting a "lonely" channel. In such cases, it may be worthwhile to limit your router to sending out signals at intervals of 20MHz. This might reduce overall throughput a bit, but it will give you a stronger signal with less dropouts:
10. Benchmark your connection the right way
There are a lot of Wi-Fi monitoring tools around to measure the impact of all the tips we just gave you and spit out bandwidth values. However, none of them come close to the accuracy of iPerf. This tool has a client for the laptop/PC you're about to measure and a server tool that sits on a PC directly connected to the router. By having analyzers on both ends, you know exactly how fast your Wi-Fi actually is.
My advice: go through your space and try out different locations for both the router and the clients. The heatmapping tools should give you a good indication of the best spot.
This article, "10 reasons your Wi-Fi speed stinks (and what you can do about it)," was originally published at ITworld. For the latest IT news, analysis and how-tos, follow ITworld on Twitter and Facebook.