Problems with speed or reception probably has something to do with how you’ve positioned and aligned your router, and possibly some of the router configuration options that you never bothered to check.
So here we’re going to look at using a tool called WiFi Analyzer to help you get your wireless set up just right. WiFi Analyzer is a free Android app that provides an overview of all the wireless networks in a given area as well as detailed signal power information for specific networks. As a bonus, it lets you use your phone like a tricorder.
Picking the right channel
For those of you who don’t speak networking geek, Wi-Fi is divided into channels, which allows multiple networks to operate in the same space without stepping on each other’s toes. If you use channel 3 and your neighbour uses channel 10, your data transfers won’t interfere with each other.
But it’s not quite as simple as picking a channel that nobody else uses. First of all, you’ve probably got a dual-band router by now, which means that it works in both the 2.4GHz radio band and the 5GHz band. So you have to pick two channels. Moreover, each band works differently, which we’ll get to in a moment.
Bring your phone near to where your router is located and fire up WiFi Analyzer. The first tab you’ll see when it pops up shows you a bunch of labelled curves, each representing a wireless network. The Y axis is the signal power of each network. The X axis is the channel used by that network. This graph shows 2.4GHz networks.
One thing you’ll see is that networks overlap — that each curve is way more than a single channel in width. That’s because channels in 2.4GHz spectrum actually overlap, and because new wireless technologies introduced since 2.4GHz was divvied into channels allow more than one channel to be used at once.
What you want to do is find the channel that gives you the most “clear air” — you want the curve representing your channel to have as little possible overlap with other networks in the area as possible.
This may require a little guesswork on your part, but it’s generally not that hard to figure out. If you tap on the fourth tab in WiFi Analyzer (the one with two stars), it will actually recommend channels for you by star rating, but you can do just as well using the visual tool. Pick a channel and make a note of it.
That’s the 2.4GHz channel sorted. WiFi Analyzer does not have a graph tool for 5GHz networks, and there’s a reason for that: 5GHz channels have larger spacing and very little overlap. You just need to find one that nobody else is using. In Australia, there are commonly nine 5GHz channels available, although many routers may only have four for the purposes of international compatibility.
In WiFi Analyzer, head to the third tab. This gives a list of all the local networks by channel. Any channel with a channel number greater than 14 is a 5GHz channel (14 or less is a 2.4GHz channel). In Australia, you’ll see channels 36, 40, 44, 48 used, and more uncommonly 149, 153, 157, 161 and 165.
Now scroll down through the list of channels to see what other people are using. From the list of channels above (36, 40, 44, 48, 149, 153, 157, 161, 165) try to find one that nobody else is using — with a preference for one of the first four of those since your router may not support the higher level channels. If you see networks using 36 and 44, for example, you can make a note of channel 40 for your own use.
Now you’ve picked out channels for your Wi-Fi networks. It’s time to set them up. The specifics of doing that will vary from router to router, but you need to log into your router (the router guide will have instructions for doing that) and head to the wireless settings.
There should be a drop down list to choose your wireless channels for both the 2.4 and 5GHz networks. Set the channels to the ones you discovered and save your settings. That should minimise the amount your Wi-Fi is competing with your neighbours’.
Getting a signal strength profile of your network
This second part is a little easier: it’s time to use your phone or tablet as a sensor, which can tell you what kinds of signal you’re getting in different parts of your house.
In WiFi Analyzer, tap on the second tab, the one that looks like a windscreen wiper. This gives you a gauge of the signal power of a single network. On the left, tap on the network name and select your own network.
If you’re right next to your router, the indicator should be way over on the right, in the green. This is four-bars territory, where the received power indicator is at -60dBm or better (we won’t go into what dBm is here, just note that the lower the value — and we’re talking negatives here, so -100dBm is lower than -60dBm — the worse the signal power is).
Ideally, you’d like your whole home to be in this range, though for most people that’s not practical. You do want to keep the bar at -80dBm or better though, while in -85dBm or worse range you’re likely to start experiencing dropouts and very poor performance.
Now grab your phone and start walking around the house, to get readings in all the locations where you might need Wi-Fi. Make sure to always hold the phone horizontal (to give a fair comparison between points) and even put it down to remove your hand from the interference equation. By default, WiFi Analyzer updates every few seconds, but you can increase the rate in the settings.
Is everywhere in your home -80dBm or better? Then you don’t really need to worry about anything. But if you are finding dips in the signal strength below that, you might have to start looking at remedies. There are a variety of remedies, but the number one trick is to move you router.
Try repositioning your router to be closer to the black zones (hopefully without creating new black zones). This might involve getting some longer cables, but its generally worth it.
Otherwise, you can also try increasing the transmit power on your router if the router supports such adjustments and removing any obstructions between the router and the zone with poor reception. Fish tanks, mirrors, metal objects and many other household items can be signal stoppers.
Ultimately, if moving the router doesn’t work, you may need to look at more radical solutions — an extra wireless access point, a range extender, better antennae or maybe even a new router. It’s not ideal, but sometimes you have to take an extra step to make Wi-Fi work for you.