WiFi Analyzer turns your Android phone or tablet into a wireless analyzer – using the information it provides can help you improve wireless performance.
It’s a free app that shows the name, signal strength, channel, security type and MAC address of nearby wireless networks – in real time and historical graphs.
WiFi Analyzer can help in 2 ways:
1. Away from home – if you want to connect to a wifi network (e.g. a free public hotspot) the app can help you find the network with the best signal strength and least interference – so you get a reliable and fast connection.
2. At home – if you have several close neighbors, they will most likely also have a wireless network. If their wireless signal is strong enough, it could interfere with yours – especially if it uses the same channel.
Interference can cause a poor connection and intermittent slowdowns/dropouts so it is important to configure your router to avoid it.
What Is A Channel? The wireless signal range in standard 2.4GHz wireless routers is divided into a number of channels. There are 11 channels (1 to 11) for wifi signals in the US whereas the UK and most of the world have 13 channels (1 to 13).
Without going into techie detail, in the US and UK only 3 of these channels do not overlap or interfere with each other and therefore provide a good strong signal – channels 1, 6 and 11. [Note: in some other countries, it may be only channels 1, 5, 9 and 13 that do not overlap]
Because there are only three good channels to choose from (in US/UK), there is a high chance that a neighbor’s router may be using the same channel as yours. This causes interference which can make your wireless connection slow or unreliable.
To avoid your router ‘clashing’ with theirs, use WiFi Analyzer to scan for nearby wireless networks and see which channel they are using – so you can change your router to use a different one if necessary. E.g. if nearby networks with a strong signal are using channels 6 and 11, you should choose channel 1 for your own wireless network.
Download and install WiFi Analyzer from Google Play here. The app has a high user rating of 4.6 stars and 5m+ installs. It is free and includes a small ad (but this can be disabled in the app settings).
Open you open the app there are several views – swipe to switch between them:
This view shows the wifi channels used and how strong the signals are – the higher the peak the stronger the signal.
Tip: signal strength is measured in dBm which is always a negative figure. A high dBm e.g. -35 is a very strong signal whereas a low dBm e.g. -85 is very weak and likely to drop the connection.
In the example above, there are three networks on channel 11, one on channel 6 and one on channel 4 – at home, you would set your router to use channel 1 for best performance (least interference) or away from home, you would use the strong network on channel 11 if possible.
This view also shows channels and signal strength but adds the type of security used (so you can tell which are free/open hotspots) and the MAC address of the routers.
This view shows the signal strength varying over time – tapping a network name tab at the top highlights that network graph.
This view is particularly useful to measure in real time how signal strength varies when moving from room to room – this can help you locate the best position for your router e.g. in the center of the house for better all round coverage. There is also a cool Sound option which makes it act like a wifi Geiger counter
The aim of all the screens is to help you find a less crowded (hopefully empty) wireless channel to allocate to your wireless router (and position it in the best location) or find the strongest hotspot signal to connect to.
What If Nearby Networks Are Using All Three Channels?
You will have to share a channel with at least one of the other networks so make sure you share with the network that has the lowest signal strength – the lower it is, the less likely it will be to cause you interference.
If there are multiple strong signals using all available channels (e.g. in an apartment block) and this interference is causing you major connection issues then consider whether you would be better off using a faster and more stable wired network instead.
Using powerline adapters to cheaply extend internet access around the home is a great solution if you can’t run additional network cables between rooms.
How To Change The Wireless Channel On Your Router
Now you know which is the best channel for your router to use, if it is not already using it then change it – see ‘set up a cable router‘ for an illustrated guide, especially the ‘Wireless Network’ section in Step 5.
If you have an ADSL router see ‘set up a ADSL router‘, especially the ‘Wireless Network’ section in Step 4.
WiFi Analyzer is one of my favorite Android apps and makes it easy to find, or set up, the best wireless network that can improve performance and prevent disconnections or slowdowns.