In a busy area multiple WiFi Routers and Access Points may cause co-channel Interference (CCI) and adjacent channel interference (ACI). This is pure physics, in short simplified description: if two APs are using the same channel that means that they are using the same frequency and the waves are interfering.

So what can you do?
Choose a channel that is empty or where (and around) the signal level is the lowest.
There are tons of WiFi info Android tools around, and you can download tools for your PC. (iOS does not give this level of access to the WiFi to Apps.)
If you don’t want to install any app, you can open a CMD prompt and use the following command to list all the Access Points, actually all transmitting devices as there may be more under the same SSID.
1 |
netsh wlan show networks mode=bssid |
The result will be something like this:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 |
Interface name : Wi-Fi There are 2 networks currently visible. SSID 1 : MyHouse Guest Network type : Infrastructure Authentication : WPA2-Personal Encryption : CCMP BSSID 1 : fa:ke:ma:ca:dd:rr Signal : 66% Radio type : 802.11n Channel : 11 Basic rates (Mbps) : 1 2 5.5 11 Other rates (Mbps) : 6 9 12 18 24 36 48 54 BSSID 2 : fa:ke:ma:ca:dd:rr Signal : 35% Radio type : 802.11n Channel : 1 Basic rates (Mbps) : 1 2 5.5 11 Other rates (Mbps) : 6 9 12 18 24 36 48 54 SSID 2 : MyHouse Network type : Infrastructure Authentication : WPA2-Personal Encryption : CCMP BSSID 1 : fa:ke:ma:ca:dd:rr Signal : 38% Radio type : 802.11n Channel : 1 Basic rates (Mbps) : 1 2 5.5 11 Other rates (Mbps) : 6 9 12 18 24 36 48 54 BSSID 2 : fa:ke:ma:ca:dd:rr Signal : 89% Radio type : 802.11ac Channel : 36 Basic rates (Mbps) : 6 12 24 Other rates (Mbps) : 9 18 36 48 54 BSSID 3 : b0:68:b6:ff:e6:cc Signal : 66% Radio type : 802.11n Channel : 11 Basic rates (Mbps) : 1 2 5.5 11 Other rates (Mbps) : 6 9 12 18 24 36 48 54 BSSID 4 : fa:ke:ma:ca:dd:rr Signal : 53% Radio type : 802.11n Channel : 6 Basic rates (Mbps) : 1 2 5.5 11 Other rates (Mbps) : 6 9 12 18 24 36 48 54 BSSID 5 : fa:ke:ma:ca:dd:rr Signal : 91% Radio type : 802.11n Channel : 1 Basic rates (Mbps) : 1 2 5.5 11 Other rates (Mbps) : 6 9 12 18 24 36 48 54 |
Check the Signal and the Channel lines and choose a free space.