Nowadays, most of internet service provider, maxis home, streamyx and unifi are come with wireless router feature, to a extent where wireless signal may congested at your residential area.
With the default setting by the vendor, most router auto channel selection always on the same 3 channels, 1, 6, and 11. Since most are using the default channel and default frequenzy from same vendor, it cause conflict.
If u use DIR-615 router, mainly for unifi. Write 192.168.0.1 at the address bar of Internet Explorer. You will come to router web settings page.
username : admin
password : <blank> If you never change original password
1. Go to wireless setup on the right side
2. Click on Manual Wireless setting
3. Under ‘WIRELESS NETWORK GLOBAL SETTINGS’ uncheck ‘Enable Auto Channel Selection‘
4. Change the wireless channel to 11
5. Save Setting
All your device should able to connect to your WiFi now. Cheers