Poor internet connection, whilst Nexus 7 tells me connection is strong. How can I boot the strength?

[AC Question]

Poor internet connection, whilst Nexus 7 tells me connection is strong.

Signal on Nexus 7 shows as strong in settings but there is very intermittent connection and internet keeps dropping out. Other devices in the house have no problems. Have rebooted Nexus, connected it to main computer to check for updates and rebooted the router...still no joy. It tells me there is an excellent connection but yet when I open Outlook it says there is no connection. Please help as cannot think what else to try. Thanks