Internet Dropping out randomly

[#1]

Hello,
I have had my Fibre internet installed at my house since i moved in back in June/July.....it has been fine and i have not had any problems at all up to last week, I have been suffering with the wifi dropping out randomly and when i have checked the devices being used it is saying "Waiting for the connection to improve etc". I am using my own Router but never had a problem with this previously, so i believe it maybe down to the ISP.....when i have rebooted my router and modem box (provided by Plusnet) the connection is then fine until it randomly disconnects again.
What checks is advised to sort this problem? I was thinking about setting up a permanent ping from my pc back to plusnet to see where the problem is coming from or using something like PingPlotter which will show exactly where the connection drops.
Any comments are welcome, i will probably have to ring plusnet later to get them to do a line test.
Cheers

[#2]

Hi there,
Your connection logs are showing  that the line has been stable for nearly 24 hours. Diagnostic tests are passing too so I'd look at this potentially as a WiFi issue.
http://www.plus.net/support/broadband/wireless_broadband/wireless_signal.shtml