I sometimes cannot re-connect to my TP-Link wireless router after re-booting it when I lose my ISP connection, though other devices on the network can connect. It usually comes back after an hour or so. Any ideas?

I live in Zambia where my connection to the ISP is not always good, so I sometimes have to re-boot my TP Link wireless router and the connection to the outdoor aerial. Quite often my network does not appear on my MacBook Pro, though other devices can connect. I have tried turning the wi-fi off then on, renewed the DHCP lease, run diagnostics, etc. It usually comes back on after an hour or two. Any ideas on what the problem may be?

I am running Yosemite 10.10.4

Thanks