ubuntu 15.10, trendnet TEW-648UBM, internet drops
I suggest you remove the addition to /etc/network/interfaces as it is ineffective.
You can install a better driver by running in terminal
sudo add-apt-repository ppa:hanipouspilot/rtlwifi
sudo apt-get update
sudo apt-get install rtl8192cu-dkms linux-firmware
and reboot.