allow-hotplug wlan1
iface wlan1 inet manual
   wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

allow-hotplug usb0
iface usb0 inet static
        address 192.168.7.2
        netmask 255.255.255.0
        network 192.168.7.0
        broadcast 192.168.7.255
        gateway 192.168.7.1

sudo ifdown usb0

sudo ifup usb0
ifconfig usb0