Today I installed TP-Link TL-WN722N usb wireless adapter on Linux Debian system. Linux does not recognize this adapter by default so you need to install it manually.

Here is my method:

1. Open sources.list with sudo:

nano /etc/apt/sources.list

2. Paste this deb command in the end of file:

# Debian 8 "Jessie"
deb http://httpredir.debian.org/debian/ jessie main contrib non-free

3. Update the list of available packages and install the firmware-atheros package:

apt-get update && apt-get install firmware-atheros

4. Connect device to your system, or reboot