2. Open Settings in your device > WLAN > Advanced > select Always in Keep WLAN on during sleep.
3. Check if you've installed some app manager that might kill AirDroid process.
For example, If you're using Huawei, the default Phone Manager app may kill the process of AirDroid when running memory cleanup feature. Adding AirDroid to the Memory cleanup whitelist will help. Open Phone Manager on your Huawei phone> System optimization> click the gear button on the top right corner> select Memory cleanup whitelist> select AirDroid and turn it on.
4. Keep the screen awake to see if it helps.
5. Different systems manage memory and battery in different ways, and some systems might kill the process of apps after a long period of inactivity.
For instance, If you're using MIUI, saving battery will restrict individual apps' background processes, WLAN and mobile data connectionc, and GPS. Turning off Manage apps' battery usage will help. Open Settings in your device> Additional settings> Battery> Manage apps battery usage> turn off Manage apps' battery usage & Restrict apps when battery is low> select Choose apps to restrict> uncheck AirDroid> cilck OK.
6. There are many factors that cause the disconnection like unstable network.
If you are using Windows, you may click the Start button and enter cmd into the Search field. If the IP address displayed on AirDroid app is 192.168.xx.xxx, then you can type ping 192.168.xx.xxx -t and press enter to see your ping output. And you may refer to the guide here for other OS: http://www.wikihow.com/Ping-an-IP-Address
The ping output can somewhat let you understand the status of your network, though not that accurate. If the ping output isn't ideal, then we advice you to ask for help from network admin.
1. If you connected your device to 2G/3G/4G network, the network will be disconnected when you receive a call. Thus the connection between your device and PC/laptop will be interrupted. You may connect your device to WiFi network and try again.
2. If you're using AirDroid Win/Mac, the connection will be interrupted when the computer goes sleep. AirDroid will restore the connection automatically when the computer connects to network again.