adb wifi often go offline, how to keep adb online?

I'm using Android tablet communicating with a USB device through USB port, the tablet only has one usb port, so I use adb wifi as my debug tool. However, when I connect adb through WIFI, the connection won't keep long(only a few minutes us usually), how to keep the adb wifi connection online all the time? Another question, is it possible to use USB HUB to connect the tablet with both USB flash-drive and my computer, and keep adb running? Many thanks!!!

Does ADB work over Wi-Fi?

To use adb with a device connected over USB, you must enable USB debugging in the device system settings, under Developer options. To use adb with a device connected over Wi-Fi, see Connect to a device over Wi-Fi. On Android 4.2 and higher, the Developer options screen is hidden by default.

After lots of unsuccessful attempts,I have noticed that turning Allow ADB debugging in charge only mode specification on , solved the problem . It makes the device online and accessable over wifi to ADB. You can find it under Developer options section.