Android Debug Bridge(adb) is a versatile command line tool that lets you communicate with an emulator instance or connected Android-powered device. Even better, you can do it without cable, and it does NOT need root access.

Setup TCP port

Connect to device via USB cable, enable “USB Debuging”. Enter the adb shell:

adb shell 

TCP Mode

Setup tcp port for adb:

setprop service.adb.tcp.port 5555
stop adbd
start adbd

USB Mode

setprop service.adb.tcp.port -1
stop adbd
start adbd

Connect to device

Connect to device via tcp:

TCP Mode

adb tcpip 5555
adb connect 192.168.2.3:5555

USB mode

adb usb

Apps to automate the process

There are also several apps on Google Play that automate this process. A quick search suggests adbWireless, WiFi ADB and ADB WiFi. All of these require root access, but adbWireless requires fewer permissions.

References:

Android Debug Bridge

Using Hardware Devices

How can I connect to Android with ADB over TCP?