Currently I am working on a project that requires connection of the Arduino and IP Camera over single Ethernet cable to a laptop and additionally supply power to a robot.

The goal is to stream Video from camera and communicate with Arduino board.

• 4 wires from Ethernet cable are required for the camera.
• 2 wires are needed for power supply.
• That leaves me with 2 spare wires for USB connection Rx/Tx but no wires left for USB ground.

My question is: Do I need to run a separate GND wire for USB connection? Or will the GND be shared over RJ45 IP camera connector? And is it safe to operate?

I am not sure how camera data transmission works, but it's logical for me to assume that camera and laptop share GND.

^{simulate this circuit – Schematic created using CircuitLab}