Abstract: A bus hub for connection via a serial bus to a serial bus host hub includes a connector to a power supply, a bus controller and a switch coupled to the bus controller and to the power supply. The switch switches the bus hub between being powered by the power supply and being powered by the power from the serial bus host hub by switching the mode of operation between self-powered mode and bus-powered mode. A system for controlling communication and power in a serial bus includes a serial bus hub for detachably coupling at least one peripheral to a computer system, and a serial bus host hub capable of delivering power to the serial bus hub. The system also includes a power supply coupled to the serial bus hub that delivers power to the serial bus hub. The system also includes a bus controller that receives signals from the computer system through the serial bus, and receiving signals from the serial bus hub.