The Universal Power Bus (UPB) protocol uses a home’s existing power lines to carry home automation messages. Using power lines instead of wireless signals has its advantages as signals transmitted over power lines can travel further distances. Also, UPB power line signals do not have to account for wall obstructions as wireless signals do. Reliability for UPB transmissions is reported to be greater than 99%.

The down side of power line protocols is that UPB is stuck to electrical outlets. Adding hidden security sensors can be difficult if they all require an electrical outlet. The same goes with adding window blind controllers or thermostats.

UPB messages are limited to a 480 bits per sec data rate. A maximum of 250 UPB devices can be in one home.

Plus Side:

• Signals can travel long distances
• Can use a peer-to-peer system or a controller based system.
• Inexpensive

Down Side:

• Don’t have convenience of wireless systems
• Bandwidth limited to 480 bits per second
• Maximum 250 devices for a home