IEEE 1451 is a family of standards that links sensors to users, similar to the way that IEEE 802 (Ethernet) provides connectivity for information systems. Currently, all working groups under the IEEE 1451 umbrella provide standard interfaces for sensors on tethered networks. But the demand for a wireless physical layer is growing and the potential market for wireless sensors is almost limitless. The wireless IEEE 1451 needs to provide seamless connectivity among sensors and users, no matter what distance separates them. And it must do this with reasonable cost and small size at each sensor node.