The emergence of ZigBee wireless networks for building automation and industrial control is discussed. Companies developing monitoring and control applications in industrial and commercial building environments are choosing ZigBee to save the cost of wiring and installation. The technology's standard includes security on a number of levels, from basic authentication to 128-bit AES encryption, with keys delivered to joining nodes by a trust center. ZigBee allows for the definition of different stack profiles for different application areas, and part of the profile definition is the depth and breadth of the ZigBee network, which defines how many ZigBee Routers (ZR) and ZigBee End Devices (ZED) can join any existing ZigBee Coordinator (ZC) or ZR.