nP Forum (www.upnp.org) and the Digital Living Network Alliance (DLNA; www.dlna.org). In addition, as mentioned earlier, January 2006 saw the successful demonstration of Bluetooth+WiMedia UWB operating smoothly together under an existing Bluetooth software stack. UWB technology has the inherent capability to optimize wireless connectivity between multimedia devices within a WPAN. The WiMedia UWB common radio platform is unique in that no other existing wireless standard can fulfill the mar- ket's stringent requirements, such as low cost, low power consumption, small form factor, high bandwidth, and multimedia QoS support. IEEE 802.15.4 (ZigBee) At the end of the 1990s, many engineers began to see that Bluetooth and Wi-Fi, while excellent short-range solutions, were not the best solutions for some applica- tions, particularly self-organizing ad hoc networks of various industrial controls, building and home automation devices, security and smoke alarms, and medical devices. With inspiration from the simple one-chip design of Bluetooth radios, community of like-minded engineers began the development of ZigBee, a wireless communication protocol designed for small building devices. The IEEE 802.15.4 standard, completed in May 2003, defines the technical specifications of the PHY and MAC layers for ZigBee. The IEEE 802.15.4 specification is mainly designed for command and control, for which a 200Kbps data rate is more than adequate. The IEEE 802.15 Task Group 4 (TG4; www.ieee802.org/15/pub/TG4.html) was chartered to investigate a solution with several key characteristics: a low data rate with a very long battery life (months to even years) and very low complexity. ZigBee operates, internationally, in the unlicensed frequency bands. Potential applications for ZigBee include sensors, interactive toys, smart badges, remote con- trols, and home and building automation tools. The ZigBee 1.0 specifications were ratified in December 2004, and version 1.1 is now in the works. As with many of the other WPAN technologies, there 