The short-distance low-power technologies for wireless access communications, including Bluetooth, Ultra-Wideband (UWB ) and Wireless Fidelity (Wi-Fi ), focus on the physical layer and Medium Access Control (MAC ) layer. Bluetooth is a wireless protocol for exchanging data over short distances. It is an alternative to RS232 data cables. UWB is a radio technology that can be used at very low energy levels for short range. It provides flexible high-bandwidth wireless access. Wi-Fi enables the wireless connection of fast-access devices and mobile devices in Wireless Local Access Network (WLAN ) and it is suitable for long distances. The standardizations of the above technologies have been developed and published soon after the emergence of these technologies. Among all the standards, Bluetooth and Wi-Fi are the most important ones.