USB2.0 is a current PC and interface equipment is widely applied universal serial bus standard. USB2.0 plug-n-play (Plug and Play;PnP), and the computer is turned on or off State, the equipment can be added or removed (Hot-Plugging). USB2.0 to set automatic detection, identification, hardware interface devices with the features above, operate so that they connect, or connect to the PC, remove adapter must be installed, reboot and reset system configuration (such as setting IRQ) trouble, hence, USB2.0, IEEE1394 end-to-end (Peer-to-Peer) operation function.In addition, USB2.0 has backward compatibility (backward compatible) features, if the USB disk drive 2 insert the old version of the USB master side, the operation will continue to function, and vice versa. USB2.0 host controller is placed on the PC, client-server, compared with IEEE1394 host controller circuits is more complex and higher manufacturing costs. But Intel will USB2.0 integration to South Bridge Hou, relative cost almost for zero, besides today interface equipment of USB2.0 interface IC, main management function are concentrated in main controller, circuit can sharply simplified, therefore makes USB2.02k of main controller plus interface equipment interface IC of cost, to than two star 1394 interface IC came low, this is Intel another a using PC for axis processing platform, and reduced IC cost and was praised of examples. USB2.0 uniform specifications of the connectors (Host-side of a type and b type in the Device-side), designed to replace the traditional interface, for example, parallel port, serial port or the PS/2 interface. So approach simplifies the system design, while allowing the user easy to use and reduces mistakes. Allows simultaneous connection of peripheral USB network can reach up to 127, its network is comprised of a tree root router (the Root Hub), router and interface devices devices (device) posed, this tree structure can be extended up to the fifth floor (Fifth Tier), and each node distance of up to 5 meters from the router. Current transfer speed USB 2 speed of up to 480Mbps, close to 0.5Gb standards, mainly used in various types of interface devices, including major hard disk, burner, DVD CD-RW and Flash memory cards, high-capacity storage systems (Mass Storage), image output and input devices such as digital cameras, video capture, TV or satellite receiver, home security monitor And broadband communication devices (Broadband) such as application support for high-speed xDSL modems, ISDN, digital PBX, WLAN (IEEE 802.11) and Bluetooth, wired and wireless communication devices, and so on.Current intellectual property (IP) and chip suppliers have also introduced support for USB applications in the digital consumer electronics products, many IP and chips have been used to achieve USB controllers, transceiver, hub and switch. To IP based USB controllers are usually integrated to the base frequency chipsets, ASIC, or other programmable logic components, and external transceivers, switches are used to support this interface and extend its functionality. Since USB2.0 is in PC based client-server as a transport mode, in mobile communications are increasingly developed now, many portable interface device data transfer if you want to do so through PC, will facilitate greatly diminished. In order to compensate for this shortcoming, Philips USB OTG was released at the end of 2001 (On-The-Go) technology, and recognized by the USB-IF. "Go" Board is the idea, the Board appointed a longitude and latitude are connected points can be found. Two of OTG compliant devices can be linked to each other, rather than through the computer, it is in the context of USB2.0, providing two USB devices to one way links.USB OTG dual-role devices, 1 (Dual-role device) concept that OTG device itself which can play the role of host port or device-side, it has a smaller transmission interface, less power consumption, optimized for mobile devices. Use of this specification will enable USB devices out of client-server, have the ability to operate independently, could get rid of the last limited to PC USB interface-related applications and digital consumer electronics devices, such as PDA, Mobile Phone and Digital Music Player to apply more deeply. Wireless technology is getting mature now, especially ultra-wideband (UWB) technology, particularly applicable to wireless USB (WUSB;Wireless USB). WUSB is comprises Agere, HP, Intel, Microsoft, NEC, Philips and Samsung jointly developed, it features three meters distance to be able to implement 480Mbps of bandwidth may waive cabling complexity, and improve the portability of the PC and peripherals, but current WUSB is also facing the challenge of how to improve the security, reliability, and lower power consumption.