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The WiMedia Alliance was a non-profit industry trade group that promoted the adoption, regulation, standardization and multi-vendor interoperability of ultra-wideband (UWB) technologies. It existed from about 2002 through 2009. ==History== The Wireless Multimedia Alliance was founded by 2002. The WiMedia Alliance developed reference technical specifications including: * physical layers and media access control (MAC) layers * Convergence architecture to provide coexistence and fairness including support for multiple applications * A protocol adaptation layer for the Internet Protocol * IP-based application profiles The WiMedia ultra-wideband (UWB) common radio platform incorporated MAC layer and PHY layer specifications based on multi-band orthogonal frequency-division multiplexing (MB-OFDM). It was intended for short-range multimedia file transfers at data rates of 480 Mbit/s and beyond with low power consumption, and operates in the 3.1 to 10.6 GHz UWB spectrum. WiMedia UWB was promoted for personal computers, consumer electronics, mobile devices and automotive networks. WiMedia Alliance and MultiBand OFDM Alliance Special Interest Group (MBOA-SIG, promoted by Intel) merged into a single organization in 2005. The merged group operated as the WiMedia Alliance. The ultra-wideband system provided a wireless personal area network (WPAN) with data payload communication capabilities of 53.3, 55, 80, 106.67, 110, 160, 200, 320, 480, 640, 800, 960, and 1024 Mbit/s. The WiMedia UWB platform was complementary to WPAN technologies such as Bluetooth 3.0, Certified Wireless USB, the 1394 Trade Group’s “Wireless FireWire” Protocol Adaptation Layer (PAL) (Non-IP Peer to Peer architecture) and Wireless TCP/IP - Digital Living Network Alliance. Different wireless protocols can operate within the same wireless personal area network without interference. In addition to these, many other industry protocols can reside on top of the WiMedia UWB platform. Those include Ethernet, Digital Visual Interface (DVI) and High-Definition Multimedia Interface (HDMI). The WiMedia PHY specification has an over-the-air uncoded capability of more than 1024 Mbit/s; the specification was promoted to support wireless video, operating at multiple Gbit/s data rates. The WiMedia Network (formerly WiNET) is a protocol adaptation layer that builds on the WiMedia UWB common radio platform to augment the convergence platform with TCP/IP services. Certified Wireless USB can operate in two ways: *''Coexistence'' Wireless USB operates on top of Wimedia UWB PHY - Wimedia UWB MAC - Convergence Layer. *''Pure'' Wireless USB operates directly on top of Wimedia UWB PHY. Bluetooth, Wireless 1394, IP (WiMedia Network) operate on top of Wimedia UWB PHY - Wimedia UWB MAC - Convergence Layer like ''Coexistence'' Wireless USB. Within the WiMedia MAC specification is the MAC Convergence Architecture (WiMCA) that allows applications to share UWB resources. WiMCA defines a number of policies, including channel-time utilization; secure association, authentication and data transfer; device and WPAN management; quality of service; discovery of services; and power management. Board members of the alliance included Alereon, CSR plc, Olympus Corporation, Samsung and Wisair. By early 2006, implementations were delayed by standardization issues. On March 16, 2009, the WiMedia Alliance announced technology transfer agreements for WiMedia ultra-wideband (UWB) specifications. WiMedia transferred all specifications, including work on future high speed and power optimized implementations, to the Bluetooth Special Interest Group (SIG), Wireless USB Promoter Group and the USB Implementers Forum. After the technology transfer, marketing and related administrative items, the WiMedia Alliance ceased operations in 2010.〔〕〔(【引用サイトリンク】title=Wimedia.org FAQ )〕〔(Bluetooth.com )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「WiMedia Alliance」の詳細全文を読む スポンサード リンク
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