|
While negotiating the FCC approval for UWB, the IEEE 802.15 member companies initiated a Study Group to adapt the emerging IEEE 802.15.3 specification to support the UWB physical (PHY) layer.
At the same time, led by Motorola, members of 802.15.3 group formed the WiMedia Alliance to act as the trade group for standards that would emerge from 802.15.3.
The idea was for WiMedia to serve the same purpose for 802.15 based technology as the Wi-Fi Alliance did supporting uniform interoperability, certification, and promotion of the 802.11 technology.
The stage was now set for what was to emerge as the most contentious IEEE standards battle to date.
The IEEE 802.15.3a task group worked on the selection of an ALT PHY (ALTernate PHYsical layer) over the course of 3 years, until January 2006. During that time over 20 proposals were evaluated for selection as the ALT PHY.
Through the IEEE's down selection process, the proposals under consideration were finally reduced to two: MB-OFDM (Multi-Band OFDM) and DS-UWB (Direct-Sequence UWB).
DS-UWB was proposed by XtremeSpectrum / Motorola / Freescale. MB-OFDM was proposed by Texas Instruments and supported by the MBOA (Multi-Band OFDM Alliance), which was initially an association of proposers that contributed to the merged MB-OFDM proposal.
As the task group worked to reduce these two proposals to a single ALT PHY specification, the task group became deadlocked, alternating between selection of the two remaining proposals for over 2 years.
Originally, WiMedia had an open membership policy, welcoming any company interested in making products utilizing the IEEE 802.15.3 high rate PAN (Personal Area Network) standards.
In 2004, several MBOA member companies joined WiMedia as promoters, giving MBOA interests a majority on the WiMedia board. Eventually, WiMedia's board, either from frustration or as an exclusionary measure, decided that the IEEE process would never suit the needs of their membership, and sanctioned creation of not only a specification for the MB-OFDM PHY, but also creation of a completely new MAC.
Concurrent with this action, the MBOA controlled WiMedia board amended WiMedia's charter to exclusively promote the MBOA proposed MB-OFDM solution being considered for standardization by the membership of IEEE 802.15. WiMedia's MBOA membership saw this as a major symbolic win for the MB-OFDM technology that could not gain consensus as the IEEE 802.15.3a technical selection.
Today, there is no ultra-wideband based IEEE PHY standard, only the IEEE 802.15.3b MAC standard that is capable of supporting operation with almost any high performance PHY. WiMedia submitted its technical specifications to ECMA (European Computer Manufacturer's Association) and subsequently published two documents, ECMA-368 and ECMA-369, which describe the current WiMedia MAC and PHY.
Return to main article Comprehensive UWB tests give video a green light but caution on wireless USB .
|
