Standards are evolving in the development of ultra wideband (UWB). Its speed potential is greater than other forms of wireless, from about 100 to 480 Mbytes/s depending upon range—usually up to 10 meters. IEEE Task Group 802.15.3a is focusing on UWB as an alternate physical layer (PHY) option for personal area networks (PANs). Last January, 31 proposals were presented for consideration, which dropped to two during a meeting of the Task Group the week of July 21 in San Francisco.
The remaining approaches are the original coded impulse version of UWB supported by XtremeSpectrum and Motorola and a newer, more complex version that incorporates orthogonal frequency division multiplexing (OFDM). The latter, supported by the other members, divides the 3.1- to 10.6-GHz UWB spectrum into 13 528-MHz bands, each of which can have up to 128 OFDM carriers. This will not only help UWB systems navigate around other services that may be affected by interference, it's also far more robust in the multipath environments in which UWB is most likely to be used. Greater range is expected as well.
The companies that favor OFDM formed a support group to push it forward. The MultiBand OFDM Alliance (MBOA) consists of many major manufacturers seeking to enter the UWB marketplace, including General Atomics, Hewlett-Packard, Infineon, Intel, Mitsubishi, NEC, Panasonic, Philips, Sharp, Staccato, Samsung, TDK, Texas Instruments, and Time Domain.
With this majority, OFDM should win the standards battle. During the July San Francisco meeting, 60% voted for the OFDM solution. A vote of 75% is required to move the proposal forward. Now, the group will answer the objections and issues of those who did not vote for OFDM. Another vote was scheduled for the group's September 14 meeting in Singapore. It's expected that the OFDM approach will be approved so that development can continue, with a fully ratified standard available in late 2004. Chip manufacturers will then have time to make products for the forthcoming next generation of home wireless devices.
For an update, go to the IEEE site at grouper.ieee.org/groups/802/15/ or the MBOA site at www.multibandofdm.org.
