The IEEE 802.11 Standards Committee has approved a physical layer option for frequency spread spectrum wireless local nets, which is based on a proposal submitted by Moutain View, California-based Proxim Inc in January. The standard uses four-level Gaussian Frequency Shift Keying modulation for high-speed – 2Mbps – transmissions – with fallback to two-level GFSK for lower speed, 1Mbps, transmissions – which is said not to cause interference between the different local net speed environments. The Committee hopes to produce a Draft Standard Document by the end of the year, and has now ratified the 2Mbps/1Mbps dual data rate standard for both frequency-hopping and direct sequence spread spectrum systems. The standard has already been implemented in Mountain View-based Proxim Inc’s RangeLAN2 product family which begins shipping later this month, according to the company. Proxim says that it is the first FCC-approved 2.4GHz frequency hopping spread spectrum wireless local network product line commercially available.
