Wireless Ethernet Compatibility Alliance (WECA) submitted to FCC ...

Wireless Ethernet Compatibility Alliance (WECA) submitted to FCC analysis of impact of deployment of radio local area networks (RLANs) at 5 GHz, concluding that sharing between RLANs operating in mobile service and radars in radiolocation service was “feasible.” In 5150-5350 MHz and 5470-5725 MHz, “worldwide spectrum allocation for mobile service designated for use by RLAN devices should be supported,” WECA said. Spectrum at 5 GHz for wireless LANs has received close scrutiny as part of World Radio Conference (WRC) 2003 planning. NTIA has raised interference concerns, questioning maturity of studies on dynamic frequency allocation systems that could be used to support global harmonization of wireless LAN operations in this band. Senate Commerce Committee Chmn. Hollings (D-S.C.) recently urged FCC, NTIA and Defense Dept. to craft U.S. stance for WRC that would consider international allocation of entire 465 MHz at 5 GHz for use by unlicensed broadband networks. Parts of band now in U.S. are allocated for both military and unlicensed broadband commercial uses, including DoD radars. WECA interference model examined sharing between RLAN devices and meteorological, radiolocation and aeronautical radionavigation radars at 5250-5725 MHz. WECA also provided interference analysis of sharing between RLANs and radars in band. “WECA believes that the interference model and the interference analysis are a critical advance supporting deployment of RLANs at 5 GHz,” group said in Sept. 3 filing. “For the first time, the industry has prepared a comprehensive analysis of the impact of the deployment of RLANs on a full range of government systems at 5 GHz.” WECA said that for most radar scenarios that were evaluated, predicted signal from future, high density population of RLAN devices is “found to be below receiver noise.” Draft U.S. proposal for WRC would provide that wireless LAN stations at 5150-5350 MHz and 5470-5725 MHz not cause harmful interference to other stations with primary allocations. Globalstar and ICO Global Communications have expressed concerns about possible primary allocation for these systems. Paper submitted by WECA examined sharing among airborne, maritime and ground-based radars and indoor and outdoor wireless LAN use. WECA analysis concluded that “potential interference levels caused by radar systems and seen by RLAN devices is, in the case of high-powered, high-gain radar systems orders of magnitude larger than the potential interference caused by RLANs and seen by radars.” WECA has separate petition pending at FCC for additional unlicensed spectrum at 5470-5725 MHz.