I occasionally see posts from France, England, Germany, Poland, also from China, Japan, Brazil etc. on the Seattle Wireless network users group asking questions about setting up wireless metro area networks using 802.11 gear plus high gain antennas, amplifiers, and custom routing software. Users groups and commercial efforts to deploy small (hundreds of users) public access networks of 802.11 are cropping up all over the globe. This will only increase as the hardware gets better with the introduction of 802.11g, 802.11a, and particularly 802.16 and "multi-mode" equipment that works on two or more standards and even over multiple bands of spectrum.
Early on in the discussion are some tidbits about how wireless should work together transparently to the user. This is already starting to happen. The "convergence" of wireless technologies for the user will be much like the convergence of various versions of graphics rendering: EGA, VGA, SVGA into multi-mode cards. Wireless is more difficult because different frequencies require differently tuned antennas and circuits. But chip companies are already sampling multi-mode parts and field trials have demonstrated such things as hand-off between 802.11b and wirlessMAN systems. At least a couple chip vendors plan multi-mode parts based on 802.11a or 11b plus 802.16. The systems manufacturers job will be to build systems that provide "seamless" hand-off between the WLAN and the wide area MAN so that all the user needs to do is be logged in securely and then can travel around in the area of coverage. Working de facto standards for handling log in across hot spots etc. need to evolve but there is progress being made. The fact that hot spots are being set up for cheap in public places and wireless mesh networking is evolving rapidly help to create a critical mass for user acceptance and utility of grass roots wireless efforts.
Voice can be delivered in "carrier class" quality at four 9s for fixed wireless networks but is more difficult for mobile wireless networks because of difficulty of uniform signal coverage. Somewhere down the road, maybe another ten years, wireless will evolve to be as universally reliable that mobile phone service is as reliable as a fixed wired connection. Of course, some areas of the country have problems with downed lines and other interruptions to fixed wireless service so achieving universal phone servic e reliability may be asking a bit much. |
