To: harryl1 who wrote (9230 ) 5/26/1999 11:44:00 PM From: MAELING Respond to
My understanding is that CAIS as an internet provider is another me too product. Their specific claim to fame is being able to hook up hotels and apartment buildings to the internet via the 4 wire set-up coming with all telephone hook-ups, rather than rewiring with Cat 5 wiring. (In a standard telephone line there are two lines for the telephone, and two lines for the bell. Turns out telephones no longer require the separate bell lines, they just send through a big-time voltage.) CAIS uses a set of resistors and capacitors to separate the frequencies just like your stereo speaker system does to filter the tweeter signal, from the mid-range, from the sub-woofer. CAIS divides into three frequency bands: one for voice, one for EtherNet, and one for future video signal. So they sort out the frequencies to provide Ethernet connection to the central server for the floor of a hotel, or an apartment building. They have a patent for this gizmo that is 50% owned by CAIS and 50% owned by InLine. There are some exceptions over which they fought a licensing battle and lost last fall. The patent is probably OK, but there are some fuzzy areas. Tut Systems has a totally different system that is easier to install and more reliable. Problem with the OverVoice thing is that as runs get longer, the frequencies drift. In a stereo, only one category of speakers is downstream. With conflicting digital and POTS signals there is the problem of 'drift' and crosstalk. You almost have to tune each installation. The hotels and apartment bldgs don't care because it is CAIS that pays for the installation. One would think that they might get good at it, but they are going to outsource the installation to a cable pulling Co. and Volt Information. Not good if you are trying to keep costs down.
