alex@grian.cps.altadena.ca.us (Alex Pournelle) (04/17/91)
Followup should probably be to one of the other existing groups, like comp.dcom.lans or maybe one of the radio conferences. Some background on wireless LANs: Motorola's Altair wireless Ethernet replacement is available NOW, and runs at full Ethernet speed. The product is meant to replace horizontal wiring in buildings, with one Control Module feeding up to six User Modules. It's just a "piece of wire" to Ethernet, not requiring any special drivers or software. Altair runs at 18 Ghz--well above almost any existing bands. It's cellular microwave, with encryption. Since 18Ghz has really high propagation losses, they only claim 40-80 feet radius (although tests have shown that you can use it in open-plan offices of 130 foot radius). Due to the very low signal strength, subharmonic interference with other products is extremely unlikely. The ecrypted signal means it's also unlikely you're going to get attacked. Probably more likely that wire will be attacked via induction pickups. Since Motorola allocates the channels (they have ten), there is little chance of interference. They also allocate reuse carefully, so you probably won't have ANY chance unless they sell bazillions of them. Someone claimed that we can't get reliable radio data over 56 KBPS. That may be true in amateur, but voice calls have been carried digitally over microwave for over thirty years: microwave T-1. And the Altair product is true Ethernet speed. NCR's WaveLAN is a secondary user (along with amateur) of a small band just above cellular. There may be a problem with signal strength and interference next to a commercial cell site. Since it's spread-spectrum, the likelihood of signal attacks isn't very high. This is a more point-to-point product, with a card per station. You can also get distance extender directional antennas in addition to the omnidirectional it comes with. jerry@truevision.com (Jerry Thompson) writes: >In article <1991Apr11.034720.26091@uncecs.edu> urjlew@uncecs.edu (Rostyk Lewyckyj) writes: >>[What band will be used?] They want to reallocate some military spectrum. Getting FCC approcal for reallocation is, as Motorola will attest, difficult. Since Motorola owns this spectrum, they don't have to worry about competing or incompatible products. >>Will it be the CB radio bands? Unlikely--way too much signal out there. >>Will it be marine bands? >>Will it be a piece of some current commercial band allocation? Most likely. >>[Will it be cellular?] Very unlikely. Way too many objections, most with huge money. >>[Why would anyone miss a few TV channels?] If they're already in use, plenty of people would. FCC has already reallocated a couple of UHF channels as public-safety. >Sounds to me like Apple has a product they want to make so they can dominate >an important flow of information and put a choke hold on it so we will all >have to pay them a lot of money to use it and then the Japenese will come in >with improvements on it because Apple was charging outrageous prices for some >lame-o hardware and then the Japenese will control the radio computer network >and start broadcasting advertisements into our computers for cars and TV's and >we will all be brainwashed and submit to their control. But I like the idea. Other than the tongue-in-someone's-cheek tone, this isn't a very valid criticism, since Apple has several partners in the venture, who are to also provide products. Alex P.S. I sell the Motorola Altair product. -- Alex Pournelle, freelance thinker Also: Workman & Associates, Data recovery for PCs, Macs, others ...elroy!grian!alex; BIX: alex; voice: (818) 791-7979 fax: (818) 794-2297 bbs: 791-1013; 8N1 24/12/3 BIX: alex
ge@dbf.kun.nl (Ge' Weijers) (04/17/91)
alex@grian.cps.altadena.ca.us (Alex Pournelle) writes: >>In article <1991Apr11.034720.26091@uncecs.edu> urjlew@uncecs.edu (Rostyk Lewyckyj) writes: >>>[What band will be used?] >They want to reallocate some military spectrum. Getting FCC approcal >for reallocation is, as Motorola will attest, difficult. Since Motorola >owns this spectrum, they don't have to worry about competing or >incompatible products. It will be even harder to get WARC or CEPT approval, as they are not likely to look favourably upon allocating bandwidth for proprietary protocols. Motorola owns this spectrum as long as they don't export the equipment. Overhere Altair is not available as far as I know. >>>Will it be the CB radio bands? >Unlikely--way too much signal out there. CB users are voters too. VERY unlikely, as # CB-users >> # AppleXXXNet users. Only bands with predictable propagation can be used. Intercontinental CB happens sometimes on a sunspot maximum. Same for other HF and VHF bands. (((News flash: on monday our LAN went WAN))) This is definitely an application for the > 1 GHz range. Perhaps it would be a good idea to get Apple c.s. to negotiate a world-wide frequency band or set of bands, and get a IEEE 802.x standard for it. At least different types of equipment should use the same collision control protocol so it all can operate on the same bands. Ge' -- Ge' Weijers Internet/UUCP: ge@cs.kun.nl Faculty of Mathematics and Computer Science, (uunet.uu.net!cs.kun.nl!ge) University of Nijmegen, Toernooiveld 1 6525 ED Nijmegen, the Netherlands tel. +3180652483 (UTC-2)