From owner-freebsd-isp Wed Jun 25 08:34:21 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id IAA28687 for isp-outgoing; Wed, 25 Jun 1997 08:34:21 -0700 (PDT) Received: from uhf.wdc.net (uhf.4d.net [207.137.157.140]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id IAA28681 for ; Wed, 25 Jun 1997 08:34:15 -0700 (PDT) Received: from localhost (bad@localhost) by uhf.wdc.net (8.8.5/8.6.12) with SMTP id LAA01068; Wed, 25 Jun 1997 11:31:12 -0400 (EDT) Date: Wed, 25 Jun 1997 11:30:16 -0400 (EDT) From: Bernie Doehner To: "Daniel O'Callaghan" cc: "Rodney W. Grimes" , freebsd-isp@FreeBSD.ORG Subject: Re: Wireless Services In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-isp@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > > I was just talking to someone about this sort of stuff. Apparently > Wavelans are spread-spectrum, but they use direct-sequence SS, rather > than frequency hopping SS. There are just a few centre frequencies which > can be set, and that is the only way to avoid collisions on neighbouring > cards. The NWID is only to code the packet so other cards will ignore it. Yes, but this is only true for 2.4 Ghz. 900 MHz. band is not wide enough! But yes, you bring up a good point, Freewave makes frequency hopping radios for 900 MHz. that are capable of being colocated to some extent without detriment to the throughput. Only thing is that they are still very expensive ($1250/unit) and only give you 115k2. Keep in mind that bps ~ Hz. (bandwidth). > I was given a brochure about BreezeCom products, which *do* do frequency > hopping SS. . > 2195 Faraday Ave, Suite A > Carlsbad, CA 92008 > 1-619 431 9880 Don't have it onhand right now (I just remmember it being up there). The Breezecom stuff is nice because it does multi-rate (it goes to lower throughput if it can't make it at 3 Mbps). However, compared to the Freewave radios they are pretty deaf (fine for indoor use, but bad for long outdoor links). Bernie