Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!lll-lcc!pyramid!prls!gordon
From: gordon@prls.UUCP (Gordon Vickers)
Newsgroups: comp.dcom.lans
Subject: Need info on "RF modems", micro-wave LAN links, etc
Message-ID: <20017@prls.UUCP>
Date: 14 Mar 89 17:09:25 GMT
Reply-To: gordon@prls.UUCP (Gordon Vickers)
Distribution: usa
Organization: Philips Research Labs, Sunnyvale, California
Lines: 41


      I am looking at alternitives for connecting to our campus LAN.
   The LAN consist mostly of VAXen and our system is just a bit too
   far awa} for fiber.

      We are with in line-of-sight of one building that is about 1.5 miles
   away. 

      I am currently curious about "RF modems" and I really don't care about
   the frequancy of transmition (yes, I know it effects throughput).

      Do I need something more sophisticated than a line driver (ala Prentice)
   and a transmitter/receiver ?  If so, what standards should I be aware of
   if I want to be multi-vender compatable (i.e. If the equipment supplier
   dissapears I'd like to be able to  replace a failed unit with that of
   another supplier without having to replace the entire system or do 
   extensive modifications).

      I know many companies use microwave and sub-microwave frequancies to
   "pipe" data to remote buildings.  Are these "RF modems" anything like
   real modems ?  Is it pretty standard to encrypt the data ? What vendors
   (for an eathernet interface) have you had experiance with ? 

      I would expect that RF modems use a syncronous protocol, any idea's on
    how I'd interface to such a beast ?  My expeviances have only been with
    async. lines and Ultrix doesn't support any sync ports.

      I am running a VAX 11/750 with Ultrix and would probably be using   DecNet though I'd expect the RF modem not to care what I was running.

      Ideal would be a box that just connects directly to the eathernet,
   you know, plug&go type stuf but cost will be an important consideration.
   In fact, I'm willing to go to considerable lenths if need be, to keep
   the cost minimal (well, under $10,000 would be nice).

      I am completely ignorant of what is ACTUALLY available so any info
   emailed to me would be greatly appreciated. 

------------------------------------------------------------------------------
Gordon Vickers 408/991-5370 (Sunnyvale,Ca); {mips|pyramid|philabs}!prls!gordon
Every extinction, whether animal, mineral, or vegetable, hastens our own demise.