gordon@prls.UUCP (Gordon Vickers) (03/15/89)
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.grenley@sunkist.UUCP (George Grenley) (03/16/89)
In article <20017@prls.UUCP> gordon@prls.UUCP (Gordon Vickers) writes: > I am looking at alternitives for connecting to our campus LAN. > We are with in line-of-sight of one building that is about 1.5 miles > away. There is (was?) a company in NY which manufactures an optical beam relay unit which might be a great fit to your application. Their name is Codenoll, I think - or something like that. They're in one of the suburbs near NYC. This info is a few years old, I don't know if they are still around. The big advantage is that no FCC permit is required - just plug it in and go. It uses "diffuse optic technology", a buzz word for an infrared beam about 10-13" diameter - the large size makes it impervious to birds, rain, etc. Data rate is 10 mbit, range is several miles. Good Luck!