October 15th, 1996

           A Direct Elementary School to College Connection

        This is a first report on our connecting up Evans Elementary
School, Alamosa School District, Alamosa Colorado directly to the
Internet via Adams State College, Alamosa.
        The connection is different from our other San Luis Valley School
connections, even where the same wireless radio is used, for it directly
connects via RS232 serial ports on the 115Kbs Free Wave Radios, to the
serial ports on the Terminal Server in the Computer Center of Adams
State College, to the serial port on a MacIntosh computer in Roger
Quintanella's 5th grade classroom at Evans Elementary.
        Because Evans Elementary is only approximately one half mile from
Adams State College, it was not necessary to connect the radio at the
college to an outside antenna - it is only equipped with the 4 inch
whip antenna on the radio itself. At Evans, a 12 inch coil antenna,
capable of being moved around on the 30 foot RF cable, with a wall
attachment is connected to the radio.
        As a consequence of such a 'simple' radio to radio connection,
it took less than 2 hours to completely set up the link and both ends.
        At the college end, the 9 Pin male serial cable that comes with
the FreeWave radio is connected to one of the 25 pin female Terminal
Server Ports (the other ports being attached to dial in modems), through
a simple 9 to 25 pin adapter. The radio sits right on the shelf next to
the terminal server, and gets power from a two prong wall plug transformer.
        In the Classroom at Evans Elementary School, the standard FreeWave
serial cable is attached to the classroom MacIntosh with a 9 pin to
Mac Din serial plug adapter.
        The TCP/IP connection over the wireless link is accomplished by
the college having an id/password login interface on the port, which
Roger then connects to using TCP/IP Netscape software on the Mac, for
an interactive login. Once passed the ID and login, he starts a PPP
session. So the protocol running between the Mac and the Internet is
PPP at 56Kbps.
        The radios communicate at 180Kbps, and the serial ports are
capable of 115Kbps. But the terminal server at the college can only be
set for 56kbps at the ports, so the session runs at that speed.
        During October and November, 1996, the teacher Roger, has been
experimenting with different small antenna locations, both inside his
classroom, up into a low attic through ceiling tiles, and through a
classroom window outside on the wall of the school under the eves.
        He has noticed different behaviors of the link, which, since
it is essentially at ground level and although only a half mile between
school and college, the signal has to either pass through at least
10 house structures, and 5 stone college building structure walls, to
reach the college computer room which is on the ground floor of the
main college building. Or it has to 'multi-path' to reach.
        In any event, as first installed, it is not a particularly
robust signal, which it would be if both ends were equipped with
rooftop omni antennas tuned to the 902-928Mhz spread spectrum
signals. Thus the observed classroom throughput is less than 56Kbps
but more than the 28.8Kbps what Roger gets with a dialup connection from
the same location.
        This can, and will be, optimized in future visits of the NSF team
to the school.
        But it works, where the alternative 56Kbs telephone company
connection would not only incur a recurring $100 to $125 monthly cost,
but also require a DSU/CSU and Router be purchased ($1,500+) for the
school end, and a corresponding connection, and cost, at the college
end.
        The 5th graders are using the link to the Internet  to go out
and research web data banks for class projects.

Dave Hughes
PI
dave@oldcolo.com