Xref: utzoo rec.ham-radio.packet:977 rec.ham-radio:4108 sci.electronics:2353
Newsgroups: rec.ham-radio.packet,rec.ham-radio,sci.electronics
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: low power license free packet?
Message-ID: <1988Feb28.002042.10339@utzoo.uucp>
Organization: U of Toronto Zoology
References: <8802111609.AA16271@decwrl.dec.com> <440@n8emr.UUCP> <357@ge-rtp.GE.COM>, <1170@trotter.usma.edu>
Date: Sun, 28 Feb 88 00:20:42 GMT

> ... There is no reason why, in a
> few years, it can't be commonplace for there to be a packet box hooked up
> to the PC in every house...

Actually, yes there is:  choose a reasonable set of assumptions about how
many such boxes there are and how much traffic each one sends, and then
ask yourself how much spectrum space is necessary for this!  Don't forget
the desire for both interactive use, i.e. low and relatively constant
latency, and fast bulk transmission.  Then ask yourself whether there is
any reasonable part of the spectrum with that much free space.  Nope.

Moreover, this is a silly way to do things.  Radio is ideal for mobile
communications and broadcasting; using it as a substitute for wires
between two fixed points in a metropolitan area is dumb, not to say wasteful.
You can already buy a box which has many of the desired properties and needs
no spectrum space whatsoever!  It's called a Telebit Trailblazer, and it
gets 14kbps over normal phone lines.  If you believe the ISDN enthusiasts,
even this is small potatoes compared to what will be available soon.

There is, actually, reason for interest in packet radio links of this kind.
Not for computers in houses, but for laptops and their fancier successors
(e.g. the fabled Dynabook).  Unfortunately, such systems tend to want even
more spectrum, and it just isn't available.  What we may end up doing is
using broadcast optical (infrared) communications, which works fine at
short ranges in suitably-equipped areas.  If your Dynabook works in your
dorm room, in the library, in the study halls, and in the classrooms (or
non-academic equivalents of the above), it will be less important that it
won't work -- or at least won't talk to the outside world at high speed --
from the beach.
-- 
Those who do not understand Unix are |  Henry Spencer @ U of Toronto Zoology
condemned to reinvent it, poorly.    | {allegra,ihnp4,decvax,utai}!utzoo!henry