Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!uunet!camex!sunfs3!kent
From: kent@sunfs3.Camex.COM (Kent Borg)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Important Petition/Technology
Summary: Anyone have details?
Message-ID: <1938@camex.COM>
Date: 12 Apr 91 16:40:32 GMT
References: <14131@ccncsu.ColoState.EDU> <1991Apr11.070636.18158@csusac.csus.edu>
Sender: news@Camex.COM
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In article <1991Apr11.070636.18158@csusac.csus.edu> emmonsl@athena.ecs.csus.edu (L. Scott Emmons) writes:
>In article <14131@ccncsu.ColoState.EDU> klingspo@mozart.cs.colostate.edu (Steve Klingsporn) writes:
>>From ccncsu!purdue!decwrl!ucbvax!pro-angmar.UUCP!awillis Wed Apr 10 13:29:13 MDT 1991
>>Apple Computer recently asked the Federal Communications Commission (FCC) to
>>allocate frequencies so computer users will be able to transmit and receive
>>information among personal computers (particularly portable and notebook-style
>>computers), using radio (instead of cables) in a local radius of about 50
>>meters indoors.  We need your help to make this possible.
...
>
>Hmmm...This already exists...ever hear of Amateur Packet radio?  The
>baud rates aren't fast, and use is stricly non-commercial, but at least
>there's no silly 50 meter limits.
>
>I won't support such a proposal as the one mentioned about.  ...

Before we all start cheering and booing, does anybody know what was in
the proposal?

From what I can gather, it sounds like a cross between the chaos of
Ethernet and the order of cellular telephones.

Unlike Ethernet (or LocalTalk), a mobile wireless medium cannot
enforce "cable length" limits.  One node cannot be sure that another
node will see a packet transmission within a certain propagation
time--nor that the other node will pick up the transmission at all, it
might be too far away.  A related difference between fixed cable and
moving wireless is what you might call Pickle in the Middle: Node A
might be within communication range of Node B, and Node B might be
within range of Node C, but Node C and A are two far apart to hear
each other.  Node B is the Pickle in the Middle.  A little like being
on the interstate in the middle of nowhere and hearing two radio
stations on the same spot on the dial.

A way arount this would be for there to be multiple frequencies for
sending data.  Nodes A & B use one frequency to talk, Nodes B & C use
another.  Now the problem is how to decide upon those frequencies.  I
expect that one or two channels might be set aside specifically for
hailing other nodes and arrange to meet on one of the data channels.
(Nodes would have spend a lot of time listening on these channels to
get their calls--er, packets.)

Unlike cellular telephones, the arranging of a data channel is not
handled by a central site, but dynamically negotiated between nodes.

Those are some guesses that might get people talking, here are some
things that I know are true about Apple's proposal:

* It is peer-to-peer.  If my radio laptop is sitting next to someone
else's, we can trade data without paying nasty fees to some central
"data company"--we don't even have to be within range of any other
nodes.  I really like this part.

* It will be "turn it on"-simple.  No knowlege of radio theory, no
choosing of frequencies.  This is essential.

* It will be listen-mostly, transmit when you want to spend the
battery power.  

* It will allow commercial services to use it (unlike ham radio where
that is illegal, for a good time go over to the ham radio group and
ask about the legality of using a ham radio to order a pizza--then
stand back).  Sitting in an airport waiting room and want to check
your email?  Go to Chooser and see what long-haul data services have
set up radio portals in your terminal.


An interesting thing I thought of.  Say my computer is plugged in and
can affort to transmit as much as it pleases, depending on how they
design the system, I could likely tell it to be a router of sorts and
offer to relay packets between nodes that are not otherwise in direct
communication.  Certainly I would want both my home and work computers
to have radio links in them so that my laptop could communicate, so
why not always leave those desktop radios running as routers?  It
might become possible to have city-wide internets moving and oozing
about.  After awhile the whole East Coast would become interneted,
soon after a lot of the San Deigo - LA corridor, certainly all of
Silicon Valley north to Marin and across the bay.  You get the idea.

(Would this mean that radio router software would have to get FCC
certification before going on the air?  One confused piece of well
distributed radio router shareware could bring the whole thing
crashing down.)

Great security issues, how do I keep people driving by outside from
printing stuff on our Laserwriter?  Or checking into our our mail
server?  Passwords, you suggest?  How do I keep people from simply
listening for what I send as a password?  Or listening in on the data
I send?

RISKS folks are going to have a *ball* with this one.

Enough of my rambling, can anybody offer some concrete details?


--
Kent Borg                            internet: kent@camex.com   AOL: kent borg
                                            H:(617) 776-6899  W:(617) 426-3577
"We foolishly did not realize that he was stupid."  - April Glasbie 3-20-91