A DSP project for consderation

[Bob Bruninga]

Here is a neat AMRAD project:

The Novice-I-BAND is a new licensefree virtual Novice band. It is intended
to serve as a gathering ground for newcomers learning the Morse Code.

See  http://www.ew.usna.edu/~bruninga/i-band.html

I-BAND is a virtual Novice band linked worldwide by the internet.  The
I-Radio is a virtual radio with all the knobs and slide-rule-dial of a
classic HAM radio.  You could download your I-Radio from the ARRL
BIG-PROJECT office (the school outreach project) and it would come with
your unique I-License call letters built in (and tied to you).

You plug your CW-KEY into the serial port (CTS line) and you are on the
"air!"...  Or use the mouse clicker...

NO, I-Band and the I-Radio do not yet exist... but why not?  The APRS
worldwide system of HUBS and steaming packets shows how easy it is to do
LIVE real-time packet on the internet.  Why not CW?

WHY I-BAND?

When I was a kid, the novice bands were full of wonderful bleeps all
jammed into a narrow slice of spectrum.  It was alive and vibrant...
Last time I checked 80m in the evening, I had to tune for several minutes
before I found a novice.  This was not encouraging as we try to get kids
interested in HAM radio.  And the ARRL is receommending eliminating the
Novice bands entirely.

But having formed Kids Radio Clubs at my kids Schools and Scout troops, I
find that middle-school kids just love to learn the Morse code.  Like
Hogwarts and Hobbits, its a neat thing... It is the code that fascinates
them and sets them apart.  I am not a CW fanatic. (See OP-ED June QST
2001. http://www.ew.usna.edu/~bruninga/darth.txt ) Its just that now in my
50's that I am concentrating on kids, I find that CW does have an
attraction.  Kids often are speechless when handed a mic.  But CW is a
secret code.  It doesnt matter what you say, it is new and different and
an end in itself.

Why I-BAND?  Because as a kid learning the morse code back in 1950's
all the kids were exposed to the code (Boy Scouts etc required it).  I
strung up bits of wire around the neighborhood to form a telegraph
system for all us kids to hone our skills.

Today, such attempts would only bring law suits.

I-Radio has *NO* bells and whistles.  It has no waterfall display, no text
display, and no voice capabilty.  It is a CW only rig and is intended that
way.  But what comes out of its speaker is about as realistic a sound as
the Novice bands used to be.

No, I-BAND and the I-Radio do not exist.  I dont know how to write that
kind of real-time DSP code, but the talent to produce it and the worldwide
Internet HUBS developed for APRS show how easy such an application can be.
All we need is a coder interested in the future of the hobby and ready for
a new challenge to win back the kids of today.

DETAILS:  Here are some more specifications on of how this system should
be designed:

USER INTERFACE:

   Frequency: Sliderule frequency display (not digital) with pointer
   Tuning:    Click and slide the pointer
   Reception: Speaker (hears everything in the passband).
   Sending:   CW Key on CTS line, or click on the key paddle icon
   Setup:     Select the following configuration items.
              Antenna: (dipole, V, long wire, etc)
              Power:   (QRP, up to legal limit)
              Fist:    (defaults to random hashed from your call)

XMIT TEXT DISPLAY:  The only input device is the CW key.  No keyboard
input of QSO text should be permitted.  But a text display of your
outgoing decoded CW is OK as feedback to the quality of your fist.

XMIT BUFFERS:  Such as CQ CQ CQ de XXXXX XXXXX are OK, but they can
only be loaded by CW Key.

STATION LIST:  A list of all stations on the "air" can be available.
The list will show calls and frequency and can be sorted either way.

PROTOCOL:

Invisible to the users, data must be exchanged worldwide in near real
time so that all copies of the I-Radio generate the proper virtual
sounds.  This is not done with streaming audio, but synthesized CW
at the receiver from fundamental characteristics received via the TCPIP
link to the central CW-HUB.  There are two kinds of TCPIP data packet.
The first contains the fixed information such as frequency, and the second
type contains the actual streaming CW text:


CALL,freq,chirp,weight,decay,tone.... [sent any time the freq changes]

CALL,spd,delay,text,on-off-bit-data                [sent periodically]

On receipt, each I-Radio uses these streaming data packets to produce
a realistic virtual sounding reproduction.  What comes out of the speaker
can be one tone, or dozens, all reproduced in accordance with each one's
"transmitted" frequency and the instantaneous setting of the I-Radio
receiver.  Each fist sounds unique because of the unique settings of
the chirp, weight, decay and tone for each user.  Chirp is the attack
waveform, weight is the weight between mark and space, decay is the
decay waveform of each bit, and tone is any second order modulation
on the pure carrier.

Initially each I-Radio is delivered with a random fist but it can be
customized by the user.

On transmission, the senders fist is first decoded locally to give
feedback to the sender, and his frequency, speed, and weight are
determined.  Then the resulting CW text stream is transmitted along with
the characteristic data to allow faithful reproduciotn on the other end.
On receipt, the incoming streaming packets are delayed slightly to assure
continuity and then are used to key the waveform based on all the
previously received parameters.

Just thinking here...  Later we can add propogation and noise models to
each band and eventually could have an unbelievable virtual reality
worldwide ham band!  But I DIGRESS!  For now, we only want a place to
learn and "play" CW!

de WB4APR@amsat.org, Bob

See I-BAND!   http://www.ew.usna.edu/~bruninga/i-band.html


de WB4APR@amsat.org, Bob

PCsat WEB  page     http://www.ew.usna.edu/~bruninga/pcsat.html
ISS-APRS FAQ:       http://www.ew.usna.edu/~bruninga/iss-faq.html
CUBESAT Designs     http://www.ew.usna.edu/~bruninga/cubesat.html
APRS LIVE pages     http://www.ew.usna.edu/~bruninga/aprs.html
APRS SATELLITES     http://www.ew.usna.edu/~bruninga/astars.html
MIM/Mic-E/Mic-Lite  http://www.toad.net/~wclement/bruninga/mic-lite.html