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Hi Frank, John, et. al.,<br>
<br>
Frank, I really like your universal way of looking at it. I think that
is what we need, so that we can use the same transport for everything.
It seems that there will also need to be some consideration for other
parameters like the sample rate, etc., but I really like the idea that
a client can also be a server for other subprocesses, and that they all
speak the same language so they can be hooked up any way you like.<br>
<br>
73,<br>
<br>
Rob<br>
<br>
On 08/11/2010 08:17 AM, Frank Brickle wrote:
<blockquote
cite="mid:AANLkTi=mmJAYipojf91EisgAwJFZGF6fRAnxYPg3nGJW@mail.gmail.com"
type="cite">
<pre wrap="">***** High Performance Software Defined Radio Discussion List *****
</pre>
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<br>
I just wanted to drop a few ideas into the discussion at this point.
They're not fully developed here, but I hope the implications will be
clear. They're fundamental design principles in the new DttSP, which
we're calling SDeRl.<br>
<br>
Note that the following comments apply only to RX, although by symmetry
they apply to TX also.<br>
<br>
(1) IF streams can come in two forms: pre-D (pre-demodulation) or
post-D (post-demodulation). *Most of the time*, what a server is
passing around is pre-D signal. Demodulation generally happens at the
client, or else is carried out by a lightweight proxy inserted between
the server and and endpoint client.<br>
<br>
(2) What a server sends to clients as IF are *channels*, generally
sub-channels of some broader-bandwidth sampled RF. The channels can all
be thought of as selected sub-bands of the full bandwidth. They are
specified in terms of center frequency, bandwidth, and time. So what a
client asks for, and gets, is always baseband with respect to a
specified frequency, and narrowband with respect to the full, upstream
RF bandwidth.<br>
<br>
(3) Channels are addressed by URI, with a quadruple of parameters:
(start time, duration, frequency, bandwidth).<br>
<br>
(4) "Servers" can be recursively created and inserted into streams as
lightweight proxies, as mentioned in (2), so as to subdivide IF
subchannels for further clients. A user-level client only needs to know
how to process a single narrowband, baseband channel.<br>
<br>
73<br>
Frank<br>
AB2KT<br>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Rob Frohne, Ph.D., P.E.
E.F. Cross School of Engineering
Walla Walla University
100 SW 4th Street
College Place, WA 99324
(509) 527-2075 <a class="moz-txt-link-freetext"
href="http://people.wallawalla.edu/%7Erob.frohne">http://people.wallawalla.edu/~rob.frohne</a>
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