[Namaste-dev] Re: System Block Diagram - Version 1, and other matters

Frank Brickle brickle at pobox.com
Thu Jun 26 14:47:29 PDT 2008


I hope I'll be permitted a little indulgence in expressing this, but there
are a couple of things about this plan of action that concern me.

(1) Is this an Amateur Service project or is it something else? Based on
what I see here, the overriding concern is to produce an off-label P25
implementation, irrespective of the sanctions in place regarding use of that
technology, frequency allocations, etc.

(2) Where are the boundaries to be drawn between US Gov, local gov
responders, and everything else? Forgive me for being uncomfortable about
this, but much of the development plan laid out here appears to involve a
deliberate blurring of boundaries, both in development resources, and
ultimate purpose of the project. How are we entitled to a free and clear use
of P25 at all, if we aren't representatives of the only agencies entitled to
such free and clear use?

I apologize if I'm being obtuse but these issues are important to get in
their proper places now, not later. In any case it seems questionable (if
not completely inappropriate) to be calling for volunteer effort in support
of what can easily be mistaken, based on the current lack of clarity, for a
para-governmental development effort.

Given the labile character of government policy making, I believe we should
all be very reluctant to commit time, intellectual property, and other
resources without a luminously clear understanding of who owns what. It was
precisely a lack of clarity in this area that led to the P25 IP fiasco in
the first place.

73
Frank
AB2KT

On Thu, Jun 26, 2008 at 9:56 AM, Bob McGwier <rwmcgwier at gmail.com> wrote:

>  This is as good "big picture" as we can get.  Thank you for this.
>
>
>
> I want to give you all some data points.  What follows is information
> unrelated to my ego.  Please take it as such.
>
>
>
> In my work on the REAL dark side of the force as opposed to the "obscure"
> signature below ;-),  I have some experience of what can be accomplished in
> the real world and am completely compared to help begin implementation of
> this along with the corresponding half on the other side.
>
>
>
> With a USRP2 and a modern PC,  I can prototype this very quickly indeed if
> we do not do the FH-CDMA.    Matt tells me "my" USRP2 are close to "in the
> mail".
>
>
>
> I will be meeting with Rick on Sunday and I will brow beat him about
> getting an svn repository up so we can begin this.
>
>
>
> Let me give you a data point.   On a single Dell 2950 with two Quad core
> Xeon at 3.16 GHz,  I can do all I/O and process down to bits communications
> channels of all sorts of signal channels in parallel.  I do, day in and day
> out,  processing of 70 channels, each one MHz wide, where I process for
> energy alarms, classify the content,  decide to send it down to a narrower
> band processor and run all of those.  There are literally thousands of
> threads in this system and some of the demodulation and decoding (forward
> error correction and removal of interleaver) is intense.   It uses the sdr
> core you can blame AB2KT and I for having started.
>
>
>
> This is not bragging, please believe me.  If I wanted to brag, I would have
> told you about it ages ago when it was first done (and told you I can
> process more data than Vanu can on his servers ;-) ).  I bring it up to try
> and move us to something concrete as quickly as possible  and to demonstrate
> my strongest possible belief we can, so we have stuff to show in October.
>
>
>
> We have, as demonstrated in Paul's diagram, an almost completely software
> defined system.  I have a novel idea.  Let's write some software.  We have
> the necessary tools available to this project  in the USRP2 and Gnu Radio to
> do rapid prototyping of this system.  We should.  It will cost only a few
> thousand dollars to do the entire ground station software prototype out to
> baseband and even build a spacecraft simulator in the same space.
>
>
>
> We can use existing plug in cards for the USRP2, again inexpensive,  to
> move it to RF.   These are NOT in our bands but we are not trying to do the
> initial experiment in the amateur satellite service.  We want to operate
> this for our own education and to build towards presenting an experimental
> R&D system to first responders in Southern California.   I have done P25
> implementations for work.  I won't be sharing those and I won't be writing
> them personally but I will be happy to "lead" others to the successful
> implementation when we get ready to provide some kind of interoperability.
>
>
>
> So,  I am going to lead this off.  It being open source and built using
> open source,  I need no one's permission to start and I hope you will
> follow.  It will be open to any and all who want to develop code for
> download and to a more limited set of developers for upload.  I can provide
> the shell of this block diagram in Gnu Radio blocks pretty quickly so we can
> begin adding the pieces for experimentation.
>
>
>
> As Astra
>
> Bob
>
> N4HY
>
>
>
>
>
> ARRL SDR Working Group Chair, AMSAT VP Engineering.
>
> Member: ARRL, AMSAT, AMSAT-DL, TAPR, Packrats,
>
> NJQRP, QRP ARCI, QCWA, FRC.
>
> "Trample the slow ....  Hurdle the dead"
>
>
>
>
>
>
>
>
>
> *From:* namaste-dev-bounces at amsat.org [mailto:
> namaste-dev-bounces at amsat.org] *On Behalf Of *Michelle
> *Sent:* Tuesday, June 24, 2008 1:30 PM
> *To:* namaste-dev
> *Subject:* [Namaste-dev] System Block Diagram - Version 1
>
>
>
> Here is the current block diagram. It's in the feed and on the web. We
> expect it to change, of course, but we wanted to post it for review and
> comment.
>
>
>
>
> http://www.delmarnorth.com/namaste/requirements/Namaste%20CBlock%20Diagram.pdf
>
>
>
>
>
> -Michelle W5NYV
>
>
>
> Potestatem obscuri lateris nescis.
>
> _______________________________________________
> Namaste-dev mailing list
> Namaste-dev at amsat.org
> http://amsat.org/mailman/listinfo/namaste-dev
>
>


-- 
"This is the Voice of Moderation. I wouldn't go so far as to say we've
actually SEIZED the radio station . . . " -- Obsidian Wings
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