Bravo ! Well said.
----- Original Message -----
From: "Duane Grotophorst" <n9dg@yahoo.com>
To: <tentec@contesting.com>
Sent: Monday, June 02, 2003 1:04 AM
Subject: Re: [TenTec] rs-232,usb,-vs-ethernet
--- n8coo@juno.com wrote:
> 1. RS-232 - basic, even the latest and greatest
> network equipment still have an RS-232 console port,
> works with almost anything.
I am however beginning to encounter newer network
equipment that does not have any RS232 ports on it.
The RS232 ports are generally used only to set up the
IP parameters initially, once that is done a web
interface is used for all further configuration.
> 3. Ethernet AND TCP/IP, now you are talking
> NETWORK. There's a big difference between serial
> communications and connecting to a network.
Those differences are precisely why it is so much more
appealing than USB or RS232, - once you sit back and
really think about it.
> A lot more to it than plugging in a cheap piece of
> hardware to your PC like a nic. SOFTWARE, HARDWARE,
> PROCESSING, ETC. These are things that your RADIO
> will have to implement, not just your PC.
I work daily with the development of a variety of
equipment that is used in broadcast and video
ingest/editing/play-out. One of the products that I
work with can stream ~40 1Mb/s low-resolution video
data streams around our lab (and at customer sites)
quite effectively and with a minimal amount of
latency, - even on the same network with all of our
other business/office traffic. Realistically though
the latency in our lab is more than we as hams would
accept with our radios. But then the worst case data
rates that I envision our radios would ever need to
move around over a network are in the ~6 Mb/s region.
This is based on a raw 32bit/192Khz sample rate, -
this is far more than any of the existing amateur DSP
IF radios now use. Perhaps however more realistic data
rates would be around the 750Kb/s (16bit/44.1 sampling
- CD quality) or 2.3Mb/s (24bit/96Khz sampling -
typical professional audio). These rates could easily
accommodate the post DSP IF processed data stream
(a.k.a digital audio). In other words the hard work of
DSP processing would be still be done nearer to the
analog RF part of the radio, - which is exactly like
radios such as the Orion and its DSP IF
predecessors/competitors already do. A CD or
'professional audio' quality data stream will surely
have fidelity enough for both speaker audio and mic
signals. So essentially we would be inserting the
Ethernet networking before the RX audio A to D and
after the mic D to A.
The key technological challenge will be to define a
'radio specific' protocol layer that preserves the
real-time nature of the signal while also handling the
required control house keeping. The bottom line is
that moving 4 or 5 of these data streams around a
100Mb switched network should not be a big problem;
even without getting exotic or implementing QoS
protocols. And most hams would be running this as a
radio dedicated network, if however they already have
a more sophisticated network they will likely also
have the knowledge to beef up the network
infrastructure as necessary.
> Could be tough on a radio manufacturer,
> esp. a small one, to make sure their radio and/or
> software is compatible with everything else out
> there. Things DO affect each other on a network.
They really only need to make sure that the radio
adheres to the proper TCP/IP standards. They can never
have any real control of the environment that the gear
ultimately goes into (which is also true of existing
gear today). However they can build in test routines
to verify the adequacy of the network as a pass/fail
test, thus making the end user responsible for the
network's suitability.
> There isn't the number of radios manufactured
> anywhere close to the number of PCs and other
> computer equipment being made. I'm sure if the
> radio manufacturers think enough will buy into into,
> literally, they will sell it.
Therein lies the key. If there were more folks wanting
this stuff there would be more action already from the
manufacturers. I believe the reason there aren't more
people wanting this stuff is because many do not think
about it, maybe this discussion here will help change
some of that. They also don't really step back and
think about other ways to approach 'radio' itself or
assembling a much more capable station, specifically
on how to take advantage of some new and readily
available technologies. It is always easier to do it
the same way as it has always been done, but that is
not always the best way.
Duane
N9DG
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