[OZAPRS] IC-2820h

Sun Jun 17 21:18:34 EST 2007

Hi Zik...

Why am I slamming it? I do have good reason. I have known about D-Star for
some time. I first saw a D-Star radio in September 2004 in Denver,
Colorado.
I believe that this was the release of the product. I think it was at very
least the release of the product in the USA. At this time I took part also
in an Icom focus group on the product. 

The major benefit is when you are running 128 kbps. This only happens with
the expensive 1.2 GHz radios, not the UHF or VHF units limited to 4800
bps.
Sure, this will work in a mobile world, but it is not a really really
great
reason to go for the system. Also, remember that voice uses AMBE. Have a
look at http://en.wikipedia.org/wiki/Advanced_Multi-Band_Excitation and
look
at the licensing costs of the scheme. $100,000 for an implementation. Sure
there are chips that do this, such as the AMBE1000, and the AMBE2000. But
try to buy a AMBE1000 these days to interface with equipment that uses it.
And the AMBE2000 is *NOT* compatible.

Could it be the reason that AMBE1000 was killed off, apart from being more
bandwidth hungry was that it would run out of patents more quickly.
Anyway,
D-Star uses the AMBE2000 from memory, which is certainly not open, and
will
not be for some while. 

Then there is the cost. The repeater for the D-Star comes with a 10 GHz
microwave link I believe. At least it did when it came out. This is
ridiculous for the ham market. It only makes sense in the NGO market,
which
has to be where it was designed to fit in. 

Next, the design of the radios is suspect. The data radio has an Ethernet
interface. This makes some sense. However control is done by USB. That is,
you need to connect your laptop to USB and Ethernet to use the device. The
radio link on the microwave repeater system is based on ATM, whereas a
totally different protocol is used for the 1.2 GHz local traffic.

On the data only 1.2 GHz 128K link, there is no support of voice in the
protocol which would be an intelligent thing to do. AT 128K, full duplex
2400 bps AMBE voice could be encoded with probably 64 kbps of data (32k
each
way) if things were designed properly. 

>From my perspective, the designers of the system looked to see what
components could be put together to get a demonstration system working,
rather than starting from scratch to see what would make sense. 

I am not saying that there is not a place for this radio. Just that this
is
not the design that we should be relying on into the future. 

OK... AM I becoming a grumpy old man and just rubbishing this because it
is
not 2M FM, or just not done properly? No. Firstly, I am only in my mid
30's,
and I love technology. A decent design implementation would take the
physical later and replace the protocol. Start from scratch, and do it
properly. Probably base it on IP, with UDP and TCP packets. On top of that
encapsulate digital voice, video, whatever. 

Anyway, I hope that explains some of my views. They are well thought out
and
not just a knee-jerk reaction. I am willing to be corrected, but I think
this sums up my view on the subject

Darryl

-----Original Message-----
From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
Behalf Of Zik Saleeba
Sent: Sunday, 17 June 2007 8:27 PM
To: VK / ZL APRS Users
Subject: Re: [OZAPRS] IC-2820h

Doesn't D-STAR stand for "Digital Smart Technologies for
_Amateur_Radio_"? It was designed by the Japan Amateur Radio League.
In what way is this not an amateur radio? Have a look at the wikipedia
page:

http://en.wikipedia.org/wiki/D-STAR

It sounds really interesting to me - it looks like it offers a whole
lot of new possibilties for amateurs. I can't quite see why you're
slamming it.

Cheers,
Zik VK3MHZ

On 6/17/07, Darryl Smith <Darryl at radio-active.net.au> wrote:
> Simply put they do not do APRS according to the Web Sites I have seen.
They
> do D-PRS, which is based on the D-STAR protocol. My recommendation is
that
> there are no members on this list who should be touching a D-STAR radio,
me
> included.
>
> D-STAR is *NOT* Amateur Radio. D-Star is Professional Radio for people
using
> Amateur Radio frequencies. It is designed for the NGO market - that is,
the
> Red Cross. It is designed to be a radio that can provide advanced
> capabilities regardless of cost for organizations who use ham
frequencies
> mostly for emergency type use. There have been reports about Icom
wanting
to
> release the D-Star range in this country. This might be the first D-Star
> compatible radio released here...
>
> Darryl
>
> -----Original Message-----
> From: ozaprs-bounces at aprs.net.au [mailto:ozaprs-bounces at aprs.net.au] On
> Behalf Of vk7arn
> Sent: Sunday, 17 June 2007 3:08 PM
> To: OzAPRS
> Subject: [OZAPRS] IC-2820h
>
> Anybody know anything of the APRS capability of these new dudes?
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