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PA2AGA > HDDIG 18.06.00 04:53l 211 Lines 7334 Bytes #-9439 (0) @ EU
BID : HD_2000_167F
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Subj: HamDigitalDigest 2000/167F
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Sent: 000618/0006Z @:PI8HGL.#ZH1.NLD.EU #:52342 [Den Haag] FBB $:HD_2000_167F
From: PA2AGA@PI8HGL.#ZH1.NLD.EU
To : HDDIG@EU
Date: Sun, 18 Jun 00 00:19:33 MET
Message-Id: <hd_2000_167F>
From: pa2aga@pe1mvx.ampr.org
To: hd_broadcast@pa2aga.ampr.org
X-BBS-Msg-Type: B
Perhaps someone will explain cost and availability of that gear.
> > Of course you can use license-free wireless LAN products. These include
> > the transmitter hardware, so you don't need to fiddle with that. You may
> > need to provide and connect an external antenna for extended range.
>
> I have a small kit for a transmitter with a 1km range. If I use a larger
> recieving antenna and a more powerful receiver could I get better range. For
> the link between the station and me all I need to get is about 1000 bps.
>
> David Findlay
--
... Hank
http://horedson.home.att.net
------------------------------
Date: Thu, 15 Jun 2000 23:25:13 -0400
From: "Rob" <Pse@NoEmail.Com>
Subject: Packet Radio
Post a message on aus.radio.amateur.digital and aus.radio.amateur.misc
Someone on these newsgroups should be able to help you out.
Please keep in mind that most (if not all) HAM RADIO licences do not permit
setting up a packet network for commercial use.
It sounds like you want to set up a TCP/IP high speed network for commercial
use (and profit). If you want to do that, you will likely have to compete
for special licences with all your Telco and ISP providers.
73's
Rob
"David Findlay" <nedz@bigpond.com> wrote in message
news:grd25.573$c5.3192@newsfeeds.bigpond.com...
> > I didn't know you were in Australia. But you should still get your
> > license - you will learn a lot.
>
> I;m going to a soon as I can. Does anyone here know about the procedures
to
> get a liscence in Aus?
>
> David Findlay
>
>
------------------------------
Date: Fri, 16 Jun 2000 06:00:18 GMT
From: bla@bla.bla (bla )
Subject: Packet Radio
In article <grd25.573$c5.3192@newsfeeds.bigpond.com>, "David Findlay"
<nedz@bigpond.com> wrote:
>> I didn't know you were in Australia. But you should still get your
>> license - you will learn a lot.
>
>I;m going to a soon as I can. Does anyone here know about the procedures to
>get a liscence in Aus?
>
>David Findlay
>
>
David , get to know some Australian Amateurs first, they are the people to put
you through your tests to get your LICENSE and ask them about how to go about
setting up your system.
cheers
------------------------------
Date: Fri, 16 Jun 2000 09:13:57 +0300
From: Paul Keinanen <keinanen@sci.fi>
Subject: Packet Radio
On Fri, 16 Jun 2000 08:09:35 +1000, "David Findlay" <nedz@bigpond.com>
wrote:
>> 10 Mbit/s only exists on some random experimental links, not in general
>> operation.
>What barriers stop it from general use?
First of all 10 Mbit/s will require a 1000 times (+30 dB) more
transmitter power than 9600 bit/s (and 1200 bit/s) for the same
distance with the same antennas. Or if the transmitter power is the
same, the distance drops to 1/30 (the inverse square law) if there are
a line of sight condition (which is quite rare for amateur
connections) or drops to maybe 1/200 distance in urban areas without
visual contact (the 1/r^4 "rule").
With the quite low ham density, how many hams could you reach from
your home station ? It has been notoriously difficult to get hams to
support common infrastructure, the local repeater in your town is
usually the only thing that can be done and get financial support from
the local ham community.
The other problem is multipath in situations when there is not a
really clean line of sight path and where extremely narrow beam
antennas are not used. Practically all amateur link are of this type,
a good line of sight link is a rarity. Commonly used modulation
methods, such as FSK and PSK do not work very well in multipath
environment. To combat multipath, some form of spread spectrum or low
symbol rate multicarrier systems such as COFDM is really needed. Until
chips intended for both receiving and _transmitting_ DAB or DVB-T
(which both use COFDM) are readily available, I do not think that
there are going to be a lot of high speed ham connections.
Practically all high speed connections require a full duplex
connection (or a half duplex connection with very fast turnaround
times), implementing this at high power levels (> 1 W) can be tricky
and may require the use of different amateur bands for each direction
with separate antennas for each band.
Paul OH3LWR
------------------------------
Date: Fri, 16 Jun 2000 06:09:36 GMT
From: nomail@rob.knoware.nl (Rob Janssen)
Subject: Packet Radio
David Findlay <nedz@bigpond.com> wrote:
>> More like 1200 bits/s. Or 9600 if you are living in a techologically
>> advanced area.
>> Some people even run 56kbps.
>> 10 Mbit/s only exists on some random experimental links, not in general
>> operation.
>What barriers stop it from general use?
It is not available as an off-the-shelf item in your local hamradio shop.
Although you might get the impression that amateur radio is about
experimentation, this is a description of the situation 20 years ago.
Today, most hams only connect ready-built equipment and mumble about how
they could never build it cheaper.
>> Do your weather stations collect 10 Mbit/s worth of data?
>No. I was actually thinking of the 10Mbit/s to use for broadcasting the data
>to other users using TCP/IP. The data from the stations would be processed
>before being sent out, and the network would also have to handle email and
>rich(HTML) content.
The few projects that describe homebuilt 10 Mbit/s links are not at all
suitable for broadcasting. They use frequencies similar to TV satellites,
and the antennas for these frequencies normally have very small beamwidths
and thus are only suitable for point-to-point use.
To use anything resembling broadcasting, you would have to setup a network
of point-to-point links with interconnecting nodes (routers).
Rob
--
+----------------------------------+--------------------------------------+
| Rob Janssen pe1chl@amsat.org | WWW: http://www.knoware.nl/users/rob |
| AMPRnet: rob@pe1chl.ampr.org | AX.25 BBS: PE1CHL@PI8WNO.#UTR.NLD.EU |
+----------------------------------+--------------------------------------+
------------------------------
Date: Fri, 16 Jun 2000 17:30:36 +1000
From: "David Findlay" <nedz@bigpond.com>
Subject: Packet Radio
> It sounds like you want to set up a TCP/IP high speed network for
commercial
> use (and profit). If you want to do that, you will likely have to compete
> for special licences with all your Telco and ISP providers.
Definately not. I want to set up a high speed, experimental wireless network
for scientific and educational use or science enthusiests. Basically what
the internet was before commercial stuff came in, but free. It would only be
over a small geographic area.
David Findlay
------------------------------
Date: Fri, 16 Jun 2000 17:47:42 +1000
From: "David Findlay" <nedz@bigpond.com>
Subject: Packet Radio
> First of all 10 Mbit/s will require a 1000 times (+30 dB) more
> transmitter power than 9600 bit/s (and 1200 bit/s) for the same
> distance with the same antennas. Or if the transmitter power is the
> same, the distance drops to 1/30 (the inverse square law) if there are
> a line of sight condition (which is quite rare for amateur
To be continued in digest: hd_2000_167G
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