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VHF Ethernet

Hi

I would like some help for creating wireless ethernet network using
VHF radio with frequency range of 130MHz-18MHz. The distance supported
shall be upto 100km LOS. Kindly advise on industry products available
for such option.

Regards

Khan
 
J

Jan Panteltje

Jan 1, 1970
0
Hi

I would like some help for creating wireless ethernet network using
VHF radio with frequency range of 130MHz-18MHz. The distance supported
shall be upto 100km LOS. Kindly advise on industry products available
for such option.

Regards

Khan

You need a license to transmit.
130MHz (18MHz bandwidh?) are you crazy?
You would be arrested the same day.
 
R

Rene Tschaggelar

Jan 1, 1970
0
Jan said:
You need a license to transmit.
130MHz (18MHz bandwidh?) are you crazy?
You would be arrested the same day.

perhaps - perhaps not. Depends on the country.

R
 
S

SioL

Jan 1, 1970
0
Rene Tschaggelar said:
perhaps - perhaps not. Depends on the country.

R

With this bandwidth it covers aircraft bands, pretty much guarantees you to be
arrested probably in 99% of countries.

SioL
 
J

John Barrett

Jan 1, 1970
0
Hi

I would like some help for creating wireless ethernet network using
VHF radio with frequency range of 130MHz-18MHz. The distance supported
shall be upto 100km LOS. Kindly advise on industry products available
for such option.

Regards

Khan

look at a product called the TNC-X -- 1200 baud packet modem -- with
appropriate software on your PC to act as a gateway, you can do TCP/IP over
packet.... the interface to the radio is audio, so just about any voice
radio will work with an appropriate cable to hook up the earphone,
microphone, and transmit switch.

Keep the frequency up as high as possible... in fact, you can basically
scrap the 18-100 mhz range, atmospheric conditions can make so you cannot
talk 10km with 100 watts under some conditions. and at the lower
frequencies, there is every chance your signal will go MUCH further due to
those same atmospheric conditions.

I also strongly suggest beam antennas at both ends, up as high as your local
laws permit.

TNC-X packet modem
http://www.tnc-x.com/

AGW Packet Engine
http://www.elcom.gr/sv2agw/

I hope you have an FCC license (or the equivalent in your area) because for
100km range, you will have to use higher power than is allowed for
unlicensed operation in most jurisdictions. If your purpose is
non-commercial, get an amateur radio technician class license, which will
allow you to operate in the 144-148mhz "2 meter" band.... 50-100 watts will
cover 100km quite nicely with a couple of 3 or 4 element yagi antennas..
Getting the technician class license is pretty simple... most countries have
dropped all morse code requirements, so its just a test you have to take to
get licensed..

And finally -- for 100km, you could most likely get away with a couple of
2.4ghz parabolic antennas and run 802.11b wifi, which takes no licensing,
uses off the shelf hardware, and has much higher data rates than 1200 baud
packet. The only issue is getting your wireless access point as close to the
antenna as possible... in a weatherproof enclosure mounted on the antenna
mast. There are linksys routers that have open source firmware, and there
are plenty of very reliable hacked firmwares that have features
specifically for setting up point to point links. You put the parabolic on
one of the antenna ports, and a small omni antenna on the other for people
around the antenna to access.
 
J

John Barrett

Jan 1, 1970
0
Jan Panteltje said:
You need a license to transmit.
130MHz (18MHz bandwidh?) are you crazy?
You would be arrested the same day.

If he meant 18mhz bandwidth -- there is nothing out there except wifi off
the shelf for that bandwidth -- and you wont be running that at 130mhz !!

I've got some 900mhz gear that will do 24khz bandwidth and thats clunky
enough !! You can get amateur television hardware that will do 6mhz bandwith
on a 1.2ghz carrier pertty easily, but then you are stuck with some pretty
intense work to modulate and demodulate the data at that rate -- whip out
your DSPs, boys !!
 
O

ok

Jan 1, 1970
0
With this bandwidth it covers aircraft bands, pretty much guarantees you to be
arrested probably in 99% of countries.

SioL- Hide quoted text -

- Show quoted text -

We have a licence for a particular frquency in range specified. No
chance of geting arrested we are doing it all by legal means. Thanks
to people all for the answers. Looking for right solution. thanks
 
J

Jan Panteltje

Jan 1, 1970
0
If he meant 18mhz bandwidth -- there is nothing out there except wifi off
the shelf for that bandwidth -- and you wont be running that at 130mhz !!


Well it is not that hard, TV at 67MHz with 6 MHz bandwidth is normal.
I have build some small VHF TV modulators in the old analog days, to
display output of stuff on the screen around ch4.
The problem is limiting the bandwidth....

I've got some 900mhz gear that will do 24khz bandwidth and thats clunky
enough !! You can get amateur television hardware that will do 6mhz bandwith
on a 1.2ghz carrier pertty easily, but then you are stuck with some pretty
intense work to modulate and demodulate the data at that rate -- whip out
your DSPs, boys !!

The other problem he has is line of sight.
At 130MHz the TV broadcast transmitter is on a > 100 meter high tower, and
radiating many kW, and 100km is at the edge of range really...
Analog TV is good old AM, and FM carrier for the sound here.

Bit egoistic approach to grab 18MHz just for your personal Ethernet and
pollute the whole area with it.

The correct approach for that distance, if wireless, is to hire an up/downlink
from a statellite provider, that comes actually cheap.
Maybe there is no satellite service like that where the OP is.
 
J

Jan Panteltje

Jan 1, 1970
0
look at a product called the TNC-X -- 1200 baud packet modem -- with
appropriate software on your PC to act as a gateway, you can do TCP/IP over
packet.... the interface to the radio is audio, so just about any voice
radio will work with an appropriate cable to hook up the earphone,
microphone, and transmit switch.

Ah, I have 1200Bd packet over 27MHz, do you have any idea how long a 1 MB download
takes?
LOL
 
Bit egoistic approach to grab 18MHz just for your personal Ethernet and
pollute the whole area with it.

I think the OP meant a freq range of 130MHz-180MHz (left out the '0')

Covers TV broadcast and stolen vehicle trackers worldwide. Should get
the cops on his ass real quick.
 
E

Eeyore

Jan 1, 1970
0
ok said:
We have a licence for a particular frquency in range specified. No
chance of geting arrested we are doing it all by legal means. Thanks
to people all for the answers. Looking for right solution. thanks

Why didn't you say you were in Oman ?

Your problem will be that all existing solutions will be based around other frequency bands.
I can't imagine it being that easy.

Graham
 
J

John Barrett

Jan 1, 1970
0
Jan Panteltje said:
Well it is not that hard, TV at 67MHz with 6 MHz bandwidth is normal.
I have build some small VHF TV modulators in the old analog days, to
display output of stuff on the screen around ch4.
The problem is limiting the bandwidth....



The other problem he has is line of sight.
At 130MHz the TV broadcast transmitter is on a > 100 meter high tower, and
radiating many kW, and 100km is at the edge of range really...
Analog TV is good old AM, and FM carrier for the sound here.

Bit egoistic approach to grab 18MHz just for your personal Ethernet and
pollute the whole area with it.

The correct approach for that distance, if wireless, is to hire an
up/downlink
from a statellite provider, that comes actually cheap.
Maybe there is no satellite service like that where the OP is.

I was being facetious -- the best solution for high data rates at that
distance is wifi over parabolics -- though he will problably need 50ft high
towers or better to pull it off -- and they aint cheap !!

a slow speed (1200 baud) it can be done easily at 144mhz with off the shelf
hardware and a ham radio license (non-commecial only)
 
J

John Barrett

Jan 1, 1970
0
Jan Panteltje said:
Ah, I have 1200Bd packet over 27MHz, do you have any idea how long a 1 MB
download
takes?
LOL

I know exactly how long it takes :)
 
J

John Barrett

Jan 1, 1970
0
ok said:
We have a licence for a particular frquency in range specified. No
chance of geting arrested we are doing it all by legal means. Thanks
to people all for the answers. Looking for right solution. thanks

can you confirm the frequency range and desired data rate ?? would help with
specifing a solution :)
 
R

Rene Tschaggelar

Jan 1, 1970
0
John said:
If he meant 18mhz bandwidth -- there is nothing out there except wifi off
the shelf for that bandwidth -- and you wont be running that at 130mhz !!

I've got some 900mhz gear that will do 24khz bandwidth and thats clunky
enough !! You can get amateur television hardware that will do 6mhz bandwith
on a 1.2ghz carrier pertty easily, but then you are stuck with some pretty
intense work to modulate and demodulate the data at that rate -- whip out
your DSPs, boys !!

18 MHz @130 MHz bandwidth is easily done with spread
spectrum. Lowers detectability and interference.

Rene
 
O

ok

Jan 1, 1970
0
18 MHz @130 MHz bandwidth is easily done with spread
spectrum. Lowers detectability and interference.

Rene
--
Ing.Buero R.Tschaggelar -http://www.ibrtses.com
& commercial newsgroups -http://www.talkto.net- Hide quoted text -

- Show quoted text -

range is 130MHz to 180MHz ...sorry for the stupid typo mistake
 
J

James T. White

Jan 1, 1970
0
Hi

I would like some help for creating wireless ethernet network using
VHF radio with frequency range of 130MHz-18MHz. The distance supported
shall be upto 100km LOS. Kindly advise on industry products available
for such option.

Regards

Khan

Another homework problem?
 
H

Homer J Simpson

Jan 1, 1970
0
I would like some help for creating wireless ethernet network using
VHF radio with frequency range of 130MHz-18MHz. The distance supported
shall be upto 100km LOS. Kindly advise on industry products available
for such option.

http://www.lpbinc.com/indexNET.htm would have the power.

Frequencies will be a tad lower.


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J

Jan Panteltje

Jan 1, 1970
0
Ah, I have 1200Bd packet over 27MHz, do you have any idea how long a 1 MB

I know exactly how long it takes :)

Sometimes it did not finish at all.... :)

It is not simply 1200 bits / second, but the packets are send as a frame,
sync pattern first, CRC is added, then the transmitter waits for a reply
(ack or reject if received CRC was wrong, because of for example interference),
and then and only then (if the band is free from other transmitters, some wait
time the transmitter listens) the next packet is send again.
Hours.
 
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