wireless network high distance

[javadamirpoor]

hi forum.
i want to create networking between two remote computer .distance is 18 miles.
what is name of devoice that do it.access point or power or nano station??
plz help me:-(

 

[horace1]

how often do you need to communicate and how much data.
e.g. if not often and a small amout of data you could use an modem and send an SMS text message or use TCP/IP to send TCP or UDP packets (you may have problems with firewalls, NAT boxes and dynamic IP addresses though)

 

[bluehole]

If you need a high volume data transfer between these 2 stations regularly You can use a Wireless point to point arrangement.
D-Link has some equipment for this purpose.

Else if you have low volume data and you are going to use it sparingly then horace1 is right.

 

[javadamirpoor]

i work in security system field.i want to transfer image of closed camera tv (cctv).i want to create wireless network between a dvr and remote computer.distance is 18 miles.i dont accesse to telephon line or adsl modem

 

[BradtheRad]

Might use a direct radio link.

Or use an amateur-use satellite as relay repeater?

Or if you have line of sight then perhaps a microwave link?

 

[betwixt]

Having some experience of this I would suggest using analog video if you have a direct signal path, use a microwave link. Take care to comply with transmission regulations in your country. A microwave link with a modest size (50cm) dish at each end and a few mW of RF should work very well and you may be able to use a domestic satellite box as the receiver. They are inexpensive and designed specifically for picking up TV signals.

Brian.

 

[saif haider]

well we r connecting a computer with switch at remote distance exceeding the 18 miles in my organisation. we just simply used a protocol connverter that converts the ethernet into E1 and then we use wireless transmitter of e1. At receiving same transmitter system also act as receiver of E1 and then same protocol converter converts e1 to ethernet. Then assigning the IP address of that remote switch we interface the computer with that switch.

 

[javadamirpoor]

Might use a direct radio link.

Or use an amateur-use satellite as relay repeater?

Or if you have line of sight then perhaps a microwave link?

please descript more about amateur use satellite or recommend a reference.tank you

---------- Post added at 11:36 ---------- Previous post was at 11:31 ----------

well we r connecting a computer with switch at remote distance exceeding the 18 miles in my organisation. we just simply used a protocol connverter that converts the ethernet into E1 and then we use wireless transmitter of e1. At receiving same transmitter system also act as receiver of E1 and then same protocol converter converts e1 to ethernet. Then assigning the IP address of that remote switch we interface the computer with that switch.

i think speed of e1 is low for image transfering or video signals.is not it?

 

[saif haider]

definitely not 2MB/sec of transmission is enough for image and video signal transfer. The e1 will work for wireless transmission of any format.

 

[betwixt]

I think the amateur satellite is a bad idea. Bandwidth is tailored for voice so the data rate would be at most 2Kb/s which is to low, the signal is relatively weak and most importantly, they are not geo-stationary so you would need an antenna tracking system at both ends. You also need a license to use them and it would almost certainly prohibit commercial use.

Brian.

 

[BradtheRad]

I think the amateur satellite is a bad idea. Bandwidth is tailored for voice so the data rate would be at most 2Kb/s which is to low...

Yes, bad idea. I only mentioned it because I believe I saw an article years ago telling how hams were able to transmit pictures to each other via satellite link. (Maybe video too).

The speed was slow because they were using radio equipment normally used for voice.

I thought there might have been increase in technology and band allocation over the years.

 

[betwixt]

The pictures are sent using a system called SSTV which typically takes 15 seconds per frame, far too slow for surveilence work.
Yes, technology has advanced but sadly the band allocations are reducing as commercial pressure persuades the authorities to give them up in exchange for cash.

Brian.

 

[BradtheRad]

Just because my high school geometry teacher would approve...

Line of sight communication will require that either transmitter or receiver be 214 feet above ground.

This is calculated mathematically by the formula for a right triangle:

4000 miles earth radius ^ 2
+
18 mile separation ^ 2
=
(4000 + tower height in miles) ^ 2

Solving for tower height yields .0405 mile.

This is theoretical line of sight allowing for curvature of the earth only. No allowance for the slightest obstruction.

It would be optimal if both transmitter and receiver can be raised at least 200 feet above ground. Or to place one on a nearby hill, etc.

 

[andre_luis]

Some modern Routers accept SIMcard chips.
Maybe this could be an option.

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