Long range 115200 bits/sec or faster wireless comm

Do you know any long range wireless communication gadget (radio modem etc.) that can be used for 115200 bits/sec continuous data transfer over 100 km ?
(Imagine you are on a boat/ship and you have a UAV. You want to fly your UAV to 100km away and you want continuous comm with the UAV. Because one end of the communication is an small airplane the smaller size and lighter weight for the gadget are peferred.)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Do you know any long range wireless communication gadget (radio modem etc.) that can be used for 115200 bits/sec continuous data transfer over 100 km ?
(Imagine you are on a boat/ship and you have a UAV. You want to fly your UAV to 100km away and you want continuous comm with the UAV. Because one end of the communication is an small airplane the smaller size and lighter weight for the gadget are peferred.)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
pretty basic really, the question you need to ask is the device going to be beyond the radio horizion. if so then it gets tricky
<Giatto Cardiacci> wrote in message
: Do you know any long range wireless communication gadget (radio modem etc.) : that can be used for 115200 bits/sec continuous data transfer over 100 km ? : : (Imagine you are on a boat/ship and you have a UAV. You want to fly your : UAV to 100km away and you want continuous comm with the UAV. Because one end : of the communication is an small airplane the smaller size and lighter : weight for the gadget are peferred.) : :
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<Giatto Cardiacci> wrote:

62 mile radius? Over 12 thousand square mile area? That's tricky, very tricky, 115kbs sort of fast, but maybe not unmanagably fast. What are weight requirements? What are budget constraints? Can you maintain "line of sight?" Can you prepare the site, i.e. lay down repeaters? Will you be near cellphone towers? What about satalite internet?
If you don't mind me asking, what for? It sounds like you have a very specific application in mind, and to be honest, I can't think of any really legitimate use. Sure, you may be able to do it, but I can't see any hobby use, and if it were a corporate or military project you wouldn't be asking so publically. Maybe I'm paranoid, but a remote control plane with a 62 mile range could be a poor man's cruise missile.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Unfortunatelly most of us are programmed by the mass media to think pesimisticly. Yes you may be right that a UAV with 100km range would be dangerous on wrong hands. But was thinking differently. Application I had in mind was monitoring the very large disaster areas. As we all learned that, unfortunate tsunami and recent earthquake can and did change the region's maps. Boats ships could not use their pre-disaster maine maps to navigate around islands. Human operated helicopters and airplanes are used for both for monitoring and for aid delivery. I think it may be possible to use long range UAVs in such humanitarian applications.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
As long as you can maintain an altitude that would suffice a somewhat line of sight from tx to rx, you should be ok. This means the farther you are, the higher you have to be...
(distance to horizon) = 3.53 x (square root of height in m)
The lower frequency you use, the better the propogation, but also the lower the data rate. This is only to a point though. You get minimum atmospheric attenuation between 80 and 100ghz, but then your definitly confied to line of sight.
The idea of sat comms is not a bad one, as long as you dont move out of the footprint of the sat signal. This can be seriously hampered by weather and other atmospherics however.
Why not program a certain bit of autonomy into it, then only use the link for very basic communication. Send your video analog instead of digital, and only use the link for basic data and course corrections/instructions etc.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<Giatto Cardiacci> wrote in message

etc.)
?
Try asking the people who flew a model plane over the Atlantic!.... They had telemetry on it of some sort.
http://www.modelaircraft.org/mag/1103/president.htm
http://tam.plannet21.com /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
SatCom! Just like the big boys do it!
<Giatto Cardiacci> wrote in message

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Giatto Cardiacci wrote:

If your budget is not so limited,or just to learn some more about what you are trying to do, go to http:\\ipmobilenetinc.com and then look into their VHF systems. They can't do your 115200, but you should see what all they can do with 19.2.
The biggest reason you can't get the speed out of the lower bands is that the FCC and other governing bodies will not let you use the bandwidth necessary.
To get any real speed out of a radio signal you have to move up into the microwave range and then use some very nasty tracking algorithms to keep your antennas aligned. In other words not happening.
IPMobileNET's diversity system is something you should look into implementing, since it allows them to run the radios at lower power and reception levels and to take advantage of signal bounce more effectively. That mostly helps inside large cityscapes.
For open ocean and at the distances you are referring to, you are probably going to have to drop back into the HF frequencies, or at least VHF, but at high wattages and some expensive antennas. I hope you have a large ship and UAV to work with.
The military uses satellites for its missile systems and or runs them antonymous.
You are asking for a lot out of an all digital system is what I'm trying to say.
I have to agree with the person who mentioned passing analog data instead of digital. Lower your baud rate and send smaller packets. Send your video back as an analog using a separate camera system from your vision system as it will give more detail than your vision cameras will anyway. Any other data I can think of you collecting will not take up any where near the packet space except the sonar data and only if you are trying to put together the composite picture on board the UAV itself. That could turn into a real processor hog and would be done better by ship board sonar mapping.
Just how much data are you trying to collect any way. Give us an idea and we could probably help you better. The company I work for built the Navy an ROV aircraft way back in the late 70's early 80's. I would like to see more about this idea. I think it could be useful if it hasn't already been done.
Eljin
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
<Giatto Cardiacci> wrote:
| Do you know any long range wireless communication gadget (radio modem etc.) | that can be used for 115200 bits/sec continuous data transfer over 100 km ?
Yes, radio modems do exist that can do 115 kbit/s. And radios do exist that can work across 60 miles, though that's generally more than line of sight unless you have a tall tower for an antenna, though if your plane has considerable altitude that'll help.
However, to get that sort of range, especially with it being that close to the maximum line of sight, you'll need either a reasonable amount of power, and/or good directional antennas. Both will be difficult to set up on a standard sized model plane.
Also, you'll either need some dedicated bandwidth, or a ham license. The former will be difficult for an individual to get. The latter is pretty easy to get, but it limits what you can do with the link.
You could use the 900, 2400 or 5800 mHz bands, which are available for use without a license, and cheap equipment exists that will give you much better than 115 kbit/s connections over that, but the power limits are so low that you won't even get a single mile of range without great effort.
Another option is a satellite link, which is what the TAM team did when they crossed the Atlantic -- though their plane was autonomous except for takeoff and landing, and I'm sure the data rate was MUCH less than 115 kbit/s. You could also use standard cell phones with data services if you're flying over areas with cell phone service. Might not work if your purpose really is emergency use, however -- emergencies tend to take out cell phone service.
| (Imagine you are on a boat/ship and you have a UAV. You want to fly | your UAV to 100km away and you want continuous comm with the | UAV. Because one end of the communication is an small airplane the | smaller size and lighter weight for the gadget are peferred.)
Lots of people have experimented with this sort of thing with various budgets and various degrees of success. Google will probably find you lots of stuff.
--
Doug McLaren, snipped-for-privacy@frenzy.com
"I believe we are on an irreversible trend toward more freedom and
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 15 Apr 2005 21:01:59 +1000, <Giatto Cardiacci> wrote:

You might want to have a look at this website detailing the engineering that went into the building and flying of a high altitude autonomous glider.
http://members.shaw.ca/sonde/index.htm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.