Hello all, I was wondering if there was any way to get an internet connection over the xbee network. I hear that the new xbee pros have a range of up to 15 miles. Since I am not interested in paying for an EVDO plan, I was wondering, regardless of data rates, if it was possible to have a large antenna unit at my house, where I can transmit a connection to my computer. Any suggestions or comments would be greatly appreciated.
Also I would like to add that I would be using an arduino ethernet shield, an xbee radio and arduino for the home "base station", just to say that this is actually relevant to the arduino forums.
The max data transfer rate of the x-bee is 9.6 kbps.... which would be incredably sloooow, even if it is possible.
No it's not, default out of the box is 9600, max is 250000 (250kbps) although your chances for lost bits over max range goes up a lot with speed.
See the table on the bottom of page 7:
I stand corrected. I was looking at the specs off sparkfun.
I guess the real question is... is it doable? Over say, a range of around 5 miles? I guess 15 miles would require a giant antenna, and the only reason that I want this is because my school doesn't provide us with internet, and it's about five miles away. The specs on the sheet that mdowning provided said that xbee-pro had a range of one mile, but i've heard up to 15... what's that discrepancy all about?
I looked at Digi's website, and they supposedly have an "XTend" RF Module that can go as far as 40 miles with a high-gain antenna LOS. Considering that I just want a usb dongle-thingy when I'm at school (lugging around a high-gain antenna at school would look just a little conspicuous) and have a high-gain antenna at my house, would that work out okay?
I think the problem with that scenario is that you could recieve the signal, but wouldn't be able to tansmit back to your base station.... Therefore it would not work. Not to mention when you add cement block walls that most schools are made of, your range greatly decreases.
hmmm.... so i guess i should stick with xbee? or is it your point that xbee is only one-way... i had the understanding that it was two-way.
what he means is that without another good antenna on your end, your xbee could receive messages from the other, but it wouldnt have enough power to transmit back to the base.
the problem with that scenario is that you could recieve the signal, but wouldn't be able to tansmit back to your base station
Sorry, but this is wrong. All other things being equal (and they're usually close), an antenna can "hear" just as well as it can "talk" (it's reciprocal).
There may be factors, e.g. disproportionate transmitter power vs. receiver sensitivity, but those are typically reasonably well balanced.
Now, if you start mixing Xbee and Xtend, I'm not sure how/if that will work.
You can increase gain on both ends. On your base station, use a yagi or some other directional gain antenna (assuming your area of operation is within the radiation pattern). On the mobile, use a higher gain omnidirectional whip. It won't be as good as a yagi, but better than a standard quarter or half wave, and way better than a chip or PCB trace antenna.
You will still have a (hard) requirement for a direct line of site that's clear to RF. Buildings, trees, etc. can and will reduce your effective range.
Well I guess I have the distance factor settled, what I need to know now is if it is even possible to stream an internet connection over xbee, and if so, how I'd get started doing that (i.e., should I use the tx/rx that comes directly from the internet, or if it is necessary for the arduino to receive the ethernet and relay/convert it and send to the arduino's serial interface.