Ok. Let's play with the numbers for 802.11g. A typical amplifierwill raise...
J
Jeff Liebermann
Well, I can see why you didn't get any answers.
1000ft is going to be a problem. All your robot has to do is go around a corner and you've lost the signal. Even if it could be made to work at 2.4Ghz, you're going to have link problems due to obstructions. The robot will probably need an omnidirectional antenna, but these have a fairly narrow vertical radiation angle. Can you insure that the antenna will remain vertical to within perhaps
+/-5 degrees of vertical? Most robots cannot. Also, your control point might need a dish or panel antenna that somewhat tracks the robot to withing about +/-15 degrees. Is this practical?
How about some clue as to your bandwidth requirements? Are you belching video in which case you need at least 150kbits/sec thruput? Is your control one way analog, in which case a model airplane radio control will be sufficient? If bi-directional, do you really need
802.11 performance, or will a 900MHz unit with perhaps 115Kbits/sec thruput be sufficient (especially if it penetrates obstructions better and has much longer range)? Basically, I need to know what you're sending, how much, how fast, and over what topography, to offer any useful suggestions.
Also, are there going to be other robots (i.e. Robot wars style competition) active at the same time that might use 2.4Ghz for either
802.11g or video? If so, you might need to deal with an interference problem.
W
William P.N. Smith
1000 feet with omnidirectional antennas on a moving platform is going to be pretty dicey. If it's all outdoors, always line of sight, and there's no significant interference it might work, but I wouldn't bet my paycheck on it.
I'd look for the highest power bridges I could find with diversity antennas, and maybe program in a "lost signal, back up a bit to re-aquire signal" routine. Disable encryption, etc...
You really want something in the VHF range for your data radios.
[Where are you located?]
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required
Report Content
You are reporting this content to the moderators. They will look at it
ASAP.