WiFi to an airplane?

[ksherman]

I am in a program called CAP (Civil Air Patrol) which is an Air Force Auxilary program for teenagers age 12-21 and a senior program for people over 21. The focus of this program more recently (due to the Homeland Security du-wap) is Search and Rescue. National Command is pushing every squadron in the program to install systems in the Cessna (CAP owns the largest single-engine plane fleet, consisting mostly of Cessna 172's) that sends streaming live video to the ground. They are offersing us to buy systems that cost upwards of $20,000, which is way too high. So I have been trying to come up with a system using WiFi, for MUCH less (mabye arround $5,000 incl. 2 laptops). Basically, my idea is to setup a base station that has a 802.11g base station with an upgraded antenna (duh), and another hub (or repeater) with an upgraded antenna in the aircraft. using a PTZ (pan, tilt zoom) camera to take the live video either to the laptop in the plane (more likely) and then transmit the video signal via WiFi down to the base station on the ground. I am planning on using omni-directional antennas, but i am not sure which ones would best suit the circumstances (something that would require expiramentation, of course). Obviously, the hubs would have their output speeds reduced to about 1-5 Megabits to increase range, and probably be flashed with a bios that increses output power. I am just wondering if you guys have any input that my help me in my quest to setup this system. Also, The planes are flying in a serch grid pattern, and are therefore not just "passing through", but staying in a general area. Thanks in advance!


ksherman

 

[jonmullen]

cross posting is bad...no cookie for you.

 

[VirtualLarry]

You need to read Cringely's columns more often. He's been writing a series of articles on his experiments with doing just what you propose.

 

[gutharius]

Are you not concerned with violating someones privacy by flying over their house and taping their actions? This is really scary and another reason why the patriot act needs to be scrapped. But that is another topic...

 

[Hyperfocal]

Originally posted by: gutharius
Are you not concerned with violating someones privacy by flying over their house and taping their actions? This is really scary and another reason why the patriot act needs to be scrapped. But that is another topic...

The Civil Air Patrol does search and rescue.

Not everything the government does is black helicopters and constitutional violations.

 

[Genx87]

Originally posted by: gutharius
Are you not concerned with violating someones privacy by flying over their house and taping their actions? This is really scary and another reason why the patriot act needs to be scrapped. But that is another topic...

rotflmao!

Put the tin foil hat on now

 

[Torghn]

Originally posted by: Genx87

Originally posted by: gutharius
Are you not concerned with violating someones privacy by flying over their house and taping their actions? This is really scary and another reason why the patriot act needs to be scrapped. But that is another topic...

rotflmao!

Put the tin foil hat on now

I think he needs a foil body suite.

 

[spidey07]

I'm thinking you would have serious power problems in terms of reach. I'm not a radio expert though.

I'm sure there are comm systems that do exactly what you want but aren't relying on consumer gear.

 

[Torghn]

Originally posted by: spidey07
I'm thinking you would have serious power problems in terms of reach. I'm not a radio expert though.

I'm sure there are comm systems that do exactly what you want but aren't relying on consumer gear.

The Navy will use 802.11b to control Cruz missiles. I think they get about 100 miles out of it before they loose connection. This is far from consumer gear, they use a directional antenna that rotates to keep the signal locked.

 

[Boscoh]

You'll likely lose an 802.11g signal before you leave the airport's airspace. I wouldn't look there. You'll likely need a grade of equipment better than consumer-level. You'll probably end up needing some kind of high-gain directional antenna that you program to rotate in order to stay in contact with a base station on the ground. I think this is how all the news stations and police departments do their feed systems. Google for something like 'helicopter video feed'. There's good info out there on this, you just have to find it.

 

[Dowfen]

Search and rescue based on consumer gear is not sounding real solid to me. You might want to consider something more reliable.

I don't know all the laws, but as far as increasing the power on the standard units goes, since it is a government operation you might check into any FCC rules you might be breaking by using a higher output power.

Personally, I think $20,000 would be the place to start to really do the job right.

Eric

 

[cmetz]

ksherman, there's a reason why military/aerospace equipment is specially made and a whole lot more expensive than consumer stuff: it's a harder problem. For one thing, if you're in the air with an omni antenna, you will be interfering with the wireless network of a whole lot of people on the ground, which is both not likely to be FCC-legal and not being a good RF citizen. Under a true search and rescue emergency situation, that would be a small price to pay to save someone's life, but you're likely to do far more training missions than real ones and you should neither be breaking the law nor be harming people's networks for your training.

 

[ksherman]

on the contrary, I would not be interferring with other Networks. In order to increase range, I plan to turn the transmission speeds down un 5Mbps. This drastic scaling down of the data rate (from a 802.11g system) would allow the signal to hop and alternate between more frequencies in teh 2.4-2.5GHz range that the WiFi uses, thus making the impact on other networks nil. I do not plan to connect to other people home networks to get connections, just the base hub. It seems that several people think we plan to tap into others hubs, but that is not the point. The point is to transmit a video siganl to the ground, to one hub on the ground, not to go around a tap into others networks.

 

[cmetz]

ksherman, you will be transmitting on a range of frequencies in the 2.4GHz band and due to your altitude with an omni antenna that signal is going to spread in a very wide cone. Your signal, no matter how weak, will be noise to any other 2.4GHz device attempting to use the same range of frequencies, and thus will interfere with their operation. If you still don't understand, please ask someone familiar with RF.