Airborne Wireless Network

[♠SARKID♠]

Okay, I pose this question in an attempt to determine feasibility.  We have a program in the brainstorming stage right now, but I'm not going to go into it.  Its too fresh of an idea and frankly, too lengthy of a concept to post about yet.  I will say that one of the things we've been looking at is using an air to ground wireless router inside of a Highbird to provide a network between remote command posts.  Does anyone know of a system that uses a standard, wireless network like you would have in you're home to do this?  The only systems I can find use aircraft > satellite > ground.  But what we want is direct aircraft > ground.  I know its legal because I've also found wireless network systems for use inside of commercial sized aircraft; networks that use the standard 2.4(?)ghz wireless network signal.

[BigMojo]

I like the idea, but I'm not sure about the feasibility of "off the shelf" systems. The longest "ranging" system I know of is this: http://www.radiolabs.com/products/wireless/networking/long-range-mobile-wifi-kit.php

At that, I think the range is a little over a mile or 3, and I'm not sure that's within the range you are looking for.

[floridacyclist]

Check with Joe Tomasone. I won't post his email publically, but you can get it off E-services or searching the net; I know he's active on the Yahoo Cap_communications board which I can't access from work. He used to install high-powered wireless routers so might have some technical answers.

[Eclipse]

Remember, anything you play with in the plane has to be approved for the airframe >and< CAP.

I had a CC a few years ago who was working this route and he got spanked pretty hard for testing
radio equipment in the airplane with out either of the above.

[c172drv]

I'd been thinking about this type of project too.  My neighbor is putting up WiMax in our area.  From speaking to him it sounds like it would be feasible.  The trick would be to put up WiMax hotspots at our repeater sites and install terminals on the aircraft.  The neat trick would be to make the aircraft capable of repeating transmissions as well to extend the reach.  It would allow for highspeed access and the ability to extend our own dedicated network across most of the area to give them access to the outside world.


John Jester

[Eclipse]

It'd be easier, quicker and tons cheaper just to get FCC waivers on using broadband cards in the aircraft.

The infrastructure you're talking about is useless unless the disaster is where the antennas are.

That's why SDIS, with all its pimples and limitations is still a viable idea.

[Larry Mangum]

CAP and the Air Force are experimenting with a project titled "Cursor-On-Target" in which a broadband card is used to send tasking, positional information and photos directly to the aircraft. The Air Force went to the FCC/FAA and requested a waiver to use the cards in the aircraft and were turned down.

[floridacyclist]

There have been rumors of using airborne wifi to relay photos and reports from RECON teams to the customer....aircraft would orbit the team while someone on the team connects and uploads their prepared zipfile or folder of reports and photos. Once that was done, the aircraft would fly back to base and either land or repeat the process in reverse. I have no idea if that was ever used in any sort of mission, practice or otherwise, but it sure sounded neat.

CAP and the Air Force are experimenting with a project titled "Cursor-On-Target" in which a broadband card is used to send tasking, positional information and photos directly to the aircraft. The Air Force went to the FCC/FAA and requested a waiver to use the cards in the aircraft and were turned down.

Regardless of what you call it, it is still a cellphone (it even has  phone number and is counted as a line by Sprint) and those are still alleged to be capable of causing problems to a cellular network from a high enough altitude. If you need internet access while operational (and not orbiting a GT or mission base), you have a much better chance with SDIS or at least the internet portion of it.

[Larry Mangum]

Currently what they do for "Cursor-On-Target" is that they land at a nearby airport and then transmit the data back to the customer.  If SDIS service was reliable then this probably would not be necessary. Unfortunately here in Washington we are lucky if we can connect to the satellite 10 to 15 minutes every hour until globalstar upgrades their constellation and or replace the failed satellites.

[Eclipse]

Currently what they do for "Cursor-On-Target" is that they land at a nearby airport and then transmit the data back to the customer.  If SDIS service was reliable then this probably would not be necessary. Unfortunately here in Washington we are lucky if we can connect to the satellite 10 to 15 minutes every hour until globalstar upgrades their constellation and or replace the failed satellites.

That's really the best way to go.  SDIS is fine for making sure you're taking a pic of the right target, etc., but its slow and as indicated unreliable at best.  Not to mention that in real-world disaster areas with lots of agencies, the birds are saturated.

How often do you really need near-time photos (as nice as they would be)?

Generally a small delay while you get on the ground is not an issue.

[Matt]

The infrastructure you're talking about is useless unless the disaster is where the antennas are.

That infrastructure would be what we would be recreating with a series of antennas, satellites (and, of course, levers and pulleys).

[♠SARKID♠]

The infrastructure you're talking about is useless unless the disaster is where the antennas are.

That infrastructure would be what we would be recreating with a series of antennas, satellites (and, of course, levers and pulleys).

Yup yup.  For everyones information, the idea me and Matt are working on involves bringing in our own antennas/equipment to work completely isolated of the destroyed infrastructure.

[CadetProgramGuy]

Somthing that IAWG looked at but was not feasable was to use the laptop in the Aircraft and orbit over Rest Areas to access teh WiFi there.  Our problem was range of the signal I believe.

[♠SARKID♠]

Thats something we've looked at.  The things is, some ground systems are available for use on some wattages in whole-numbers, so you're looking at a pretty respectable signal.  Combine that with being airborne and its gold.

[♠SARKID♠]

As per floridacyclist's recommendation, I contacted Joe Tomasone on the matter and received this reply.

Cadet Turkal,

    I read the thread on captalk but as I am not a member there and don't have time to sign up today to answer there, so I will answer you here.  You may republish there if you like.

As it happens, I was involved in a test using GA aircraft to access high-powered (200mw) WiFi access points on the ground.  We tried a variety of antennas in the aircraft ranging from inverted omnidirectional vertical antennas with 9dbi gain to a "hockey puck" with a 180 degree over-the-top radiation pattern and 2-3dbi gain if I recall correctly.  The WiFi units on the ground had 9dbi omnidirectional antennas as well and were communicating between themselves.  The aircraft orbited at 1000' while we took RSSI measurements on the ground and in the air. 

The results, as we somewhat expected, were less than stellar.  A typical laptop wifi access card (50mw) usually gets a range of 100' or so in an average building when accessing a WiFi access point running 100mw into a unity gain antenna.   We knew that we were still going to stretch things with 200mw and 9dbi of gain (which, incidentally, is outside FCC regulations for Part 15 devices) on each end,  and we were right.  We were able to connect, but only for short periods of time, and usually only within a very short distance from the access point in question.  Further, we had to continually bank the aircraft in a manner unrealistic for a Highbird flight so that the omnidirectional antenna in the aircraft faced the ground.  As you may be aware, the radiation pattern above and below a vertical antenna is significantly less than off the sides.  This made the banking a necessity. The "hockey puck" failed to connect at all.   The radiation pattern, while directing more energy towards the ground, had such a wide beamwidth that the gain was insufficient to permit connection.

Ideally, if you wanted to try this, you'd want an antenna that had an expanding conical pattern from the top of the antenna.   The problem is, the commercial application for such an antenna is nil; so I don't think you'd have much luck finding one.   At that, you'd still need to run more power on each end than most commercial equipment provides - the highest I've seen that is readily available at a normal commercial price
is 100mw.

I would have to conclude that WiFi is not a viable technology for what you propose.  I also saw a reference to WiMax, but to my knowledge the mobile WiMax standard has not yet been ratified (I may be wrong, it would be a good idea to check, but I was hearing 2009 on that).  The current point-to-point WiMax would not work at all for a Highbird application.  When products conforming to the WiMax Mobile standard become available, it might be worth testing as WiMax has a much greater range than WiFi.

Alternatively, you might look towards using high-gain antennas to link the command posts depending on how far apart they are.  For reference, with the same 200mw units on 802.11a, we were able to connect at distances of 4-5 miles at 20' HAAT on hurry-up poles using 26dbi parabolic gain antennas.  You should be able to roughly equal this distance with 100mw on 802.11b/g given the same height.  Of course, we were losing a lot of signal since at that height we were still in the Fresnel zone, so if you had a higher building, you might have more success.  WiFi generally likes clean line-of-sight paths; and when you have sufficient height, you can go quite a distance.  We did a successful link in a National Park from a mountaintop repeater site to a road on the side of another mountain - roughly 2500' HAAT on both sides.  The distance?  20 miles.   

Yourself and any other members of the captalk group are free to contact me with questions; my email is {{{contact me for email}}}.


Regards,

--

1st Lt. Joe Tomasone, CAP
Communications Officer
Group 3, Florida Wing, Civil Air Patrol

*Formatting edits mine*

All in all I think we'll have to scrub our airborne plan.

[Matt]

Bummer, guess we just have to use the high gain parabolic dishes...  limited to I guess... 20.1 miles... bummer.

[ammotrucker]

My Group has talk with most all of the major broadband carriers and they has stated that most of the broadband while using a tower would lock you out of the system if you hit more then 10 towers at any one time.  This is an easy fix which most of the carriers would do only because of the importants of the field that we are assoicated with.

But they would require the aircraft to be below 1000' AGL. 

The general concensus is still that the FAA/FCC will not allow this as to the possible interferance with onboard equipment. 

So that said why not use broadband and do slow touch and go or land and taxi back to transmit then retake off.

Just a thought.  We are modifing our SDIS to this format as GlobalStar is useless in S Florida

[MikeD]

Ohh Ohh, something on CapTalk I know about.....

I've been involved in some work NASA does with airborne networks.  I also know of some work where a couple of guys at AFFTC modified a WiFi router to operate on "standard" L-Band telemetry gear since the range people do not like spread spectrum, for reasons I don't understand. 

We flew a prototype system on a GA-type airplane where we had a link range over 100 miles, the aircraft was using a "standard" telemetry transmitter and antenna, for bidirectional ethernet/internet.  Granted we had our nice range aimable dish on the ground.   

Can someone please PM me with Joe Tomasone's email address, and the email for the point of contact for the Cursor on Target project?  I worked with CoT some at an old job.

Thanks,
Mike

[♠SARKID♠]

So that said why not use broadband and do slow touch and go or land and taxi back to transmit then retake off.

Because thats not what we want it for.  The system was meant to be a connection between command posts via an aircraft, not a connection from aircraft to command post.  It was basically supposed to be an airborne WiFi repeater.  Having the plane land would completely defeat the purpose.

We'll find an alternate way, I'm sure of it.  Matt is looking at the directional/dish antennas, I've been tinkering with a balloon idea.  Either way, we'll make it work (if we get the money  )

MikeD - PM sent

[floridacyclist]

OK, so now that we've established the objective (remember, always let your objective drive your thinking, not the methods) we have a better idea of what you're trying to do. How far apart are the two command posts? This could be as simple as a plastic box with two parabolic or yagi antennas, one pointing at each command post and a stock Linksys router all mounted on top of a TV antenna tower. Given your objective of linking two relatively fixed points, this makes more sense than putting up a high-bird and burning a lot of fuel and time, plus losing connectivity at every shift change.

You might also look at multiple ways to access the internet and use some sort of internet linking with telephone backup. Have you looked at 900Mhz spread-spectrum serial radios? I understand those have a lot more range, but I'm not sure how much bandwidth they can pass.

Check with some of the folks at www.part-15.org or www.part15.us. I don't believe they are connected to the old www.part15.org folks who re-wired New Orleans wirelessly in the first few weeks after Katrina, but they seem to be into this kind of thing. I know in Mississippi we had a bunch of guys in there from part15 shooting wireless from water tower to water tower and then distributing it around town; it seemed wierd driving around an area of such total devastation yet having high-speed wireless on my laptop LOL

If these guys can bounce relay-to-relay to help bring a whole town back into the 20th century, they should have a pretty good clue as to what you're up to. Lt Tomasone would be a good resource as well if he has time with his new baby.