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802.11 for Vehicles?
mantid asks: "I am about to do a long trip (1 year) in a VW Vanagon, and would like to set up wireless net access from within the vehicle. What is the most effective system for hassle-free, permanent, long-term installation? Note, this is not just for wardriving, many truckstops, netcafes, and coffee shops are now offering legit net access. I just don't want to have to bring laptop inside to do it. Please suggest tried and true antenna types as well as tips/concerns/issues."
(This is a little off topic, but hopefully not too far.)
I've used FlyingJ hotspots on the road, and you don't really need a special antenna -- in general, the reception is fine from inside the car with a normal pcmcia wifi card.
The parking lots are pretty big, and there are places where the reception isn't great, but it's usually pretty easy to drive to another part of the lot to improve your signal. I worked under the theory that the networks were designed to provide the best signals to the truckers, so I tended to park closer to the truck section.
Most of the problems I had seemed to be caused by mistakes on the FlyingJ side of things. I think they had a fairly bloody roll out. In order to user their system, you have to create an account and login.
You do that by pulling up a browser, and letting it detect the proxy server settings automatically. If you haven't logged in, the proxy server redirects you to a page where you can submit your cc or login if you already have an account.
I found that at a lot of locations, things weren't working. My computer couldn't find the proxy server, or whatever. At a couple of locations the system was just open -- there was no login, and it worked fine.
In general, though, it's pretty cool. The FlyingJ's were spaced out so that I could check my email and surf the web a couple of times a day. It's not expensive, and when it works, it works pretty well. I could use ssh and vnc to pull up my home desktop, and it was useable.
I bought the cheapest accounts, 15 minutes at a time. That turned out to be a good plan, mostly because some truck stops didn't have working networks.
It's tempting to look at your route and tell yourself, "I'll be able to hit these two other truck stops in the next 24 hours -- so I'll save money and buy a 24 hour account." The problem is that sometimes the next truck stop didn't work when I got there. It would have sucked to have paid more, expecting to be able to use a wireless net that was down.
I took two road trips, one maybe 8 months ago, and another about 6 months ago, and the FlyingJ system was substantially more reliable the second time around. So I'd expect them to have something reasonably solid now, But I wouldn't pay for a long term account until I *knew* it was solid.
You might consider using wifinder.com or wi-fihotspotlist.com to find out where your next hotspot will be. Just make sure to copy down several locations for possible next destinations -- you'd hate to get to your next spot and discover it missing and have no way to access the internet to find a hotpsot.
Two wrongs don't make a right, but three lefts do.
The best way to get 802.11b/g coverage from your vehicle is to use a real external antenna. This leaves you with two options - buy something that's magnetic mount (easily available on the Net) or punch a hole in the roof and put a real antenna and mount in.
For my 2.4 solution, I installed an "NMO" antenna mount on the roof of my Expedition (drilling holes doesn't bother me - there's a total of 15 antennas mounted on the roof using NMO mounts, each of which requires a 3/4"-diameter hole).
First, find you an 802.11 card with an external antenna connector. The Orinoco 802.11b-only Gold works very nicely. Buy a pigtail to convert from the little push-on connector on the edge of the card (MCX?) to something more standard, like an N.
Next, buy the appropriate mount and antenna. The mount coax will be somewhat inflexible and will have a solid center conductor, so you'll need to be careful not to crush/damage it.
Maxrad mounts
And an antenna:
Maxrad antennas
I use the BMAXC24503 model. The 5db gain is nicer, but longer.
Drill a hole in the roof, install the mount, run the coax down through one of the pillars, connect to your pigtail, and connect to the card. You'll be amazed at the difference over your internal "antenna" (more like a dummy load.)
Installing antennas (drilling holes in the roof) is not for the faint of heart. Check with your local 2-way radio installers, and they might be able to put the antenna in for you for not too much money.
First, the connector on the Lucent/Avaya/Orinoco/Proxim equipment is known as "MC" or MC-Card". Cisco and others use MMCX, which is just a hair bigger and slightly differently shaped. IIRC, the Senao card uses MMCX, and you should consider it for your trip because it has higher output power and better receive sensitivity than any of the others.
:)
Second, yeah the card's integrated antenna is crap. Anything external that's even close to the right band will do better. I disagree that external mounting is a big deal. For stumbling, an omnidirectional antenna is good because you just mount it and leave it. But for using hotspots at truck stops and such, you can manually position a higher gain antenna for best signal. The directionality will help a lot if you're at the edge of the parking lot, or if you decide to surf from the Flying J while parked at the TravelAmerica. Obviously, it's easier to aim an antenna if it's inside the vehicle with you. This also helps minimize losses from long antenna cables. I'm not worried about metallic window tint on your Vanagon interfering with the signal.
For antenna designs, the cylindrical waveguide cantenna can't be beat for simplicity, but it's never wise to point weird-looking tubes out the window of a vehicle, moving or otherwise. (Print out a copy of this Ask Slashdot posting, or something else to indicate that you're nonmalicious in the event that you get questioned.) I can't emphasize this enough, our society is pretty paranoid already, but the police are trained to recognize potential threats, and a scruffy dude pointing a metal tube at things is pretty high on the grab-your-gun index.
Trevor Marshall's Bi-Quad antenna design is absurdly compact, reasonably directional, and very easy to build. Marty's instructions clarify a lot of the things Trevor didn't show in detail. If you have an old double-wide jewel case around, you can build the little biquad into it for a totally nonthreatening appearance.
As for extended roadtrip suggestions: Consider a battery isolator and dual-battery setup, if it's within your budget. I was in the market for such a unit recently, and Hellroaring seems to have the best-designed product with a ton of helpful app notes and install guides.
If most of your portable gear runs from AA's like mine does, you might be pleased to know that many of the recent NiMh chargers run from a wall-wart, instead of building the entire power supply into the charger unit. Presumably, this makes the UL listing process easier by moving the mains supply out of the unit, to a transformer that can be separately listed and doesn't need to be re-qualified each time the charger gets revised. It benefits you, because the wall-wart steps down to 12 volts and the charger takes it from there. Ergo, it's dirt simple to make a car cord for such a charger, and it's more efficient than running through an inverter.
While on the subject of vehicle DC wiring, check out the Powerpole connector. It's become the standard in the amateur radio community for 12 volt supplies, because lighter sockets suck. Powerpoles are genderless, polarized, and very reliable if crimped correctly in the first place. Crimp+solder is even better.
If you're the paranoid/prepared type, ghost your laptop's basic setup onto a spare drive and keep it (wrapped in antistatic foam) elsewhere in the vehicle. You don't want to be stuck 1800 miles from home with a crashed drive in one hand, freshly reinstalled laptop in the other, trying to figure out how to download the drivers for your wireless card when said card is your only means of internet access.
Good luck, have fun, drive safe, and post some pictures from your trip!