2010-05-16

High powered WIFI and some notes on data access

Thought I would post a couple pictures of our high-powered WIFI setup (already posted on our facebook page), although we haven't yet used it, aside from testing, it looks like it will be a great option where open wireless access points are accessible.

The setup we went with was a Ubiquity Bullet2HP, with an 8.5db gain omni antenna. We purchased our setup via Data Alliance, who we found excellent to deal with. Total cost, including the homemade power adapter, was around $140. And that includes a $12 120VAC power adapter that I will likely never use again (now that I have my 12VDC power setup). I think this is a much more attractive and powerful solution than the pre-built kits you can buy, and quite a bit cheaper too.



The Bullet2HP has an output power of 1watt, so 10x the transmit power of the 100mw adapter in your laptop. When I first connected everything, my laptop could see 3-5 access points. The bullet, in the same location, was able to see 42! Of course this all depends on having access to publicly-accessible open access points, or begging for the passwords for WEP/WPA protected networks.

Power for this device is over unused wires in a normal CAT5 cable. This makes wiring the device a cinch - just a single cable goes to the Bullet2HP, and the other end terminates at a POE (Power Over Ethernet) injector which has 1-port for the bullet, 1-port for the local LAN/computer, and some sort of power connection. I purchased a 120VAC POE adapter for testing, but built a homemade 12VDC unit.

Here's my 12VDC POE injector:


Basically it's really simple, given two RJ-45 jacks, you wire pins 1-1, 2-2, 3-3, and 6-6. Then on JUST the POE side (you do not want to wire power to the LAN/computer side) you wire power to both pins 4 and 5, and ground to pins 7 and 8. The bullet will take anything between 11-24VDC, so no need for any special power regulation at all - just wire it through a fuse to the boat's onboard DC system! I built my own using a  wiring jack from Fry's, but you can also buy prewired units if you are more comfortable with that. If you wire this wrong there's a good chance of destroying either the Bullet, your computer, or both! Obviously any such project is at your own risk!

Here's the assembly as it currently stands, wired through a 750ma fuse to a regular cigarette lighter. Long term I plan to hardwire this into an unused switch in the DC panel, once I have the antenna+bullet permanently mounted out on the rail, but for now it's handy to have it portable as I finish testing.


As far as mounting goes, I came across a great idea courtesy of someone on one of the sailing forums. Apparently, the Bullet2HP will just fit inside of 1+1/2" thin-walled PVC. I'll drill a hole through the bottom end-cap and caulk in the CAT5 cable, and assemble a completely water-tight tube for the whole thing, bolting it outside with a couple of U bolts.

Of course WIFI has it's limits - if no open/available access point is within range, then it's useless. We don't plan on this being our only data connection. I plan on having redundancy as far as that goes. Current plan is some combination of the following:


  • Ubiquity Bullet2HP WIFI as outlined here.
  • Internet cafes/shore WIFI where we find them. Chris has an awesome ASUS netbook with an 8-hour battery life. It's really small, so easy to take to shore.
  • Verizon now offers a contract-free data-only cell plan. Thinking about picking up one of the USB modems and using this when we are US coastal waters. It's pay-as-you need it, and not overly expensive. And you can pay by the week, or by the month, and otherwise it costs nothing not to use it.
  • In Mexico, there's a cheap data-only cell plan from Telcel, using USB modems - known as Banda Ancha. A large number of cruisers use this method, which works well anywhere cell service is available in Mexico. As we get into the further reaches of the Sea of Cortez we will likely be out of range of this.
  • Inmarsat has announced a new satellite telephone which should hit the streets this summer for $500-600. With it's built-in GPS and messaging, this provides a viable position-tracking mechanism, which is not only worldwide (unlike SPOT), but gives phone, two-way messaging, and data access as well.
And I'm not committing to all of the above - these are just the available and most-sense options right now. SSB/Pactor is probably out of scope for now due to hardware costs, plus I don't have time to get my amateur radio license (oh why did I let my previous one expire in 2000? SIGH!).

Are we so addicted to data that we need all this? Actually, anyone that knows me (and has laughed at our ancient Nokia cellphones), knows that although I'm a geek, we lead a somewhat Luddite and simple life in many ways. For us, we want to be able to provide reliable positions reports via yotreps, and we need decent e-mail access for Jacob to finish school. Beyond that, we do want to keep in touch with our family and friends, all of who are very important to us. Plus, the ability to upload to this blog with stories and pictures of our adventures falls in here too. And then finally, and I apologize for the "inside reference", but I know that Sai won't sleep unless he knows that I am somehow accessible regardless of where I am.

1 comment:

  1. Data only in the future though ;)

    Will data services be available on IsatPhone Pro?

    A circuit-switched data service at 2.4kbps is expected to be available on IsatPhone Pro by Q1 2011. Users will be able to upgrade their firmware on the handset to use this.

    ReplyDelete

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