Community Forums

Jack Mayer · 01-29-2014, 10:15 AM

I had previously published a DIY Guide to building your own CPE (a wifi capture device). I took it down around a month ago because too many network novices were attempting to build it and getting themselves in trouble.

Since taking it down I have gotten a LOT of requests for it. So I have decided to allow access to it again. But let me be clear - I DO NOT support the building of these devices. It is far to difficult to debug from afar. So if you do not have confidence in your networking abilities consider very carefully before you tackle this project. On the other hand, the device and antenna can be had for well under $100 so you do not have much to lose if you are a hobbyist and want to play with this. Have fun - and do not call me if it does not work. If you have suggestions on the document I'd like to hear from you - I will update it over time.

Building You Own WiFi Capture Device.

wa8yxm · 01-29-2014, 02:00 PM

Rather than capturing cellular signals (Which I happen to be doing just now with a straight Samsung Galaxy S-III) when I'm in a park with Wi-Fi, I have a genuine Wi-Fi Capture system.. How good is it? Well a couple at the park here in SC I visit which has Wi-Fi were complaining that since the router was moved they can no longer see it from their RV.

I was 3 rows past them (From the router) and had a clear view, signal between 25 and 40 percent saturation on the limiters (anything over 20 is excellent).

First: I have a vintage Linksys WGA-54G
I modified it (Well I actually did not modify IT so much) in accordance with episode 3 of AmateurLogic.TV - Amateur Radio + Technology :. AmateurLogic.TV Show .: One difference, In the show GEORGE re-cuts the antenna on the Linksys device... I trusted Linksys engineers to design the antenna and did not re-cut mine,, Just put the can over it as per George's instructions and protected it some from weather.

I then mounted it on a wood base, which can be set on a step ladder, on the roof, on the picnic table or on top of a telescoping flag pole 25 feet up to see over the roofs of all the interfering RV's.

smiller · 01-29-2014, 03:14 PM

Homebuilt devices are almost always more capable and configurable than canned solutions, and often less expensive as well. But the learning curve is steep and while I'd recommend such a solution for an experienced person I think it would be a very frustrating proposition for most. But it's good to have the information available so people can make their own choice.

EDALLSAILS · 01-29-2014, 05:07 PM

Why go to the trouble and expense? I bought a WiFi hot spot device for 29.95 from www.FreedomPop.com Monthly fee starts at $19.95. Only thing cheaper is going to McDonalds. If 4G service is available it pickit and if only 3 G it gets that. Where we live in Florida WiFi service is very questionable. Had century Link DSL and it was over 100 bucks a month. Now at home I use FreedomPop and when we travel I just bring the device with me. safe travels.... ed

wa8yxm · 01-30-2014, 09:16 AM

Yes Edallsails. but .. How much service do you get for 20/month? I have seen services that offer, for example, 1 gig for 15 bucks.. Ok, good deal if ALL I did was E-mail but I used 6.6 Gig last month.. At 15 per gig (or part thereof) that would be 90 dollars. PLUS taxes, that's what I pay for my cell phone, and in addition to unlimited data (6.5 Gig high speed, 4g if its there) I get unlimited SMS and Yakety Yak (Voice minutes).

I do admit my Linksys solution takes a bit of learning to set it up, Some places I need to do it one way, some another, some a third, but I do have the experience to figure it out, and the guy who designed the Cantenna mod is an engineer... Still, it's not for the faint of heart.

whem2fish · 01-30-2014, 10:31 AM

A cantenna google I got better signal with antenna mounted on a old dish tv dish

Jack Mayer · 01-30-2014, 12:11 PM

All of these things work. Some with better performance than others. If you are a hobbyist then the sky is the limit. You can build your own antennas, etc. None of it is insurmountable to someone that has the will and time. And none of it is particularly expensive.

The Ubiquity solution falls into the category of "more money than home built components, but easier than many hand built solutions".

As smiller cautions, MOST people will not spend the time and frustration required to learn this stuff. But there are good solutions available for those that choose to.

There are LOTS of what I consider "half baked" solutions being advertised on the web. Some even work. Most are not worth the money. So be cautious of what you buy with a packaged solution. And anyone claiming that they can capture wifi from "miles away" is being disingenuous. That simply does not happen unless you control both ends or have exceptional circumstances which are unlikely to be replicated.

spinn · 01-30-2014, 12:22 PM

Amen to what Jack wrote. It takes a very large investment of time, some money and a high tolerance for frustration (and often a career) to learn the many aspects of the technology we use today. Even the most accomplished engineer/technician will occasionally throw in the towel when it comes to home brew systems and opt for a good commercial solution.

Steve

EDALLSAILS · 01-30-2014, 12:36 PM

FreedomPop offers a half dozen different plans. All are No contract plans. I get 2 gig for 19.95. You can get 4 gig for 28 bucks. And they have other plans for higher usage. By the way I am not connected or affiliated with freedonPop. I just want reliable service, availability at a lower price than what I've been paying from Century Link DSL that only works in my home. The 2 GIG for 19.95 is adequate for our needs. When something better comes along I'll move if FreedomPop doesn't stay competitive. The President promised USA wide access to the internet, I suppose he'll give us that right after he fixes Obama care. Hear a rumor that Al Gore was going to be appointed the czar, after all he invented the internet. safe surfing... ed

NeilV · 02-01-2014, 12:36 AM

I got a deal $29 on a parabolic Wifi antenna some years ago and it serves me well in most instances. Increasing the size of the dish with some aluminum foil sometimes helps to. The only drawback is that you have to aim it which is not too difficult if it is a public building with free WiFi such as a large library with multiple access points and seamless roaming that you are going for however zeroing in a single antenna can sometimes be difficult at the greater distances.

Thanks for posting the info.

Gormleys · 02-01-2014, 08:05 AM

Jack -

I am impressed with the professional write-up and experience you have posted on your Wi-Fi Capture Device. It is detailed and easy to read. Thanks for providing it. This is the type of professional information and experience that makes the Forum worthwhile.

Jack Mayer · 02-01-2014, 01:12 PM

Quote:

Originally Posted by Gormleys

Jack -

I am impressed with the professional write-up and experience you have posted on your Wi-Fi Capture Device. It is detailed and easy to read. Thanks for providing it. This is the type of professional information and experience that makes the Forum worthwhile.

Thank you. I appreciate it. Hopefully people will see that you CAN get professional results with a little/lot of effort. But you do have to have some perseverance if you get into a problem.

Using a cantenna or old sat antenna with a higher powered radio can get you some amazing improvements. As long as you are willing to go through the work. Even using the simple Bullet with a directional antenna can give you some amazing point-to-point links. I've used nanostations as P2P links routinely at two miles or more. In one case extending a high speed backhaul from the RV park owners house over to the campground from almost 3 miles. The stuff is out there....you just have to find it and learn how to use it.

SteveUpp · 02-01-2014, 07:26 PM

Jack

Nice write up! Have you ever come across a campground that had both 802.11g and 802.11a (5Ghz)? I wonder if we'll begin seeing dual band wifi much in these outdoor environments? 5Ghz has shorter range but with 802.11ac the use of 3x3 MIMO makes it a viable alternative to 2.4Ghz and there is more spectrum available in the 5Ghz band.

If that becomes more popular it will increase the complexity and antenna requirements of an outdoor CPE.

For now a single band, single antenna bullet is probably all that is needed, but I wonder what your opinion is. If you wanted to future proof...would you consider building an 802.11ac CPE?

FlyingDiver · 02-01-2014, 07:54 PM

Quote:

Originally Posted by SteveUpp

Jack

Nice write up! Have you ever come across a campground that had both 802.11g and 802.11a (5Ghz)? I wonder if we'll begin seeing dual band wifi much in these outdoor environments? 5Ghz has shorter range but with 802.11ac the use of 3x3 MIMO makes it a viable alternative to 2.4Ghz and there is more spectrum available in the 5Ghz band.

I've run into a few of them. The KOA in Terre Haute, IN had both bands as I recall.