Auto-Pointing Wifi Antenna?

[stubones99]

Has anyone ever thought about making a self pointing wifi antenna so you would get good wifi reception even at a distance, regardless of the swing of the boat at anchor?

Does anyone make one for WIFI?

I know they make gyro stabilized sat antennas but have not seen a wifi antenna.

All it would take is a small radome (vacuum molded plastic), a backfire wifi high gain antenna, and a small arduino (or similar) microprocessor. The processor would connect to the wifi receiver on board and report signal strength. The backfire antenna would be mounted on a pivot post and have a servo motor rotate it around the post. The servo motor could step in 15 degree steps in all 360 degrees and mark all wifi sources and then pick the best one available. Most arduino boards have an option of a keypad / keyboard and small display.

The backfire dish is one of the highest gain compact antenna you can get (16db) in an 11 inch dish. Mount the pivot point near the front of the dish, and it would spin all 360 degrees on its axis, and require a dome slightly ore than a foot across and about a foot tall.

Is there any interest in something like this?

[goboatingnow]

firstly , the highest available WIFi signal may not be accessible, ( it could be locked) Then you have the problem of trying to force the antenna to track intermediate level signals.

Secondly the hidden node issue plays a large part in throughput. If you are far away and many of the other wifi nodes cannot hear you , you can get a seemingly good signal, but poor actual throughput.

Given the number of potential Wifi networks out there these days, I suspect the system would be constantly hunting between signals causing you to drop connections

a good Omni is a better get,

Personally 4G will sweep al lot of hotspots away, certainly in Europe , I rarely bother with hotspots in cities as I get excellent 4G

[Suijin]

No I don't think there is, for a couple of reasons:

- Boats are generally always moving, either rocking, yawing, pitching, or swinging at anchor. The antenna would spend a significant amount of time hunting to follow a signal.

- It's complicated in terms of both the mechanicals and electronics in pursuit of a benefit that can be largely achieved by throwing more power at a bigger antenna.

Also, finding a usable wifi access point is partly about signal strength and quality, but also about finding one that is open. Directional antennas are not so great at providing site surveys that list all of the available signals in a format that you can view, sort, etc. to find the strongest open unsecured non-commercial access point.

[Paul L]

Plus the signal paths are not very straight. They bounce off of many surfaces and arrive at the antennas from various directions.

[stubones99]

I understand the problems (having done quite a few wireless networks in the past). I also know that the local (Port Canaveral) casino cruise boats use wifi locations on tops of hotels for their connectivity and use a computer controlled antenna to track where they are in relation to the wifi hot AP's on the hotels as they cruise up and down the coast taking their client's money ...

Works for them, I know it could work for us.

I understand an Omni antenna will work, and yes, you can get up to about 6db gain on an omni if you compress the vertical band and not need to aim it. The only way to increase gain is to deflect it from another direction or dimension.

The highest gain antennas are very directional, and the bigger the better. That doesn't work on a boat very well.

As far as open access AP's, that would be fairly simply, since when you told it to search for AP's, it would show open ones, as well as closed ones. If you have the passphrase for a closed one, you could select that one, enter the passphrase and be off and running.

I wouldn't worry too much about rocking of the boat (if it's at anchor), since if you have more than about 20 degrees of rock, you're probably not working on the computer. The backfire antenna has about 20+/- elevation in it's center lobe.

By having a GPS and compass on the Arduino controller, it would know where it found the AP you selected (or it chose), and when the boat swings at anchor, the stepper motor would bump the antenna back to peak signal strength.

This would probably work up to about a mile out, from what I know. If you need less range, a high gain Omni (5-7db gain) may work with no moving parts and lower wind load.

It's a thought, but as my father taught me, just because it could be done, doesn't mean it should be done...

Thanks for your input!

Stu

[hellosailor]

bones, moving parts are just SO Steampunk!

What the techies do these days is called "diversity antennas". Someone was showing around a prototype for wifi maybe five years ago, but I never heard that it went into production. Basically the router has six, eight, a dozen antennas onboard and they are all "flat" circuit antennas. An onboard CPU looks at the signals from each antenna, compares for the strongest, and then connects to the strongest signal and hands it off according to programmed parameters.

Car phones used to do this using two antennas, but after 30 years of better electronics...diversity antennas are the way to go. In the long run, cheaper and more reliable than trying to swing things around with servos. Way more compact, too.

[sy_gilana]

Yes, I use an old tillerpilot for that, actually a sat dish, but the principle is the same, works when its calm but if you are rolling na-uh.

[nimblemotors]

I had a customer with an offshore boat want something like this when I manufactured and sold WiFi equipment. The higher gain antennas narrow beam just won't work well in a moving boat. I suggest a 13.5db gain 90-degree sector antenna, big improvement over a 6 or 8 omni.
SuperPass Antenna Shop - SPDG16F2 Product Page
This might be just fine with a manual rotation.

[916senna]

The technology required already exists in the hobby model aircraft.
FPV flyers use a video downlink to fly the model.
They have a gps in the plane transmitting its position and the receiving antenna on a servo system to point a very high gain antenna both horizontally and vertically at the constantly moving aircraft.
You would just need to feed it a position to point at.
Googling will uncover lots of detailed knowledge.
Hobby King has lots of the parts needed.



Sent from my iPad using Cruisers Sailing Forum

[Dr. Strangelove]

Originally Posted by stubones99

It's a thought, but as my father taught me, just because it could be done, doesn't mean it should be done...
Stu

I though the same thing about 10 years ago or so when LG or Samsung came out with a refrigerator with a TV in the door. A buddy of mine and I were standing there looking at it, shaking our heads. I said "Just because you CAN put a TV in the door of a refrigerator doesn't mean it needs one..."

[K_V_B]

Originally Posted by goboatingnow

Personally 4G will sweep al lot of hotspots away, certainly in Europe , I rarely bother with hotspots in cities as I get excellent 4G

I think a good G4/G3 antenna in the top of the mast would be very useful. Especially in a year or so, when roaming charges will go away.

[stubones99]

Originally Posted by hellosailor

bones, moving parts are just SO Steampunk!

What the techies do these days is called "diversity antennas". Someone was showing around a prototype for wifi maybe five years ago, but I never heard that it went into production. Basically the router has six, eight, a dozen antennas onboard and they are all "flat" circuit antennas. An onboard CPU looks at the signals from each antenna, compares for the strongest, and then connects to the strongest signal and hands it off according to programmed parameters.

Car phones used to do this using two antennas, but after 30 years of better electronics...diversity antennas are the way to go. In the long run, cheaper and more reliable than trying to swing things around with servos. Way more compact, too.

It is actually "Antenna Diversity" and most cell phones now have fractal antennas since they have no idea where you are in relation to the tower...

NASA actually broadcasts their GPS location during launches for all the tracking cameras and telescopes to follow...

I guess if you can't get within 500 yards of a AP, then do without WIFI...

thanks for all the input.
Stu

[Paul L]

Originally Posted by hellosailor

bones, moving parts are just SO Steampunk!

What the techies do these days is called "diversity antennas". Someone was showing around a prototype for wifi maybe five years ago, but I never heard that it went into production. Basically the router has six, eight, a dozen antennas onboard and they are all "flat" circuit antennas. An onboard CPU looks at the signals from each antenna, compares for the strongest, and then connects to the strongest signal and hands it off according to programmed parameters.

Car phones used to do this using two antennas, but after 30 years of better electronics...diversity antennas are the way to go. In the long run, cheaper and more reliable than trying to swing things around with servos. Way more compact, too.

This is probably a better approach than a mechanical solution. There are multi-antenna WiFi routers around with Atheros chipsets that have Open-Source firmware available.