Long-Distance WiFi Device

[Sumner]

Originally Posted by xan

... I imagine 12-48V is a bit harder (ie - power input and cost) than 12 or 24V..

I use one of these in the 18 volt version, but there is a 48 volt one ....

Tycon Power Systems Power over Ethernet (PoE) Power Sources, 9-36VDC In, 18V, 24V, or 48VDC Out 30W DC to DC Convertor and PoE Inserter, tp-dcdc-1224,tp-dcdc-1212,tp-dcdc-1248,

Probably don't need it as the Bullet will work on 12 volts. Just wanted to maximize the install. The rest of it is here....

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More here....

Long Distance WiFi Index

We are extremely satisfied with this setup and anchor out all the time as remote as we can and I've connected a little over 4 miles (slow but useable) and closer 1-2 miles at much faster rates. If this is new to you I'd suggest buying a complete setup with the help that will give you from some one like Island Time PC here (no affiliation),

Sum

[siroismi]

Thank you for the info.

I already have the 15dBi so I'll start with that and see.

Michel

[djdeakyne]

Originally Posted by s/v Jedi

that's one of the myths yes. Let's assume above data; this means that at 4 degrees angle, the gain is -3dB, i.e. 15-3=12dBi which is still double that of the 9dBi version.

People who use a 15dBi antenna are very happy with them and never report problems about too narrow radiation patterns AFAIK.
That said, the 9dBi omni's are fine too and I much prefer directional over higher gain as elimination of noise works as good as increasing gain so you get double bang. This is why the NanoStations do so well.

cheers,
Nick.

Hi Nick,
I don't understand your calculations. -3db? How's that?
Here is the e-plane radiation pattern of a 15db omni antenna
At 4 degrees off center, you are way down on gain.

http://www.odessaoffice.com/wireless...na/15_omni.jpg

Also, I know you have been on this thread for a long time. There have been negative comments about 15db antennas. Not just mine on page 76. I thought I was going to have killer wifi with it. The linksys built-in was much better.

Still in Panama?
Cheers, Dave

On another note, my assumption here is that if you need Long-Distance Wifi, you are out in an anchorage or underway and therefore the boat is moving around and your system must be designed to to handle real world perturbations. Otherwise, if you are in a marina, "Long-Distance" may mean the length of the dock. Even the worst setups should work in a marina, so there really isn't any comparison.

[hellosailor]

Nick, I would suggest the problem is not a 4-degree heel of the boat. Bear in mind that before you even start, the wifi antenna on the boat and shore point will usually NOT be at the same height, so the initial "flat" connection will not be flat at all, it will have perhaps ten degrees of variation in it. Now add you four degree heel, and read the antenna's performance 14-15 derees off flat. Substantially degraded!

What will happen in real life? I suppose if you have tall mast, and watch the signal strength while hauling your antenna aloft, you can get a better match. But in real life I suspect you will be starting with at least a 10-degree misalignment of the antennas. And then of course, heaven help you if the shore antenna was also a high-gain with a flat pattern.<G>

[s/v Jedi]

I know I'm skipping details. Two points:

1. the 4 degrees I mention is not heel of the boat but the opening angle of the antenna pattern.

2. the -3dB I mention is what the industry uses to define specifications. i.e. when they tell you that the opening angle is 4 degrees, they mean that at 4 degrees the radiated signal is -3dB compared to the 0-degree signal at the same distance. -3dB means the signal is half. So 15-3=12dB is only half of a 15dB signal but still twice that of a 9dB signal.

There are many variables and possible (installation) problems. When you use something else than the Ubiquity products, especially anything with coax cable, the problems multiply uncontrolled.

I'll check a bit back in the thread as I've been away for a while but for now I think that everybody with a Ubiquity Bullet with 15dBi omni is extremely happy with that setup.

ciao!
Nick.

[djdeakyne]

Originally Posted by s/v Jedi

I know I'm skipping details. Two points:

1. the 4 degrees I mention is not heel of the boat but the opening angle of the antenna pattern.

2. the -3dB I mention is what the industry uses to define specifications. i.e. when they tell you that the opening angle is 4 degrees, they mean that at 4 degrees the radiated signal is -3dB compared to the 0-degree signal at the same distance. -3dB means the signal is half.
ciao!
Nick.

Hi Nick,
You are correct, by definition, the beamwidth is the opening angle. (The angle of the main lobe where you have lost half your power (-3db)). In that case, the beam height of that 15db omni is even smaller than the angle to the edges of the lobe.



For hellosailor,
I see what you point is but in reality, 1 degree at 1 mile is worth 90 feet (Height = Distance*SIN(Beam Angle)). A 4 degree beam has a height of 360 feet. At 1/2 mile the beam height is 180 feet. At 1/4 mile, the beam height is 90 feet, etc. So unless you were very close and/or the hotspot was up on a hill, there would not be any real issue with the antenna pattern assuming it was totally calm at anchor.

However,
When you are rolling at anchor with that high gain omni, your beam is swinging up and down by the height ratios described above. The more you roll, the less power will be received by the hotspot and by your antenna.

If you are lucky enough to have the hotspot on the bow or stern, no big deal. If it is on your beam, not so good. I don't think this is a myth.

Cheers, Dave

[s/v Jedi]

If you roll that much at anchor, I would not worry about my wifi anymore

[djdeakyne]

Originally Posted by s/v Jedi

If you roll that much at anchor, I would not worry about my wifi anymore

I'm on a catamaran. No worries here, but I see plenty of monohull masts flailing around much more than 4 degrees.

[Ziggy]

Originally Posted by s/v Jedi

that's one of the myths yes. Let's assume above data; this means that at 4 degrees angle, the gain is -3dB, i.e. 15-3=12dBi which is still double that of the 9dBi version.

Nick,
This is a disingenuous argument, at best. Yes, by definition, if the half power beamwidth is 4 deg, then at +/- 2 deg the gain will be 3 dB down. But what is the gain of the 15dBi antenna at, say, +/- 5 deg? It may very well have a null in the antenna pattern, with no output at all.
If you can make sure that the antenna is installed within +/- 2 deg of vertical and the boat remains perfectly level, that's great. But it doesn't take much of a wave to heel more than that.

[Sumner]

We run an Engenius 8dBi antenna ...



...and are very happy with results (up to a little over 4 miles). We are usually on remote anchorages.

I'd like to see someone try both antennas (8-9 dBi / 12-15 dBi) at the same location, same hot spot with some rolling/movement of the boat on anchor. Maybe I might try that at some time. Have done that with an Alpaha vs. Bullet and in my mind in that setting the Bullet is much better...

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What it boils down to is that if it is working then use what you have, but nothing is going to cover every situation. Put the antenna up high and if you are in close and the hot spot is low to reach the most people you might not connect and visa versa. The same can be said for the signal strength you are operating at and the dBi of the antenna.

We can rarely connect to home connections. Not because of being protected, but because their hardware is not good enough to receive our signal back. It is easy to forget that it is a two way street. Most of our connections are to marinas, hotels/motels, resorts, public hotspots and places like Home Depot that have professionally installed equipment that was put in with the public in mind. Home servers just don't have the equipment to do that. We have on occasion connected to a home system that was within 1/4 mile of the boat, but I think that is about it.

So has anyone tried different antennas in the same location?

Sum

[s/v Jedi]

When you are so close that radiation patterns miss each other it will work anyway because of the close proximity.

There is only one negative comment about a high gain omni and that was on a linksys router IIRC (maybe even with coax?!). There are countless Bullets with 15 dBi's that work fine.

[paulbennett]

Thanks for the information friends. Ubiquiti now offers a more weatherproof "titanium" version of the bullet 2. I wonder if anyone has an opinion on whether these are worth the extra expense. They offer two versions, an M2 and M5, which I suppose refers to signal strength (?) does anyone have experience with either of these? Summer, if you we're doing your install now would you go for the titanium M5? Why/why not?

Paul
s/v Dafne

[W32PAMELA]

The "M" indicates AirMax hardware, the "2" is for 2.4 Ghz and the "5" is for 5 Ghz. You don't want an M5 unless you have specific knowledge of a 5 Ghz access point you want to use. Almost all public and most private wifi is 2.4 Ghz.

I don't think the titanium offers a huge improvement over the weatherproofing available with a stock BM2HP other than the cable gland for the cable entrance.

The Titanium aluminum case should survive UV exposure much better than the plastic used on the stock BM2HP.

[Gashmore]

I have shifted to installing the "titanium" M2 although in 50 odd installations of 2HPs over 4 years I have had only one report of water damage and that one had been laid on the side deck for 3 days in the rain. As long as it stays vertical, the N connector is tight and the little plastic grommet is installed properly the 2HP will stay dry.

The M2 is a 2.4Ghz unit and the M5 is a 5Ghz. Power and sensitivity are essentially the same for both. There are far more 2.4Ghz signals out there right now. While the 5Ghz band is less congested 2.4Ghz carries over longer distances. On a boat you are more concerned with range and availability than congestion.

I moved to the M2 because it supports b,g & n protocol. The 2HP only handles b & g. Most of my boats are in the Caribbean where until recently n signals were a rarity so it wasn't an issue but 2.4ghz 802.11n access points are getting popular and give considerably better performance at distance than b or g.

BTW, until recently the establishments that I installed access points for considered it a promotional feature and the base stations I installed were all open but in the last year, primarily because of abuse, almost all are either secured or have a pay window.

[mlahrkamp]

Regarding Bullet2HP weatherproofing and Itanium version: From our experience with many 1000s now installed on boats all over the world, we have only had a handful that have experienced water ingress. When installed vertically, there should not be an issue with water. The Bullet2HP and BulletM2 are both rated as IP65 by Ubiquiti and are shown as such in our e-store.

On the subject of N mode over B and G: This works best when the antenna arrangement is a 2x2. The single omni (1x1) attached to the Bullet M2 does not allow exploitation of all of N mode capabilities for speed and distance. Additionally, the Bullet2HP and BulletM2 are rated up to 30dbm (@1-24mbps) with receiver sensitivity being better by 1dbm in the Bullet2HP over the BulletM2. Note also that the Bullet's best performance for tx power and rx sensitivity is when operating in the slower B mode. Power and sensitivity drop off when the speeds get higher.

On the subject of 15dbi omni antenna attached directly to a fully cranked Bullet (any high power version): this greatly exceeds the maximum legal tx power of all countries in the world (by up to 11dbm over for even the most permissive countries) and is therefore not recommended. Unless the station you are connecting with is also exceeding their max legal limit, the probability is that you will not experience any significant usable range increase. Remember as well, you need receiver sensitivity that is capable of hearing those stations that your increased tx power is capable of reaching.

Cheers,