Re: Mobile communications - 4G, WiFi

Brent Cameron
 

Those directional antennas generally have a +/- 3  degree plane off vertical. Using the old (and very handy)  1 in 60 rule (1 degree at 60nm is equal to a distance across that arc of 1 nautical mile or 6000 feet).it’s easy to calculate that if you are say 1/10 mile from the source antennas, then you can be as much as 30 feet off plane and still get a decent signal. ( 6000/ 60 / 10 * 3 degrees = 30’)   I’m not sure that I’d put the directional antenna on top of the Mizzen as the extra height isn’t doing you any favours up really close  but Eric has a good solution (at say 15’ off the water) as that would easily allow you to hit an antenna at that elevation but also up to 45 in at that distance (the further out you are, the less it’s a problem- 1/2 mile would be 150’, 1 mile is 300, etc. ’Anyway, unless you are sitting right on top of the source antenna, in which case your computers would likely get Wi-Fi anyway, it won’t make much difference where you mount it.  The range is still likely to be fairly close just because of the signal strength so unlike VHF (or AIS),  boosting your antenna to get additional line of sight isn’t going to make much difference anyway. 

Brent Cameron, Future Amel owner & Amel Owner's Registry Moderator

On Jan 22, 2020, 10:27 AM -0500, Ryan Meador <ryan.d.meador@...>, wrote:
Gerhard, thanks for including those diagrams.  That makes it a lot more clear what I was trying to say in my earlier post.  The directional antennas are great if you can be sure it will always be pointed in the right direction.  On a mooring, it's not going to work very well.

You bring up a good point about the DHCP configuration.  The easiest way to fix it is isn't to turn off DHCP on one of them, it's to ensure they assign from separate IP ranges and ensure one is plugged into the uplink port of the other.  Then the downstream router will get an IP from the upstream one just like any other device.  I recall this was very easy to set up with the Mikrotik routers.

Ryan and Kelly
SM 233 Iteration
Boston, MA, USA


On Wed, Jan 22, 2020 at 5:31 AM Gerhard Mueller via Groups.Io <carcode=me.com@groups.io> wrote:
I still have the old Ubiquiti Bullet 2HP which is similiar to the Groove.
Depending the conditions I use 2 different kinds of antennas.
The usual rod antenna has the characteristics as shown below:
<WiFi-Rundstrahlantenne.png>
360 degrees horizontal but only a small angle vertically.
That means the antenna should be mounted as near as possible to the horizontal line to the access point.
However a directional antenna has this characteristic:
<WiFi-Sektorantenne.png>
That is nearly same quality horizontal and vertically.
So if you know the direction to the access point take this one.

Another thing to know: My Bullet as well the Groove are routers. When you attach them to another router in your network on board the boat then only one router in the network can be configured as DHCP server which handles the IP addresses in your network. Otherwise the network is blocked.
--
Gerhard Mueller
Amel Sharki #60
Currently Kalamata, Greece


--
Brent Cameron

Future Amel Owner & Amel Owner Registry Moderator

Oro-Medonte, Ontario, Canada

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