Modifying Wifi equipment for better penetration

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QuantumFluxCapacitor
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Modifying Wifi equipment for better penetration

Post by QuantumFluxCapacitor » Wed Jan 13, 2016 7:18 am

Hello.

I am new to this board. I am in no way an RF engineer, but I am an IT engineer with a good deal of experience with WiFi equipment.

It is for this reason I have created this thread. I am working on a project in which I need to get a broadband, high data rate signal through a triple-glazed window ( of an ocean rated oil tanker) each pane 1cm thick. To make matters worse, the access point is up to 1000 meters away.

The use of a sector antenna will focus the signal more, and using the right antenna behind the window will also be a huge factor.

The location is in the Netherlands, and in the 5GHz WiFi spectrum, the top 3 bands are permitted to transmit outdoors at 1 Watt Eirp. It's a no-brainer that these threee bands are key to success.

But as I said, I am no radio frequency engineer.

What I need, so i can build a first generation test setup, is numbers. I am looking for interested persons to crunch some numbers for me.

For instance, with the information given, what can be said of the possibilities, can one caculate theoretical limits to what can be put into practice?

Of course this all raises many more questions than answers. So fire away, what do you need to know?

Thanks in advance,

Paul.

dbuckley
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Re: Modifying Wifi equipment for better penetration

Post by dbuckley » Wed Jan 13, 2016 2:23 pm

I'd suggest asking this question in the Ubiquiti forums, they will probably have solutions to meet your needs.

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PID_Stop
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Re: Modifying Wifi equipment for better penetration

Post by PID_Stop » Wed Jan 13, 2016 4:24 pm

You will also need to know the composition of the glass you're trying to penetrate. There are buildings in our community with leaded glass windows, and trying to get a microwave signal through them can be difficult to impossible, even as low as 2GHz.

-- Jeff

QuantumFluxCapacitor
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Re: Modifying Wifi equipment for better penetration

Post by QuantumFluxCapacitor » Mon Jan 18, 2016 4:19 am

Thank you for the responses. I already have Ubiquiti in my sights as far as equipment goes, but there's a good chance i will need to use a custom antenna. The glass panes fitted in oil tankers are very thick but are specially produced to be as transparent as possible for radio waves as the steel of the ship shields the cabins nearly completely. I know this because a friend of mine who is a sailor said that with the advent of mobile phones in the late 90's all seavessels still had EM shielding windows and the companies spent a fortune replacing all the windows so people could make phone calls from inside when in port or just off the coast. All ships built after 2000 have this type of pane installed, that should account for 95% of the world's fleet. So this should give us better chances of a good penetration, especially if a full Watt of transmission power is permitted. This is offset by the distance to the access point, which can be up to 800 or maybe even 1000 meters. The accesspoints will have sector antennas so the signal isnt attenuated too fast.

If all fails, there's the option to request a license and use wifi with greater transmission power than normally allowed.

But if anyone can give tips/hints/suggestions/advice on anything, for example odd things that are good to know, please don't hesitate. Thanks!

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Deep Thought
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Re: Modifying Wifi equipment for better penetration

Post by Deep Thought » Mon Jan 18, 2016 10:31 am

Keep in mind that while your AP transmit power may be higher, the other end will still be what it was before and the link will still fail. You are almost always better off using a higher-gain directional antenna which also increases the received signal levels and cuts down on off-axis interference sources.
Mark Mueller • Mueller Broadcast Design • La Grange, IL • http://www.muellerbroadcastdesign.com

QuantumFluxCapacitor
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Re: Modifying Wifi equipment for better penetration

Post by QuantumFluxCapacitor » Thu Jan 21, 2016 4:24 am

dbuckley wrote:I'd suggest asking this question in the Ubiquiti forums, they will probably have solutions to meet your needs.
I have and I did get some suggestions leading me the way to the right solution. not there yet, but its a start.

QuantumFluxCapacitor
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Re: Modifying Wifi equipment for better penetration

Post by QuantumFluxCapacitor » Thu Jan 21, 2016 4:25 am

PID_Stop wrote:You will also need to know the composition of the glass you're trying to penetrate. There are buildings in our community with leaded glass windows, and trying to get a microwave signal through them can be difficult to impossible, even as low as 2GHz.

-- Jeff
Thanks for your reply. Most sea vessels have RF transparent windows so crew can use mobile phones inside the ship.

QuantumFluxCapacitor
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Re: Modifying Wifi equipment for better penetration

Post by QuantumFluxCapacitor » Thu Jan 21, 2016 4:31 am

Deep Thought wrote:Keep in mind that while your AP transmit power may be higher, the other end will still be what it was before and the link will still fail. You are almost always better off using a higher-gain directional antenna which also increases the received signal levels and cuts down on off-axis interference sources.
Thanks for your reply. That's something I already anticipated and It looks like we are going to go for a UBNT airmax PTP or PTMP proprietary link to beam to the ship, while a fully wireless router which is integrated into one unit with the two radio/antennas (that is our intention) handles the traffic and replicates a 2.4G client network inside the cabin. As receiving antenna the Nanobeam AC 19 is a good candidate as it has a swivel base for better aiming, and the client network can be handled by a unifi AP AC-lite. So it's not true repeating that's being done, just routing really.

Of course one's advice aint the other's. I am open to any suggestion.

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