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Old 06-12-2011, 19:16   #1081
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Quote:
Originally Posted by hellosailor
Nick, a repeater isn't necessarily a bad thing. If it is designed to be hoist up your own mast, for your own boat, if could be suitably low power so that someone 100 yards away wasn't bothered by it. Sizing the bubble...maybe automatically stepping the power just to match the user connection? Could make it a good neighbor.

Or, stepping it up to max power and letting all the nieghbors share on it.<G>
I'm sorry but that does not make sense at all. On what do you base that? The AP will see the repeater and bandwidth is immediately reduced by 50% plus overhead. That is pretty bad in my book.

Also, if you can receive it's signal from ir being hoisted in your mast and you being inside the boat, then every boat within at least a mile can receive it too. It can't be contained in a bubble without creating a Faraday cage around it.

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Old 07-12-2011, 09:40   #1082
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Re: Long-Distance WiFi Device

Nick, I've seen both routers and devices (smartphones and computers) that can't see each other when they are barely 50' apart, because they are using such low power. With a 25mW radio, as many laptops have, they just don't have much range. And I'm afraid to ask how low the power level in some smartphones is, I've seen them go deaf way sooner.

I know, you're talking about transmitting in free space but STILL...The AP will only see the receiver if there is sufficient signal strength. At some point that becomes background noise levels and they can tolerate each other. In a world where everyone uses max power max time, that won't work out. Somewhere in between will be reality.
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Old 07-12-2011, 16:17   #1083
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Let me try to explain in another way: a repeater is a pretty dumb device. It listens to the channel and when it receives a data packet, it simply re-transmits it... hence the name repeater. This means that every packet is on the air twice, effectively halving the bandwidth.

There is no way around it, air-time is valuable and it's wasted by the repeater.

About transmit power... how much power would be needed to transmit a signal that can be received on the moon?

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Old 07-12-2011, 16:47   #1084
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Re: Long-Distance WiFi Device

Nick, "how much signal" doesn't matter until you put it in context: signal to noise.

I can communicate with the International Space Station using five watts, but the same five watts won't work a terrestial repeater mounted on a skyscraper 20 miles away. And yes, both are line of sight, nearly the same frequency.

There's just a wee difference in the equipment on each end, as well.

One repeater, low power, on one boat, maybe 1/4 mile away from anyone else? I suspect the reality is that the next boat in the next anchorage won't suffer any real effects from it. There are simply too many variables (signals, noise, locations, etc.) to condemn the concept.
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Old 07-12-2011, 19:09   #1085
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Quote:
Originally Posted by hellosailor
Nick, "how much signal" doesn't matter until you put it in context: signal to noise.
Correct, it was just to illustrate that low power does not limit distance. The record for moon bounce is 3 mW.

But for the repeater... it does have contact with the AP or it wouldn't be a repeater. It will repeat everything from the AP and any clent it receives, and as this is a carrier-sense, multiple-access media, the AP will be silent when the repeater talks. Half the bandwidth is gone.

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Old 08-12-2011, 05:17   #1086
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Re: Long-Distance WiFi Device

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Originally Posted by s/v Jedi View Post
Oh no... Pls. stop, that's about the worst setup. Repeaters kill the bandwidth that needs to be shared by all.

It's in this thread a zillion times: if you need to ask, go to Island Time PC or wififorboats.com and get the kit.

cheers,
Nick.

To clarify, the R36 is not a repeater. It is a router.
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Old 27-12-2011, 22:26   #1087
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Re: Long-Distance WiFi Device

I'm interested in switching to the ubiquity bullet 2HP, connected to a wifi router inside the boat.

Can you guys recommend a 12v injector that can be wired directly to the ships power?

Also wondering if you're wiring the router to 12v, or is everyone just using an inverter? It looks like most linksys routers are 12v... can I just cut the wall-wart off the cable and wire it directly? Or is there another/better way to connect it all to ships power?
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Old 27-12-2011, 22:36   #1088
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Re: Long-Distance WiFi Device

Just wanted to say that I bought a WirieAP. Pretty happy with it. I try to avoid doing product reviews until after at least a year of experience but the installation and overall product quality as been great. I actually had to shield the antenna a bit with some foil because it was too powerful. So far, so good. Using it to make this post right now.
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Old 28-12-2011, 03:06   #1089
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Re: Long-Distance WiFi Device

Quote:
Originally Posted by callmecrazy View Post
I'm interested in switching to the ubiquity bullet 2HP, connected to a wifi router inside the boat.

Can you guys recommend a 12v injector that can be wired directly to the ships power?

Also wondering if you're wiring the router to 12v, or is everyone just using an inverter? It looks like most linksys routers are 12v... can I just cut the wall-wart off the cable and wire it directly? Or is there another/better way to connect it all to ships power?
There are lots of generic 12VDC POE injectors around. Check amazon.com.

I have just cut the wall wart off any number of otherwise 12V routers from Linksys and Netgear. Works fine.
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Old 28-12-2011, 06:15   #1090
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Re: Long-Distance WiFi Device

Also, you can buy multi-voltage DC-DC converters for just a few bucks. These will allow you the freedom to use any voltage input devices. I use a 12V one for 12V router and POE, just to keep a steady constant voltage rather than the 12.3-14.8V that the ship sees throughout its day.

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Old 28-12-2011, 06:31   #1091
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Re: Long-Distance WiFi Device

Quote:
Originally Posted by rebel heart View Post
I actually had to shield the antenna a bit with some foil because it was too powerful. So far, so good.
Why and how are you 'shielding' the antenna? Are you suggesting that you are wrapping the antenna with tin foil?
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Old 28-12-2011, 06:56   #1092
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Re: Long-Distance WiFi Device

Quote:
Originally Posted by Auspicious View Post
There are lots of generic 12VDC POE injectors around. Check amazon.com.

I have just cut the wall wart off any number of otherwise 12V routers from Linksys and Netgear. Works fine.
This might be a stupid question, but is there polarity on the 12V netgear router leads? IE if I just cut the wire, does it matter which is +/-?

Thanks,
Scott
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Old 28-12-2011, 07:49   #1093
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Re: Long-Distance WiFi Device

I just installed a Bullet HP and wireless router; love it. I suggest that you go to Island Time Computers and purchase the Bullet kit with wireless router. You can go to Amazon and purchase the parts separately but then you have to know whats parts to purchase. Also the Bullet is subject to damage by water; ITCP has a housing for the Bullet that prevents as much as possible water intrusion. You can connect 12 v wireless routers to your battery but need to make sure polarity is correct or you will damage the router. The conductors are usually marked and the positive usually is the center of the plug. I have no connections with ITCP just love the service.

Tom
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Old 28-12-2011, 08:14   #1094
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Quote:
Originally Posted by mlahrkamp

Why and how are you 'shielding' the antenna? Are you suggesting that you are wrapping the antenna with tin foil?


ciao!
Nick.
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Old 28-12-2011, 16:10   #1095
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Re: Long-Distance WiFi Device

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Originally Posted by mlahrkamp View Post
Why and how are you 'shielding' the antenna? Are you suggesting that you are wrapping the antenna with tin foil?
Yup. Might sound crazy but I had a lot of packet loss until I did so. I've been in touch with the manufacturer and have run everything past him, and in my day job I'm a software developer who used to do network administration. I'm not great with wireless but the basics of rf signal propagation I can at least take a decent stab at.

The marina's antenna is a straight shot away and there's no way to reduce the output power on the wirie's alfa unit via the software. Pop some foil over the antenna and my packet loss went from ~50% to 5-10% in a split second. Take it off and the packet loss is back again.

RF in general is black magic; never liked working with it because there are just too many variables.
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