500km link posible?

here in Matiguas Nicaragua bandwidth is really expensive but 500km away (line of site from mountain near by) is Costa Rica with decent infrastructure and decent prices.
considering the following it should be possible to do a link

transmit power 500mW 24db
antenna gain send 36dbi
antenna gain receiver 36dbi
free space loses at -160db
that leaves -64db at the receiving end, enough for a stable link, assuming the Fresnel zone is free

it’s a pretty risky link, but if you already have the materials, why not try?
you should use xr5, rb433ah (you can’t get more than 100mbit anyway, so rb600 or rb800 is useless), short cables and dish antennas (as big as possible - even 2 meters or more if you can).
That would help you in case of bad atmospheric conditions.

However, i’m not sure if nstreme can cope with such a big distance. We need some inside info from mikrotik guys :wink:
Ah, nstreme is the only way to go.

keep us updated.

he he, some time ago I read the article on cnet.com about ~380km wireless link. Here is http://www.eslared.org.ve/articulos/Long%20Distance%20WiFi%20Trial.pdf

30dbi dish for 160$
http://www.streakwave.com/Itemdesc.asp?ic=RocketDish-5G30&eq=&Tp=
for wireless 11n 2x2 and with a good card you should get well above 100mbps if the signal is above -60db i would be happy with 100mbps the signal will take 1.6ms to travel, i guess that means an act time out of more then 3.2ms other then that the routeros could care less i would think
are there any 11n 2x2 amplifiers out there?
the fresnel zone is huge at 500km, 3800m according too http://www.afar.net/fresnel-zone-calculator

better check this http://tiktube.com/?video=196, before start your experiment.

you could make record, take a leaf from the longest links that have been done (there is a 304km link in the forum)

you’d better not use n till is not well tested and developed. We can’t use it stable on 20km links, let alone 500…
xr5 with nstreme would be the safest bet :wink:

I would recommend doing a Link Analysis with Radio Mobile

Edit: I agree with KillerOPS as well: “(as big as possible - even 2 meters or more if you can). That would help you in case of bad atmospheric conditions”

You should look for serious antennas (If you can afford Radio Wave - excellent performance). You should plan to count with a good fade margin at least 20 dB or more if possible :wink:

On the other hand, is it possible to establish a repeater point in between?

Are you sure you have LOS to 500 km away?
The highest point in Costa Rica is 3,819m.
In Nicaragua, it is Mogoton at 2,438 m.

My calculations show that in the best case scenerio, you have only 400 km of LOS.
What makes you believe that you have LOS to Costa Rica?

Talk to http://www.columbus-networks.com/, maybe they can get your some bandwidth to the coast of Nicaragua.

its more like 400 something Km but I’m somewhat sure that i have line of site. i am still investigating exactly where in in Costa Rica the link would terminate so i am not sure exactly how long. it might turn out to be 320km. does anyone know how to extract a altitude profile for a link from google earth? i need it to know how free the Fresnel zone is…

http://www.columbus-networks.com/ is a lot closer (210km) to Bluefields (i think they have pick up there) then too Costa Rica but i think there will be a line of site problem since the cost is around see level and the mountain here is 1320m.

Please send your coordinates and I will do the calculations for you with RM.

You would have pretty wild fading on a link that long if it worked at all.

thqnks MJA ill get to that latter
what cause fading??

They have access to local fiber.
Post your email address ctech4285, I’ll put you in touch with the head of wholesale accounts.

sweet, ctech4285 at gmail.com

Technically the link will work provided you have clearance and are in a vacuum. The issue is reliability. At the distances you are looking at you can not have a quality link. If you get lucky it may work but fading due to the atmospheric conditions will make the link unstable. It may work for weeks or months then stop working for minutes days or months. It is not something you would want to use in production even if you can get the ends to link. My 2 cents is if you have some time to wast it would be fun to try, if you intend it to be used to service other people, don’t even bother.