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Mikrotik link calculation source code...

Posted: Tue Nov 08, 2011 4:16 pm
by angboontiong
Dear dude..

I knew the mikrotik is providing the link calculation on they web, but some how, it too far away for us and sometime it's no respond to us.

can i have the source code and put it into my centos server?

then i can do the link calculation locally.

thanks.

Re: Mikrotik link calculation source code...

Posted: Tue Nov 08, 2011 6:15 pm
by sadeghrafie
I'm not sure the Mikrotik do it. but I have work with Motorola link planner. It is a good tool for Motorola. If you put correct info to it, you will receive the nearest result to reality.
I hope Mikrotik has some plan to release such tool.

Re: Mikrotik link calculation source code...

Posted: Tue Nov 08, 2011 10:20 pm
by angboontiong
I'm not sure the Mikrotik do it. but I have work with Motorola link planner. It is a good tool for Motorola. If you put correct info to it, you will receive the nearest result to reality.
I hope Mikrotik has some plan to release such tool.
Yes, mikrotik is having that link, u goto http://www.mikrotik.com/test_link.php
just, the link some time may not work properly.

ubnt did the good job for it, but i put hope on mikrotik more than that...

Re: Mikrotik link calculation source code...

Posted: Tue Nov 08, 2011 10:23 pm
by sadeghrafie
I know about MT link calc and I used it before, I mean they will not give source code :)

Re: Mikrotik link calculation source code...

Posted: Wed Nov 09, 2011 9:27 am
by normis
Paste this into your website html:
<iframe src="http://www.mikrotik.com/test_link.php" width="380" height="680"></iframe>

Re: Mikrotik link calculation source code...

Posted: Wed Nov 09, 2011 11:59 am
by angboontiong
Paste this into your website html:
<iframe src="http://www.mikrotik.com/test_link.php" width="380" height="680"></iframe>
Hi Normis...
can we put the calculation in our own server, as the link provided by you, the calculation still need go to mikrotik server.

if then, we still may facing the calculation error or no respond from mikrotik server due to the internet connection issue.

thanks.

Re: Mikrotik link calculation source code...

Posted: Wed Nov 09, 2011 12:19 pm
by normis
Solve the internet issues by switching all the routers to mikrotik :)

Re: Mikrotik link calculation source code...

Posted: Wed Nov 09, 2011 12:28 pm
by angboontiong
Solve the internet issues by switching all the routers to mikrotik :)

^_^....

Great suggestion, we are on the way...

Re: Mikrotik link calculation source code...

Posted: Thu Nov 10, 2011 7:13 am
by reverged
Can MT at least publish the formulas/assumptions used to generate the output? Things like cable loss values, any adjustments for connections, etc.

I am seeing about 2~3dB difference between the MT site and my calculations. (my results are worse, which is good). It could be rounding somewhere.

Also, I notice that once you plug in values and get an answer, varying the TX power at site 1 does not change the signal at site 2....it changes the signal at site 1 (same for the opposite), which makes no sense to me. These might be reversed on the page?

Re: Mikrotik link calculation source code...

Posted: Thu Nov 17, 2011 12:26 am
by chronos
Another nice wifi signal calculation: http://en.jirous.com/calculation-wifi
Direct link to flash file: http://en.jirous.com/img/vypocet-wifi-en.swf

Re: Mikrotik link calculation source code...

Posted: Wed Jul 09, 2014 1:22 pm
by el berto
But... are Site1 and Site2 inverted, aren't they?

distance=2.2km

Site 1 parameters:
Wireless card power=14dBm
Antenna gain=16 dBi
Cable length= 0

Site 2 parameters:
Wireless card power=12dBm
Antenna gain=18 dBi
Cable length= 0

Resulting signal levels:
Site1 = -67
Site2 = -69

On 2.2km @ 5700MHz I have 115 dB of attenuation.

So, 14 (wireless card power Site1) +16 (antenna gain Site1) -115 (attenuation) +18 (antenna gain Site2)= -67 (received signal level at Site2), instead -69 as result from link calculator
and, 12 + 18 -115 + 16 = -69 (received signal at Site1), instead -67 as result from link calculator.

Re: Mikrotik link calculation source code...

Posted: Wed Aug 12, 2015 6:32 pm
by mmv
In Mikrotik Wireless Link Calculator receive signal level also depends on Rx sensitivity of both Sites.
I can't understand why.
wieless_calculator.jpg

Re: Mikrotik link calculation source code...

Posted: Fri Aug 14, 2015 1:17 pm
by el berto
Attenuation at 5GHz on 1 km should be 108dB, so with:
Output power=5dBm
Antenna gain=16dB
Attenuation=108dB

5+16-108+16=-70dB as receiving signal level; this should be regardless RX sensitivity..... or am I wrong?

Re: Mikrotik link calculation source code...

Posted: Fri Aug 14, 2015 2:34 pm
by mmv
Attenuation at 5GHz on 1 km should be 108dB, so with:
Output power=5dBm
Antenna gain=16dB
Attenuation=108dB

5+16-108+16=-70dB as receiving signal level; this should be regardless RX sensitivity..... or am I wrong?
I agree. Additional 1 dB loss may be some internal loss.

But whu and how RX sensitivity make impact on rx power on both sides?!
I know, noise-floor-threshold work like receiver attenuation and if is set higher that current noise-floor it lower RX power on site where set. But it different parameter that RX sensitivity?

Re: Mikrotik link calculation source code...

Posted: Mon Aug 21, 2017 2:14 pm
by pcjc
For some products, the link calculator doesn't appear to allow over-riding the transmit power?

I tried to look at a hypothetical link with an SXT5, but the TX power + antenna gain locked in when selecting that product sum to 42dBm, exceeding the regulatory approvals in the UK. As I understand (and I'm not an expert on this) you are allowed 23dBm on band A (Indoor), 30dBm on band B (Outdoor), and up to 36dBm (Outdoor with license).

My understanding is that the radiated power limits are not Tx power, but effective isotropic power, so (TX power + antenna gain - cable losses). It might help Wireless PtP link newbies like myself to make that clearer on the calculation page, that Tx-power is device emitted power, and possibly just summarise the radiated equivalent power in the calculation sheet - so people can check against local regulatory requirements.

Peter