Mikrotik link calculation source code...

angboontiong · November 8, 2011, 2:16pm

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.

sadeghrafie · November 8, 2011, 4:15pm

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.

angboontiong · November 8, 2011, 8:20pm

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…

sadeghrafie · November 8, 2011, 8:23pm

I know about MT link calc and I used it before, I mean they will not give source code

normis · November 9, 2011, 7:27am

Paste this into your website html:

<iframe src="http://www.mikrotik.com/test_link.php" width="380" height="680"></iframe>

angboontiong · November 9, 2011, 9:59am

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.

normis · November 9, 2011, 10:19am

Solve the internet issues by switching all the routers to mikrotik

angboontiong · November 9, 2011, 10:28am

^_^…

Great suggestion, we are on the way…

reverged · November 10, 2011, 5:13am

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?

chronos · November 16, 2011, 10:26pm

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

el_berto · July 9, 2014, 10:22am

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.

mmv · August 12, 2015, 3:32pm

In Mikrotik Wireless Link Calculator receive signal level also depends on Rx sensitivity of both Sites.
I can’t understand why.
wieless_calculator.jpg

el_berto · August 14, 2015, 10:17am

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?

mmv · August 14, 2015, 11:34am

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?

pcjc · August 21, 2017, 11:14am

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