hi guy's, we have a epmp1000 in ptp master slave link from 330m awaym and near LOS. we see each module . link is 200mbits, -53Db, 4ms ping. but i do not know the signification for the 'ealign'  tool.  

in the tower , module A, the ealign tool variate from -45 to -80 Db very rapidly. and from basement module B, ealign is very stable  around -53Db. is somebody explain to me?

thanks a lot


The eAlign tool is supposed to help installers with the process of alignment of the subscriber modules (physically set the subscriber module in a position where it gets the strongest and most balanced signal possible) for better performance.

Is your unstable eAlign results coming from the device in ePTP Slave or Master mode? If it is coming from the ePTP Master, I believe it is a RSSI misreporting due to an implementation defect.

Which sw version are you using?


indeed, the eptp master is located in a tower, yesterday the wind mostly pull me out of the tower. lots af vibration. is vibration can cause this issue

version is the last. 2.6.1, the graphic below goes from -45 to -80.

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Never seen anything like it.

What antenna is at each side of that link? (integrated CPE // force200 // force180 // dish of some kind?)

What kind of tower do you have there? any pictures available?

If you're using a connectorized unit, is there any possibility one of the RF cables are cracked/not properlly tightened?

antenna s is , Epmp1000, distance 335meters, water tower hight 225 foot, attached to the frame. integrated antenna, outdoor shielded network cable.  this is the water tower, both Epmp are near LOS

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I don't see any reason for wind-induced vibration to cause a -35db signal swing there.

The antenna would need to twist/swing by some +/- 10 degrees to cause fluctuations like that.
It appears not to be the case.

I have the impression that there is a road in the LOS, maybe vehicles passing in front of the link could cause the signal degradation?

The first thing i would try is to make the ground-side of the link a little higher.

I've seen this on PMP100 before and it ended up being an issue with sync.

Are you using GPS Sync on the master?  If so, what happens when you set it to internal?

edit: from looking at the pics closer, appears both sides are SM's, so it's probably not sync

Thanks for the info. I believe this is still a RSSI reporting issue. We will look into it.


hi, i heard about the freznel zone, how do we calcul it in the 2.4ghz? there a pille of rock in front of the slave. do you think there is a problem with that?  the slave is located on the garage side and i can move the antenna at the top with a 10 foot pole. so it could be 25 foot higher.thank you for your time

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There are several online Fresnel Zone calculators, for example http://www.proxim.com/products/knowledge-center/calculations/calculations-fresnel-clearance-zone. It is worth checking it out.

BTW, which ePMP1000 platforms are you using as Master and Slave? I see your Slave in the picture is a ePMP1000 with Integrated Antenna. Are you using the same as Master?


hi, i calculate the fresnel zone, result is 13,foot at mid distance, & 10 foot for 80% fresnel.

so i think it is the point from the garage, we have a rock pile in front of the antenna, so it give near LOS, on thursday, il will reinstal the garage antenna, on the garage top, with a 10 foot mast. it think it will help a lot.

what do you think?

yes sir, both are Epmp1000 ver 2.6.1


If the rocks are high enough to interfere with the fresnel zone, it could be an issue. Giving the radio additional elevation should help.



hi, i have moved the antenna higher, a the garage's top and put the acces point at the water tank in ''accespoint standard wireless''  , station at the garage and at the main entrance in SM with wireless. 

RSSI signal is then normal at -52 for the garage & -48 for the main entrance. i think that the RSSI issue is solved.,

thanks a lot.