What you are seeing (improvements) is a combination of a better radio (epmp) 
and the effect of GPS sync radios in a low to mild interference environment.. 

You will see such improvements thruout.. unless you run into heavy interference 
or another GPS radio (out of sync) operating on that channel. 

:) 

Faisal Imtiaz 
Snappy Internet & Telecom 
7266 SW 48 Street 
Miami, FL 33155 
Tel: 305 663 5518 x 232 

Help-desk: (305)663-5518 Option 2 or Email: [email protected] 

> From: "Christopher Gray" <[email protected]>
> To: [email protected]
> Sent: Thursday, September 10, 2015 10:34:14 PM
> Subject: Re: [AFMUG] UBNT vs ePMP Signal Strength?

> These are both NLOS links [which ePMP appears to handle better]. The 
> throughput
> increase may not have been as great if the links were LOS.
> On the link I switched today, I was averaging around 7.5 Mbps one-way with the
> Rocket M2 right before switching. After switching to ePMP, one-way tests were
> averaging about 13.5 Mbps. This is on a clean 5 MHz channel with several trees
> in the way. The power is turned up all the way (25 dBm minus 1 dB cable loss
> for the 24 dBi dish, and 27 dBm minus 1 dB cable loss for the 18 dBi dish).

> If I setup the weaker link with ePMP to start, I would have seen -80 dBm and
> told the customer I would not do it. Even at -72 dBm with the Rockets I was
> hesitant. The ePMP links have been stable even through some heavy rain
> (throughput dropped to about 11.5 Mbps on the weak link). I'm going to try it
> for a while and keep my Rockets ready. At this point, I'm assuming the ePMP 
> 2.4
> GHz RSSI calculations are artificially low.

> -Chris

> On Thu, Sep 10, 2015 at 3:18 PM, Brian Sullivan < [email protected] >
> wrote:

>> I am not sure why the signals would read differently, but i'm curious how you
>> arrived at the 60 to 70% throughput increase.
>> Other than the ability to sync, I thought the main difference between UBNT's 
>> M
>> series and ePMP was the user interface??

>> On 9/10/2015 2:06 PM, Christopher Gray wrote:

>>> I just changed two low bandwidth 5 MHz width PTP links from Rocket M2 
>>> radios to
>>> ePMP 2.4 GHz non-sync radios. The "signal strength" is about 10 dB lower 
>>> with
>>> the ePMP radios. Do they use a different mechanism to calculate signal
>>> strength?

>>> Link 1:

>>>     * 2x Rocket Dish RD-2G24
>>>     * Antennas were not re-aimed when switching radios
>>>     * Radio outputs are maximized on both systems to FCC PTP limits
>>>     * UBNT signal read -62 dBm Tx / -61 dBm Rx
>>>     * ePMP singal reads -72 dBm Tx / -70 dBm Rx

>>> Link 2:

>>>     * 1x Rocket Dish RD-2G24
>>>     * 1x L-Com DPD 18 dBi Dish
>>>     * Antennas were not re-aimed when switching radios
>>>     * Radio outputs are maximized on both systems to FCC PTP limits
>>>     * UBNT signal read -70 dBm Tx / -72 dBm Rx
>>>     * ePMP singal reads -80 dBm Tx / -82 dBm Rx

>>> Both links were stable, and both links appear stable now. Both ePMP links 
>>> have
>>> 60-70% more throughput. Do I just need to adjust my mental meter 10 db? Are 
>>> the
>>> new signals actually as concerning as they feel?

>>> Thanks - Chris

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