best practice ptp link between epmp force 110

What are the best practice to implement Point to Point Link between two epmp Force 110 (no sync) across 5km with LOS. I need 10Mpbs up/down whit lowest latency as posible because of VoIP.

What should I configure on the field "Acces Ponint Mode"
TDD, ePTM Master or TDD PTP

What should I configure on the field "Suscriber Module Mode"
TDD or ePTP Slave

Power control.
Antena Gain, Should I always configure antena datasheet value?, for this scenario should be 25dBi
Trasmitter Output Power. max is 30, but for this distance and bit rate, what do you suggest?

Down/UP ratio. 75/25 70/50 30/70 or Flexible
Frame size: 2.5 or 5ms, I think it should be 2.5 (VoIP)
And finally, wha chaanel bw do you suggest? 5,Ā  10, 20, or 40. I thinkĀ  5 or 10 is ok for 10Mbps up/down and 5km f distance with LOS, what do you think.

Any other suggest.?



Some things to consider:

- TDD (TDD and TDD PTP modes are basically same implementation, with limitation of only one client in TDD PTP mode being the only difference between them) have slightly higher latency than ePTP but TDD do allow traffic prioritization (QoS). ePTP does not support QoS.

- Configuring the correct Antenna Gain will keep you legal.

- Since sync is not required, TDD Flexible or 50/50 would probably make sense. Using Flexible also improves latency over using 50/50.


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A lot of your questions will have to be answered by doing a spectrum analysis. You'll need to see what spectrum is available and how much. For links like that, we've stuck with 10/20MHz and TDD PTP. You won't be able to use ePTP because that doesn't allow for any QoS tags.

As far as power goes, you can use the Link Planner to see what to expect and adjust from there. If you don't plan on using any type of sync/frequency reuse, you'll be OK in flexible mode. If you do plan to use sync, you'll need to plan accordingly.

I don't have as much experience with these links as some others on here, but this is my $.02.


For short PTP links, we have had a very good experience with 2.5ms frame size.Ā 

It cuts the latency significantly (5-7 vs 15ms ), keeps the Qos capabilities, and in some cases outperformedĀ 
the "flexible" setting in troughput.