Hi,
I am a bit confused how to interpret my linkplanner result using PTP670 as below.
If the requirement stated “availability 99.99% achieved at 64QAM 0.75 single and fade margin not less than 20dB”; does this mean that the result has failed (since IP Throughput Availability % at 64QAM 0.75 single is 0.8%)?
But result at performance shown IP Throughput Availability % Predicted is 100.00%.
Performance *
Mean IP Throughput Predicted 217.30 Mbps
Mean IP Throughput Required 5.00 Mbps
Minimum IP Throughput Required 25.00 Mbps
Minimum IP Throughput Availability Predicted 100.0000% (unavailable for 1 secs/year)
What is the relation between these two %?
Thank you in advance
The PTP 670 makes a decision based on the quality of the signal as to whether to use the single mode branch for modulations above QPSK or the dual mode branch. In this example the quality of the signal is good and therefore there is a very high probability that it will use the dual modes and only a low probability that it will use single modes. I think that your requirement is looking for “at least 64 QAM 0.75 single” and therefore you can add the availability of the 64 QAM 0.75 single (0.8629%) to the availability of the 16QAM 0.63 Dual (99.1360%) as this has a higher data rate. This gives a total availability of 99.9989% of achieving a data rate of at least 74.85Mbps.
In your lower set of results you have set a Minimum IP Throughput Required to 25 Mbps (much lower than that for 64 QAM 0.75 single) and the Minimum IP Throughput Availability Predicted of 100% is the availability for the 25 Mbps not for the 64QAM. If you want to see the Minimum IP Throughput Availability Predicted match the 64QAM 0.75 Single requirement then you need to increase the Minimum IP Throughput Required to above the level for mode just below, so in this case anything between say 60 and 70 Mbps will push you into at least 64QAM 0.75 Single mode.
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