450i PTMP Asymmetric Speeds

Hey guys, 

Exhausted pretty much all avenues on this one. I have a single SM connected to a PMP450 AP, signal is OK (-62 and -63 downlink / uplink) and aggregate speed of a link test back to the AP is around 109.52 Mbps,  7924 pps ("Link Test Without Bridging"). Downlink ratio is set to 50%, contention slots 4 and frame period 5ms on the AP.

I'm not able to get more than 84 down 26 up even with the above set. RADIUS is giving the SM a bandwidth allocation of 40/40, and with consideration of the aggregate I'd have expected it to reach this speed...

Full link test results attached. Would appreciate any feedback.



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I have forwarded this to the development and support teams.



Can you show us your configuration -> radio tab? It seems like you have noise on the UpLink (UL) that is causing a mediocre SNR of 20-21dB, limiting your modulation mode to mostly QPSK/16QAM and very little 64QAM. 64QAM encodes 4 bits per symbol while 256QAM encodes 8 bits per symbol so you're passing about half as much capacity as your max throughput in that direction, which would max out at around 60Mbps in a 20MHz channel. You're seening about 25Mbps which is expected given the RF conditions and your relatively low modulation modes. 

Try running a spectrum scan and finding a channel that is clean in both UL and DL directions. You can also set a higher traget receive level to increase your UL RSL if the link is close enough. This can be set in the config->radio tab. You don't want to set it too high if you have other PMP450(i) AP's at that location. A good target if it's not a DFS band is around -55 to -60 dBm.