Path B modulation

It seems like after we rolled out  13.2 software that we see some of our 7-9 mile links not modulate as high on path B when they are realatively inactive.  Is this normal?  

I know the epmp gear will do something similar to this during periods of inactivity when SM isn't asking for data but I never noticed this with PMP 450 13.1.3 software.  Path A pretty much stays at 256 QAM but path B will shows a pretty consistant  16QAM modulation until the SM starts pushing some data.   SNR and signal rate look good.  Spectrum looks clean (3695.00).  I will say that the link tests push the expected bandwidth we want to see but I just want to know if this behavior is normal for an SM?  I'm using a KP Performace feedhorn/reflector and link is registered at 8X/6X.


Well, after much testing I can confirm that Path B does "sleep" when not in use and then lights up when you run data through it.  Didn't notice this happening on previous firmware but this is probably a  more efficient way to do things.  Just wanted to follow up on my post.  

Thanks Nathan. Let us know if there is anything else you need.


Both paths are always included in the modulation rate.

1X MIMO-B is QPSK on one path

2X MIMO-B is QPSK on both paths

4X MIMO-B is 16-QAM on both paths

6X MIMO-B is 64-QAM on both paths

8X MIMO-B is 256-QAM on both paths

13.2 added new MIMO-A modulation levels:

1X MIMO-A is QPSK duplicated on both paths

2X MIMO-A is 16-QAM duplicated on both paths

3X MIMO-A is 64-QAM duplicated on both paths

4X MIMO-A is 256-QAM duplicated on both paths

The radio tries to get the best throughput for the radio conditions.

When in-active what modulation rates do you see when idle and then after a link test?


Whoops. Copy/Paste error. My post is now updated with the right MIMO-A rate adapts.

The SM is always at full modulation on Path A.  Path B modulation "kicks up" to full modulation only after I see some traffic flowing and it will get full 256 QAM and pretty much stay there until traffic starts winding down.  I never noticed this happening before prior to 3.2 Firmware so I was just wondering if it was normal.  The link tests and speed tests give me the bandwidth I want to see but I just wanted to make sure it wasn't something going wrong.  So far, so good.  These 450's ROCK!