down sides of harq

We have been playing with some indoor CPEs, they seem to work very well, but only with a large harq settings at low powers. neg 75 and up harq isn’t needed.
We can get 2mb or so down to neg 90, but the harq setting is at 5 to achieve this, at power signals less harq on the indoor CPEs gives us less throughput… no harq and the connection is unusable.

From what I have gathered harq is primarily handled on the CPE side, but what kind of an effect on performance from the AP would running this high of a harq setting have?

i know qpsk really hurts sector performance, we’ve deployed in 6 sector setups so we can run at lower powers. The thought of a self install is just too good.

mgthump wrote:
We have been playing with some indoor CPEs, they seem to work very well, but only with a large harq settings at low powers. neg 75 and up harq isn't needed.
We can get 2mb or so down to neg 90, but the harq setting is at 5 to achieve this, at power signals less harq on the indoor CPEs gives us less throughput... no harq and the connection is unusable.

From what I have gathered harq is primarily handled on the CPE side, but what kind of an effect on performance from the AP would running this high of a harq setting have?

i know qpsk really hurts sector performance, we've deployed in 6 sector setups so we can run at lower powers. The thought of a self install is just too good.


We've tested some CPEs too. We stick at 6MBit/s downstream with some irregular behavior. Sometimes it helps
to play with downlink backoff. Sometimes not. We get this behavior even in perfect conditions (facing each other
with reduced power). We doublechecked the behavior with a PMP320SM to be sure all is configured correct.
The PMP320 performs with 12MBit/TCP in the same situation (which is the max we get for a single CPE).

I'm quite sure this performance problems are not a real wireless problem for which HARQ would be the
appropriate solution. I believe it has to do something with Scheduling/Interoperability.
Using HARQ under perfect condition decreases Max Performace of a CPE way below 10MBit.
Moto told me that the sector performance is not reduced by using HARQ so it should only
hurt single CPEs.

i think your right with the scheduler, the moto CPE gets exactly double the thruput at the same power levels with the same 5 points in harq, it runs mostly ok at bad signals without harq, the indoor CPEs pukes below 80 without harq

with -50 on the indoor CPE without harq i can only get 6.3mb down, 1.1 up. it won’t shift in to matrix B also.

I also got a chance to test motos claim to no loss in performance with harq, and it seems to be true. i used 4 indoor CPEs at -88 to -90 in qpsk 3/4 and i got 6.1 down combined. (link budge table claims 6.5) thats close enough for me.

I’ll see if i can bug the manufacture for firmware updates.