Down Link Capacity how to improve?

My down link capacity is all over the place on a couple of clients.  It fluxiates bewteen 100 and 10% and it's worrisome.  What is causing this and what can I do to help the issue? 

there are a lot of reasons that could happen.  

the number one thing to watch is your quality.  if your quality is all over the board as well, you're taking interference.  

a few things to double check, the customer's router channel, make sure you have a 5 or 10mhz of channel space between the edges of your channels.   

if it's not your customer's router, using a narrower CPE to block out interference can help.  IE going from a force 180 to a force200 will narrow the field and lower the chances of interference hurting your performance.  

the other possibility is path obstructions and poor signal.  if your quality is solid, and your RSSI is jumping wildly or is low, you may have path obstructions.  either re-locating the Client or increasing gain can compensate for those effects. 

a few other things, but this accounts for the majority of those issues. 

Give us a little more detail. Urban; rural enviorment. Strong RSSI; weak RSSI. RSSI in relation to MCS levels and throughput. SNR levels, edetect results. Is it constant or random? It is impossible to help you diagnose the issue with the information given. Some "Performance" screenshots of suffering SM's will help. 

Maybe start with one SM and give as much detail as possible on it's inflictions. 

In my experience the "Downlink Capacity" number is only useful (if even then) when the radio is activly passing data.  Just before posting this I logged into one of our AP's and went to the Monitor > Wireless section. Almost every single radio had 100% Downlink Quality but the "Downlink Capacity" was all over the place (42 radios, most 100% Q but Capacity ranged from 20% to 100%).

So I picked one customer radio that had 100% Quality but was only showing Yellow 33% Capacity.  I opened the radio in another window so that I could run a 20 second link test on the customer radio while watching the Monitor > Wireless list on the AP .  A few seconds (5 probably since that is the default refresh rate on the GUI) after starting the link test the Capacity jumped up to Blue 88%.  After the test stopped it dropped down to Yellow 40%.

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Capacity is generally a reflection of your MCS state relative to MCS 15.   if all of your downlink packets are successfully being sent via MCS 15, you're at 100% efficiently.   anything less than 15, your efficiency will head down. 

your quality is largely based on link errors, if your retransmits are high and you're having link errors, your quality will drop. 

being in a metro environment your likely getting sporadic noise which is causing the fluctuations.   high gain CPEs and narrow sectors can help reduce these ill effects.     

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9 posts were split to a new topic: Force400 F425 Link Quality flapping between 100% and 0%