Wireless Access

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Frequent Contributor II
Posts: 120
Registered: ‎10-31-2012

Will a bigger AP really help?

I am looking over the specs, on the different 3xx series WAPs,  I need to deploy enough for 1000 users in a large area.   The users will be all smart-phones,  and so not likely to take advantage of 4x4 MIMO.  All models say they can handle up to 255 associations (obviously not well) but the question is do the higher-end models offer something by the way of onboard memory or processing power that will make them handle high user capacity much better then the lower-end models.  Also considering that I could likely get 12 lower ends for the price of 8 higher end WAPs.    If it is important I will be outdoors (temporary, sunny dry environment)  using external sector antennas, and will utilize 20mhz channels including DFS.

 

 

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Aruba Employee
Posts: 31
Registered: ‎11-19-2007

Re: Will a bigger AP really help?

Assuming this is a high density deployment where you don't have those users spread out over a large area then yes you are better off going with the 'biggest' / highest performance AP you can afford vs buying (more) cheaper APs. The CPU and RAM upgrades allow the higher performance APs to more efficiently process the increased traffic in the air as many clients compete for airtime. 

 

I recommend you take a look a the VHD VRD as well: http://community.arubanetworks.com/t5/Validated-Reference-Design/Very-High-Density-802-11ac-Networks-Validated-Reference-Design/ta-p/230891

Cheers!
Marcus Wehmeyer
Frequent Contributor II
Posts: 120
Registered: ‎10-31-2012

Re: Will a bigger AP really help?

Hi Marcus,

 

The VHD Guide is very useful thank you,  There seems to be some debate however over how much the RAM/CPU come into play.  The Guide references the internal specs of the older model WAPS but not the 3xx series.  The 325 usesQualcomms ipq8064 chip has a faster CPU, more flash but less RAM then the 225,  I have not been able to find specs on the processing and memory capabilities of the other 3xx models.   http://community.arubanetworks.com/aruba/board/message?board.id=IAP&message.id=13332#M13332   I am referencing this thread,  indicating the design most likely has more to do with better results then the specific model chosen.   Since cost is an issue I can get more low end model WAPs spreading users over more 20mhz channels, then with more expensive units.   So the question seems to boil down more to should i get more spectrum or more CPU/Memory.     There are some charts on the VHD that indicate speed differences for up to 100 clients on different older 2xx series WAPs, they are specific to 2 and 3 stream 80mhz channel connections rather then the expected single stream clients that outdoor mobile devices would likely use.

 

I don't say all this to be argumentative but because I want to as best as possible vet my thoughts before making the decision to purchase gear.  Thank you for your input.

 

 

 

Aruba Employee
Posts: 31
Registered: ‎11-19-2007

Re: Will a bigger AP really help?

I don't really see a major advantage one way or the other based on your situation. 

I'm assuming your 1000 users is the max attendance at the event / inside your coverage area. 

 

1000 users with a 30% take rate will be 300 associations

 

Assuming even distribution of APs and Clients:

300 / 12 = 25 users per AP

with 75% on 5Ghz that would be 19 on 5Ghz and 6 on 2.4Ghz

 

300 / 8 = ~37 users per AP

again 75% on 5Ghz that's 28 on 5Ghz and 9 on 2.4Ghz

 

Based on those numbers I'd agree that you are better off with more channels available. 

Cheers!
Marcus Wehmeyer
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