What is maximum speed based on the datasheet for AIR-CAP3502I

[wfqk]

Hi I got a datasheet for AIR-CAP3502I. Please see the below link. It looks like that the maximum speed is 300Mbps or 54Mbps. I am not sure which one is correct. How to explain the two rates? I would like to know what is its maximum speed. Thank you

802.11n Version 2.0: PHY data rates up to 300 Mbps

Data Rates Supported: 802.11a: 6, 9, 12, 18, 24, 36, 48, and 54 Mbps

https://www.cisco.com/c/en/us/products/collateral/wireless/aironet-1250-series/data_sheet_c78-594630.html

[Flavio Miranda]

Hi

The doc shows as follow:

802.11a: 6, 9, 12, 18, 24, 36, 48, and 54 Mbps

802.11g: 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, and 54 Mbps

802.11n data rates (2.4 GHz and 5 GHz):

Which means, 802.11a and 802.11b reachs the maximum speed of 54Mbps, they are legacy protocol.

 802.11n, which is newer then those, can reach up to 300 Mbps but it depends on which MCS index you device is and the channel width. 

 802.11n uses a different form do achieve the data rates. 

-If I helped you somehow, please, rate it as useful.-

[Rasika Nayanajith · Accepted solution]

It is 300 Mbps with 802.11n (802.11a/g max speed limited to 54Mbps). With 802.11n there are different possible data rates based on Modulation & Coding Scheme (MCS) it use.

In 802.11n, data rates depend on spatial stream, modulation scheme, channel width & guard interval. If you look at given data sheet, 3502 is 2 SS (spatial stream), 40MHz capable(in 5GHz band only) AP.

2x3 multiple-input multiple-output (MIMO) with two spatial streams

20- and 40-MHz channels

If you see below you will understand with above (2SS, 40MHz) you will get 300Mbps

http://mcsindex.com/

Note that these are theatrical values, in practical environment you will not achieve those values.(you may see 50-60%). Also that is total capacity of the AP, if you have single client (802.11n, 40MHz capable , 2SS) attached to given AP that would be the best case scenario.

When you have multiple clients, each clients throughput will be drastically reduced. So do not expect 100-200 Mbps in each client.

You can see different clients capability from this URL

http://clients.mikealbano.com/

HTH

Rasika

*** Pls rate all useful responses ***

[wfqk]

Thank you so much for you both explanation! Do you think it is possible? if we put two AP together (for test, we can put two AP1131, which can reach maximum speed 54Mpbs without 802.11n) then the users can get traffic from two AP, that would be increase speed on users side. I dont think it is possible. but i do not know its clear explanation on it.  Can you explain? 

[Scott Fella]

You will not increase theoretically throughput. You add another AP to help distribute the client load. That’s if clients balance well between the two. To increase throughput, you need to have an access point that is 802.11ac. I didn’t mention 802.11n because all AP’s shipping new are 802.11ac.