Cisco Systems AIRRM3000ACAK9 manual 802.11ac Primer How is it different from 802.11n?

802.11ac Primer – How is it different from 802.11n?

4.If you require 3 spatial stream coverage for the fastest throughput, and/or you are looking for the best BYOD experience, the Cisco Aironet 3600 and 2600 Series Access Points with ClientLink 2.0 will perform better than the AP 3500. The AP 3600 can beamform to 802.11n clients, so it is important to understand the data requirements if you are mixing Cisco Aironet 1260, 3500 and 3600 Series Access Points in the same areas.

5.While site surveys are generally recommended, if the design is done at half power and Cisco RRM is in place, sometimes a limited site survey (coverage check) is adequate for smaller venues. If this is a very challenging environment such as train connectivity, Gas & Oil verticals, large hospitals, etc., Cisco has an Advanced Services team that can be contracted to help you get up to speed or perform your installation. See your Cisco account team for more information.

6.Cisco AP 3600 was introduced in the 7.1.91 or higher code stream and is supported by the following: Cisco 2500, 7500, 5508 and WiSM2 Series Controllers and WCS 7.0.220 or higher and NCS 1.1 or higher. The AP 1600 and 2600 was introduced in the 7.4 release.

7.The rule of thumb coverage plan is: 1 AP per 5,000 square feet for data and 1 per 3,000 square feet for voice and location services.

8.Some clients (especially older ones) do not support the UNII-2 extended client channels 100-140, so if you have lots of older clients you may want to disable them in the DCA channel list.

Note More and more clients support these channels all the time, as will the newer 802.11ac clients.

802.11ac Primer – How is it different from 802.11n?

802.11ac is backwards compatible with 802.11n but is coming in “Waves” which are different features and functionality. New features and functionality often require new hardware, or as in the case of the AP 3600 the ability to introduce new hardware within the base unit. An Access Point that is not modular typically requires a complete hardware replacement. The AP 3600 utilizes a dual core processor with one core supporting new hardware via the feature module option. The first release of 802.11ac (Wave-1) brings the following features over 802.11n

802.11ac Wave-1 features include:

•Faster PHY rate 1.3 Gbps over the typical 450 Mbps of 802.11n

•Introduction of faster modulation 256 QAM over the 64 QAM of 802.11n – This creates many new data rates similar to 802.11n but in many cases faster rates with single stream and multiple stream devices

•Ability to bond 80 MHz channels versus 40 MHz bonding of 802.11n – This can greatly enhance the throughput of devices that only support 1 spatial stream by extending the usable bandwidth of the device (often portable battery operated devices lacking multiple radios) spatial streams.

•Explicit Compressed Beam Forming – This is similar to what was proposed in 802.11n and is a method whereas the client can take advantage of sounding mechanisms to essentially tell the Access Point how to better beam form the signal back to the client. This functionality only works with 802.11ac clients and is supported with the Cisco Wave-1 module but this does not negate the value of Cisco Client Link which is still used by the primary 802.11n radios as Client Link benefits all 802.11a,g, and n clients.

•With regard to Cisco products, the 802.11ac module is a 5 GHz only as 802.11ac does not scale well in 2.4 GHz due to the limited channels and bandwidth limitations (it is not practical to bond channels in 2.4 GHz) in an enterprise deployment and non-standard “turbo modes” don’t scale.

Cisco Aironet Series 1600/2600/3600 Access Point Deployment Guide, Release 7.5

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