Cisco Aironet 2702i AIR-CAP2702I-E-K9 Folheto

 

 

© 2014 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public Information. 

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Enterprise networks considering an investment in infrastructure Wi-Fi have two excellent choices: (1) buy 802.11n 

APs, since they deliver a remarkable level of performance, they are available today, and 802.11n is widely 

deployed in client products, or (2) wait for 802.11ac APs and their state-of-the-art performance. A third option 

avoids the wait: invest in a modular 802.11n AP such as the 

, which is 

readily field-upgradable to 802.11ac, or the Cisco Aironet 3700 Series Access Point, which supports an integrated 

802.11ac radio. 

802.11ac will have a few effects on existing 802.11a/n deployments, even if the deployment is not upgraded to 

802.11ac immediately: (1) the wider channel bandwidths of neighboring APs require updates to radio resource 

management, or RRM (and in particular the dynamic channel assignment algorithm), and (2) 802.11a/n wireless 

intrusion protection systems (WIPS) can continue to decode most management frames such as beacon and probe 

request/response frames (that are invariably sent in 802.11a format) but do not have visibility into data sent in the 

new 802.11ac packet format. 

One thing not to worry about is compatibility. 802.11ac is designed in a deep way to coexist efficiently with existing 

802.11a/n devices, with strong carrier sense, a single new preamble that appears to be a valid 802.11a preamble 

to 802.11a/n devices, and extensions to request-to-send/clear-to-send (RTS/CTS) to help avoid collisions with 

users operating on slightly different channels. 

2. What Is 802.11ac? 

First, 802.11ac is an evolution of 802.11n. If you want to learn more about 802.11n, jump to the Appendix. If you 

are already familiar with the channel bonding, MIMO, and aggregation introduced by 802.11n, and y

ou don’t need 

a refresher, read on. 

802.11ac is an evolutionary improvement to 802.11n. One of the goals of 802.11ac is to deliver higher levels of 

performance that are commensurate with Gigabit Ethernet networking: 

● 

A s

eemingly “instantaneous” data transfer experience 

● 

A pipe fat enough that delivering a high quality of experience (QoE) is straightforward 

In the consumer space, the target is multiple channels of high-definition (HD) content delivered to all areas of the 

house. The enterprise has different challenges: 

● 

Delivering network with enterprise-class speeds and latencies 

● 

High-density environments with scores of clients per AP 

◦ 

Which are exacerbated by the 

 trend, such that one employee might carry two or even three 

802.11 devices and have them all consuming network resources at the same time 

● 

The increased adoption of video streaming 

802.11ac is about delivering an outstanding experience to each and every client served by an AP, even under 

demanding loads. 

Meanwhile, 802.11 is integral to a hugely broad range of devices, and some of them are highly cost, power, or 

volume constrained. One antenna is routine for these devices, yet 802.11ac must still deliver peak efficiency. 

The one thing that 802.11ac has in its favor is the evolutionary improvement to silicon technology over the past 

half-dozen years: channel bandwidths can be wider, constellations can be denser, and APs can integrate more 

functionality.