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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Figure 6.    Channel Options for 160 MHz and 80+80 MHz 

 

Neither 160 MHz nor 80+80 MHz are recommended for typical enterprises, given the currently available spectrum. 

As shown in 

, RRM becomes a much more complicated task. It must: 

● 

Avoid channels with radar (if present). 

● 

Uniformly spread the channel bandwidth used by each AP and preferably spread the AP’s primary 20-MHz 

channel too. 

● 

Avoid a channel that overlaps with other 20-, 40-, 80-, 160-, or 80+80 MHz APs nearby. 

● 

Within an 80-MHz channel bandwidth (for example), decide whether to align primary 20-MHz channels with 

other APs or deliberately not align primary channels. This is not a clear-cut choice: 

◦ 

If the primary channels are aligned, virtual carrier sense works completely, yet all 20- and 40-MHz traffic 

(including broadcast, multicast, and data traffic to 802.11a/n devices) is sent in series. During these 

times, 40 or 60 MHz of bandwidth is unused. Still, if the clients are predominantly 802.11ac, this is 

generally the best approach in terms of throughput and airtime fairness. 

◦ 

Conversely, if one AP’s primary channel is assigned to the lower 40 MHz and another AP’s channel is 

assigned to the upper 80 MHz, 20- and 40-MHz traffic can be parallelized (as shown in 

). If 

clients are predominantly 802.11a/n, this is the better choice. And when the whole 80 MHz is free, as 

measured by physical carrier sense and/or RTS/CTS with bandwidth indication, 80-MHz communication 

between 802.11ac devices is still allowed. 

Certainly it is difficult to get the most out of 802.11ac without coordination of AP channel assignment, typically 

under the aegis of an effective centralized RRM algorithm.