Cisco Cisco Aironet 3700i Access Point Livre blanc
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Next we examine how the competition is handling the transition to 802.11ac and high density. Miercom recently
published a
the Aruba architecture does not handle increasing numbers of clients very well. Figure 4 shows performance as
clients are added incrementally, starting with 5 clients and scaling up to 60 clients.
Figure 4. Comparison of Scalability for a High-Density Environment
In conclusion, 802.11ac allows for speeds never before seen on a Wi-Fi access point. Also, the expectations from
high-density deployments are placing ever-increasing demands on WLAN infrastructure. Cisco has fully
anticipated, comprehended, and addressed these new and evolving demands. Turbo Performance, as a critical
component in the HDX solution suite, can enable exceptional performance and scalability.
Dynamic Bandwidth Selection (DBS) - Automatically Choose the Best Channel Width
Every advancement in Wi-Fi technology includes corresponding complexities and tradeoffs. For example, much of
the speed improvements in the evolution from 802.11b to 802.11g/a, to 802.11n and to 802.11ac are achieved by
simply doubling the RF channel width. Increasing channel width from 20 MHz to 40 MHz effectively doubles
over-the-air speed. And increasing channel width from 40 MHz to 80 MHz doubles that speed again.
Of course, wider channels are more susceptible to interference (since a wider channel
can “hear” more).
Furthermore, with wider channels, the number of available non-overlapping channels decreases making mutual
interference an increasing problem. Being able to send data over the air faster is very important, but if the devices
in your WLAN are waiting more often to send data because the wider channel is more likely to be busy, then
disappointment and unrealized expectations will occur. Keep in mind that because air is shared for Wi-Fi it uses a
listen-before-talk protocol.
Also, in a real world, it is highly unlikely to have homogeneous device types. The client mix will include legacy
devices that simply cannot operate at 80 MHz or 40 MHz. This means that spectrum could be wasted if the network
is configured for a greater channel width than most of its devices can handle.