Cisco Cisco Prime Network Control System Appliance White Paper

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How to Manage a Cisco Cius Capable Wireless Network

Designing a wireless LAN that effectively supports business-critical data, voice, and video services is simplified

with the Cisco Wireless Control System (WCS) suite of built-in planning and design tools. As an aid to the thorough

pre- and post-deployment site surveys required for any Cisco Cius deployment, Cisco WCS planning and design

tools simplify the process of defining access point placement and determining access point coverage areas for both

standard and irregularly shaped buildings. They also enable immediate assessment of the WLAN

’s readiness to

support voice and video over WLAN for Cius. Most problems with wireless networks stem from the improper design

and deployment as it relates to RF propagation and poor access point placement.

Another common cause of poor call quality and other network-related issues is an incorrect configuration of the

Cisco Wireless LAN Controllers in the environment. WCS also comes bundled with a VoWLAN Audit Tool. You can

use this tool to validate the controller configuration against deployment guide recommendations or the

preconfigured criteria for a given environment. after optimization has occurred.

Other Cius Wi-Fi Considerations

Bluetooth

Cisco Cius is Bluetooth capable. There will be the obvious attraction to add a Bluetooth ear bud, Bluetooth

keyboard and Bluetooth mouse. The Cius is designed to hand off a call to Wi-Fi that is started while the device is

docked and running on Ethernet. This means that when the Cius tablet is being undocked, it will be transferring the

call to Wi-Fi when the device is moving away from the Bluetooth accessories. This will hamper the transition to Wi-

Fi if the call is transitioning to 2.4 GHz.

The Cius can also transfer a call from Wi-Fi when it is being docked. When this happens there may be up to three

Bluetooth accessories trying to pair to the Cius. In an area where there is a high density of users, Bluetooth usage

should be discouraged because simultaneous pairing of just three Bluetooth devices can cause a 2.4-GHz

VoWLAN call to drop. It is therefore recommended that 5 GHz be the primary Wi-Fi WLAN for Cius in an area with

a high density of users.

5-GHz Band

If there are known future application deployments that may include Cius, they too should be considered in capacity

planning. The 5-GHz spectrum provides the most flexible method of high-bandwidth design as there are 21

channels available in the 5-GHz spectrum. These channels do not have frequency overlap as is the case with the

2.4-GHz spectrum. Therefore, 21 access points could share the same floor space and not interfere with each other

or the clients associated with them when in 5-GHz 802.11a mode. The 5-GHz 802.11n wide channel mode (40

MHz) provides for nine non-overlapping channels. When standard 20-MHz wide channels in the 5-GHz 802.11n

band are used, there are 21 non-overlapping channels just as in 802.11a. Many 802.11a clients do not support all

the available 5-GHz channels. It may be necessary to exclude certain channels from RRM dynamic assignment.

Cisco Cius can operate in 20-MHz wide channel and 40-MHz channel mode. This allows the Cius to be fully

functional alongside an Intel laptop that is performing at 300-Mbps data rates. The Cius has the same range on a

40-MHz wide channel as a 20-MHz channel.