Cisco Unified Wireless Ip Phone 7925G, 7925G-Ex, 7926G Overview; Requirements; Site Survey; Rf Validation - Cisco 7925G Deployment Manual

Cisco Unified Wireless IP Phone 7925G, 7925G-EX, 7926G Overview

The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G provide mobile communication within enterprises. The
levels of voice quality performance that have come to be expected from Cisco products are maintained in the Cisco Unified
Wireless IP Phone 7925G, 7925G-EX, and 7926G with the inclusion of Cisco Compatible eXtensions (CCX).
Cisco's implementation of 802.11, employing CCX, permits time sensitive applications such as voice to operate efficiently
across campus wide wireless LAN (WLAN) deployments. These extensions provide fast roaming capabilities and an almost
seamless flow of voice traffic, whilst maintaining security as the end user roams between access points.
It should be understood that WLAN uses unlicensed spectrum, and as a result it may experience interference from other devices
using the unlicensed spectrum. The proliferation of devices in the 2.4 GHz spectrum, such as Bluetooth headsets, Microwave
ovens, cordless consumer phones, means that the 2.4 GHz spectrum may contain more congestion than other spectrums. The 5
GHz spectrum has far fewer devices operating in this spectrum and is the preferred spectrum to operate the Cisco Unified
Wireless IP Phone 7925G, 7925G-EX, and 7926G in order to take advantage of the 802.11n data rates available. Despite the
optimizations that Cisco have implemented in the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G, the use of
unlicensed spectrum means that uninterrupted communication can not be guaranteed, and there may be the possibility of voice
gaps of up to several seconds during multimedia conversations. Adherence to the deployment guidelines will reduce the
likelihood of these voice gaps being present, but there is always this possibility. Through the use of unlicensed spectrum, and
the inability to guarantee the delivery of messages to a WLAN device, the Cisco Unified Wireless IP Phone 7925G, 7925G-EX,
and 7926G is not intended as a medical device and should not be used to make clinical decisions.

Requirements

The Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G are IEEE 802.11a/b/g wireless IP phones that provide
voice communications.
The wireless LAN must be validated to ensure it meets the requirements to deploy the Cisco Unified Wireless IP Phone 7925G,
7925G-EX, and 7926G.

Site Survey

Before deploying the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, or 7926G into a production environment, a site
survey must be completed by a Cisco certified partner with the advanced wireless LAN specialization. During the site survey
the RF spectrum can be analyzed to determine which channels are usable in the desired frequency band (2.4 GHz or 5 GHz).
Typically there is less interference in the 5 GHz band as well as more non-overlapping channels, so 5 GHz is the preferred
frequency band for operation and even more highly recommended when the Cisco Unified Wireless IP Phone 7925G, 7925G-
EX, or 7926G is to be used in a mission critical environment. The site survey will include heatmaps showing the intended
coverage plan for the location. The site survey will also determine the access point platform type, antenna type, and access
point configuration (channel and transmit power) to use at the location. It is recommended to select an access point with
integrated antennas for non-rugged environments (e.g. office, healthcare, education, hospitality) and an access point platform
requiring external antennas for rugged environments (e.g. manufacturing, warehouse, retail).
See the Designing the Wireless LAN for Voice section for more information.
Refer to the Steps to Success website for additional information.
http://www.cisco.com/go/stepstosuccess

RF Validation

In order to determine if VoWLAN can be deployed, the environment must be evaluated to ensure the following items meet
Cisco guidelines.
Signal
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