Wlan Standards And Technologies; 802.11 Standards For Wlan Communications - Cisco 7925G Administration Manual

WLAN Standards and Technologies

The following figure shows a typical WLAN topology that enables the wireless transmission of voice for
wireless IP telephony.
Figure 2: WLAN with Cisco Unified Wireless IP Phones
When a wireless IP phone powers up, it searches for and becomes associated with an AP. As users move from
one location to another, the wireless IP phone roams out of range of one AP into the range of another AP.
The wireless IP phone builds and maintains a list of eligible APs and reconnects to an AP in that list. See
Association, on page 34
The AP uses its connection to the wired network to transmit data and voice packets to and from the switches
and routers. Voice signaling transmits to the Cisco Unified Communications Manager server for call processing
and routing. APs are critical components in a WLAN because they provide the wireless links or "hot spots"
to the network.
Each AP has a wired connection to an Ethernet switch, such as a Cisco Catalyst 3750 Series, that is configured
on a LAN. The switch provides access to gateways and the Cisco Unified Communications Manager server
to support wireless IP telephony.
For more information on WLANs, APs (including supported models), antennas, and wireless IP telephony,
see Cisco Unified Wireless IP Phone 7925 and 7926 Series Deployment Guide at
US/products/hw/phones/ps379/products_implementation_design_guides_list.html.
WLAN Standards and Technologies
This section describes WLAN standards and technologies.

802.11 Standards for WLAN Communications

Wireless LANs must follow the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards that
define the protocols that govern all Ethernet-based wireless traffic. The Cisco Unified Wireless IP Phone
supports the following standards:
Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G Administration Guide
24
for more information.
VoIP Wireless Network
AP
http://www.cisco.com/en/