Hardware Components - Cisco AIRONET CB21AG User Manual

Chapter 1 Product Overview and Installation

Hardware Components

The client adapters have three major hardware components: a radio, a radio antenna, and two LEDs.
Radio
The client adapters contain a dual-band radio that is both IEEE 802.11a and 802.11b/g compliant. The
radio uses both direct-sequence spread spectrum (DSSS) technology and orthogonal frequency division
multiplexing (OFDM) technology for client applications in the 2.4-GHz Industrial Scientific Medical
(ISM) frequency band and OFDM technology in the 5-GHz Unlicensed National Information
Infrastructure (UNII) frequency bands. The client adapters operate with other IEEE 802.11a or
802.11b/g-compliant client devices in ad hoc mode or with Cisco Aironet access points and other IEEE
802.11a or 802.11b/g-compliant infrastructure devices in infrastructure mode.
Radio Antenna
The type of antenna used depends on your client adapter:
•
•
LEDs
The client adapters have two LEDs that glow or blink to indicate the status of the adapter or to convey
system messages.
Table 1-2
Status LED (green)
Off
Blinking slowly
On
Alternating blink:
Cisco Aironet 802.11a/b/g Wireless LAN Client Adapters (CB21AG and PI21AG) Installation and Configuration Guide for Windows Vista
OL-16534-01
PC-Cardbus cards have an integrated, permanently attached 0-dBi gain, dual-band 2.4/5-GHz
diversity antenna. The benefit of the diversity antenna system is improved coverage. The system
works by enabling the card to sample and switch between its two antenna ports in order to select the
optimum port for receiving data packets. As a result, the card has a better chance of maintaining the
radio frequency (RF) connection in areas of interference. The antenna is housed within the section
of the card that hangs out of the Cardbus slot when the card is installed.
PCI cardshave a 1-dBi gain, dual-band 2.4/5-GHz antenna that is permanently attached by a 6.6-foot
(2-meter) cable. A base is provided with the antenna to enable it to be mounted to a wall or to sit
upright on a desk or other horizontal surface.
Table 1-2 provides interpreations of the the LEDs.
LED Operating Messages
Activity LED (amber)
Off
Off
Off
On Off
Off On
Condition
Client adapter is not receiving power.
Client adapter is in power save mode.
Client adapter has awakened from power save mode.
Client adapter is scanning for the wireless network
for which it is configured.
Hardware Components
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