1-3
Cisco Aironet 340, 350, and CB20A Wireless LAN Client Adapters Installation and Configuration Guide for Windows
OL-1394-07
Chapter 1 Product Overview
Hardware Components
Note
In the first three product model numbers, the first x represents the client adapter series (340 or 350), and
the second x indicates the wired equivalent privacy (WEP) level of the card, where 0 = no WEP
capability, 1 = 40-bit WEP, and 2 = 128-bit WEP. If the last two product model numbers contain K9, the
card is 128-bit WEP capable.
Terminology
The following terms are used throughout this document:
•
client adapter—Refers to all five types of adapters.
•
PC card, LM card, PCI card, mini PCI card, or PC-Cardbus card—Refers to a specific adapter.
•
workstation (or station)—Refers to a computing device with an installed client adapter.
•
infrastructure device—Refers to a device that connects client adapters to a wired LAN, such as an
access point, bridge, or base station. Throughout this document, access point is used to represent
infrastructure devices in general.
Hardware Components
The client adapter has three major hardware components: a radio, a radio antenna, and two LEDs.
Radio
Different radios are used for the 2.4-GHz and 5-GHz client adapters:
•
The Cisco Aironet 340 and 350 series PC, LM, PCI, and mini PCI cards are IEEE 802.11b-compliant
client adapters. They contain a direct-sequence spread spectrum (DSSS) radio that operates in the
2.4-GHz Industrial Scientific Medical (ISM) license-free band. The 340 series 30-milliwatt (mW)
radio and the 350 series 100-mW radio transmit data over a half-duplex radio channel operating at
up to 11 Mbps. These cards operate with other IEEE 802.11b-compliant client devices in ad hoc (or
peer-to-peer) mode or with Cisco Aironet 340, 350, 1100, and 1200 Series Access Points (with a
2.4-GHz radio) and other IEEE 802.11b-compliant infrastructure devices in infrastructure mode.
They are approved for indoor and outdoor use.
DSSS technology distributes a radio signal over a wide range of frequencies and then returns the
signal to the original frequency range at the receiver. The benefit of this technology is its ability to
protect the data transmission from interference. For example, if a particular frequency encounters
noise or interference or both, enough redundancy is built into the signal on other frequencies that
the client adapter usually will still be successful in its transmission.
•
The Cisco Aironet AIR-CB20A PC-Cardbus card is an IEEE 802.11a-compliant client adapter. It
contains an orthogonal frequency division multiplexing (OFDM) radio that operates in the
Unlicensed National Information Infrastructure (UNII) 1 and UNII 2 license-free bands located in
the lower 5-GHz portion of the radio frequency spectrum. The 20-mW radio transmits data over a
half-duplex radio channel operating at up to 54 Mbps. This card interoperates with other IEEE
802.11a-compliant client devices in ad hoc mode or with Cisco Aironet 1200 Series Access Points
(with a 5-GHz radio) and other IEEE 802.11a-compliant infrastructure devices in infrastructure
mode. It is approved for indoor use only except in the United States, which allows for outdoor use
on channels 52 through 64.
