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Cisco Aironet Wireless LAN Client Adapters Installation and Configuration Guide for Windows CE
OL-1375-03
Chapter 1 Product Overview
Hardware Components
Hardware Components
The client adapter has three major hardware components: a radio, a radio antenna, and two LEDs.
Radio
The Cisco Aironet 340 and 350 series PC and LM 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
80211b-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.
Radio Antenna
The type of antenna used depends on your client adapter:
•
PC cards have an integrated, permanently attached diversity antenna. The benefit of the diversity
antenna system is improved coverage. The system works by allowing the card to switch and sample
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 PC card slot
when the card is installed.
•
LM cards are shipped without an antenna; however, an antenna can be connected through the card’s
external connector.
Note
External antennas used in combination with a power setting resulting in a radiated power level above
100 mW equivalent isotropic radiated power (EIRP) are not allowed for use within the European
community and other countries that have adopted the European R&TTE directive or the CEPT
recommendation Rec 70.03 or both. For more details on legal combinations of power levels and
antennas in those countries, refer to the
“Declaration of Conformity for RF Exposure” section on
and the
“Channels, Power Levels, and Antenna Gains” section on page D-1
LEDs
The client adapter has two LEDs that glow or blink to indicate the status of the adapter or to convey error
messages. Refer to the
