The client adapter is composed of three major parts, as shown in Figure .
The three parts of a wireless client adapter are a radio, antenna, and LED.
Each one is described below.
Radio
The radio transmits data over a half-duplex radio channel
operating up to 54 Mbps depending on the wireless technology.
Antenna
The type of antenna used depends on the client adapter,
as follows:
- 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, although an antenna can be
connected through the external connector of the card. If a snap-on antenna is
used it should be operated in diversity mode. Otherwise, the antenna mode used
should correspond to the antenna port to which the antenna is connected.
- PCI client adapters are shipped with a 2 dBi dipole antenna that attaches
to the antenna connector on the adapter. However, other types of antennas may
be used. PCI client adapters can be operated through the right antenna port
only.
Light-emitting Diodes (LEDs)
The client adapter has two
light-emitting diodes (LEDs) that glow or blink to indicate the status of the
adapter or to convey error indications
. The LEDs and
their interpretation are described for the PC Card in Figure
.
The green LED on the PC card is the status LED. It has several modes of
operation:
- Blinking once every half-second indicates that the card is operating in
infrastructure mode and is scanning for an access point with which to
associate.
- Blinking on once every two seconds means that the card is in infrastructure
mode and is associated to an access point.
- A solid green light means that the card is operating in ad hoc mode and
will not communicate with an AP.
The amber LED is the RF Traffic LED. It has two primary modes of
operation:
- Blinking amber LED light indicates RF traffic
- A amber LED indicates that the card is resetting and is not in an
operational mode. Typically this means that the driver has not been installed
properly or has not loaded properly.
All possible ON/OFF combinations of the two LEDs are shown in the table
in Figure
.