The WLAN Card is used with a personal computer to access a Wireless
Local Area Networks (WLAN), which can extend or replace traditional wired computer networks by transmitting and receiving data radio waves using Spread-Spectrum
There are four main standards for WLANs: 802.11, 802.11a, 802.11b, and 802.11g.
The last 3 standards operate in the same environment without causing interference with each other. The 802.11b is the dominant standard with 11-Mbps rates in the 2.4HGz band. The 802.11a is capable of reaching 54-Mbps rates in the 5GHz band. The 802.11g standard also has 54-Mbps but is compatible with 802.11b. The 802.11b technology implements the Digital Sequence Spread Spectrum (DSSS) modulation. The 802.11a/g implements the Orthogonal Frequency Division Multiplexing (OFDM) modulation.
Core Subsystem include:
- RF/IF Front End
- filters/amplifies RF signal and performs RF-to-IF conversion to
generate I and Q data for ADC and DAC.
- Baseband Processor of Physical Layer (PHY)
- modulates and demodulates I and Q data and performs carrier sensing, transmission and receiving frames.
- Medium Access Controller (MAC)
- controls the communication (access) between client and applications.
- Power Conversion
- receives power supply via the host interface.