4 Troubleshooting
This chapter provides solutions to problems usually encountered during the installation and operation
of the adapter.
1. What is the IEEE 802.11g standard?
802.11g is the new IEEE standard for high-speed wireless LAN communications that provides for
up to 54 Mbps data rate in the 2.4 GHz band. 802.11g is quickly becoming the next mainstream
wireless LAN technology for the home, office and public networks.
802.11g defines the use of the same OFDM modulation technique specified in IEEE 802.11a for
the 5 GHz frequency band and applies it in the same 2.4 GHz frequency band as IEEE 802.11b.
The 802.11g standard requires backward compatibility with 802.11b.
The standard specifically calls for:
A. A new physical layer for the 802.11 Medium Access Control (MAC) in the 2.4 GHz frequency
band, known as the extended rate PHY (ERP). The ERP adds OFDM as a mandatory new
coding scheme for 6, 12 and 24 Mbps (mandatory speeds), and 18, 36, 48 and 54 Mbps
(optional speeds). The ERP includes the modulation schemes found in 802.11b including
CCK for 11 and 5.5 Mbps and Barker code modulation for 2 and 1 Mbps.
B. A protection mechanism called RTS/CTS that governs how 802.11g devices and 802.11b
devices interoperate.
2. What is MIMO?
MIMO (multiple-input multiple-output)
, a
technique for boosting wireless bandwidth and range
by taking advantage of multiplexing. MIMO algorithms in a radio chipset send information out
over two or more antennas. The radio signals reflect off objects, creating multiple paths that in
conventional radios cause interference and fading. But MIMO uses these paths to carry more
information, which is recombined on the receiving side by the MIMO algorithms
Many wireless-LAN vendors expect that some form of MIMO will be the basis of work just starting
in the IEEE 802.11n Task Group, which is creating a specification for WLANs having at least
100M bit/sec throughput. MIMO doubles the spectral efficiency compared with that of current
WLANs.
3. What is the IEEE 802.11b standard
？
The IEEE 802.11b Wireless LAN standard subcommittee, which formulates the standard for the
industry. The objective is to enable wireless LAN hardware from different manufactures to
communicate.
4. What does IEEE 802.11 feature support
？
The product supports the following IEEE 802.11 functions:
z
CSMA/CA plus Acknowledge Protocol
z
Multi-Channel Roaming
z
Automatic Rate Selection
z
RTS/CTS Feature
z
Fragmentation
z
Power Management
28
