Ralink 300N, Руководство пользователя

Страница: 82 / 85

75
4-3 Glossary
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 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.
3. What does IEEE 802.11 feature support?
The product supports the following IEEE 802.11 functions:

CSMA/CA plus Acknowledge Protocol

Multi-Channel Roaming

Automatic Rate Selection

RTS/CTS Feature

Fragmentation

Power Management
4. What is Ad-hoc?
An Ad-hoc integrated wireless LAN is a group of computers, each
has a Wireless LAN card, Connected as an independent wireless
LAN. Ad hoc wireless LAN is applicable at a departmental scale for
a branch or SOHO operation.