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IEEE 802.11g

The 802.11g standard is a WLAN standard from 2003 and operates in the ISM band at 2.400 GHz to 2.4835 GHz. In many countries, this frequency range between 2.412 GHz and 2.472 GHz is divided into twelve channels whose center frequencies have a frequency spacing of 5 MHz. The frequency spread of the channels is 25 MHz, so that the signals of the individual channels overlap and interference also occurs. In this case, the 25 MHz wide channels are converted into 300 kHz wide subcarriers as in 802.11a.

There are some non-overlapping channels for pilot tones. As a modulation method, 802.11g uses Orthogonal Frequency Division Multiplex( OFDM) and achieves a gross transmission rate of up to 54 Mbit/s, the net data rate is 32 Mbit/s. The data rate is gradually reduced depending on the received field strength. Since 802.11g must be backward compatible with 802.11b, it can also use complementary code keying( CCK). CCK keying provides data transmission rates of1, 2, 5.5 and 11 Mbps. For coding, 802.11g uses quadrature amplitude modulation (QAM64).

Specifications of 802.11g

Specifications of 802.11g

To avoid interference in communication between 802.11b and 802.11g devices, there is a compatibility mode. In this mode, an 802.11g transmitter broadcasts its ready-to-transmit( CTS) before the actual transmission, which 802.11b clients can follow. In 802.11g, the CCK-OFDM and CCK- PBCC modulation methods are also optionally permitted. A maximum data rate of 33 Mbit/s is specified for the Packet Binary Convolution Code (PBCC).

After certification by the WiFi Alliance, 802.11g corresponds to WiFi 3.

Englisch: IEEE 802.11g
Updated at: 13.08.2019
#Words: 235
Links: standard (STD), integrated signal management (ISM), gigahertz (GHz), indium (In), frequency (f)
Translations: DE

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