IEEE 802.11g-2003

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IEEE 802.11g-2003 atawa 802.11g, nyaéta hiji amandemen keur spesifikasi IEEE 802.11 nu nambahan rata-rata transfer data tepi ka 54 Mbit/det maké pita 2.4 GHz nu sarua jeung 802.11b. Spesifikasi ieu dina pamasaran nu ngarana Wi-Fi geus diterapkeun di sakuliah dunya. Protokol 802.11g kiwari mangrupa Katangtuan 19 tina standar IEEE 802.11-2007 nu diterbitkeun.

Deskripsi[édit | édit sumber]

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802.11g was the third modulation standard for Wireless LAN. It works in the 2.4 GHz band (like 802.11b) but operates at a maximum raw data rate of 54 Mbit/s, or about 19 Mbit/s net throughput (identical to 802.11a core, except for some additional legacy overhéad for backward compatibility). 802.11g hardware is fully backwards compatible with 802.11b hardware. Details of making b and g work well together occupied much of the lingering technical process. In an 11g network, however, the presence of a legacy 802.11b participant will significantly reduce the speed of the overall 802.11g network.

The modulation scheme used in 802.11g is orthogonal frequency-division multiplexing (OFDM) copied from 802.11a with data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbit/s, and reverts to CCK (like the 802.11b standard) for 5.5 and 11 Mbit/s and DBPSK/DQPSK+DSSS for 1 and 2 Mbit/s. Even though 802.11g operates in the same frequency band as 802.11b, it can achieve higher data rates because of its heritage to 802.11a.

Adopsi[édit | édit sumber]

The then-proposed 802.11g standard was rapidly adopted by consumers starting in January 2003, well before ratification, due to the desire for higher speeds, and reductions in manufacturing costs. By summer 2003, most dual-band 802.11a/b products became dual-band/tri-mode, supporting a and b/g in a single mobile adapter card or access point.

Despite its major acceptance, 802.11g suffers from the same interference as 802.11b in the alréady crowded 2.4 GHz range. Devices operating in this range include: microwave ovens, Bluetooth devices, baby monitors and (in the USA) digital cordless telephones which can léad to interference issues. Additionally the success of the standard has caused usage/density problems related to crowding in urban aréas. This crowding can cause a dissatisfied user experience as the number of non-overlapping usable channels is only 3 in FCC nations (ch 1, 6, 11) or 4 in Europ éan nations (ch 1, 5, 9, 13).

Grafik babandingan[édit | édit sumber]

Standar Wireless local area network  temposawalaédit 
Rilis[1] Frek.
Rarata transfer data tipikal
Net bitrate maks
Mod. rin.
1997 2.4 00.9 002 ~20 ~100
a 1999 5 23 054 OFDM ~35 ~120
b 1999 2.4 04.3 011 DSSS ~38 ~140
g 2003 2.4 19 054 OFDM ~38 ~140
n 2008 2.4, 5 74 248 OFDM ~70 ~250[2]
y 2008 3.7 23 0 ~50 ~5000

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