Revisiting of Channel Access Mechanisms in Mobile Wireless Networks through Exploiting Physical Layer Technologies

Table 1

IEEE 802.11 standards for throughput improvement.

Version	Release Time	Maximum Data Rate	Frequency Band (GHz)	Bandwidth (MHz)	Modulation
802.11-base version	Jun. 1997	2 Mbps	2.4	20	BPSK, QPSK; DSSS, FHSS
802.11b	Sep. 1999	11 Mbps	2.4	20	BPSK, QPSK; DSSS (CCK)
802.11a	Sep. 1999	54 Mbps	5	20	BPSK, QPSK, 16-QAM, 64-QAM; OFDM
802.11g	Jun. 2003	54 Mbps	2.4	20	BPSK, QPSK, 16-QAM, 64-QAM; OFDM, DSSS
802.11n	Oct. 2009	600 Mbps	2.4 & 5	20, 40	BPSK, QPSK, 16-QAM, 64-QAM; OFDM, MIMO
802.11ac	Dec. 2013	6.933 Gbps	2.4 & 5	20, 40, 80, 160	BPSK, QPSK,; 16-QAM, 64-QAM, 256-QAM; OFDM, MIMO, MU-MIMO
802.11ax	Approx. 2019	>10 Gbps	<6	----	BPSK, QPSK, 16-QAM, 64-QAM,; 256-QAM, 1024-QAM, OFDM, MIMO, MU-MIMO, OFDMA