VANETS: Which to take, 802.11a or 802.11g
IEEE 802.11b enjoys international acceptance, as the 2.4-GHz radio frequency band is almost universally available and no license is needed (also in Switzerland, see 3.7.1). 802.11b hardware can transmit data at speeds of up to 11 megabits per second.
IEEE 802.11g operates in the same frequency band as 802.11b, and is therefore backwards compatible with most of the older WLAN hardware. 802.11g+ hardware can transfer data at up to 108 Mbps, or at 11Mbps if operating with 802.11b devices.
IEEE 802.11a, which operates around the 5 GHz band, enjoys relatively clear-channel operation in the United States, South Korea and Japan. In other areas, such as the EU and Switzerland, the 5 GHz band is mostly assigned to the military and to radar applications. At the beginning of 2004, Switzerland granted in-building use of the 5.2GHz band.
802.11a also provides for up to 54 Mbps throughput, but is not interoperable with 802.11b. One does not have to be a prophet to see that 802.11g will make it because of its compatibility with 802.11b, the availability and the characteristics of the frequency band. That is why we concentrated on the b and g standards for the simulations.