Types of Wireless NIC
Wireless NIC, or network interface cards, can be divided into categories, depending on the type of wireless network to which they are connecting. They can be internal or external by using USB ports.
The different types vary in bandwidth, range and penetration.
Wireless A is the first standard following the original wireless specifications. It uses the 5Ghz frequency range to avoid the overcrowded 2.4Ghz range other standards use. The 5Ghz has a limited range and does not penetrate walls as readily as the 2.4Ghz range. Wireless A is limited to 54Mbps theoretical bandwidth, which translates into 20Mbps in real conditions.
Wireless B was the first wireless standard adopted by the public. Because it uses the 2.4Ghz band it was limited to 11Mbps bandwidth when equipment came out at the beginning of this century. It was widely adopted because it had a lower price than Wireless A and offered a longer range and better wall penetration. Wireless B is not compatible with Wireless A equipment.
Wireless G is an evolution of Wireless B that uses the same type of frequency modulation as wireless A. It allows for the same 54Mbps bandwidth as wireless A, with the range and wall penetration of wireless B. Just like wireless A, the 54Mbps bandwidth is theoretical. The actual bandwidth is about half. Wireless G is compatible with wireless B equipment.
Wireless N is the latest standard. Many manufacturers released "Pre-N" hardware as early as 2007 to allow their customers access to the faster speed. Most "Pre-N" hardware will work only with access points and NIC from the same manufacturer. Wireless N final became available in October 2009, and allows bandwidth up to 300Mbit. Wireless N uses several antennas to transmit the data on different channels.