History of Wireless

In the late 1970s, IBM issued the results of their experiment in designing a WLAN with IR technology, other companies such as Hewlett-Packard (HP) to test the WLAN with RF. The two companies reached only 100 Kbps data rate. Because not meet the IEEE standard is 802 to 1 Mbps LAN products are not marketed it. New in 1985, (FCC) set the band Industrial, Scientific and Medical (ISM band) is 902-928 MHz, 2400-2483.5 MHz and 5725-5850 MHz that are not licensed, so that the development of commercial WLAN into a serious stage. Then in 1990 the WLAN can be marketed with a product that uses spread spectrum technique (SS) in the ISM band, 18-19 GHz licensed frequencies and IR technology with data rate> 1 Mbps.

In 1997, an independent agency called the IEEE to make specifications / standards of the first WLAN-coded 802.11. Appropriate equipment 802.11 standards work at a frequency of 2.4 GHz, and the data transfer speed (throughput) theoretical maximum of 2Mbps.
In July 1999, the IEEE again issued new specifications called 802.11b. Theoretical data transfer speed maximum that can be achieved is 11 Mbps. The speed of data transfer is comparable to traditional Ethernet (IEEE 802.3 10Mbps or 10Base-T). Tools that use the 802.11b standard works on the 2.4 Ghz frequency. One of the lack of wireless devices that work on this frequency is the possibility of interference with cordless phones, microwave ovens, or other equipment that uses radio waves at the same frequency.

At the same time, the IEEE 802.11a specification which make use different techniques. 5GHz frequencies used, and supports theoretical data transfer speeds up to 54Mbps. Radio waves emitted by 802.11a equipment is relatively difficult to penetrate walls or other obstructions. Range of radio waves is relatively shorter than 802.11b. Technically, the 802.11b is not compatible with 802.11a. But now enough hardware manufacturers that make equipment that supports both these standards.

In 2002, the IEEE made a new specification that can combine the advantages 802.11b and 802.11a. Specifications coded 802.11g works at a frequency of 2.4 GHz with a theoretical data transfer speeds up to 54Mbps. 802.11g equipment is compatible with 802.11b, so interchangeable. Let's say a computer that uses 802.11g network card can take advantage of 802.11b access point, and vice versa.
In 2006, 802.11n was developed by combining technologies 802.11b, 802.11g. The technology is known by the term brought MIMO (Multiple Input Multiple Output) technology is the latest Wi-Fi. MIMO is based on Pre-802.11n specification. The word "Pre-" states "Prestandard versions of 802.11n". MIMO offers increased throughput, superior reliability, and increase the number of clients connected reply. MIMO penetrating power of the barrier better, besides a wider range so that you can put a laptop or Wi-Fi clients as they pleased. MIMO Access Point can reach a variety of Wi-Fi equipment imaginable in every corner of the room. MIMO technically superior to his elder brother 802.11a/b/g. MIMO Access Point can recognize the radio waves emitted by Wi-Fi adapter 802.11a/b/g. MIMO support backward compatibility with 802.11 a / b / g. Wi-Fi equipment can produce MIMO data transfer speed of 108Mbps.