This document provides a brief overview of various wireless networking technologies, wireless protocols, and standards.

Transmission of data over the air has evolved over many years -starting with the use of smoke signals, pigeon express, infrared, to various flavors of 802.11 protocol standards, and proprietary standards such as Bluetooth.

As networking technologies have evolved, so have the data throughput rates, transmission range, and accuracies of wireless networks. Some of the more common wireless networking protocols and technologies are described below in the order in which they have evolved over time:

• Infrared: Infrared signals have a rather limited range, and are capable of significantly low data throughput rates. As you may recall, TV Remote manufacturers were some of the early adopters of infra-red technology. Use of infrared spectrum for data transmission is still prevalent in computer peripherals -such as infrared keyboards, infrared mice, interfaces for PDAs, and a few other handheld devices. For infrared devices to communicate, they not only need to be in relatively close proximity (within a few feet, actually), they also need a clear line of sight.
  
  

• 802.11: is one of the early standards ratified by the Institute of Electrical and Electronic Engineers (IEEE) specifying the use of 2.4GHz frequency spectrum for Wireless Local Area Networks or WLANs. Depending upon the WLAN path length, signal strength, etc., the maximum data transfer rates achievable using 802.11 standard were somewhere in the range of 1.0Mbs to 2.0Mbs.
  
  

• 802.11b: was actually ratified by IEEE before 802.11a was ratified. Like the original 802.11 standard, 802.11b also makes use of 2.4GHz spectrum, but provides a far greater data transfer rate of between 5.5 Mbps and 11 Mbps.
  
  

• 802.11a: standard specified use of 5 GHz spectrum. There were not many that switched from 802.11b to 802.11a standard considering it was rather cost prohibitive to do so.
  
  

• 802.11g: standard is one of the newer standards, but allows for backward compatibility with the older 802.11b (2.4GHz) devices. The 802.11g supports data transfer rates as high as 54 Mbps.
  
  

• Bluetooth: Bluetooth deployment has been far greater in Europe than it has been in America, but it has been picking up some pace lately. Bluetooth technology standard is designed for short distance wireless connectivity.