Sunday, September 6, 2009

Timeline of Wireless Technology

Timeline of Wireless Technology

What is wireless communication? In layman's language it can be described as using technology to transfer information over a distance without using any wires. Wireless communication is not new and has been in use for well over 125 years now. Through this article we trace the origin of this technology and its evolution to its present form. Here is the timeline of wireless technology.


The principle of wireless communication was presented by German physicist Heinrich Hertz in the year 1887. Hertz demonstrated how electromagnetic waves could be transmitted across free space. This was an expansion of the theory of electromagnetic theory of light put forth earlier by James Maxwell and Michael Faraday. Though Hertz managed to demonstrate it, he never tried to take it any further, even remarking that it would be of no significance.


Nikola Tesla transmits radio waves in St. Louis, Missouri.


Guglielmo Marconi is awarded the British Patent for 'Improvements in transmitting electrical impulses and signals and in apparatus there-for'. What this effectively means is that he was granted the rights to the Radio.


Nikola Tesla demonstrates a remote control boat. It would be amusing to know that people watching this demonstration thought Tesla was controlling the boat using his mind, as nobody seemed to have any information about radio waves at that time.


Amplitide Modulation (AM) is used by Reginald Fessenden to broadcast his voice over the North Atlantic. This mode of radio transmission is the same as Shortwave and Medium wave in use today.


First transatlantic transmission takes place. AT&T achieves this radio transmission from Arlington, Virginia to Paris using the Eiffel Tower to hold the receiving antenna.


Radio Corporation of America (RCA) is incorporated by General Electric (GE) on Oct. 17 specifically to acquire the assets of the wireless radio company American Marconi from British Marconi.


Shortwave (SW) radio is developed. It is called Shortwave because the wavelength of light is shorter than visible light due to the higher frequency. Shortwave Radio (also known as High Frequency or HF radio) has a frequency of 2.310 Megahertz to 25.820 Megahertz. The benefit of Shortwave radio is that the waves can bounce off the ionosphere (the layer of atmosphere consisting of ions or charged particles), enabling transmission to the other side of the world without actually having a direct line of sight.


Frequency Modulation or FM is developed by Edwin H. Armstrong. FM transmission is less prone to noise associated with AM transmission and therefore results in a clearer broadcast. Also, it is possible to transmit stereo signals, making it suitable for musical radio broadcasts.


The GSM (Groupe Special Mobile) group is formed and decides on a digital system for its cellular systems


After decades of stagnation in wireless communication technology, 802.3 standard is created by IEEE and additions to its specifications are made regularly.


GSM Technical details are worked out in this year. A narrowband time division multiple access (TDMA) system is also planned.


L-band radio is demonstrated (digital radio). The Global Positioning System (GPS) operates in the L-Band. Also, first GSM specifications are released.


The first GSM call is made in Finland (March) on the Radiolinja network, which got its GSM license in 1990. This is the precursor to Wi-Fi developed by NCR Corporation in the Netherlands with speeds up to 1-2 Mb/s.


First GSM network outside Europe network is launched in Australia on April 27 providing service to 53% of the Australian population.


IEEE 802.11 (also known as Wi-Fi) standard is created. This original 802.11 specification has a maximum bandwidth of 2 Mb/s.


The Bluetooth Special Interest Group (SIG) was formed in September of 1998 by Ericsson, Intel, IBM, Toshiba and Nokia. The formal announcement of the SIG takes place next year on May 20, 1999.


IEEE 802.11b is added to the 802.11 standard. Transmission speeds up to 11 Mb/s are possible. Bluetooth 1.0 (IEEE 802.15.1) specification is released. In this, all hardware identifies itself in the handshake process and renders anonymous data reception and transmission impossible. EV-DO (Evolution Data Optimized) is developed by Qualcomm.


The first consumer Bluetooth product - a wireless headset and phone adapter for mobile phones is released by Ericsson.


The first 3G network is commercially launched in September by NTT DoCoMo, Japan. In December, IEEE 802.16 standard, also known as WiMAX, is created.


The first UMTS network is launched allowing high-speed applications such as mobile TV and video calling.


EDGE is deployed by AT&T on Singular network in the USA. IEEE 802.11g is added to the 802.11 standard, allowing transmission speeds up to 54 Mb/s. Bluetooth specification 1.2 is released. This new specification includes Adaptive Frequency-hopping (AFH), which reduces RF interference.


Newest version of IEEE 802.16 is added and it completely changes the WiMAX standard. This has a new scheduling algorithm, which makes WiMAX much more scalable than Wi-Fi. Instead of the random way in which subscribers compete in Wi-Fi, they compete once for a time to call when they connect to the network, thereby reducing collisions when transmission occurs at specified times. Bluetooth specification 2.0 is released. This new specification is not only backward compatible but also introduces Enhanced Data Rate (EDR), which allows transmission of data up to 3 MB/s.


802.11n - the latest in Wi-Fi standards will be formally approved in November 2009 (although devices sporting this standard are already available, they are not necessarily conformant with the final specifications).

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