The Evolution of LANs from Wired to Wireless
To better understand where we are today, it is important to understand how
networking evolved from wired to wireless.
Ethernet has become the predominant LAN technology in the wired world. Defined
by the Institute of Electrical and Electronic Engineers (IEEE) with the 802.3
standard, it has provided an evolving, high-speed, widely available and
interoperable networking standard. Ethernet originally provided 10 megabit per
second (Mbps) transfer rates evolving to include the 100Mbps transfer rates
required for network backbones and bandwidth intensive applications.The open
IEEE 802.3 standard resulted in a wide range of suppliers, products and price
points for Ethernet users. Ethernet standards guarantee interoperability,
enabling users to select products from different vendors, reasonably secure that
they would work together.
The first wireless LAN technologies operated in the 900MHz band and were low
speed (1-2Mbps), proprietary offerings. Despite these shortcomings, the freedom
and flexibility of wireless allowed these early products to find there way into
vertical markets like retail and warehousing where mobile workforces used
hand-held devices for inventory management and data collection.
In 1991 realizing that in order for wireless LANs to gain broad market
acceptance, to govern wireless LAN technology Aironet pushed with other wireless
makers for standards.
Around 1992, wireless LAN makers began developing products operating in the
unlicensed 2.4 GHz frequency band. This opened two additional vertical markets.
Healthcare, with a highly mobile workforce, began using portable computers to
access patient information. And as computers made there way into the classrooms,
educational institutions began installing wireless networks to avoid the high
cost of wiring buildings.
In June, 1997 the IEEE, the body that defined the dominant 802.3 Ethernet
standard, released the 802.11 standard for wireless local area networking. IEEE
802.11 standard supports transmission in infrared light and two types of radio
transmission within the unlicensed 2.4GHz frequency band: Frequency Hopping
Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS).
Article by Cisco Systems |
