IEEE 802.11 (legacy mode) or more correctly IEEE 802.11-1997 or IEEE 802.11-1999 refers to the original version of the IEEE 802.11

wireless network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking allows homes, telecommunications networks, and business installations to avoid the costly process of introducing cables int ...

ing standard released in 1997 and clarified in 1999. Most of the protocols described by this early version are rarely used today.

Description

It specified two raw data rates of 1 and 2 megabits per second (Mbit/s) to be transmitted via

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

(IR) signals or by either frequency hopping or

direct-sequence spread spectrum In telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. The direct-sequence modulation makes the transmitted signal wider in bandwidth tha ...

(DSSS) in the Industrial Scientific Medical frequency band at 2.4 GHz. IR remained a part of the standard until IEEE 802.11-2016, but was never implemented. The original standard also defines carrier sense 0 access with collision avoidance ( CSMA/CA) as the medium access method. A significant percentage of the available raw channel capacity is sacrificed (via the CSMA/CA mechanisms) in order to improve the reliability of data transmissions under diverse and adverse environmental conditions. IEEE 802.11-1999 also introduced the binary time unit TU defined as 1024 μs. At least seven different, somewhat-interoperable, commercial products appeared using the original specification, from companies like Alvarion (PRO.11 and BreezeAccess-II), BreezeCom, Digital / Cabletron (RoamAbout), Lucent, Netwave Technologies (AirSurfer Plus and AirSurfer Pro), Symbol Technologies (Spectrum24), and Proxim Wireless (

OpenAir The core idea of artificial intelligence systems integration is making individual software components, such as speech synthesizers, interoperable with other components, such as Commonsense knowledge (artificial intelligence), common sense knowled ...

and Rangelan2). A weakness of this original specification was that it offered so many choices that interoperability was sometimes challenging to realize. It is really more of a "beta specification" than a rigid specification, initially allowing individual product vendors the flexibility to differentiate their products but with little to no inter-vendor interoperability. The DSSS version of legacy 802.11 was rapidly supplemented (and popularized) by the 802.11b amendment in 1999, which increased the bit rate to 11 Mbit/s. Widespread adoption of 802.11 networks only occurred after the release of 802.11b which resulted in multiple interoperable products becoming available from multiple vendors. Consequently, comparatively few networks were implemented on the 802.11-1997 standard.

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