Information about LOAs from 1993 forward has been posted. It was first compiled in 1993 to provide information about the known patents that may affect the practice of IEEE Standards. Operational procedures relating to the Patent Policy are found in Section 6.3 of the IEEE SA Standards Board Operations Manual. The Patent Policy is set forth in Section 6 of the IEEE SA Standards Board Bylaws. The IEEE SA Records of IEEE Standards-Related Patent Letters of Assurance list IEEE Standards for which Letters of Assurance (LOA) have been received from patent owners in accordance with the IEEE SA Patent Policy. They have a data rate of 27 Mbps and operate in 5.9 GHz band.IEEE SA RECORDS OF IEEE STANDARDS-RELATED PATENT LETTERS OF ASSURANCE They include network communications between vehicles moving at high speed and the environment. IEEE 802.11pДЁ02.11 is an amendment for including wireless access in vehicular environments (WAVE) to support Intelligent Transportation Systems (ITS). It provides a marked improvement over previous standards 802.11 by incorporating multiple-input multiple-output antennas (MIMO antennas). It has variable data rate ranging from 54 Mbps to 600 Mbps. IEEE 802.11nДЁ02.11n was approved and published in 2009 that operates on both the 2.4 GHz and the 5 GHz bands. 802.11g devices also faces interference from other devices operating in 2.4 GHz band. It is fully backward compatible with 802.11b. It operates in the 2.4 GHz band (as in 802.11b) and provides a average throughput of 22 Mbps. However, since 2.4 GHz band is pretty crowded, 802.11b devices faces interference from other devices.ДЇurther amendments to 802.11b are 802.11ba, 802.11bb, 802.11bc, 802.11bd and 802.11be. It has a higher data rate of 11 Mbps as compared to 2 Mbps of 802.11, due to which it was rapidly adopted in wireless LANs. It uses the same modulation technique as 802.11, i.e. IEEE 802.11bДЁ02.11b is a direct extension of the original 802.11 standard that appeared in early 2000. Besides it provides error correcting code. It provides a maximum data rate of 54 Mbps operating in the 5 GHz band. IEEE 802.11aДЁ02.11a was published in 1999 as a modification to 802.11, with orthogonal frequency division multiplexing (OFDM) based air interface in physical layer instead of FHSS or DSSS of 802.11. It provided 1 Mbps or 2 Mbps data rate in the 2.4 GHz band and used either frequency-hopping spread spectrum (FHSS) or direct-sequence spread spectrum (DSSS). IEEE 802.11 was the original version released in 1997. Also, they have support for both centralised base station based as well as ad hoc networks. All the standards use carrier-sense multiple access with collision avoidance (CSMA/CA). There are several standards of IEEE 802.11 WLANs. WiFi or WLAN uses high frequency radio waves for connecting the nodes. IEEE 802.11 standard, popularly known as WiFi, lays down the architecture and specifications of wireless LANs (WLANs).

Ieee 802 standards list