{"id":77113,"date":"2020-01-22T10:36:16","date_gmt":"2020-01-22T05:06:16","guid":{"rendered":"https:\/\/www.vskills.in\/certification\/tutorial\/?p=77113"},"modified":"2024-04-12T14:24:07","modified_gmt":"2024-04-12T08:54:07","slug":"wireless-lan-basics-3","status":"publish","type":"page","link":"https:\/\/www.vskills.in\/certification\/tutorial\/wireless-lan-basics-3\/","title":{"rendered":"Wireless LAN Basics"},"content":{"rendered":"\n

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The 802.3 family is for Ethernet LANs and the 802.11 family is for WLANs. Both standards define a frame format with a header and a trailer, with the header including a source and destination MAC address field, each 6 bytes in length. WLANs use radiated energy waves, generally called radio waves, to transmit data, whereas Ethernet uses electrical signal flowing over a cable (or light on optical cabling). If two wireless devices send radio waves in the same space as the same frequency, neither signal is intelligible, so a half – duplex (HDX) mechanism must be used. WLANs use the carrier sense multiple access with collision avoidance (CSMA\/CA) algorithm to enforce HDX logic.<\/p>\n

Wireless-capable devices communicate with a connector WLAN device called an access point (AP) to send and receive frames. APs connect WLAN clients (connecting devices) with Ethernet LAN or internet as implemented.<\/p>\n

Various international organizations are involved in WLAN standardization as<\/p>\n\n\n\n\n\n\n
Organization<\/strong><\/td>\nRole<\/strong><\/td>\n<\/tr>\n
IEEE<\/td>\nStandardization of wireless LANs (802.11)<\/td>\n<\/tr>\n
Wi-Fi Alliance<\/td>\nIndustry body for interoperable products<\/td>\n<\/tr>\n
ITU-R<\/td>\nStandardization of radiated energy communication<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

IEEE introduced WLAN standards with the creation of the 1997 ratification of the 802.11 standard which was replaced by more-advanced standards of 802.11b, 802.11a, and 802.11g as per order of ratification. The WLAN standards are described in the table below as<\/p>\n\n\n\n\n\n\n\n\n
Feature<\/strong><\/td>\n802.11 a<\/strong><\/td>\n802.11 b<\/strong><\/td>\n802.11 g<\/strong><\/td>\n<\/tr>\n
DSSS speed<\/td>\n<\/td>\n11 Mbps<\/td>\n11 Mbps<\/td>\n<\/tr>\n
OFDM speed<\/td>\n54 Mbps<\/td>\n<\/td>\n54 Mbps<\/td>\n<\/tr>\n
Non-overlapping Channels<\/td>\n12<\/td>\n3<\/td>\n3<\/td>\n<\/tr>\n
Total Channels<\/td>\n23<\/td>\n11<\/td>\n11<\/td>\n<\/tr>\n
Frequency Bands<\/td>\n5 GHz<\/td>\n2.4 GHz<\/td>\n2.4 GHz<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

WLANs work in either of two modes as<\/p>\n