ITEE ITEE-1 | Page 269

Reference Precautions when installing wireless LANs A wireless LAN enables communication within the range of radio waves, which requires security considerations beyond that of a cable-based LAN. Authentication functions and communication encryption functions are often used to provide security. ●Wireless LAN Wireless LAN is a technology for building networks using radio waves or infrared rays. Since no cables are used, wireless LANs are used in places where the office layout is changed frequently, the wiring is complicated, or a tidier appearance is necessary. Since there are several wireless LAN standards, care must be taken to match the supported standards. If the standards are not the same, communications will not be possible. Several types of wireless LANs are summarized below. Standard IEEE 802.11a Frequency Transmission band rate 5.2GHz IEEE 802.11g 54Mbps Fast data rate. Uses higher frequencies and is sometimes affected by obstructing objects, but is resistant to noise as it uses a frequency that is not usually shared with other electronic equipment. 54Mbps Fast data rate. Compatible with 802.11b. Low frequency band tends to be unaffected by obstructing objects. However, communication quality is inferior to 802.11a, as it uses a frequency that is often shared with other electronic equipment. 11Mbps Technology is more affordable than high-speed standards. Low frequency band tends to be unaffected by obstructing objects. However, communication quality is inferior to 802.11a, as it uses a frequency that is often shared with other electronic equipment. 2.4GHz IEEE 802.11b Wireless LAN Characteristics Hub Wired LAN (Ethernet) Access point Access point Wireless LAN (IEEE 802.11b) 263