Wireless networkDevelopment experience:
What is itWlan:
Wlan is the product of a combination of computer networks and wireless communications technology, freeing itself from user cable requirements
Wifi is wlan with 802. 11
802. 11 is an agreement to define wireless standards
Classification of wireless networks:
Wireless persoNal area network (personal wireless network): within 10 m, working at 2. 4ghz (bluetooth)
Wireless local area network: less than 100m, 2. 4/5ghz (wifi)
Wireless metro area network: less than 5kmBandRequirements for use
Wireless wide area network (wire wide area network): less than 15 km, frequency use requirement (used by major operators)
802. 11 agreement version, frequency segment, rate comparison:
802. 11: 2. 4ghz at 2 mbps
802. 11b: 2. 4ghz at 11 mbps
802. 11a: 5ghz, 54 mbps
802. 11g: 2. 4ghz at 54mbps
802. 11n (wifi4): 2. 4/5ghz at 600 mbps
802. 11ac (wifi5): 5ghz, > 1 gbps
802. 11ax (wifi6): 2. 4/5ghz, rate 11gbps
802. 11ac compatible 802. 11n/g/a/b
802. 11n compatible with 802. 11a/b/g
Two ssids can be configured to support the double frequency 802. 11 protocol, working in different bands
Wlan's advantages over cable networks:
Mobility, flexibility, scalability, economy
Wapi: wireless lan identification and safety infrastructure, a mandatory security standard for china's wireless lan
Wlan technology is defined in the frequency bands of 2. 4ghz, of which 2. 4ghz bands are divided into 14 overlapping and mislisted 20 mhz wireless carrier channels (802. 1g/n in 2. 4ghz is 20mhz and 802. 11a is 22 mhz), with a central frequency interval of 5 mhz, 802. 11a/n working in the additional channel 5ghz bands (802. 1a/n in 5ghz requires 20 mhz per channel)
In china, the 1-13 channel is allowed, with three completely non-duplicated channels, 1, 6, 11 (2, 7, 12 and 3, 8, 13)
There are 13 5ghz and 5 allowed in china (802. 11a)
Trust binding:
Multiplier transmission rate by binding the two adjacent 20mhz channels into 40 mhz (not folded)
5ghz channel binding
802. 11a:
802. 11b
802. 11g
802. 11n
802. 11n support for mimo technology
802. 11n mac tier improvement technology
802. 11ac
