Knowledge about wifi protocol in BMS and smart home.

Hi dears..
I've searched much about wifi protocol and brands and it's devices and applications but didn't find answer enough.

Can u help me about these???

Wi-fi is not just a simple technology. I could help you with it. If i know what exactly want.
Legacy 802.11

Released in 1997
Two raw data rates of 1 and 2 Mbps
Frequency hopping spread spectrum (FHSS) or direct-sequence spread spectrum (DSSS)
Three non-overlapping channels in industrial, scientific, medical (ISM) frequency band at 2.4 GHz
Originally defined carrier sense multiple access with collision avoidance (CSMA-CA)
802.11a

Released in 1999
Data rates with varying modulation types: 6, 9, 12, 18, 24, 36, 48 and 54 Mbps
Orthogonal frequency-division multiplexing (OFDM) with 52 sub-carrier channels
12 non-overlapping unlicensed national information infrastructure (UNII) channels in 5 GHz frequency band
802.11b

Released in 1999
Data rates with varying modulation types: 1, 2, 5.5 and 11 Mbps
High-rate direct-sequence spread spectrum (HR-DSSS)
Three non-overlapping channels in industrial, scientific, medical (ISM) frequency band at 2.4 GHz
802.11g

Released in 2003
Data rates with varying modulation types: 6, 9, 12, 18, 24, 36, 48 and 54 Mbps; can revert to 1, 2, 5.5, and 11 Mbps using DSSS and CCK
Orthogonal frequency-division multiplexing (OFDM) with 52 sub-carrier channels; backwards compatible with 802.11b using DSSS and CCK
Three non-overlapping channels in industrial, scientific, medical (ISM) frequency band at 2.4 GHz
802.11n

Data rates with varying modulation types: 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, 54 Mbps; see table below
Orthogonal frequency-division multiplexing (OFDM) using multiple-input/multiple-output (MIMO) and channel bonding (CB)
Three non-overlapping channels in industrial, scientific, medical (ISM) frequency band at 2.4 GHz
12 non-overlapping unlicensed national information infrastructure (UNII) channels in 5 GHz frequency band with and without CB

Thank you so much..
What is the time of the last part?

wi-fi(Wireless Fidelity) is the technology.
IEEE 802.11 (legacy mode) — or more correctly IEEE 802.11-1997 or IEEE 802.11-1999 — refer to the original version of the IEEE 802.11 wireless networking standard released in 1997 and clarified in 1999. Most of the protocols described by this early version are rarely used today.
It specified two raw data rates of 1 and 2 megabits per second (Mbit/s) to be transmitted via infrared (IR) signals or by either frequency hopping or direct-sequence spread spectrum (DSSS) in the Industrial Scientific Medical frequency band at 2.4 GHz. IR remains a part of the standard but has no actual implementations.