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WLAN BAsis - Coggle Diagram

- - - - WLAN: 2.4 GHz and 5 GHz bands
        High power consumption
        Flexible design and multiple users supported
        Main technology: 802.11a/b/g/n
      - The Wireless Metro Area Network (WMAN) ) is used for backbone network coverage.
        Uses applied bands. You can also use the public bands but interference exists.
        Main technology: WiMax (802.16)
      - Wireless Personal Area Network (WPANs) are P2P or small wireless networks that provide wireless access for individual users
        Characteristics: easy to use, low cost, convenient
        Main technology: Bluetooth technology. It works on the 2.4 GHz band.
      - The Wireless Wide Area Network (WWAN) is used by carriers for wireless coverage
        Low bandwidth, accounting based on time or traffic
        Main technology: 2G/3G, satellite transmission
    - - ir DA
        A P2P transmission technology. This technology is applicable to short-distance transmission and there is no block between the two ends. The transmission rate is 16 Mbit/s. The technology is cheap but the device used has a short lifespan.
      - Home RF
        A combination of IEEE802.11 and DECT. Works on the 2.4 GHz band and provides a maximum of 2 M bandwidth within 100 m.
      - Bluetooth
      - GSM, UMTS, LTE
        Works on the 900 M, 1800 M, 1900M, and 2100 M bands. Used
        for mobile network data transmission and WWAN coverage.
  - - - Flexibility
      - Scalability
      - Mobility
      - Economicalness
- - - - Modulators
        
        AM: Amplitude modulation (AM) is a form of modulation in which the amplitude of a carrier wave is varied in direct proportion to that of a modulating signal
        
        FM: Frequency modulation is a form of modulation in which the frequency of the carrier is varied according to that of a modulating signal.
        
        PM: Phase modulation is a form of modulation in which the deviation between the carrier phase and the reference phase is varied in direct proportion to that of the modulating signal. That is, the initial phase of the carrier wave varies with that of the
        digital baseband signal
  - - - Phase Signal Enhancement
        If two wireless signals working at the same frequency have the same phase when they reach the receiver, the two signals will overlay to enhance the signal effect.
      - Phase Signal Attenuation
        If two wireless signals working at the same frequency have the opposite phases when they reach the receiver (180 degrees in difference), the signal strength attenuates
- - - - IEEE 802.11 b/g/n specify WLANs tyo operate in the 2.4 GHz frequency band > divided into 14 overlapping 20 Mhz carrier channels (interval btw center frequencies of each 2 is 5 Mhz.)
        
        Channel Binding
        In the traditional 802.11 standard, air interfaces work at a bandwidth of 20 MHz. The 802.11n technology binds two neighboring 20 MHz channels to form a 40 MHz channel to double the transmission rate. In actual applications, the two bound 20 MHz channels can also be used as two separate channels, one as the primary channel and the other as the sec channel
      - IEEE 802.11 a/n specifu WLANs to operate in the 5Ghz FBand that is divided into more channels