1. PHYSICAL TOPOLOGY
   1. def
      1. how individual interconnected devices are physically connected
   2. concerns with
      1. NIC card
      2. other devices
         1. hubs
         2. switches
         3. RF transceiver
   3. BUS
      1. tranmission media
      2. 1 cable
         1. connect all devices
         2. span all network
      3. bus terminator
      4. PROS
         1. install easy
         2. less cables
      5. CONS
         1. configure difficult
         2. troubleshoot hard
         3. error prone
            1. if bus encounters failure
   4. RING
      1. each device = 2 connectors
         1. to neighbor
      2. PROS
         1. identify problem easy
      3. CONS
         1. difficult install & configure
   5. STAR
      1. device is centrally connected to one ACCESS POINT
      2. Hub/Switch
         1. signal booster/repeater
            1. allows the signal to travel further
         2. each machine connecting directly to the hub
         3. easiest topology to design and implement
      3. PROS
         1. easy to configure
         2. easy to troubleshoot
         3. not error prone
            1. isolate faulty segments
      4. CONS
         1. hard to install
         2. more cable
   6. MESH
      1. connected to every other device on LAN.
      2. PROS
         1. easy to troubleshoot
      3. CONS
         1. difficult to install
   7. CELLULAR
      1. connect by radio frequency
      2. PROS
         1. Relatively easy to install
         2. NO reconfigure when moving or adding users.
         3. faulty isolation easy
      3. CONS
         1. hub failure -> problematic
2. CELLULAR
   1. establish connection
      1. radio frequency
      2. CELL TRANSCEIVER
         1. access point = FIXED location
         2. users move between access points
         3. Transceiver range
      3. SATELLITE
         1. access points = moving orbital satellites
   2. HAND-OVER TECHNOLOGY
      1. user to move between two access points
      2. overlap 'transceiver range' between adjacent cells
3. SIGNALLING
   1. ATTENUATION
      1. the further the distance between
         1. sender
         2. receiver
         3. deteriorate signals
   2. digital
      1. PROS
         1. simpler & cheaper equipments
         2. less error/noise & interference
      2. CONS
         1. more attenuation
   3. analogue
      1. PROS
         1. Allows multiplexing techniques
            1. maximise cable bandwidth use
         2. less annutation
      2. CONS
         1. error pron from
            1. noise
            2. interference
4. TRANSMISSION MEDIA
   1. type
      1. COPPER WIRE
         1. transmit electrical signal
         2. digital/analogue
      2. FIBER OPTIC
         1. high energy laser light
         2. analogue
      3. WIRELESS
   2. BANDWIDTH
      1. measure how much data can be transmitted
      2. type
         1. broadband
            1. cable TV
         2. baseband
5. CABLE transmission media
   1. UTP
      1. features
         1. basic technology
            1. mature & stable
         2. type
            1. cat 5
            2. cat 6
         3. RJ45 connector
         4. 4 pairs of wires
            1. 10 twisted per meter
         5. max length = 100m
      2. PROS
         1. relatively inexpensive.
         2. easily install/managed/reconfigure
      3. CONS
         1. >1000Mbps data transmission
         2. high antenuation
   2. STP
      1. features
         1. like UTP
         2. sheathed in foil -> shield from interference
      2. pros
         1. fairly mature & stable
         2. higher bandwidth than UTP
      3. cons
         1. expensive than UTP
         2. harder to install
         3. still high antenuation
   3. COAX
   4. FIBER OPTIC
      1. features
         1. single/multi mode
         2. various formfactor
            1. simple PC connector
            2. inter-continent connector
         3. need a special interface card for computer
         4. max length = 1 km
      2. pros & cons
         1. pros
            1. high bandwidth
            2. low annuatation rate
         2. cons
            1. expensive
            2. high-precision manufacturing / complex installation.
            3. hard to configure
6. WIRELESS TRANSMISSION MEDIA
7. MULTIFLEXING
   1. FREQUENCY
   2. TIME
   3. STATISTICAL TDM