F451 data transmission

LAN: Local Area Network

WAN: Wide Area Network

NIC: Network Interface Card

Network Hardware:

• Routers
• Servers
• Printer servers
• File servers
• Email servers
• Bridges
• Gateways

How is data transmitted?

Binary numbers are sent as either electronic pulses or fibre optic light beams.

Methods of Transmitting:

Serial: one wire, one bit at a time.

Parallel: multiple wires, to transmit more data.

Simplex: One direction, eg one direction are simple minded.

Duplex: Both directions simultaneously, eg phone.

Half Duplex: Both directions - one at a time, eg walkie talkie.

Handshaking:

• Signal sent between 2 devices to ensure they are both ready to communicate.
• 1st device sends a handshake signal which is acknowledged by the other device.
• This states that each is now ready for communication.

Bit rates:

• Rate of bits that can be sent in 1 second.
• Measured in Baud.

High Bit Rate:

• A streaming video watched over a network would require a high bit rate.
• Large amount of data being transferred.
• Watching a video is time sensitive.
• A low bit rate will result in buffering.

Transmission errors:

• Binary numbers can be corrupted during transmission.
• Echoing back.
• Parity.
• Odd & even (number of ones).
• Check sum.
• Part of the transmission protocol.

TYPES OF NETWORK:

• Bus: 
• Can function with a broken computer.
• If main connection fails it all goes to goop.
• Ring: 
• If one computer breaks the whole ring breaks.
• Cheap fast.
• Star: 
• Most common kind of network.
• Mesh:
• //pending
• Tree:
• //pending
• Line: 
• Each computer connected to each other in a 'line'.
• If one goes down they all do.
• Fully connected:


• All parts connected directly.