Communication methods

Communication methods

1. Baud rate

   • Number of line signal changes per second- 1 Baud=1 signal change per second

2. Bit rate

   • Number of bits transmitted per second. Bit rate can be higher thant baud rate if more than one voltage level is used to encode the bits

3. Bandwidth

   • The range of signal frequencies that the transmission medium can use. Greater bandwidth=greater bandwidth

4. Latency

   • The time delay between the moment something is initiated and the moment the first effect starts

5. Data transmission

   • Serial data transmission
     • Single bits sent one after the other along one wire
   • Parallel data transmission
     • Bits sent down several wires simultaneously. Used over short distances due to skew. Expensive to cable
   • Guided data transmission
     • Using cable
   • Unguided data transmission
     • Wireless
   • Asynchronous data transmission
     • Data arrival cannot be predicted by receiver so start bit signals data arrival and synchronises transmitter and receiver temporarily,followed by stop bit. Stop and start bits are different values

6. Communication protocol

   • Set of pre agreed signals,codes and rules to be used for data exchange between two computers, or a computer and peripheral

7. Handshaking protocol

   • A data transmission protocol that involves an exchange of signals- are you ready/yes/here it is/busy/that's it/ready again

8. Baseband

   • Whole bandwidth of a medium dedicated to one channel at a time. Used in Local Area Networks

9. Broadband

   • Bandwidth of transmission medium carries several data streams at a time. Used in Wide Area Networks