04-01-2013, 10:37 AM
Communications Systems
[attachment=46410]
Characteristics of Communication Systems
must be a Sender and Receiver
A protocol is a set of rules which governs the transfer of data between computers. Protocols allow communication between computers and networks.
Handshaking is used to establish which protocols to use. Handshaking controls the flow of data between computers
protocols will determine the speed of transmission, error checking method, size of bytes, and whether synchronous or asynchronous
Examples of protocols are: token ring, CSMA/CD, X.25, TCP/IP
5 Basic Components
Every communication system has 5 basic requirements
Data Source (where the data originates)
Transmitter (device used to transmit data)
Transmission Medium (cables or non cable)
Receiver (device used to receive data)
Destination (where the data will be placed)
Transmission Media Speed
Bandwidth:The amount of data which can be transmitted on a medium over a fixed amount of time (second). It is measured on Bits per Second or Baud
Bits per Second (bps): A measure of transmission speed. The number of bits (0 0r 1) which can be transmitted in a second (more)
Baud Rate: Is a measure of how fast a change of state occurs (i.e. a change from 0 to 1) (more)
Packets and OSI
After the file is divided into packets extra information is required to make sure it all goes back together correctly. The OSI model helps to look after this.
The OSI model also provides much more information which is included with each package.
OSI 7 Layer Model
OSI “Open System Interconnection”
OSI is not a protocol but a list of protocols divided between 7 layers with each layer having a different set of functions.
Each packet is layered/packaged with protocols from each of the layers as it is processed.
The process of layering the protocols around each package is called encapsulation. The final encapsulated data packet is called a frame.
[attachment=46410]
Characteristics of Communication Systems
must be a Sender and Receiver
A protocol is a set of rules which governs the transfer of data between computers. Protocols allow communication between computers and networks.
Handshaking is used to establish which protocols to use. Handshaking controls the flow of data between computers
protocols will determine the speed of transmission, error checking method, size of bytes, and whether synchronous or asynchronous
Examples of protocols are: token ring, CSMA/CD, X.25, TCP/IP
5 Basic Components
Every communication system has 5 basic requirements
Data Source (where the data originates)
Transmitter (device used to transmit data)
Transmission Medium (cables or non cable)
Receiver (device used to receive data)
Destination (where the data will be placed)
Transmission Media Speed
Bandwidth:The amount of data which can be transmitted on a medium over a fixed amount of time (second). It is measured on Bits per Second or Baud
Bits per Second (bps): A measure of transmission speed. The number of bits (0 0r 1) which can be transmitted in a second (more)
Baud Rate: Is a measure of how fast a change of state occurs (i.e. a change from 0 to 1) (more)
Packets and OSI
After the file is divided into packets extra information is required to make sure it all goes back together correctly. The OSI model helps to look after this.
The OSI model also provides much more information which is included with each package.
OSI 7 Layer Model
OSI “Open System Interconnection”
OSI is not a protocol but a list of protocols divided between 7 layers with each layer having a different set of functions.
Each packet is layered/packaged with protocols from each of the layers as it is processed.
The process of layering the protocols around each package is called encapsulation. The final encapsulated data packet is called a frame.