2.1 Data Representation

• Packets are small chunks of data made up of a header, payload an a trailer
• The packet header contains The source IP (the ip of sender); Destination IP (the ip of receiver); The packet number (order of packets) and the Error checker (checks if the packet is correct)
• The payload contains the main piece of data
• The Packet Trailer contains an additional error checker and the end of packet notification to show it's the end of the packet.
• Serial transmission is when one bit is sent at a once in 1 direction across a single wire
• Parallel transmission is when mulitiple bits are transmitted simultaneously over a single wire
• Simplex transmission is data sent in one direction at once
• Half-duplex transmission is data sent in both directions but not simultaneously
• Full-duplex transmission is when data is sent in both directions simultaneously
• Disadvantage for serial transmission is slow transmission speeds especially over long distances
• Advantage for Serial transmission is that it's cheap and less likely to have errors
• Disadvatages to Parallel is that it's expensive and delays can be caused when it doesn't arrive in chronological order
• Advantages to Parallel transmission is it's fast especially for large quantities of data.
• Disadvantages to Simplex is data can only be sent in one direction, so you need two wires for bidirectional transmission. and can only send one bit of data making it slow
• Advantage to Simplex is it's cheap
• Disadvantage to Half-duplex transmission is only one bit at a time
• Advantage to Half-duplex data can be sent bidirectionally using a single wire.
• Disadvantage to Full-duplex is It's expensive
• Advantages to Full-duplex is faster transmission speed as multiple bits can be sent at once. data can be sent in both directions simultaneously.
• USB (Universal Serial Bus) is a asynchronous (data isn't sent in the correct order) serial data transmitter. USB is the industry standard.
• Devices are automatically detected and drivers are automatically, simplifying the data transmission process for the user.
• Disadvantage - The maximum cable length for USB is roughly 5 metres, limiting its use over long distances.
• Advantage - Cable connectors for USB fit in only one way, preventing incorrect connections and ensuring compatible data transmission.
• Disadvantage - Older versions of USB, such as USB 2.0, have limited transmission rates.
• USB Advantage - As USB usage is standardised, there is a lot of support available online and from retailers.
• Disadvantage - Very old USB standards may not be supported in the near future, such as USB 1.1 and USB 2.0.
• Advantage - Several different data transmission rates are supported by USB, newer types of USB have faster transmission speeds
• Advantage - Newer USB standards are backwards compatible with older USB standards.