pg 177 questions 8-10

8) Asychronous data transmission is where the transmitter and the receiver are not kept in sync. The receiver is only synchronised with the transmitter only at the time of transmission.

9) The start bit signals impending data, and wakes up and sychronies the timer. The stop bit signals the end of the data, and the data can then be manipulated for whatever purposes required.

10) A communication protocol is a set of signals and codes used to ensure correct communication between computers or a device such as a printer.

11) A handshaking protocol is a data transmission protocol that involves an exchange of signals. It first checks to ensure the receiving device is still there. Then it checks to see if it’s ready. The sending device waits for the a reponse which indicates the receiving device is ready to receive
Upon receiving this signal the sender device coordinates the sending of the data and informs the receiver that it is receiving the data



Text of message

Mum: I’m so confused, my life lacks meaning because I cannot define a serial data transmission, or a parallel data transmission, or a Universal Serial Bus, or bandwidth, or latency, or a baud rate, or a start bit or a stop bit.

Jonny: Well mother, firstly a serial data transmission is a type of data transmission, where various bits are sent to an endpoint. This is where you send each bit one at a time, as opposed to parallel data transmission in which bits are sent in waves (all at once). There are advantages to serial transmission, data integrity is generally more certain and the ports themselves are cheaper to produce. Parallel data submission is capable of sending more data in one wave, meaning that receiving data will allow for a greater throughput. Bandwidth is the total amount of data which can be outputted by an internet connection, for example, your bandwidth (i.e. bitrate) is measured in bits/bytes per second more commonly these days as megabits or megabytes with a megabit usually being an eighth of a megabyte. Latency is usually defined as the time in between two actions, or in networking, the time taken to send a signal and to receive one or more back from a server. A baud rate is similar to bitrate, however, it varies where a voltage is greater than one, as it is a measure of the ‘pulses per second’. A universal serial bus is a type of serial transmission in which data is sent one bit at a time, usually in the form of a USB Stick or USB connector. A start bit signals the impending arrival of data, waking up the receiver whereas the end bit signals the end of data.
I hope that answers your queries.