Chapter 2 - Communication and Internet technologies

data transmission in one direction only

data transmission in two directions but not at the same time

data transmission in two directions at the same time

data sent one bit at a time over a singe wire or channel

several bits of data sent down several wires/channels at the same time

data being transmitted in an agreed bit pattern

a continuous stream of data which is accompanied by timing signals generated by an internal clock

an asynchronous serial data transmission method which has become an industry standard

the device is automatically detected can only be entered one way around (prevents false connections) device drivers are automatically loaded

Allows us to see if any bits have been skewed in data transmission can either be odd or even number of 1’s (parity complete with parity bit)

Uses an acknowledgement to indicate data is received correctly A timeout is used which is the time allowed to elapse before an acknowledgement is received

an additional value known as checksum is sent at teh end of the block of data the checksum is based on the number of bytes in the block if the checksum does not match on the receivers end, then an error has occoured

the data is returned to the sender the sender then compares the data received with the data sent if they are different then an error in data transmission has occoured

the data could become skewed when transferred back and not have been affected when sent to the receiver

a company that provides the user with access to the internet - usually with a monthly fee gives a user an account and email address

an address which each device is given when connecting to the internet - will be different each time the device connects

uniquely idenitifies a devic connected to the internet - the MAC address does not change but can be LAA or UAA

an essential part of HTML documents: includes semantics and structural mark ups of the documents

the style of the document: how the document will appear on a user’s computer screen

a set of rules which must be obeyed when transferring files over the internet

software which allows a user to display a web page on the computer screen - it interprets/translates the HTML from the website and shows the result