Serial data transmission- a form of data transmission in which the bits of each character are sent one at a time along a single communication path [one path] eg. mouse, USB- Universal Serial Bus, Internet
Parallel transmission data- a form of data transmission in which the bits of each character are all sent simultaneously, resulting in extrememly fast communication but requiring a communication path for each bit.
[8 paths] eg. some printers with parallel port
- faster, but over longer distances the data goes out of sync and takes a longer time to arrive, therefore serial is preferred over longer distances
Signal Direction
Simplex- data links that allow the data to move in one direction. In a simplex link there is no need for a return data signal [one way communication] eg. radio, traditional free-to-air television
Half Duplex- data links that allow the data to move in both directions, but not at the same time [one way at a time] eg. UHF radio
Full Duplex- (also known as duplex) data links allow the data to move simultaneously in both directions. [Both devices in the link must be able to send and receive at the same time] eg. mobile phones, landline telephones
Synchronous- communication links use agreed times for data to be transmitted and received [happen at the same time- real time] eg. phone calls, skype, text chat, dedicated video conference
Asynchronous- no set time for the data to be transmitted or received [out of time-delayed] eg. text message, e-mails, blogs, forums, podcasts, videoblogs
Useful links: http://learningwithcomputers.pnworks.com/Synchronous-Communication
Google 'examples of synchronous communications csu hsc edu' and open powerpoint
Data Signals
Bandwith- the number of bits moving at any given time
Baud- transmission cycle; every transmission occurs in a cycle or transmissions per cycle; how times per second data(bits) is transmitted
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