Digital data transmission
This method is used internally within the computer, for example the internal buses, and sometimes externally for such things as printers, The major issue with this is "skewing" because the wires in parallel data transmission have slightly different properties not intentionally so some bits may arrive before others, which may corrupt the message.
Manchester encoding is less susceptible to having errors go undetected, because if there is no transition in midsignal the receiver knows that an error must have occurred.
Because it requires less signal processing and less chances for error than parallel transmission, the transfer rate of each individual path may be faster.
Thus, serial transmission is considerably slower than parallel transmission—eight times slower in the case of 8-bit ASCII because there are 8 bits. It is up to the receiver to recognize and separate bits into bytes. Serial transmission requires only one communication channel.
Data bits are sent in burst mode without maintaining gap between bytes 8-bits. The digital revolution has also resulted in many digital telecommunication applications where the principles of data transmission are applied. The sender sends all the bits at once on all lines.
Analog data transmission
Synchronous Serial Transmission Timing in synchronous transmission has importance as there is no mechanism followed to recognize start and end data bits. The current tendency is to replace traditional telecommunication services by packet mode communication such as IP telephony and IPTV. Examples of such channels are copper wires, optical fibers, wireless communication channels, storage media and computer buses. Because it requires less signal processing and less chances for error than parallel transmission, the transfer rate of each individual path may be faster. Digital serial transmissions are bits sent over a single wire, frequency or optical path sequentially. Data transmitted may be digital messages originating from a data source, for example a computer or a keyboard. Telephone exchanges have become digital and software controlled, facilitating many value added services. The watt is the fundamental unit of electrical power. In general, bipolar signaling experiences fewer errors than unipolar signaling because the symbols are more distinct. It is up to the receiver to recognize and separate bits into bytes. A change from high to low is used to represent a 0, whereas the opposite a change from low to high is used to represent a 1. It takes n iterations or cycles to transmit n bits.
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