Data TransmissionThe purpose of this report is to describe some common data transmission terms. This document will discuss various data transmission (communication) protocols and how they are used in data communication. Synchronous and Asynchronous: Asynchronous serial transmission is a technique used in RS232 serial communication. The data is framed by a series of control bits known as start bits, stop bits, parity bits and error control bits. A transmit clock signal is used to synchronize the data on the transmission line to the receiving end. At the receiver, a clock signal, known as the receive clock, which corresponds to the transmit clock, is used to decode the transmitted data back to the original by removing the control bits. Synchronous transmission sends data packets, unlike asynchronous transmission, which sends data one bit at a time. The data is surrounded by start and end frames. The initial frame tells the receiver to synchronize its internal clock and wait for incoming packets. The final frame marks the end of the packet. Low-speed data transmission uses asynchronous transmission. Since asynchronous transmission does not include error checking, it is not very efficient. Synchronous transmission, on the other hand, is very efficient. Data is transmitted in blocks. Synchronous communication is particularly suitable for high-speed data transmission. The protocol has error checking capabilities. Analog and digital: Analog signals represent continuously changing signals, such as a sound wave emitted from a speaker or an alternating current (sine wave) traveling on a wire. Digital signal, on the other hand, is a digital representation of an analog signal, it can be turned off or on. AM - Amplitude Modulation and FM - Frequency Modulations are means by which to transmit the analog signal. DM – Digital modulation is used to transmit digital signal (Analog vs Digital Transmission, 2005)X on and X off:X on / X off is a handshake control signal used to control the flow of data communication. It works like this. A printer connected locally to the computer uses the X off control signal to notify the computer that the print buffer is full and that it should stop sending data. When the printer is ready for more data, the X on signal is sent to signal the computer to resume data transfer. Simplex and Duplex: Simplex transmission is used to transmit data in only one direction. It's like a one-way street for data. Duplex transmission means that data is transmitted in both directions.