Technology

Synchronous Transmission
Synchronous transmission of data does not use start and stop bit for sending data fragments where the sender and the receiver are clocked. Blocks of several characters are transmitted as a unit in what is called a frame. The header and the trailer bits are inserted at the end of a block.

Asynchronous Transmission
Asynchronous transmission of data uses both the start and the stop bits and supply 38.4kbps speed as this is a character by character transmission and each character has a start and stop bit and an extra bit known as parity bit which ensures, that no bit sent matches the start and the stop bit sequence.

Analog Signal
An analog signal is a continuous signal in form of a wave and suffers less attenuation and can be multiplexed to increase its band width.

The disadvantage of this signal is that its more proms to errors from noise and interference. Usually its slower than the digital signal.

Digital Signal
Digital signal is a series of on and off electronic pulses, with time signals that is discrete. This type is signal is normally faster than analogue signal but suffer greater signal attenuation.

XON and XOFF are used in data transmission as control characters using a particular code. The XOFF is normally used by receiving device to inform the transmitting devices to stop broadcasting.

Simplex Transmission
Simplex transmission of data is where data travels in one direction only, its usually unidirectional. Used in radio broadcast where there is a radio transmitter and radio receiver.

Duplex Transmission
Duplex transmission is divided into half simplex and full duplex where in half duplex, data is sent in both directions but one direction at a time like in the walkie-talkie. In full duplex data is sent in both directions simultaneously as in telephone conversation.

Serial Transmission
Serial transmission of data involves strings of bits that are transmitted one after the other in a sequence through a single transmission

Parallel Transmission
In parallel transmission of data every bit in a character is transmitted in its own channel. Other bits of a given character are transmitted simultaneously.


Baseband
Baseband is a transmission mode which only allows one single high speed signal to be carried at a time. A digital signal uses the complete bandwidth of a cable which constitutes a single channel and there is no frequency division thus signal travels over short distances.

Broadband
Broadband transmission mode accommodates a number of separate frequency bands. This system uses analog signaling which is unidirectional transmission with a range of frequencies. In this transmission data signals travels longer distances before being attenuated (Bates, 2002).

Serial Line Internet Protocol (SLIP)
This is a type of protocol that is used in communication between two telecommunication equipment previously configured to communicate between each other over modem or serial ports link. SLIP does not offer error detection and being used alone is not suitable over error prone dial up.

Point-to-Point Protocol (PPP)
This is a data link protocol used in setting up a link directly over two telecommunication nodes over synchronous and asynchronous line. PPP can provide compression, encryption transmission and authentication connection over physical networks like phone line, mobile telephone and fiber optic connection.

Hypertext Transfer Protocol (HTTP)
This is a protocol that provides a standard way for servers and web browsers to transmit and request files on the World Wide Web. HTTP is as well used in downloading files and the web page is normally transmitted without any encryption (Blank, 2004).

File Transfer Protocol (FTP)
This is a protocol for exchanging files over TCPIP network and used for transmitting multiple files. FTP is used in transferring data efficiently and more reliably and promotes file sharing.

Transmission Control Protocol (TCP)
This is a connection oriented protocol of the internet protocol suite that provides reliable transport delivery between computers as information is transmitted over the internet.  TCP controls the rate at which data is transmitted and any traffic congestion using applications such as file transfer and internet.

Internet Protocol (IP)
This is the protocol that is used in data communication from one computer to another over the internet. Each host has a unique address that distinguishes it from the others on the internet.