4thclassassignment
- 1. Assignment On 4th class note Course title : Data communication Course code : CSE 313 Submitted to Pranab bandhu nath Senior Lecturer Department of CSE City University Submitted by Md.ismail Id: 1834902082 Batch : 49th (B) Department of CSE City University Submission date : 01.09.2021
- 2. when data is sent over physical medium it means to first cover in to electro magnetic signals.Data itself can be converted into signals block type data transfer. Signal Analog signal digital signal Analog signal An analog signal is time-varying and generally bound to a range but there is an infinite number of values within that continuous range.For example human voice. Digital signal A digital signal is a signal that represents data as a sequence of discrete values. A digital signal can only take on one value from a finite set of possible values at a given time.For example document on a disk. Fiber optic cable A fiber optic cable is a network cable that contains strands of glass fibers inside an insulated casing. Digital modulation Modulation is the process of converting data into radio waves by adding information to an electronic or optical carrier signal. The simplest modulation, a type of unipolar encoding, is simply to switch on and off a DC signal so that high voltages represent a '1' and low voltages are '0'. Digital modulation ASK FSK PSK ASK(Amplitude shift keying)
- 3. ASK refers to a type of amplitude modulation that assigns bit values to discrete amplitude levels. It transfer signal using fiber optic cable . FSK FSK refers to a type of frequency modulation that assigns bit values to discrete frequency levels. It transfer signal using coaxial cable. High frequency - 1 Low frequency - 0 Phase-shift keying (PSK) Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency reference signal (the carrier wave). It transfer signal using router or brouter Reference : https://www.monolithicpower.com/en/analog-vs-digital-signal