Thursday, March 5, 2026
type here...
Home Blog Page 9

Different Types Of Connecting Devices

Rajeshwari Chiluveru
-
0

Connecting Devices:

Based on high level, the connecting devices is classified into networking devices and internetworking devices. In this the repeaters are used in physical layer for providing electrical specifications for the signals.

Whereas bridges are used in the data link layer and physical layer for addressing protocols and routers will be used at the network layer which is useful for providing internetworking between compatible networks. As well as gateways are used at all layers in the OSI model for providing translation services between incompatible networks.

Repeater:

In osi reference architecture a repeater is used at physical layer in order to regenerates the signal for electronic devices.signal travelling across a physical wire travel some distance before they become weak, or corrupted as other signals noise interfere. A repeater receives such signal, which is weak or corrupted and regenerates the signal.

Working of the repeater:

For instance let us consider a sample network (LAN), in this host A wants to send a packet having the bit stream 10011001 to host D. let check once the two hosts are on the same LAN, but on different portion of the LAN. When the host A sents a signal to host D the signal may becomes weak, with this the host D may not able receive the same signal it may get corrupted as 10011011 before it reaches to host D. however, even before this can happen, at the lowest level, the repeater simply prevents this from occurring by taking the input signal corresponding to bits 1001100. Regenerating it to make a sign with an equivalent bit format and therefore the original signal strength, and sending it forward.

Bridge:

It is operated at both physical and datalink layer of the OSI protocal hierarchy. Bridge consisting of computer with it’s own processor and memeory card, two NIC cards to connect to two portions of a network.

The main intention behind using a bridge is to divide the entire larger network into smaller subnetworks, known as segments.

Purpose switching to bridge:

Unnecessary traffic is minimized, links in errors are identified and isolated so that the traffic does not go through it. Security features or access control can be implemented.

Routers:

Router is operated at three layers in OSI model,which routes the packets based on their logical address.router normally used to connect LAN and WAN in the inernet and routing table is used to take decisions about the routes. They are usually dynamic and require routing protocals in order to update.

Gateway:

Gateway is operated at the seven-layer in the OSI model and five layers on the internet. A gateway takes an application message, read it, and interrupt it. It can be used as a connecting device between two internetworks that use two different models. Let’s consider an example, well a network is designed to use an OSI model that can be connected to another network using the internet model.

TO PLOT POLES AND ZEROS OF THE GIVEN TRANSFORM FUNCTION

Rajeshwari Chiluveru
-
0

Z TRANSFORM

 For discrete time linear time-invariant system with impulse response h[n], the response y[n] of the system to a complex exponential input of the form z-1 is

Y[n] =H[z].zn

Where H[z] =  zn                  ——-2

For z=ejw with  real (i.e., with |z| =1), the sum in above equation corresponds to the discrete-time Fourier transform of h[n].

Generally, when |z| is not restricted to unity, then summation in equation 2 is referred as z transform of h[n].

Z transform for the discrete time signal x[n] is determined as

X[z] =  zn          

Where, z= a complex variable.

Program:

clc;

clear all;

close all;

%enter the numerator and denominators coefficients in square brackets

num=input(‘enter numerator co-efficients’);

den=input(‘enter denominator co-efficients’);

% find poles and zeros

poles=roots(den)

zeros=roots(num)

% find transfer function H(s)

h=tf(num,den);

% plot the pole-zero map in s-plane

sgrid;

pzmap(h);

grid on;

title(‘locating poles and zeros on s-plane’);

%plot the pole zero map in z-plane

figure

zplane(poles,zeros);

grid on;

title(‘locating poles and zeros on z-plane’);

Output:

Enter numerator co-efficients [2 -12 4 5]

Enter denominator co-efficients [3 4 5 6]

Poles =

  -1.2653 + 0.0000i

  -0.0340 + 1.2568i

  -0.0340 – 1.2568i

Zeros =

    5.5594

    0.9262

   -0.4855

  • GAUSSIAN NOISE:

Gaussian noise will be defined as statistical noise which features a probability density function of the traditional distribution (also referred to as Gaussian distribution). In other words, the valuestha the noise can combat are Gaussian-distributed. It is most ordinarily used as additive noise to yield additive white Gaussian noise (AWGN). Gaussian noise is correctly defined because of the noise with a Gaussian amplitude distribution.

Program:

clc;

clear all;

close all;

%let’s generates the given set of 2000 samples for Gaussian distributed random numbers

x=randn(1,2000);

%to plot the joint distribution for both the sets using dot.

subplot(211)

plot(x,’.’);

title(‘scatter plot of gaussian distributed random numbers’);

ymu=mean(x);

ymsq=sum(x.^2)/length(x);

ysigma=std(x);

yvar=var(x);

yskew=skewness(x);

p=normpdf(x,ymu,ysigma);

subplot(212);

stem(x,p);

title(‘ gaussian distribution’);

© Web Vidyalayam , All rights reserved. WEB VIDYALAYAM® is part of A Savvy Web LLC

About Us

Popular Category

Editor Picks