Data Communications

Good Essays
Short Questions:

Differentiate between guided media and unguided media.
Differentiate between an analog and a digital electromagnetic signal.
What are three important characteristics of a periodic signal.
What is the relationship between the wavelength and frequency of a sine wave.
Define fundamental frequency.
What is the relationship between a signal's spectrum and its bandwidth.
What is attenuation?
Define channel capacity.
What key factors affect channel capacity?

Problems:

Figure 1 shows the frequency domain function for a single square pulse. The signal pulse could represent a digital 1 in a communications system. Note that an infinite number of higher frequencies of decreasing magnitudes is needed to represent the single pulse. What implication does that have for a real digital transmission system?

Suppose that a digitised TV picture is to be transmitted from a source that uses a matrix of 480 x 500 picture elements (pixels), where each pixel can take on one of 32 intensity values. Assume that 30 pictures are sent per second. (This digital source is is roughly equivalent to broadcast TV standards that have been adopted.) Find the source rate R (bps)
Assume that the TV picture is to be transmitted over a channel with 4.5Mhz bandwidth and a 35dB signal-to -noise ratio. Find the capacity of the channel (bps).
Discuss how the parameters given in part (a.) could be modified to allow transmission of colour TV signals without increasing the required value for R.
What is the channel capacity for a teleprinter channel with a 300Hz bandwidth and a signal-to-noise ratio of 3dB, where the noise is white thermal noise?
A digital signalling system is required to operate at 9600bps.
If a signal element encodes a 4-bit word, what is the minimum required bandwidth of the channel?
Repeat part (a.) for the case of 8-bit words.
Given the narrow (usable) audio bandwidth of a telephone transmission facility, a nominal SNR of 56dB (400,000), and a

You May Also Find These Documents Helpful

  • Satisfactory Essays

    Data Communications

    • 469 Words
    • 2 Pages

    Introduction Data communications (Datacom) is the engineering discipline concerned with communication between the computers. It is defined as a subset of telecommunication involving the transmission of data to and from computers and components of computer systems. More specifically data communication is transmitted via mediums such as wires, coaxial cables, fiber optics, or radiated electromagnetic waves such as broadcast radio, infrared light, microwaves, and satellites. Data Communications = Movement…

    • 469 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    data communication

    • 640 Words
    • 3 Pages

    What is Data Communications? Next Topic | TOC The distance over which data moves within a computer may vary from a few thousandths of an inch, as is the case within a single IC chip, to as much as several feet along the backplane of the main circuit board. Over such small distances, digital data may be transmitted as direct, two-level electrical signals over simple copper conductors. Except for the fastest computers, circuit designers are not very concerned about the shape of the conductor or…

    • 640 Words
    • 3 Pages
    Satisfactory Essays
  • Better Essays

    Data Communications

    • 6424 Words
    • 26 Pages

    used, a high voltage on a communications medium can represent a logical 1 and a low voltage of can represent a logical 0. Different methods of encoding exist these are used for different types of communication between electrical devices. Distortion, noise, and cross talk on a cabling medium are factors that prevent the accuracy of transmitted data to be intact. For these reasons different encoding methods exist. An example is when 2 wires are used to transmit music data to a speaker Digital signals…

    • 6424 Words
    • 26 Pages
    Better Essays
  • Satisfactory Essays

    Data Communication

    • 6574 Words
    • 27 Pages

    for67757_fm.fm Page i Saturday, January 7, 2006 12:00 AM DATA COMMUNICATIONS AND NETWORKING for67757_fm.fm Page ii Saturday, January 7, 2006 12:00 AM McGraw-Hill Forouzan Networking Series Titles by Behrouz A. Forouzan: Data Communications and Networking TCP/IP Protocol Suite Local Area Networks Business Data Communications for67757_fm.fm Page iii Saturday, January 7, 2006 12:00 AM DATA COMMUNICATIONS AND NETWORKING Fourth Edition Behrouz A. Forouzan DeAnza College with…

    • 6574 Words
    • 27 Pages
    Satisfactory Essays
  • Good Essays

    data communications

    • 17792 Words
    • 115 Pages

    CHAPTER 12 ROUTING IN SWITCHED NETWORKS A NSWERS TO Q UESTIONS 12.1 The average load expected over the course of the busiest hour of use during the course of a day. 12.2 The tradeoff is between efficiency and resilience. 12.3 A static routing strategy does not adapt to changing conditions on the network but uses a fixed strategy developed ahead of time. With alternate routing, there are a number of alternate routes between source and destination and a dynamic choice of routes is…

    • 17792 Words
    • 115 Pages
    Good Essays
  • Satisfactory Essays

    Data Communication

    • 758 Words
    • 4 Pages

    02. Compare and contrast between the bus and star topology.  A network architecture in which a set of clients are connected by a shared communications line, called as a bus.  A network consists of one central switch, hub or computer which acts as a conduit to transmit messages, called as a star.  Bus networks are the simplest way to connect multiple clients, but often have problems when two clients want to transmit at the same time on the same bus.  The star topology is a computer…

    • 758 Words
    • 4 Pages
    Satisfactory Essays
  • Good Essays

    Data and Communication

    • 1200 Words
    • 5 Pages

    Databases and Data Communication BIS 320 September 16, 2013 Lisa Ricks Databases and Data Communication Databases are great when you want to create a model of data such as numbers for figuring out how much you can spend on a new home when you are in the buying marketing, you can use excel to figure out how much you can spend and a monthly payment. You can also use a database to track of shipping components from a trade show that you are in charge of. You can use a database to organize…

    • 1200 Words
    • 5 Pages
    Good Essays
  • Better Essays

    mmTASK 1 a) Explain the following types of data communication networks and their applications * Public switched telephone network (PSTN) * Local area networks (LANs) * Metropolitan area networks (MANs) * Wide area networks (WANs) * Packet switched data network (PSDN), * Integrated services digital network (ISDN) Public switched telephone network (PSTN) Public Switched telephone network (PSTN) is the global collection of interconnects originally designed to…

    • 2106 Words
    • 9 Pages
    Better Essays
  • Good Essays

    DATA COMMUNICATION COEN 3193 Assignment No. 1 Brief History of Data Communication Submitted by: Camille A. Bonito BSCpE IV-2 Submitted to: Florinda H. Oquindo TIMELINE OF HISTORY OF DATA COMMUNICATION 1800 Telegraph defined from the Greek... TELE = Afar GRAPHOS = Write 1809 First telegraph in Bavaria. Samuel Soemmering. Used 35 wires with gold electrodes in water. Detection at distant end 2000 feet away was by the amount of gas caused by electrolysis. 1828 First telegraph in the USA…

    • 1345 Words
    • 6 Pages
    Good Essays
  • Satisfactory Essays

    do you mean by data communication? Ans: It is the exchange of data between two devices via some form of transmission medium such as wire cable. The communicating system must be part of a communication system made up of a combination of hardware and software. The effectiveness of a data communication system depends on three fundamental characteristics: delivery, accuracy and timeliness. 2. What is simplex? Ans: It is the mode of communication between two devices in which flow of data is unidirectional…

    • 3391 Words
    • 14 Pages
    Satisfactory Essays