Data Communications

• 39 hrs lectures
• 13 hrs laboratories
• 13 hrs pc labs

Students will be introduced in detail to data transmission systems and the possibilities of realizing data communication in these systems. The subject matter discussed is focused mainly on codes, their types and their application. Based on the range of the subject matters the student should be able, after a successful completion of the course, to solve all the standard problems that appear in this type of data communication.

The aim of the course is to introduce students to the basic knowledge of data communication, tools for its realization, and to the conditions of its realization in contemporary as well as prospective telecommunication systems.

Fundamentals of electrical and electronic engineering and electro-magnetic signals transmission.

• Mac Kay, D.J.C.: Information Theory, Inference and Learning Algorithms, Draft 1.9.7., June 10, 1999.
• Stallings, W.: Data and Computer Communications, Prentice Hall Internationals Editions, 1994.
• Němec, K.: Datová komunikace, Skripta pro předmět Datová komunikace. VUTIUM, Brno, 2000.

• Mac Kay, D.J.C.: Information Theory, Inference and Learning Algorithms, Draft 1.9.7., June 10, 1999.
• Stallings, W.: Data and Computer Communications, Prentice Hall Internationals Editions, 1994.
• Kolektiv autorů: CCITT Blue Book, Volume VIII, Fascicle VIII.1, Data Communication over The Telphone Network, Geneva, 1989.

1. Information theory. Information source: Amount of information, entropy, redundance. Discrete communication system: Static and dynamic characteristics of the source, transmission channel, receiver. Coding: Realization principles, signification for transmission, examples of application.
2. Data transmission. Fundamental concepts and terminology: Frequency, spectrum, bandwidth,bit rate, data transfer rate. Data and signals, sorts of transmission and their examples. Data corruption during transmission: Outer influence, inner influence. Transmission reliability. Transmission media.
3. Coding of analog and discrete signals. Explanantion of the concepts "analog data" and "digital data". Four possible systems for data transmission: Systems "digital data and digital signals", "digital data and analog signals","analog data and digital signals" and "analog data and analog signals". Application and realization regions of these systems.
4. Coding for redundance reduction. Fundamental methods: Prefix codes, Huffman code. More complex methods: Compression of bit sequences, one- and double-line encoding in the fax system.
5. Anti-error coding. Method for the simulation of interfering effects. Detection and correction of errors. Example of a decoding Table. Principles of anti-error coding. Protection capability of codes. Classification of anti-error codes.
6. Block codes. Methods of setting block codes: Generation and control matrix, generation polynomials. Data protection by cyclic codes: Model of the protection process, possibilities of encoder and decoder realization. Examples of block codes.
7. Tree codes. Classification of tree codes: Fundamental trees codes, trellis codes, convolution codes. Methods of setting convolution codes: Generation polynomials, generation matrix. Protection capability of tree codes. Encoding and decoding process realization.
8. Anti-error code protection systems (ACPS). Example of the formation of ACPS. Position of ACPS in a superior transmission system. Requirements made on ACPS and their solution possibilities. Examples of ACPS.
9. Special modulations which make use of the anti-error protection principles. Systems with multilevel phase keying. Artificial increase in modulation system redundancy. Anti error coding in a phase keying system.
10. Scrambling technology. Necessity of uniform distribution of signal energy. Fundamental scrambler. Scramblers with N counters for N periods. Spectral characteristics of output signal. Scramblers and phasing. Transmission security during scrambling.
11. Encryption basics. Principles of data security: Cryptography and cryptoanalysis, cryptographic system, cryptographic key, rules of cryptology. Methods of classical cryptology. Public key encryption.
12. Security assurance in networks. Security problems in computers networks. Encryption in networks. Verification of access. Authentication of users. Endangerment by active nodes. Monitoring of traffic. Data integrity.
13. Queuing theory. Description of queuing system (QS): Properties, structure, significance of individual parts. Queuing theory characteristics: Kendall classification of QS, other parameters of QT. Examples of application QS in technical practice: Node throughput of communication networks, desig

1. Stochastic parameters of data transmission.
2. Synchronous and asynchronous communication on point-to-point data link.
3. Data signal protection by general block codes.
4. Data signal protection by cyclic block codes.
5. Data signal protection by convolution codes.

1. Data signal compression in data communication systems.
2. Scrambling in data communication systems.
3. Fundamentals of encryption technology in data communication systems.
4. Anti-error protection code systems in data communication systems.
5. Simulation of the influence of transmission parameters on data signal.

Study evaluation is based on marks obtained for specified items. Minimimum number of marks to pass is 50.

A precondition for awarding the credit pass is a successful completion of laboratory measurements and computer practice. The student can miss 20% of practice if properly excused. The missed practice must be made up for by agreement with the instructor.

Continual checking of classwork: At the end of each laboratory or computer practice, the instructor checks the presentation of results of the assignment given and awards points. The points obtained for laboratory measurements and computer practice (a maximum of 30 points in a semester) are a part of the evaluation in the examination and thus of the final assessment.