RETI E TECNICHE PER LA COMUNICAZIONE MULTIMEDIALE
Gian Luca Foresti
– Teaching activities finalized to the main theoretical concepts of computer networks and multimedia systems, wireless networks and protocol of audio-video streaming. The lectures are supplemented with specific assignments involving the study and individual performance by the students of exercises and case studies provided by the teacher. The correction of such assignments takes place in the classroom with presentations by students of the work done.
– Laboratory activities are aimed at developing the student’s ability to apply their knowledge on real application cases regarding computer networks and multimedia systems. The laboratory classes are integrated with the planning activities of the group that include the creation of an easy multimedia system that can transmit data and information. The teaching materials and slides are made available on the E-learning platform of the University of Udine. Such materials are reserved for students enrolled in the course.
In particular, the student will acquire specific skills and knowledge on
– the basic concepts of techniques and
protocols for the transmission of multimedia
data (images, video, audio tracks, etc.)
through the Internet and, more generally,
through communication channels;
– the main techniques for signal analysis
in time and frequency domain;
– the fundamental elements of data transmission techniques over wireless and LAN networks.
The student must be able to analyze the main communication protocols and the data used in the various levels of a network architecture, and be able to design a multimedia application that uses computer networks.
1. Introduction – Scope, applications, historic evolution, main characteristics and layers, networks topologies and architectures, network protocols, error control, flow control, packets and messages, service primitives, circuit and packet switching, routing and internetworking.
2. Principal components of a network and data transmission techniques – Optical and electrical transmission media, signal bandwidth, channel bandwidth, cross-talk, attenuation and distortion, analog and digital signal transmission (PCM, multiplexing), principal components of a network (modem, multiplexer, bridge, router, switch).
3. The ISO/OSI model.Architecture, services and protocols. The physical layer. The data-link layer. Protocols for flow (Stop&Wait, sliding window, Go-Back-N) and error control. HDLC protocol. Examples and exercises.
4. The network level – Routing techniques (routing by network, address label swapping, source routing), router architecture, routing tables, static routing algorithms (fixed directory routing, flooding e selective flooding) and dynamic routing algorithms (distance vector and link state). The IP protocol, IP addresses, sub-nets and netmask.
5. The transport and the application levels – Services provided to upper layers, addresses of transport layer, establishing a connection, releasing a connection. Three-ways handshake. The transport level in Internet: the UPD (User datagram protocol) and TCP (Transport control protocol) protocols. Telnet, File Transfer Protocol (FTP), Domain Name Server (DSN), Simple Network Management Protocol (SNMP), electronic mail, ftp, World Wide Web, multimedia documents. Wireless networks, Multimedia applications and computer network security. Examples and exercises.
6. Wireless networks – Introduction, advantages/disadvantages of wireless networks compared to wired networks, classification of wireless networks, power-line networks, optical networks, radio networks, microwave networks, cellular networks, satellite networks, spread-spectrum transmission techniques: direct sequence e frequency hopping. Examples and exercises.
7. LAN wireless – Introduction. LAN IEEE802.11, LAN IEEE802.11 network levels, IEEE802.11 physical level, Orthogonal Frequency Division Multiplexing (OFDM) IEEE 802.11, High Rate Sequence Spread Spectrum (HR DSSS) IEEE 802.11b, Orthogonal Frequency Division Multiplexing (OFDM) IEEE 802.11g, IEEE802.11 MAC level, access point, roaming, registration of nodes. CSMA / CA (Collision Avoidance). Error probability, Bluetooth protocol, Bluetooth frame structure.
8. Video and audio streaming – Definition of streaming and differences with the simple sequential data transmission. Introduction to the correlation concept and definition of temporal redundancy. Introduction of the “change detection” and “motion detection” concepts. Principal coding schemes developed so far as (MPEG, H.263,) and their main usages in the modern transmission channels. Examples and exercises.
9. Multimedia Streaming – Single streams synchronisation (e.g. audio, video, text, etc.). Specialised techniques for multimedia data acquisition, transmission, reception and synchronised playing.
During the course, specific laboratory exercises on the network configuration and installation are planned:
(1) Physical connectivity to a network: network adapter, connectors, patch panels, hubs, switches, transmission medium
(2) Installation, configuration and maintenance of a TCP / IP network
(3) SW programs integrated into operating systems and use of networking software for allocation of public / private IP network addresses
(4) Management of domains / workgroups / gateway, configuring Router DSL / ADSL, use of NAT
(5) Configuring a Wireless Access Point and a Wi-Fi network (WLAN).
(6) Client-Server Applications with PHP programming.
TESTI DI RIFERIMENTO
 D.E. Comer “Computer Networks and Internet”, (Sesta Edizione), Prentice Hall, 2018
 G.L. Foresti, Reti e Tecniche per la Comunicazione Multimediale, McGraw-Hill Create, 2015.
 A.S. Tanembaum, D.J. Wetherall, Fondamenti di Reti di Calcolatori, Pearson Education Italia, (Quinta Edizione), 2013.