How to Stream Video over a Network or the Internet

Damien Stolarz

Number of words	1880
Computer science content	high
Math content	low
English language complexity	medium

Sub-areas covered

Computer networks
Transferring data through the Internet

Learning objectives

to understand different kinds of transfer: radio, television, telephone, internet
to recognize general differences in the data transfer of radio, television, telephone and the Internet
to understand why internet video streaming is vulnerable to delays, and why delays do not affect radio, television and telephone

Keywords

streaming protocol

set of rules to make sure that data will be supported in real time

circuit switching network (komutacja łączy)

a network in which computers establish a constant bandwidth connection before they start to share any data

router

a network device used for sending data packets across computer networks

routing

the process of selecting paths in a network along which data can be sent.

Internet provider (dostawca internetu)

a company that sells bandwidth and access to the Internet

peering

the movement of information between parts of the Internet that belong to different Internet providers

broadcast (rozgłaszanie)

the transmission of data from one computer in the network to all others that are available inside the network

Internet

the worldwide system of computer networks

network protocol (protokół sieciowy)

a set of rules that governs communications between computers in a network.

bandwidth (przepustowość, szerokość pasma)

an amount of data that can be transferred through a specific path in the network (usually expressed in kb/s [kilobits per second])

Summary

The text, divided into several parts, familiarises the reader with the problem of receiving video data transferred through a network (especially the Internet). The author outlines the methods of transferring data by means of phone lines, radio waves and television wires. He explains why the transfer of data is not problematic in those cases, while in computer networks it poses a real problem. After giving a brief account of the basis of the global network, the author describes the transfer of video data through the Internet. The article gives detailed descriptions of methods of transferring that type of data and lists reasons why receiving them can be a problem.

Tekst przybliża czytelnikowi problem odbioru danych wideo transportowanych przez sieć, zwłaszcza przez Internet. By naświetlić problem przesyłania tego typu danych autor artykułu opisuje sposób transferu danych przez linię telefoniczną, fale radiowe oraz sieć telewizyjną. Zaznacza on powody, dla których wymienione rozwiązania nie nastręczają problemów typowych dla sieci komputerowych. Artykuł przedstawia także zarys funkcjonowania intersieci oraz opisuje główne powody, dla których przesyłanie i właściwe odbieranie tego typu danych jest problematyczne.

Pre-reading questions

What do you know about the history of TV and radio?
- The first use of radio took place Franklin Institute in Philadelphia in February 1893. It was the demonstration of wireless telegraph. Transmission of voice was the invention of the beginning of XX century. Development of TV was divided into two paths: the mechanical and electrical and purely electrical. The first idea of construction the TV (electromechanical) was abandoned about 1925. Demonstration of first color television display was given on August 16, 1944.
Do you know the origins of the Internet?
- The first idea of global network of computers was created by J.C.R. Licklider. He moved to the Defense Advanced Research Projects Agency (DARPA) to develop it. The first connection of two computers (by the phone line) took place in 1965. The first form of the Internet, called ARPANET, was brought online in 1969. In those time, the first ideas of reliability of connections (nowadays included in many protocols) was implemented into networks.
Which kind of media do you find important and valuable?
- I find the Internet the most important and valuable kind of media. Any information that can be found in other media (tv or radio) can also be found in the Internet.
Can you explain how connections are made between ‘users’ of radio, TV and the Internet?
- The radio waves are divided into frequency which enables the receivers to distinguish the channels. The same way of transferring data in the wireless TV is used to receive from broadcasting stations. When using cable connected TV receiver no division of data stream is needed as one channel is received through the cable in time. In the Internet every media is shared so protocols (describing the way the data is transferred) need to provide effective way to avoid collisions of the packets.