The AM and FM Radio Changes in the Multimedia Radio Emergence

Introduction

Radio broadcasts have undergone several transformations since the beginning of their commercial use in 1920. Among these transformations is a scenario of hegemony of broadcasters in AM, which between the 1920s and 1950s were the main source of real-time information for society; the change of content by the emergence of television and the beginning of consumption in mobility, made possible by the development of transistor receivers; and the emergence of FM radio, which came to be used for music broadcasts, while the AM radio was dedicated to the spoken word. The current period of the radio is marked by digital and multiplatform transmissions. The radio stopped transmitting only in analog broadcasting in AM or FM to broadcast also in digital broadcasting, using different standards such as the European Digital Audio Broadcasting (DAB) and Digital Radio Mondiale (DRM), the North American In-Band On Channel (IBOC) and the Japanese Broadbanding Services (ISDB-TN); in cable broadcasts (accessible through the television, which serves as an interface for receiving content, generally in subscription services, which displays not only transmitted sound, but visual content such as studio images, video clips of the displayed songs and news and interactions in the form of text) and the Internet (through streaming technology in a process called webcasting, which allows continuous downloading that produces real-time streaming of content, which can display both audio-only content and any type of language such as video, video with text, sound with texts, sound with photos, among others, since what is transmitted are binary codes that can be transformed into any type of language). Chris Priestman (2006, p.34) says that “the live streaming is truly the web equivalent of an analogue radio broadcast: it carries the output from the broadcast studio or an outside broadcast unit in real time”. Therefore, we can say that the webcasting sound made by webradio is the equivalent to sound broadcasting on the Internet.

The webcasting process is based on packet switching technology. Wazlawick (2016, p.230) states that until the invention of packet switching in 1965 to transmit information between two points on a network, it was necessary to establish a connection between two points and to transmit all the information until the disconnection of the connection, which made the communication band dedicated from beginning to end, blocking the other messages, in which it was estimated that the bandwidth time was 90% wasted. With packet switching the information would be divided into small blocks and transmitted one at a time within the network in different paths, by other lines that were activated, in which when arriving at the receiver the data were regrouped. This action can be considered the genesis of streaming technology, where data is sent shortly after processing (for example, the first two seconds after sound production) and in small blocks are transmitted in separate paths and grouped on arrival to the receiver, which rebuilds on the machine the content transmitted by the station.

Based on Santaella (2007), we can affirm that radio was part of two generations of technologies: the second generation, called diffusion technology, in which products are developed through electro-electronic technologies, making possible the great irradiation of the radio signal and a great penetration of the content in several places, and the fourth generation, called access technology, in which are developed products for consumption in a virtual space, which have access through the graphical interface, which allows us access to the virtual content.