cording to Figure 3.9. Observe the convergence that is also taking place in the end-user terminals, with alternative channels for the same content. The convergence between a PC and a mobile terminal (MT) is sometimes called wireless Internet. The mobile device also becomes an entertainment channel, exemplified by a convergence TV-MT. This convergence is sometimes called mobile media. The terminal convergence is applicable at the service and application layer. The underlying transport part becomes increasingly fragmented into a number of existing and new technologies. Bearing this broader view in mind, this chapter focuses on the technical convergence. 3.4.2 TRANSITION FEATURE 2 Digitization: A Necessary Convergence Enabler Let's come back for a while to the world as it was in the 1960s and early 1970s. All the activities related to telecommunications, represented by telephony, radio and television, Networks and Technologies were based on analogue transmission. Images, newspapers, books, music records and films were just media and nobody would have ever thought to associate them with telecommu- nications, except when TV and radio broadcast them. Computers were the only equipment that was clearly digital. Big mainframes mostly took care of the repetitive and rather boring office jobs that many of our fathers and grandfathers had done manually. The associated telecommunications was in its early childhood. The environment was centralized, and the bit rates required to interconnect a remote dumb terminal had a speed from 50 to a maximum 300 bits/s. Each industry branch had its own techniques, patterns, codes and major players. The world was analogue, as it had always been, and the media industries were completely independent. Today the telecom services are mainly digital, that is, they are represented by ones and zeroes. What is not yet digital will be converted to digital sooner or later. 'The IT world is made of bits'. Thus the ultimate substance of a service is bits. The bits represent voice, TV pictures, books, ne