Chapter 1
Introduction

1.1 Introduction

The development of telecommunications and communication technologies in the twenty-first century, at least in its first half, has an unambiguous direction toward a single goal, and that is the Internet as a single platform for all services through a global network. However, the initial concept of telecommunications was based on real-time services such as voice communication between users over a telephone network (i.e., telephony), or diffusion of video and/or audio (i.e., television and radio). If we go even further in the past, one may mention the telegraphy in the nineteenth century as the first telecommunications technology for data transmission based on the usage of electrical signals.

However, the world of telecommunications or ICT (Information and Communication Technologies) is continuously evolving and changing, including the technologies, regulation and business aspects. Going from the telegraphy as main telecommunication service in the nineteenth century, then the telephony and television (including the radio diffusion) as fundamental telecommunication services in the twentieth century (and they continue to be nowadays), and Internet phenomenon by the end of the twentieth and beginning of the twenty-first century, telecommunications have changed and the technologies have changed. But, in such process was kept the backward compatibility for the flagship services, such as telephony and television, and their integration with the new services, such as Internet native services [e.g., World Wide Web (WWW), electronic mail (e-mail), etc.].

Regarding the development of the telecommunications so far, one may distinguish among four key phases:

1. The automation of the telephone exchanges and networks at the end of the nineteenth and the beginning of the twentieth century;
2. The transition from analog to digital telecommunication systems from the 1970s to 1990s;
3. The integration of the circuit-switched telephone networks, such as Public Switched Telephone Networks (PSTN) and Public Land Mobile Networks (PLMN), with the packet-based Internet in the 1990s and 2000s;
4. The convergence of all telecommunication services, including telecom-native services (such as telephony and TV/radio) as well as Internet-native services (such as WWW, e-mail, peer-to-peer services, etc.), over the broadband Internet as a unified global networking platform (regardless of the access network type, either wired or wireless), toward the Next Generation Networks (NGN), in 2010s and 2020s.

The four phases of telecommunications development have resulted in exponential increase of number of telecommunication networks and number of users. The nineteenth century can be denoted as a century dedicated to telegraphy. At the end of the nineteenth century the telephony was invented and telephone networks started to be implemented around the world. The twentieth century was dedicated mainly to telephony as primary service in telecommunications worldwide. At the end of the twentieth century appeared the Internet for public usage. Nowadays, in the second decade of the twenty-first century, all telecommunications services are being transferred to Internet. Hence, from this point of view, one may say (or predict) that twenty-first century will be dedicated to Internet and will be information centric. The framework of such development is set by the ITU (International Telecommunication Union) in the NGN concept. The main requirement for accomplishment of such task is broadband access to Internet, including fixed broadband, as well as mobile broadband. The broadband is a term used to describe the Internet access data rates which can provide access to all existing telecommunication services at given time including the currently most demanding ones such as video or multimedia streaming services (e.g., TV over the Internet). The birth and rise of the Internet, as well as broadband access to the global Internet network, has influenced the “look” of the telecommunications (i.e., the ICT).

So, today we have several important segments in the ICT globally. Telephony is still one of the primary services, where one can distinguish between fixed telephony and mobile telephony. Further, Internet is usually identified by certain types of services such as WWW, e-mail, peer-to-peer services, and many more, provided in so-called best-effort manner. Best-effort principle is based on connection control by the end point of the communication (called hosts, such as computers, servers, mobile terminals, etc.), where network nodes perform basically routing of all packets from all services without differentiation among them. Finally, Internet requires broadband access, including fixed broadband and mobile broadband, with aim to provide capabilities for different types of services including the most demanding ones regarding the available data rates (i.e., the bandwidth). These five segments form the outlook of today's telecommunications. The number of users for fixed telephony, mobile telephony, individual Internet users, and users with fixed and mobile broadband access to Internet are shown in Figure 1.1 (for more details a reader may refer to [[1]]). It is obvious that mobile telephony has overtaken the number of telephone users from the fixed telephony a decade ago. Hence, the number of mobile users increases exponentially and it is targeting the total population on Earth. Mobile telephony is personal, while fixed telephony is related to a certain location (e.g., a home or an office). Hence, the market capacity for the fixed telephony is several times smaller than the market capacity for the mobile telephony. However, it is likely that mobile telephony will be soon saturated by reaching 100% of the world population. On the other side, the mentioned trend of integration between traditional telecommunications and the Internet, which have been developed separately at the beginning of each of them, is finally resulting in transition of telecommunication world into the Internet world, and vice versa. The number of Internet users is increasing exponentially in the past two decades, almost in parallel with the rise of number of mobile users, as it can be seen in Figure 1.1. The broadband is crucial for the Internet. However the exponential rise of the broadband access started 10 years ago, including fixed broadband access and mobile broadband, and currently it is in a similar position to mobile telephony a decade ago (Figure 1.1). Hence, the highest market potential (in the ICT world) currently is the broadband Internet. Similar to the mobile-to-fixed telephony comparison, the mobile broadband is personal and hence will have faster exponential growth and higher penetration compared to the fixed broadband. On the other side, the fixed broadband will always have a higher capacity due to scarce radio spectrum resources over a given geographical area.

Figure 1.1 Global development of ICT

According to the discussions above, in the following part we will cover the main aspects of the traditional telecom world, and then the traditional Internet world, which converge nowadays to NGN as defined by the ITU (International Telecommunication Union). However, the ITU was established in 1865, when there was only the telegraphy present as a telecommunication service, and hence it was originally founded as the International Telegraph Union. Later the word “Telegraph” in the name of the ITU was replaced with the word “Telecommunication”, with the aim to cover the broader range of services after the invention of telephony and later the invention of radio broadcast and television. Today the ITU is part of the United Nations (UN), as a specialized UN agency for ICT. It is main international organization for telecommunications, which provides harmonization regarding the radio frequency spectrum worldwide through the sector International Telecommunication Union-Radiocommunication (ITU-R). Also, ITU develops technical standards as well as provides harmonization for usage of ICT technologies globally via its sector International Telecommunication Union-Telecommunications (ITU-T). Finally, ITU strive to improve the access to ICTs to developing countries and underserved communities worldwide through its sector International Telecommunication Union-Development (ITU-D), because everyone in the world has a fundamental right to communicate.

1.2 Traditional Telecom World

Traditional telecom world is mainly based on the telephony, which is the most important service in it. Hence, on the way toward the NGN, the telephony is still one of the most influential services. The other important traditional telecommunication service is television (also, coming from the first half of the twentieth century, while main spreading of the television worldwide happened in the second part of the last century). However, from the beginning the television was not offered by telecom operators which provided the telephony. Instead, the television was provided via separate broadcast networks, either terrestrial or cable. Traditional telecommunication networks are in fact the telephone networks, and hence they are in the focus in the following sections.

1.2.1 History of Telephony

The current look of the telecommunications started in the nineteenth century with the invention of the telephone by Alexander Graham Bell in 1876. However, telephony as a service even at the beginning required large number of users to have telephones, so they could call each other. So, the telephony has never been a service that could be dedicated to a privilege...