Current Mobile Technologies and Markets

The majority use GSM-based systems, but there are many people who use other
networks’ technologies. This total number of users is expected to grow to 3 billion
users before 2010 as the newer 3G technologies are adopted and the developing
markets begin to take off.

Mobile Generations
Mobile networks are commonly divided into three “generations,” with the third
generation (3G), of which UMTS is one such system, currently being deployed in
networks around the world.

First-generation (1G) systems were analog systems, designed with the simple
aim of making speech services available on the move. They included technologies
such as TACS (Total Access Communication System), NMT (Nordic Mobile Telephone),
and AMPS (Advanced Mobile Phone System). However, even these simple
systems led to annual market growth rates of 30 to 50 percent, leading to around
20 million subscribers by 1990.

However, quality was poor and capability and reliability were low. Thus, as
demand grew, the current range of 2G systems was developed to take their place. The
most well-known of these systems are GSM (Global System for Mobile Communications),
cdmaOne, and the system known in the United States simply as “TDMA,” or
by its standardization label of “IS-136.” These systems were characterized by a move
to representing information digitally and brought the following broad changes:

More consistent and reliable quality of speech

Increased capacity and spectrum efficiency through more advanced modulation
and access schemes

Easier implementation of advanced voice services, text messaging, fax, plus
the addition of basic access to data networks

Enhanced security and fraud prevention

However, even in the move from 1G to 2G (Figure 1.38), the basic aim was still
to optimize for speech services delivered over wide areas (macro cells). 1G and 2G systems
are therefore all characterized by circuit switched networks, which are well suited
to symmetric, real-time “conversational” services. The term “2.5G” is sometimes used
to describe enhancements to second-generation systems that aimed to optimize parts
of these systems for data applications using packet switching techniques.

The latest move, to 3G, further advances digital systems with the particular
aim of increasing the ability to use data applications on the move (i.e., mobile
computing or the wireless office), and to enable “multimedia” services, which may
mix voice, graphics, video, music, etc. To achieve this, a key change is in increasing
the ability of mobile systems to transfer larger quantities of information much
faster.

A factor throughout the evolution of mobile technology has been
the constant improvement in semiconductor and microwave technologies. While
such changes allow for building smaller and more sophisticated mobile equipment,
they also result in the expectation of users for more complex, data-intensive applications
and services.

The GSM Family of Technologies
GSM is a second-generation digital network, supporting voice and simple data services,
including “dial-up” data and text messaging. However, the term “GSM” is also
used to describe the more recent advances in the GSM family: GPRS and EDGE.

The Development of GSM
During the early 1980s, analog cellular telephone systems were experiencing rapid
growth in Europe, particularly in Scandinavia and the United Kingdom, but also
in France and Germany. Each country developed its own system, which was incompatible
with everyone else’s in equipment and operation. This was an undesirable
situation because not only was the mobile equipment limited to operation within
national boundaries, which in a unified Europe were increasingly unimportant, but
there was a very limited market for each type of equipment, so economies of scale,
and the subsequent savings, could not be realized.

The Europeans realized this early on, and in 1982 the Conference of European
Posts and Telegraphs (CEPT) formed a study group called the Groupe Spéciale
Mobile (GSM) to study and develop a pan-European public land mobile system.
The proposed system had to meet certain criteria:

Good subjective speech quality
Low terminal and service cost
Support for international roaming
Ability to support handheld terminals
Support for range of new services and facilities
Spectral efficiency
ISDN compatibility

The developers of GSM chose an unproven (at the time) digital system, as
opposed to the then-standard analog cellular systems such as AMPS in the United
States and TACS in the United Kingdom. They had faith that advancements in
compression algorithms and digital signal processors would allow the fulfillment
of the original criteria and the continual improvement of the system in terms of
quality and cost.

In 1989, GSM responsibility was transferred to the European Telecommunication
Standards Institute (ETSI), and phase I of the GSM specifications was published
in 1990. Commercial service started in mid-1991, and by 1993 there were
36 GSM networks in 22 countries, with 25 additional countries having already
selected or considering GSM. This is not only a European standard; South Africa,
Australia, and many Middle and Far East countries have chosen GSM. By the
beginning of 1994, there were 1.3 million subscribers worldwide. The acronym
GSM now stands for Global System for Mobile telecommunications.