32.1 EVOLUTION OF CELLULAR RADIO
Bell Labs conceived the concept of cellular radio in the early 1940s. The prevailing
technology, however, could not cope with the complexities involved, and World War
II imposed other priorities. After the war, commercial public mobile radio operating
in the 150-MHz band began in 1946 in St. Louis, Missouri, United States (Section
17.3). A system operating in the 450-MHz band followed in 1956. There were almost
1.5 million mobile users in 1964, when AT&T introduced an Improved Mobile Telephone
System (IMTS), system MJ operating at 150 MHz and system MK operating
at 450 MHz via 25- to 30-kHz FM channels. Various mobile radio systems followed,
mainly in North America and Europe. Those systems operated on a limited number
of channels in the 40-, 80-, and 160-MHz bands. Operation was in a manual mode;
an operator could establish a call between two mobile subscribers or between a
mobile subscriber and a subscriber on the PSTN.
The mobile terminals equipped with electronic vacuum tubes were large, heavy,
had a high power consumption, needed shock-protected mountings, and were
expensive. Transistorizing in the 1970s brought substantial improvements, but the
limited number of radio channels constrained the network capacities. Improvement
in the equipment and services and the opening of the 450- and 800-MHz bands for
public mobile radio in the 1980s enlarged the number of subscribers to about 600,000
worldwide by 1985 but caused even more network congestion.
An approach toward a better use of the available radio spectrum, a trunking
technique, was introduced in the late 1970s. Trunking provides organized sharing of
a small number of RF channels by a large number of professional mobile radio users.
These users were mainly taxi drivers, transport enterprises, emergency services, andgovernment organizations.1
The subscribers share access to a mobile radio network
without being aware of other users. Tens of thousands of subscribers shared trunking
networks in places such as London, Los Angeles, Rotterdam, Sydney, Tel Aviv, and
Toronto in the early 1980s.2
Trunking improved the use of the radio spectrum, but it did not solve the problem
of congestion on the public mobile radio networks. The creation of an altogether new
concept became a necessity. About 150,000 subscribers used mobile radio in 1978,
when the FCC invited the U.S. telecommunications industry to bring forth proposals
for a more e¤ective land/mobile telephone system. AT&T responded with a proposal,
originating from the above-mentioned Bell Labs’ idea in the 1940s, called the
cellular Advanced Mobile Phone System (AMPS), whereby a set of frequencies could
be reused within a system of cells. Each cell would have its own transmitter/receiver
station that would be connected to the PSTN. Mobile telephone users traversing the
cells would change automatically to the frequency of the cell entered, thus constantly
keeping in touch with, or in reach of, the PSTN. AMPS was demonstrated successfully
in Chicago in 1978, but matters of competence of the relevant authorities and
interference with frequency bands used by the military and for TV delayed the
introduction of cellular radio in the United States until 1983.
In the meantime, the concept of cellular radio communication was discussed in a
paper called ‘‘Fundamental Problems of Nationwide Mobile Radio Telephone System,’’
written by K. Araki and published in NTT’s Electrical Communications Laboratories
Technical Journal, Vol. 16, No. 5, in 1967. Japan, a very densely populated
country with plenty of public pay telephone booths, never had a public mobile
radiotelephone system apart from public radio paging, introduced in 1968. Research
into a land mobile telephone system suitable for Japan was initiated in 1953 by the
Electrical Communications Laboratories of NTT and resulted in 1967 in the abovementioned
publication in which a nationwide cellular radio system operating in the
800-MHz band was proposed. In the same year, NTT began development of the
proposed cellular system. Trials with laboratory equipment were made in the Tokyo
metropolitan area in 1971. A pilot system could then be tested successfully, in 1975.
After further system improvements, the world’s first cellular radio service was begun
in Japan on December 3, 1979 with a cellular radio system called MCS (mobile
control station). Thus the cellular radio era started in 1979 in Japan.
Cellular radio, even in its first analog version, is the most e¤ective version of
mobile radio. It provides radio coverage of large geographical areas by seamless
overlapping cells in a honeycomb configuration. Cellular radio networks provide
more versatile services to mobile users as obtained at fixed locations from the PSTN.
Figure 32.1 shows the basic configuration of a cellular radio network and Technology
Box 32.1 gives a brief explanation. Cellular radio became the fastest-growing
public telephone service. In the industrial world, it o¤ers the highly mobile user con-tinuous accessibility,
whether on foot or in a vehicle. In the developing world, it
o¤ers a quick, low-cost substitute for poor-quality or nonexisting fixed telephone
networks, thus solving the problem of long waiting times for network access.
32.2 ANALOG CELLULAR RADIO
In addition to AMPS and MCS, were cellular radio systems such as the Scandinavian
Nordic Mobile Telephone (NMT), the Total Access Communication System
(TACS) in the U.K., C 450 in Germany, RadioCom 2000 in France, and Radio
Telephone Mobile System (RTMS) in Italy. All those cellular radio systems operated
in an analog mode and were not compatible with each other. The mobile terminalswere conceived for installation
in vehicles, with the possibility of removing them
from vehicles for temporary transportable use. For exclusive portable use, a simplified
version of cellular radio was developed called cordless telephone (CT), with
small cells, mainly in pedestrian areas. Table 32.1 shows the distribution of cellular
radio at the end of 1997. Beginning that year, analog cellular penetration stagnated
and gradually decreased, due to the superior quality of digital systems.
TECHNOLOGY BOX 32.1
Basic Cellular Radio Network
Cellular radio networks provide radio coverage to mobile stations (MSs) in large
geographical areas by seamless overlapping cells. Each cell has its own radio base
station, usually called a base transceiver station (BTS). A number of base stations
are connected with a common base station controller (BSC). All BSCs of a coverage
area are connected with a mobile-service switching center (MSC), which performs
switching between the mobile subscribers and constitutes the interface to
the PSTN/ISDN. Mobile subscribers traveling from cell to cell are switched over
automatically to the base station of the next cell by a procedure called handover,
so that uninterrupted conversation is granted and no calls will be missed. The
mobile subscriber reports its location automatically to the MSC via the BTS of the
cell in which he or she has arrived. The MSC registers this in location registers so
that calls to network subscribers can be routed to the cell where the subscriber
called has reported its presence.
The locations of subscribers belonging to the coverage area of the MSC are
permanently registered in a Home Location Register (HLR). Subscribers arriving
from another coverage area are temporarily registered in a Visitor Location Register
(VLR). A special Equipment Identity Register (EIR) checks the status of the
MS’s identity number. Each MS has its International Mobile Station Identity
(IMEI) number, which enables the EIR to identify an unauthorized (stolen,
cloned, or other type of fraud) MS. An Authentication Center (AuC) checks the
authentication of a subscriber attempting to use the network. The corresponding
information is stored in a subscriber identity module (SIM) card which the subscriber
has to insert in a MS before it can be used. Instead of a SIM card, some
cellular systems use a user identification module (UIM) or subscriber identity security
(SIS) card. An operation and maintenance center (OMC) controls the system
elements, provides security management, and collects billing and accounting
information.
32.2.1 Analog Cellular Radio in Japan
The Japanese analog cellular radio systems operated in the 800-MHz band. The first
system, MCS L1, had 600 radio channels with a channel separation of 25 kHz. Themobile units still had a
volume of 6600 cm3 and a weight of 7 kg. Transportable
units introduced in 1985 weighed 3 kg, had a volume of 2300 cm3, and 5 W of output
power. The first portable units came in April 1987, with a weight of 750 g, a volume
of 500 cm3, and 1 W of output power. A second version, MCS L2, was introduced in
1988 with a channel spacing of 12.5 kHz and 6.25 kHz with interleaved channels,
resulting in 2400 radio channels.
Initial growth was slow until nationwide roaming was introduced in 1984 and
cellular radio was liberalized in 1985. There were 100,000 subscribers when two new
operators, Daini Denden Inc. (DDI) and Nippon Indou Tsushin Corp. (IDO),
joined the cellular market in 1988. IDO also used the MCS L2 system, whereas DDI
introduced J-TACS (Japan TACS), based on the British TACS system (Section
32.2.4). In 1989, DDI introduced the Handy-Phone, based on Motorola’s TAC portable.
With a volume of 221 cm3 and a weight of 303 g, it marked the beginning of
handset miniaturization. In 1991, DDI and IDO introduced N-TACS (narrowband
TACS) from Motorola with 1200 channels and a bandwidth 12.5 kHz.
32.2.2 Analog Cellular Radio in Scandinavia
The Swedish engineer MaЁkitalo conceived the Nordic Mobile Telephone (NMT)
system when working for the Swedish Telecommunications Administration, Televerket.
3 The system, operating in the 450-MHz band, has 180 radio channels with a
spacing of 25 kHz or 225 channels with a spacing of 12.5 kHz. A second system,
NMT 900, operating in the 900-MHz band, was introduced in 1986, with 1000
channels at 25-kHz spacing or 1999 interleaved channels when using 12.5-kHz
spacing.
The NMT system was put into operation by the telecommunications administrations
of Denmark, Finland, Norway, and Sweden in 1981–1982 and soon found
applications beyond the Scandinavian countries: first in The Netherlands, Saudi
Arabia, and Spain in 1982; Malaysia, Oman, Tunisia, and Turkey in 1985; and successively
worldwide.
32.2.3 Analog Cellular Radio in North America
The American AMPS operates in the 800-MHz band with 832 radio channels at 30kHz spacing. Narrow-AMPS (N-AMPS), with 2580 radio channels at 10-kHz spac-ing, followed in 1991.
Commercial operation began in the United States in 1983. The
AMPS system was used all over the Americas, starting in Canada in 1985, one year
later in Mexico and Colombia and outside the Americas in Korea and Australia
in the next years, followed by China, Hong Kong, Indonesia, Laos, Malaysia, New
Zealand, Pakistan, the Philippines, Singapore, Taiwan, Thailand, Vietnam, and all
Latin American countries.
32.2.4 Analog Cellular Radio in Western Europe
The British Total Access Communication System (TACS) was introduced in the U.K.
in 1985. The U.K. government, as a pacemaker in telecommunications liberalization,
had invited potential operators, excluding the fixed network operators British Telecom
and Mercury, to apply for a 25-year license for the operation of a cellular radio
network. The successful tenderers were Vodafone (then a subsidiary of Racal Millcom
Ltd., since 1988 independent Vodafone Group plc), and Cellnet (a BT/Securicor
partnership). They agreed on a modified version of the U.S. AMPS developed by
Motorola, which was then named TACS. The system operated 1000 radio channels
with a spacing of 25 kHz in the 900-MHz band. An extended TACS (called ETACS)
with 1640 radio channels at 25-kHz spacing, followed in 1988. Outside the
U.K., TACS was introduced in Ireland and Hong Kong in 1985, and one year later
in Bahrain and Kuwait, soon followed by Austria, China, Italy, Kuwait, Pakistan,
Spain, and many other countries.
In Germany the cellular radio C 450 system was introduced in 1985. The nomination
C indicated that it was the third national public mobile network, after the
noncellular networks A, introduced in 1958, and B, introduced in 1972. The A and B
networks operated in the 160-MHz band. The A-Net, with terminals weighing 16 kg,
had 10,500 users in 1972 (served by 600 operators), when the B-Net was introduced.
The B-Net reached a maximum of 26,911 subscribers in 1986. The cellular system C
450 operated 222 radio channels with a channel spacing of 20 kHz in the 450-MHz
band. It was the first system that applied a subscriber identity card, the forerunner of
the SIM (see Technology Box 32.1). The C 450 system was also introduced in South
Africa in 1986.
In France in 1985 a system was introduced called RadioCom 2000, which also
operated in the 450-MHz band using 170 radio channels at a spacing of 20 kHz.
In Italy, in addition to TACS, a 450-MHz band system called RTMS (Radio
Telephone Mobile System) was used.
32.3 DIGITAL CELLULAR RADIO
In the mid-1980s, when analog systems were introduced, the first market forecasts
predicted 500,000 subscribers by 1990. The actual demand, however, far superseded
this expectation, and there were 10 million analog cellular radio subscribers in 1990
and two years later, almost 15 million subscribers in 30 countries. By that time, cellular
networks in Chicago, Los Angeles, and New York each had over 500,000 subscribers
and London over 750,000, which again caused substantial congestion. Once
more, a new approach was required: a change from analog to digital operation.
Digital operation not only improves transmission quality but facilitates data trans-mission and speech encryption
and allows di¤erent multiple-access modes, which
substantially increase the capacity of a cellular network. Three multiple-access
methods are used, as illustrated in Figure 32.2 and explained briefly in Technology
Box 32.2.
Five di¤erent second-generation (2G; the analog cellular radio systems were then
1G systems) digital cellular radio systems were developed; the global system for
mobile communication (GSM) in Europe, two digital-AMPS systems (D-AMPS
TDMA and CDMA) in the United States, and two personal digital cellular systems
(PDC 800 and PDC 1500) in Japan. Furthermore, the analog CT systems were
succeeded by digital personal communications networks (PCNs), in which persontoperson communication was provided using a single national—and eventually
international—personal telephone number, independent of home or o‰ce.
Introduction of these digital cellular radio systems in the early 1990s caused an
enormous boost in telecommunications, especially after prepaid service replaced
subscription contracts. Prepaid service was first o¤ered by the German operator D1
(later T-Mobil) in 1995 to increase Christmas sales. One year later, the Italian operator
Telecom Italia Mobile (TIM) o¤ered rechargeable prepaid cards with the slogan
‘‘no activation fee, no subscription, no monthly bill,’’ which made cellular radio
worldwide a mass consumer product. Handsets bundled with prepaid cards were sold
in the supermarket like washing detergent. By year-end 2000, 61% of all European
cellular users and almost 30% of all cellular radio users worldwide used a prepaid
card.
Another impetus to cellular radio was given by the introduction of nonvoice
small message services (SMSs), which o¤er text messages showing a maximum of 160
characters on the display of the handset at a marginal cost and with a minuscule
impact on network capacity. SMS was introduced on GSM networks in Europe in
the mid-1990s, soon followed in Asia and since the end of 2000 in the United States
on non-GSM networks. SMSs in the Chinese language became possible in the year
2000 with the introduction of handsets on which eight basic strokes of the Chinese
characters are allocated to the 1 to 0 keys of the keypad in an eZiText4 mode. At the
end of the century, SMS messages were being sent worldwide at a volume of 20 billion
per month and still rising.5 In 1996 the analog NMT system was enhanced to
include SMS.
Cellular radio became the fastest-growing sector of telecommunications. Deregulation
and privatization were first applied on cellular radio operation so that competition
became a dominant factor for growth. Most countries got at least two competing
operators. Optimistic market observers, including the author of this book,
dared to forecast in 1990 around 36 million subscribers by 1995 and a maximum of
100 million by the beginning of the new century for cellular radio, including PCN.
By 1995, instead of the 36 million forecasted, there were 80.3 million analog and
digital cellular subscribers worldwide, of which there were 36 million in North
America, 22.5 million in Europe, and 21.8 million in the Asia-Pacific region. The
distribution was AMPS, 51%; TACS, 17%; GSM, 14%; NMT, 6%; PDC, 4%; DAMPSTDMA, 2%; PCN, 2%; and others, 4%.6 The tremendous development
of cellular radio in the last decade of the twentieth century is documented in Table
32.2, whereas Table 32.3 shows the distribution to the major cellular systems of the
worldwide 490 million cellular subscribers by year-end 1999. One year later there
were 740 million subscribers: 39.4% in Europe, 34% in the Asia-Pacific region, 16%
in North America, 8.5% in Latin America, and 2.1% in Africa.
Cellular growth surpassed growth in the fixed telephone networks. In 1993, Cambodia
was the first country where the number of mobile subscribers exceeded the
number of fixed lines (albeit at a mobile teledensity of 0.81 and a fixed-line teledensity
of 0.25), followed by Finland in 1998 (with a mobile teledensity of 67 and a
fixed teledensity of 55). Austria, Coˆ te d’Ivoire, Hong Kong SAR, Israel, Italy, Korea
(Republic), Paraguay, Portugal, Uganda, and Venezuela followed in 1999, and a
further 23 countries in 2000. In that year the end users bought a total of 413 million
cellular handsets,8 of which 30.6% were made by Nokia, 14.6% by Motorola, 10% by
Ericsson, 6.5% by Siemens, 5% by Samsung, and 33.2% by others.
The 10 operators with the highest number of subscribers at the end of the twentieth
century are summarized in Table 32.4. The largest market was the United
States with 110 million subscribers, followed by China with 85.3 million; Japan, 66.8;
Germany, 48.1; Italy, 42.2; and the U.K., 40 million cellular radio subscribers.
32.3.1 Global System for Mobile Communication
In 1981, a joint Franco–German study was initiated to develop a binational cellular
radio system, with the desired side e¤ect of counterbalancing the Scandinavian NTM
system. Fortunately, the CEPT (Committee of European Post and Telecommunications)
recognized the challenge of a pan-European cellular system and used the study
as an incentive to extend cooperation from Franco–German to pan-European.
CEPT decided to set up a working group under the French language name Groupe
Speґciale Mobile, hence the abbreviation (GSM), which after worldwide penetration
of the system was changed to Global System for Mobile Communication. This group
was given the task of defining and working out the specifications for a cellular system
that could be introduced across Europe in the early 1990s. In line with the ongoing
evolution from analog to digital in switching and transmission, it became obvious
that this new system should be a digital system.
In 1986, the European Union issued a directive to all members states to clear the
frequency band of 890 to 915 MHz for transmission from mobile to base station and
935 to 960 MHz for the reverse direction for the operation of 124 radio channels for
the future pan-European cellular radio network. On September 7, 1987, a memorandum
of understanding (MoU) was signed in Copenhagen by 13 European countries9
committing them to implement a common digital cellular radio system on their networks,
including roaming with the networks of the other MoU-signature operators,
by July 1, 1991. The completion date was later advanced by one year. In 1989 the
responsibility for the GSM specifications passed from CEPT to the newly created
European Telecommunications Standards Institute (ETSI), located at Sophia Antipolis
in the south of France.
By 1990, the GSM working group, embracing hundreds of engineers, could complete
the specifications.10 A race began for the first networks to open commercial
operation by July 1, 1992. The Finnish operator OY Radiolinja AB was the winner
starting in December 1991. A further seven operators met the July 1, 1992 date.
Within one year all other original MoU-signature operators had begun commercial
GSM operation, and surprisingly, also operators outside Europe in Australia,12 New
Zealand, and Hong Kong. Full national coverage and international roaming has
been reached for at least 90% of the population in countries with GSM networks.
In 1991, ETSI extended the GSM specification and added 374 radio channels
in the frequency band 1710 to 1880 MHz for a Digital Cellular System 1800 (DCS
1800), to be used for the personal communications networks (PCNs; see Section
32.4). The British company Mercury One-2-One launched the first network with
DCS 1800 equipment on September 7, 1993. In Asia the first network based on DCS
1800, supplied by Nokia, was launched in Thailand on September 28, 1994, under
the name Worldphone 1800. It started with an initial capacity of 60,000 subscribers
served in 140 cells in Bangkok and its suburbs. In 1997, the various DCS 1800 systems
using GSM technology were renamed GSM 1800 to di¤erentiate them from
networks applying CDMA or another technology in the 1800-MHz band.
GSM planning in the 1980s had been based on 10 million subscribers all over
Europe, North Africa, and part of the Middle East by the end of the century. In fact,
this number was almost reached at the end of 1995, with few subscribers in North
Africa (only 16,500 in Morocco) but an unexpected large number in South Africa
and even more in the Asia-Pacific region.13 Table 32.5 summarizes worldwide GSM
deployment by the end of 1995 and 2000.
One of the key advantages of GSM is the use of sophisticated encryption derived
from military technology known as A5, which at least until early 199914 was never
cracked. Export of GSM equipment with the A5 algorithm was restricted temporarily by COCOM regulations15 and a simplified A5/2 algorithm had to be used, which,
however, was still very secure against call interception.
GSM has a transmission speed of only 9.6 kbps, which is suitable for voice, SMS,
and low-speed data services. From mid-1990, systems with more advanced data
transmission were developed as 2.5G (between the second and third generations)
solutions:
1. High-speed circuit-switched data (HSCSD), by combining channels o¤ering
full-ISDN 64 kbps in circuit-switched mode
2. General packet radio service (GPRS), by combining channels and a new coding
o¤ering up to 115 kbps in packet-switched mode
3. Enhanced data rates for GSM evolution (EDGE), for speeds up to 384 kbps in
wide-area applications and up to 554 kbps in local areas (EDGE is also compatible
with the U.S. D-AMPS-TDMA system)
4. GSM/EDGE radio access network (GERAN), as Phase 2 EDGE, o¤ering data
rates up to 1920 kbps
The next addition to GSM was a facility for Internet access on GSM terminals
called the Wireless Access Protocol (WAP). This protocol was developed by cooperation
between Ericsson, Motorola, Nokia, and UP in 1999. To enable the presentation
of Internet on the small screen of a mobile handset, a special wireless markup
language (WML) was developed as a counterpart to the Internet HTML (hypertext
markup language). WAP is not only for GSM but is compatible with all digital cellular
standards. Figure 32.3 shows a handset with a WAP Internet browser as the
state of the art in 1999. A further facility is location-based service using triangulation
on signals either from multiple base stations or from a GPS (see Chapter 27, footnote
32).
GSM not only went far beyond its originally planned geographical borders, it also
succeeded in entering into other domains, such as conventional Private Mobile Radio
(PMR), railways, airplanes, and maritime communications. Conventional PMR
services include features such as group call services, dispatch capabilities, fleet
management, and flexible private group communication. In 1998, L.M. Ericsson
launched the GSMPro solution, which added those and other PMR facilities to the
worldwide GSM network.
Railway operating systems in Europe still di¤er from country to country, with
di¤erent power supply, signaling, and incompatible analog communication systems.
Now, at least a pan-European rail communication system is under development
based on a GSM-R(ail) standard which was accepted by 32 countries in a MoU in
1997. The majority of the rail operators agreed to implement GSM-R by 2003. The
standards for GSM-R are being elaborated by ETSI. The radio spectrum will be in
the 900-MHz band, slightly above the GSM band.
The use of GSM on airplanes was launched on Malaysian Airlines (MAS) and
Singapore Airlines (SIA) in 1999. This service was o¤ered by Skyphone Mobil Connect, a subsidiary of BT Skyphone System, in a combination of GSM and the
Inmarsat satellite network. The radio-frequency part of the GSM handset is switched
o¤ so as not to interfere with an airplane’s electronics, but facilities such as SMS,
Internet, and central billing can be used. In 2000, the same company started trials for
use of GSM on cruise liners.
By the end of the twentieth century there were almost half a million GSM subscribers
(500,000,000 in May 2001) in 350 networks in 170 countries. While GSM
was a European invention and almost 98% of the West European population is
covered by GSM, 40% of all GSM customers were based outside Europe, and the
largest single-country customer base, about 83 million, was in China.
32.3.2 D-AMPS System
The development of digital cellular radio in the United States started much later than
in Europe, for the obvious reason that for over 90% of AMPS subscribers in the
United States, transborder roaming was no issue, and once it became an issue it
could easily be implemented between the United States and Canada and Mexico in
the common analog AMPS system. International roaming on the analog AMPS has
been established on the North American cellular networks and also with AMPS
operators in Hong Kong and Australia. In the late 1980s, however, concern arose
that capacity problems would also arise with analog AMPS system and that a digital
system should be developed.
In March 1988, the U.S. Telephone Suppliers Association (USTSA) and the information
technology group of the Electronic Industries Association (EIA) formed the
Telecommunications Industry Association (TIA), which then created subcommittee
TR-45, given the task of producing a digital cellular standard. A vigorous debate
started as to whether to base the new system on TDMA or on CDMA technology.16
TIA made a balloted selection by its members in favor of TDMA in 1990. In the
same year the standard IS-54 was issued, specifying the transition from AMPS to
digital AMPS (D-AMPS), increasing the capacity by a factor of 3, but still using
an analog control channel (to prevent a further three-year delay on implementation).
To facilitate the transition it was decided to apply TDMA and to use the same frequencies
as were used for AMPS. Moreover, dual-mode operation was mandated on
the old analog and the new digital networks. The first commercial D-AMPS network
began operation in 1993. A second digital cellular standard, named IS-95 or
cdmaOne, was developed by Qualcomm in 1991, based on the CDMA access mode.
In 1994, with IS-136, a full digital specification for D-AMPS-TDMA became available,
including enhanced TDMA, which accommodates up to 10 voice/data channels
per RF channel. Motorola developed a noncompatible digital standard called iDEN
(integrated digital enhanced network), providing voice and text.
In addition to the frequencies in the 800-MHz band, the band from 1850 to 1950
MHz was allocated using the same or other technologies for the newly planned Personal
Communications Services (PCS; Section 32.4), called PCS 1900. Surprisingly,
the first PCS 1900 network did not use the American technologies IS-95 or CDMA
but the European GSM adapted to U.S. conditions. This GSM network began
operation in Washington, DC, in November 1995. Quickly, half a dozen operators
implemented PCS 1900 networks based on GSM in the United States and Canada.
In 1997, those networks were named GSM 1900 to di¤erentiate them from PCS networks
using CDMA or IS-95. By 1995, Cellular Digital Packet Data (CDPD) data
transmission at a speed of 19.2 kbps was introduced on AMPS networks.17
At the end of the twentieth century, one analog and four noncompatible digital
systems were in operation, including the PCS networks, distributed approximately as
summarized in Table 32.6. To enable communication in the networks with di¤erent
technologies, dual-band, triband, and dual-band dual-mode handsets were introduced.
18 More complicated interstandard handsets, enabling roaming between networks
with GSM, TDMA, CDMA, and iDen technologies, were announced for
introduction by late 2001 at the GSM Global Roaming Forum in Miami in 2000.
Outside the United States, D-AMPS-TDMA was adopted widely in countries that
had already installed analog AMPS systems, especially in Latin America. Ironically,
the world’s first network with the American CDMA system was put into operation
not in the United States, but in Hong Kong, where the private operator Hutchison
launched a CDMA network on September 28, 1995. With dual-mode handsets supplied
by Qualcomm, subscribers could freely use analog AMPS and digital CDMA,
which became progressively available with 120 cells in Hong Kong. In January 1996,
CDMA was launched in Japan and Korea. In Korea it became the national standard
for operation in the 1700-MHz band, supported by early technology transfer
agreements from Qualcomm with the Korean companies Samsung and Hyundai.
Remarkably, in October 2000, the state-owned Chinese manufacturer Zhongxing
Telecom Equipment Co. (ZTE) developed the world’s first handsets with interstandard
SIM cards for global roaming in CDMA and GSM networks.