23-07-2012, 03:01 PM
3rd Generation Mobile Communications Systems
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1 Introduction
1.1 The cellular concept
Mobile (radio) communication is understood as exchange of information between two or more
users of which at least one user equipment is not located at a fixed position and may be moving
around.
In cellular systems, radio communication takes place between a mobile station (MS) and a fixed
station which is referred to as radio base station (RBS). Normally, in a cellular system, there is
no direct communication between two mobile stations (there may be however extensions to
cellular systems which allow also direct communication between MSs).
The geographic area in which a mobile station is able to exchange radio signals with a radio base
station is called a (radio) cell. A cellular system consists of set of (possibly overlapping) cells
where each cell is served by one radio base station.
At one (antenna) site (“Standort”) several radio base stations may be co-located. By using sector
antennas it is possible to establish several cells from a single site (see Figure 1).
The transmission direction from an MS to a RBS is denoted as uplink (sometimes also referred to
as reverse link). The transmission direction from an RBS to an MS is denoted as downlink
(sometimes also referred to as forward link).
uplink
downlink
Omni-directional
RBS antennas
120-degree sector
RBS antennas
3rd Generation Mobile Communication Systems Page Version 1.12
1-2 01.08.2000
1.2 Historical development of mobile communication systems
1.2.1 First-generation systems
The first mobile cellular radio systems are based on analog transmission technology (at later
stage employing digital signalling) and were designed for support of telephone speech service.
1946 First mobile telephone service in the USA introduced by AT&T (single-cell,
manual operation)
1979 Pre-commercial operation of Advanced Mobile Phone System (AMPS) in US,
MCS-L1 introduced in Japan by NTT (AMPS based, 25 kHz channels)
1981 Commercial operation of NMT450 (Saudi Arabia and Sweden)
1983 First commercial operation of AMPS (Chicago)
1985 System C450 in commercial operation in Germany
TACS system (AMPS based) in commercial operation in UK
1.2.2 Second-generation systems
With the second-generation systems digital radio technology was introduced. Initially designed
for circuit switched services such as telephone speech and low rate data. Further evolutions of
second generation systems also support packet transmission with low-to-medium peak bit rate,
e.g. General Packet Radio Service as supplement to GSM circuit switched services.
1982 GSM development started by “Group Speciale Mobile”
1988 ETSI formed in Europe
MCS-L2 introduced in Japan (12.5 kHz channels)
1992 All major European operators start commercial operation of GSM networks
1993 First DSC1800 system in commercial operation in UK
1994 Commercial operation of D-AMPS (IS-54) in US started
1994 Commercial operation of PDC in Japan started by NTT
1995 Commercial operation of N-CDMA system (IS-95) in
Hong Kong/Korea
1995 PCS1900 (D-AMPS in 1900 MHz band, IS-136)
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1.2.3 Third-generation systems
The future third-generation systems shall be distinguished from the second generation primarily
in terms of the services offered to the users. Third-generation systems shall provide high-speed
transmission rates and more efficient support of packet services. Spectrum-efficient high-speed
data transmission has become feasible due to the advances in digital technology, both with
respect to signal processing algorithms and integrated circuit technology.
Discussion of a potential successor system for GSM started in ETSI and other standard
developing organizations already in the late 1980, even before any second-generation system was
in commercial operation. The ETSI-term for the future system was Universal Mobile
Telecommunications System (UMTS). Simultaneously, the International Telecommunication
(ITU) also started discussions on a potential future mobile system initially referred to as Future
Public Land Mobile System (FPLMTS) and started to specify a set of system requirements.
Due to the huge world-wide success of GSM, the interest among European network operators
and manufacturers to consider a completely new system was rather low until to the mid 1990s.
Only after the ITU has taken the initiative to formulate a concrete roadmap towards a new mobile
system to be deployed in the early 2000s, the specification activities for UMTS in ETSI were
ramped up in 1995. Some pressure on ITU to speed-up 3G activities mainly came from Japanese
operators and manufacturers, when it was predicted that the Japanese 2G-system PDC will soon
reach its capacity limits. In contrast to the GSM community, in Japan there was only very little
interest in a further evolution of PDC due to its small share of the international market.
The ITU term for the future 3G system was later changed to IMT-2000, International
Telecommunications System for the 2000s. As part of the roadmap, a deadline for submission of
proposals for IMT-2000 by the regional standardization development organizations was agreed to
be in July 1998.
In Europe, research studies on candidate radio technologies for 3G systems started around 1989
with funding by the Commission of European Communities (CEC) in the RACE Mobile project
line. From 1991 – 1995 two CEC funded research projects called Code Division Testbed
(CODIT) and Advanced Time Division Multiple Access (ATDMA) were carried out by the major
European telecom manufacturers and network operators. The CODIT and ATDMA projects
investigated the suitability of wideband Code Division Multiple Access (CDMA) and Time
Division Multiple Access (TDMA) based radio access technology for 3G systems. This work was
later continued in the FRAMES (Future Radio Wideband Multiple Access System) project and
became the basis of the further ETSI UMTS work until decisions were taken in 1998.
In January 1998 ETSI selected two radio transmission technologies (from originally 4 different
proposals) for UMTS terrestrial radio access (UTRA), referred to as UTRA FDD and UTRA
TDD, which were submitted to ITU as candidates for IMT-2000.
The terrestrial radio transmission technologies proposed to ITU in July 1998 are listed in
Table 1. The proposals included a number of different Wideband CDMA (WCDMA) based
radio access technologies, from ETSI, TTC/ARIB (Japan), TTA (Korea), ANSI T1 (USA) and
TIA (USA), which can be grouped into two types. The one type of proposals requires
synchronized base stations and is building up on the IS-95 2G radio transmission technology.
The other group of concepts does not rely on base station synchronization (there are however
also cases were it is also needed).
By the end of 1998 two specification development projects were founded by the regional
standardization organizations, 3GPP (3rd Generation Partnership Project) and 3GPP2. The goal of
3rd Generation Mobile Communication Systems Page Version 1.12
1-4 01.08.2000
both 3GPP and 3GPP2 was to merge a number of the W-CDMA based proposals into a single
one, see Table 1. 3GPP2 was concerned with the IS-95 based systems.
The split of standardization activities into two camps was partly caused by a dispute on
Intellectual Property Rights (IPR) on W-CDMA technology between various telecom
manufacturers. After these IPR issues were resolved in mid 1999, the members of 3GPP and
3GPP2 agreed on a harmonized global IMT-2000 CDMA proposal. This agreement then paved
the way for a harmonized overall concept of a ITU IMT-2000 family of 3G systems as shown in
Figure 2.
The IMT-2000 family of 3G systems includes
• Three types of Core Network technology:
• GSM based (using Mobile Application Part (MAP) protocols on top of SS7 protocols for
signalling)
• ANSI-41 based (IS-634 protocols for signalling)
• Internet Protocol based (in future, to be specified)
• Five types of Radio Access Network technologies
• UTRA FDD (W-CDMA)
• UTRA TDD (W-CDMA combined with TDMA)
• cdma2000-MC (N-CDMA with multiple carriers on downlink, W-CDMA uplink)
• UWC-136 (TDMA, TDD and FDD modes)
• DECT (TDMA, TDD); an extension to today’s DECT technology to enable the support
of 3G services in wireless phones
[attachment=28524]
1 Introduction
1.1 The cellular concept
Mobile (radio) communication is understood as exchange of information between two or more
users of which at least one user equipment is not located at a fixed position and may be moving
around.
In cellular systems, radio communication takes place between a mobile station (MS) and a fixed
station which is referred to as radio base station (RBS). Normally, in a cellular system, there is
no direct communication between two mobile stations (there may be however extensions to
cellular systems which allow also direct communication between MSs).
The geographic area in which a mobile station is able to exchange radio signals with a radio base
station is called a (radio) cell. A cellular system consists of set of (possibly overlapping) cells
where each cell is served by one radio base station.
At one (antenna) site (“Standort”) several radio base stations may be co-located. By using sector
antennas it is possible to establish several cells from a single site (see Figure 1).
The transmission direction from an MS to a RBS is denoted as uplink (sometimes also referred to
as reverse link). The transmission direction from an RBS to an MS is denoted as downlink
(sometimes also referred to as forward link).
uplink
downlink
Omni-directional
RBS antennas
120-degree sector
RBS antennas
3rd Generation Mobile Communication Systems Page Version 1.12
1-2 01.08.2000
1.2 Historical development of mobile communication systems
1.2.1 First-generation systems
The first mobile cellular radio systems are based on analog transmission technology (at later
stage employing digital signalling) and were designed for support of telephone speech service.
1946 First mobile telephone service in the USA introduced by AT&T (single-cell,
manual operation)
1979 Pre-commercial operation of Advanced Mobile Phone System (AMPS) in US,
MCS-L1 introduced in Japan by NTT (AMPS based, 25 kHz channels)
1981 Commercial operation of NMT450 (Saudi Arabia and Sweden)
1983 First commercial operation of AMPS (Chicago)
1985 System C450 in commercial operation in Germany
TACS system (AMPS based) in commercial operation in UK
1.2.2 Second-generation systems
With the second-generation systems digital radio technology was introduced. Initially designed
for circuit switched services such as telephone speech and low rate data. Further evolutions of
second generation systems also support packet transmission with low-to-medium peak bit rate,
e.g. General Packet Radio Service as supplement to GSM circuit switched services.
1982 GSM development started by “Group Speciale Mobile”
1988 ETSI formed in Europe
MCS-L2 introduced in Japan (12.5 kHz channels)
1992 All major European operators start commercial operation of GSM networks
1993 First DSC1800 system in commercial operation in UK
1994 Commercial operation of D-AMPS (IS-54) in US started
1994 Commercial operation of PDC in Japan started by NTT
1995 Commercial operation of N-CDMA system (IS-95) in
Hong Kong/Korea
1995 PCS1900 (D-AMPS in 1900 MHz band, IS-136)
3rd Generation Mobile Communication Systems Page Version 1.12
1-3 01.08.2000
1.2.3 Third-generation systems
The future third-generation systems shall be distinguished from the second generation primarily
in terms of the services offered to the users. Third-generation systems shall provide high-speed
transmission rates and more efficient support of packet services. Spectrum-efficient high-speed
data transmission has become feasible due to the advances in digital technology, both with
respect to signal processing algorithms and integrated circuit technology.
Discussion of a potential successor system for GSM started in ETSI and other standard
developing organizations already in the late 1980, even before any second-generation system was
in commercial operation. The ETSI-term for the future system was Universal Mobile
Telecommunications System (UMTS). Simultaneously, the International Telecommunication
(ITU) also started discussions on a potential future mobile system initially referred to as Future
Public Land Mobile System (FPLMTS) and started to specify a set of system requirements.
Due to the huge world-wide success of GSM, the interest among European network operators
and manufacturers to consider a completely new system was rather low until to the mid 1990s.
Only after the ITU has taken the initiative to formulate a concrete roadmap towards a new mobile
system to be deployed in the early 2000s, the specification activities for UMTS in ETSI were
ramped up in 1995. Some pressure on ITU to speed-up 3G activities mainly came from Japanese
operators and manufacturers, when it was predicted that the Japanese 2G-system PDC will soon
reach its capacity limits. In contrast to the GSM community, in Japan there was only very little
interest in a further evolution of PDC due to its small share of the international market.
The ITU term for the future 3G system was later changed to IMT-2000, International
Telecommunications System for the 2000s. As part of the roadmap, a deadline for submission of
proposals for IMT-2000 by the regional standardization development organizations was agreed to
be in July 1998.
In Europe, research studies on candidate radio technologies for 3G systems started around 1989
with funding by the Commission of European Communities (CEC) in the RACE Mobile project
line. From 1991 – 1995 two CEC funded research projects called Code Division Testbed
(CODIT) and Advanced Time Division Multiple Access (ATDMA) were carried out by the major
European telecom manufacturers and network operators. The CODIT and ATDMA projects
investigated the suitability of wideband Code Division Multiple Access (CDMA) and Time
Division Multiple Access (TDMA) based radio access technology for 3G systems. This work was
later continued in the FRAMES (Future Radio Wideband Multiple Access System) project and
became the basis of the further ETSI UMTS work until decisions were taken in 1998.
In January 1998 ETSI selected two radio transmission technologies (from originally 4 different
proposals) for UMTS terrestrial radio access (UTRA), referred to as UTRA FDD and UTRA
TDD, which were submitted to ITU as candidates for IMT-2000.
The terrestrial radio transmission technologies proposed to ITU in July 1998 are listed in
Table 1. The proposals included a number of different Wideband CDMA (WCDMA) based
radio access technologies, from ETSI, TTC/ARIB (Japan), TTA (Korea), ANSI T1 (USA) and
TIA (USA), which can be grouped into two types. The one type of proposals requires
synchronized base stations and is building up on the IS-95 2G radio transmission technology.
The other group of concepts does not rely on base station synchronization (there are however
also cases were it is also needed).
By the end of 1998 two specification development projects were founded by the regional
standardization organizations, 3GPP (3rd Generation Partnership Project) and 3GPP2. The goal of
3rd Generation Mobile Communication Systems Page Version 1.12
1-4 01.08.2000
both 3GPP and 3GPP2 was to merge a number of the W-CDMA based proposals into a single
one, see Table 1. 3GPP2 was concerned with the IS-95 based systems.
The split of standardization activities into two camps was partly caused by a dispute on
Intellectual Property Rights (IPR) on W-CDMA technology between various telecom
manufacturers. After these IPR issues were resolved in mid 1999, the members of 3GPP and
3GPP2 agreed on a harmonized global IMT-2000 CDMA proposal. This agreement then paved
the way for a harmonized overall concept of a ITU IMT-2000 family of 3G systems as shown in
Figure 2.
The IMT-2000 family of 3G systems includes
• Three types of Core Network technology:
• GSM based (using Mobile Application Part (MAP) protocols on top of SS7 protocols for
signalling)
• ANSI-41 based (IS-634 protocols for signalling)
• Internet Protocol based (in future, to be specified)
• Five types of Radio Access Network technologies
• UTRA FDD (W-CDMA)
• UTRA TDD (W-CDMA combined with TDMA)
• cdma2000-MC (N-CDMA with multiple carriers on downlink, W-CDMA uplink)
• UWC-136 (TDMA, TDD and FDD modes)
• DECT (TDMA, TDD); an extension to today’s DECT technology to enable the support
of 3G services in wireless phones