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The Universal Mobile Telecommunications System (UMTS) is a
third generation Third generation may refer to: * ''Third Generation'' (album), a 1982 album by Hiroshima * ''The Third Generation'' (1920 film), an American drama film directed by Henry Kolker * ''The Third Generation'' (1979 film), a West German black comedy b ...
mobile cellular system for networks based on the
GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such as ...
standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the
International Telecommunication Union The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
IMT-2000 IMT-2000 (International Mobile Telecommunications-2000) is the global standard for third generation ( 3G) wireless communications as defined by the International Telecommunication Union. In 1999 ITU approved five radio interfaces for IMT-2000 as a ...
standard set and compares with the
CDMA2000 CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatible ...
standard set for networks based on the competing
cdmaOne Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology. It was developed by Qualcomm and later adopted as a standard by the Telecommunications Industry Association in TIA/EIA/IS-95 release published in 1995. The ...
technology. UMTS uses wideband
code-division multiple access Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication ...
(
W-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators. UMTS specifies a complete network system, which includes the
radio access network A radio access network (RAN) is part of a mobile telecommunication system. It implements a radio access technology. Conceptually, it resides between a device such as a mobile phone, a computer, or any remotely controlled machine and provides con ...
(
UMTS Terrestrial Radio Access Network UTRAN (short for "UMTS Terrestrial Radio Access Network''") is a collective term for the network and equipment that connects mobile handsets to the public telephone network or the Internet. It contains the base stations, which are called Node B's ...
, or UTRAN), the
core network A backbone or core network is a part of a computer network which interconnects networks, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building ...
(
Mobile Application Part The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to users. The ...
, or MAP) and the authentication of users via SIM (
subscriber identity module A typical SIM card (mini-SIM with micro-SIM cutout) A GSM mobile phone file:Simkarte NFC SecureElement.jpg, T-Mobile nano-SIM card with NFC capabilities in the SIM tray of an iPhone 6s file:Tf sim both sides.png, A TracFone Wireless SIM card ha ...
) cards. The technology described in UMTS is sometimes also referred to as
Freedom of Mobile Multimedia Access Freedom of Mobile Multimedia Access (FOMA) is the brand name of the W-CDMA-based 3G telecommunications services being offered by the Japanese telecommunications service provider NTT DoCoMo. It is an implementation of the Universal Mobile Telecom ...
(FOMA) or 3GSM. Unlike
EDGE Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed by ...
(IMT Single-Carrier, based on GSM) and CDMA2000 (IMT Multi-Carrier), UMTS requires new base stations and new frequency allocations.


Features

UMTS supports maximum theoretical data transfer rates of 42 
Mbit/s In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...
when
Evolved HSPA Evolved High Speed Packet Access, HSPA+, HSPA (Plus) or HSPAP, is a technical standard for wireless broadband telecommunication. It is the second phase of HSPA which has been introduced in 3GPP release 7 and being further improved in later 3GPP ...
(HSPA+) is implemented in the network. Users in deployed networks can expect a transfer rate of up to 384 kbit/s for Release '99 (R99) handsets (the original UMTS release), and 7.2 Mbit/s for
High-Speed Downlink Packet Access High Speed Packet Access (HSPA) is an amalgamation of two mobile protocols—High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA)—that extends and improves the performance of existing 3G mobile telecommunicat ...
(HSDPA) handsets in the downlink connection. These speeds are significantly faster than the 9.6 kbit/s of a single GSM error-corrected circuit switched data channel, multiple 9.6 kbit/s channels in
High-Speed Circuit-Switched Data In communications, Circuit Switched Data (CSD) is the original form of data transmission developed for the time-division multiple access (TDMA)-based mobile phone systems like Global System for Mobile Communications (GSM). After 2010 many teleco ...
(HSCSD) and 14.4 kbit/s for CDMAOne channels. Since 2006, UMTS networks in many countries have been or are in the process of being upgraded with High-Speed Downlink Packet Access (HSDPA), sometimes known as 3.5G. Currently, HSDPA enables
downlink In a telecommunications network, a link is a communication channel that connects two or more devices for the purpose of data transmission. The link may be a dedicated physical link or a virtual circuit that uses one or more physical links or shar ...
transfer speeds of up to 21 Mbit/s. Work is also progressing on improving the uplink transfer speed with the
High-Speed Uplink Packet Access High Speed Packet Access (HSPA) is an amalgamation of two mobile protocols—High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA)—that extends and improves the performance of existing 3G mobile telecommunicat ...
(HSUPA). Longer term, the
3GPP Long Term Evolution In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA standards. It improves on those standards' capacity and speed by usi ...
(LTE) project plans to move UMTS to 4G speeds of 100 Mbit/s down and 50 Mbit/s up, using a next generation air interface technology based upon
orthogonal frequency-division multiplexing In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital commun ...
. The first national consumer UMTS networks launched in 2002 with a heavy emphasis on telco-provided mobile applications such as mobile TV and
video calling Videotelephony, also known as videoconferencing and video teleconferencing, is the two-way or multipoint reception and transmission of audio signal, audio and video signals by people in different locations for Real-time, real time communication. ...
. The high data speeds of UMTS are now most often utilised for Internet access: experience in Japan and elsewhere has shown that user demand for video calls is not high, and telco-provided audio/video content has declined in popularity in favour of high-speed access to the World Wide Web either directly on a handset or connected to a computer via
Wi-Fi Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
,
Bluetooth Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
or
USB Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...
.


Air interfaces

UMTS combines three different terrestrial
air interface The air interface, or access mode, is the communication link between the two stations in mobile or wireless communication. The air interface involves both the physical and data link layers (layer 1 and 2) of the OSI model for a connection. Physic ...
s,
GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such as ...
's
Mobile Application Part The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to users. The ...
(MAP) core, and the GSM family of
speech codec Speech coding is an application of data compression of digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic d ...
s. The air interfaces are called UMTS Terrestrial Radio Access (UTRA). All air interface options are part of
ITU The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
's
IMT-2000 IMT-2000 (International Mobile Telecommunications-2000) is the global standard for third generation ( 3G) wireless communications as defined by the International Telecommunication Union. In 1999 ITU approved five radio interfaces for IMT-2000 as a ...
. In the currently most popular variant for cellular mobile telephones, W-CDMA (IMT Direct Spread) is used. It is also called "Uu interface", as it links User Equipment to the UMTS Terrestrial Radio Access Network. Please note that the terms
W-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
,
TD-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
and
TD-SCDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
are misleading. While they suggest covering just a
channel access method In telecommunications and computer networks, a channel access method or multiple access method allows more than two terminals connected to the same transmission medium to transmit over it and to share its capacity. Examples of shared physical med ...
(namely a variant of
CDMA Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication ...
), they are actually the common names for the whole air interface standards.


W-CDMA (UTRA-FDD)

W-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
(WCDMA; Wideband
Code-Division Multiple Access Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication ...
), along with UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface standard found in 3G
mobile telecommunications Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Telephony is supposed to specifically point to a voice-only service or connection, though sometimes the l ...
networks. It supports conventional cellular voice, text and
MMS MMS may refer to: Science and technology Network communication protocols * Multimedia Messaging Service for mobile phones * Microsoft Media Server, a content-streaming protocol (mms://) * Manufacturing Message Specification for real time proces ...
services, but can also carry data at high speeds, allowing mobile operators to deliver higher bandwidth applications including streaming and broadband Internet access. W-CDMA uses the
DS-CDMA In telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. The direct-sequence modulation makes the transmitted signal wider in bandwidth than th ...
channel access method with a pair of 5 MHz wide channels. In contrast, the competing
CDMA2000 CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatible ...
system uses one or more available 1.25 MHz channels for each direction of communication. W-CDMA systems are widely criticized for their large spectrum usage, which delayed deployment in countries that acted relatively slowly in allocating new frequencies specifically for 3G services (such as the United States). The specific frequency bands originally defined by the UMTS standard are 1885–2025 MHz for the mobile-to-base (uplink) and 2110–2200 MHz for the base-to-mobile (downlink). In the US, 1710–1755 MHz and 2110–2155 MHz are used instead, as the 1900 MHz band was already used. While UMTS2100 is the most widely deployed UMTS band, some countries' UMTS operators use the 850 MHz (900 MHz in Europe) and/or 1900 MHz bands (independently, meaning uplink and downlink are within the same band), notably in the US by
AT&T Mobility AT&T Mobility LLC, also known as AT&T Wireless and marketed as simply AT&T, is an American telecommunications company. It is a wholly owned subsidiary of AT&T Inc. and provides wireless services in the United States. AT&T Mobility is the thi ...
, New Zealand by
Telecom New Zealand Spark New Zealand Limited is a New Zealand telecommunications company providing fixed-line telephone services, a mobile phone network, internet access services, and (through its Spark Digital division) ICT services to businesses. It was know ...
on the
XT Mobile Network The XT Mobile Network is a UMTS and LTE mobile network run by Spark New Zealand (formerly Telecom New Zealand). The network was initially built nationwide on WCDMA/UMTS 850 MHz, with 2100 MHz infill in major urban areas. The UMTS netw ...
and in Australia by
Telstra Telstra Group Limited is an Australian telecommunications company that builds and operates telecommunications networks and markets voice, mobile, internet access, pay television and other products and services. It is a member of the S&P/ASX 20 ...
on the
Next G Telstra Group Limited is an Australian telecommunications company that builds and operates telecommunications networks and markets voice, mobile, internet access, pay television and other products and services. It is a member of the S&P/ASX 20 ...
network. Some carriers such as
T-Mobile T-Mobile is the brand name used by some of the mobile communications subsidiaries of the German telecommunications company Deutsche Telekom AG in the Czech Republic (T-Mobile Czech Republic), Poland (T-Mobile Polska), the United States (T-Mobile ...
use band numbers to identify the UMTS frequencies. For example, Band I (2100 MHz), Band IV (1700/2100 MHz), and Band V (850 MHz). UMTS-FDD is an acronym for Universal Mobile Telecommunications System (UMTS)
frequency-division duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
ing (FDD) and a 3GPP
standardized Standardization or standardisation is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization ...
version of UMTS networks that makes use of frequency-division duplexing for duplexing over an UMTS Terrestrial Radio Access (
UTRA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
) air interface. W-CDMA is the basis of Japan's NTT DoCoMo's
FOMA Freedom of Mobile Multimedia Access (FOMA) is the brand name of the W-CDMA-based 3G telecommunications services being offered by the Japanese telecommunications service provider NTT DoCoMo. It is an implementation of the Universal Mobile Tel ...
service and the most-commonly used member of the Universal Mobile Telecommunications System (UMTS) family and sometimes used as a synonym for UMTS. It uses the DS-CDMA channel access method and the FDD duplexing method to achieve higher speeds and support more users compared to most previously used
time-division multiple access Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, o ...
(TDMA) and
time-division duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
(TDD) schemes. While not an evolutionary upgrade on the airside, it uses the same
core network A backbone or core network is a part of a computer network which interconnects networks, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building ...
as the 2G GSM networks deployed worldwide, allowing dual-mode mobile operation along with GSM/
EDGE Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed by ...
; a feature it shares with other members of the UMTS family.


Development

In the late 1990s, W-CDMA was developed by NTT DoCoMo as the air interface for their 3G network
FOMA Freedom of Mobile Multimedia Access (FOMA) is the brand name of the W-CDMA-based 3G telecommunications services being offered by the Japanese telecommunications service provider NTT DoCoMo. It is an implementation of the Universal Mobile Tel ...
. Later NTT DoCoMo submitted the specification to the
International Telecommunication Union The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
(ITU) as a candidate for the international 3G standard known as IMT-2000. The ITU eventually accepted W-CDMA as part of the IMT-2000 family of 3G standards, as an alternative to CDMA2000, EDGE, and the short range
DECT Digital enhanced cordless telecommunications (Digital European cordless telecommunications), usually known by the acronym DECT, is a standard primarily used for creating cordless telephone systems. It originated in Europe, where it is the common ...
system. Later, W-CDMA was selected as an air interface for
UMTS The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
. As NTT DoCoMo did not wait for the finalisation of the 3G Release 99 specification, their network was initially incompatible with UMTS. However, this has been resolved by NTT DoCoMo updating their network. Code-Division Multiple Access communication networks have been developed by a number of companies over the years, but development of cell-phone networks based on CDMA (prior to W-CDMA) was dominated by
Qualcomm Qualcomm () is an American multinational corporation headquartered in San Diego, California, and incorporated in Delaware. It creates semiconductors, software, and services related to wireless technology. It owns patents critical to the 5G, 4 ...
, the first company to succeed in developing a practical and cost-effective CDMA implementation for consumer cell phones and its early
IS-95 Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology. It was developed by Qualcomm and later adopted as a standard by the Telecommunications Industry Association in TIA/EIA/IS-95 release published in 1995. The ...
air interface standard has evolved into the current CDMA2000 (IS-856/IS-2000) standard. Qualcomm created an experimental wideband CDMA system called CDMA2000 3x which unified the W-CDMA ( 3GPP) and CDMA2000 (
3GPP2 The 3rd Generation Partnership Project 2 (3GPP2) is a collaboration between telecommunications associations to make a globally applicable third generation ( 3G) mobile phone system specification within the scope of the ITU's IMT-2000 project. In ...
) network technologies into a single design for a worldwide standard air interface. Compatibility with CDMA2000 would have beneficially enabled roaming on existing networks beyond Japan, since Qualcomm CDMA2000 networks are widely deployed, especially in the Americas, with coverage in 58 countries . However, divergent requirements resulted in the W-CDMA standard being retained and deployed globally. W-CDMA has then become the dominant technology with 457 commercial networks in 178 countries as of April 2012. Several CDMA2000 operators have even converted their networks to W-CDMA for international roaming compatibility and smooth upgrade path to LTE. Despite incompatibility with existing air-interface standards, late introduction and the high upgrade cost of deploying an all-new transmitter technology, W-CDMA has become the dominant standard.


Rationale for W-CDMA

W-CDMA transmits on a pair of 5 MHz-wide radio channels, while CDMA2000 transmits on one or several pairs of 1.25 MHz radio channels. Though W-CDMA does use a direct-sequence CDMA transmission technique like CDMA2000, W-CDMA is not simply a wideband version of CDMA2000 and differs in many aspects from CDMA2000. From an engineering point of view, W-CDMA provides a different balance of trade-offs between cost, capacity, performance, and density; it also promises to achieve a benefit of reduced cost for video phone handsets. W-CDMA may also be better suited for deployment in the very dense cities of Europe and Asia. However, hurdles remain, and
cross-licensing A cross-licensing agreement is a contract between two or more parties where each party grants rights to their intellectual property to the other parties. Patent law In patent law, a cross-licensing agreement is an agreement according to which two ...
of
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A p ...
s between Qualcomm and W-CDMA vendors has not eliminated possible patent issues due to the features of W-CDMA which remain covered by Qualcomm patents. W-CDMA has been developed into a complete set of specifications, a detailed protocol that defines how a mobile phone communicates with the tower, how signals are modulated, how datagrams are structured, and system interfaces are specified allowing free competition on technology elements.


Deployment

The world's first commercial W-CDMA service, FOMA, was launched by NTT DoCoMo in
Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
in 2001. Elsewhere, W-CDMA deployments are usually marketed under the UMTS brand. W-CDMA has also been adapted for use in satellite communications on the U.S.
Mobile User Objective System The Mobile User Objective System (MUOS) is a United States Space Force narrowband military communications satellite system that supports a worldwide, multi-service population of users in the ultra high frequency (UHF) band. The system provides ...
using geosynchronous satellites in place of cell towers.
J-Phone is a Japanese multinational conglomerate holding company headquartered in Minato, Tokyo which focuses on investment management. The Group primarily invests in companies operating in technology, energy, and financial sectors. It also runs th ...
Japan (once
Vodafone Vodafone Group Public limited company, plc () is a British Multinational corporation, multinational Telephone company, telecommunications company. Its registered office and Headquarters, global headquarters are in Newbury, Berkshire, England. It ...
and now
SoftBank Mobile is a Japanese multinational conglomerate holding company headquartered in Minato, Tokyo which focuses on investment management. The Group primarily invests in companies operating in technology, energy, and financial sectors. It also runs the ...
) soon followed by launching their own W-CDMA based service, originally branded "Vodafone Global Standard" and claiming UMTS compatibility. The name of the service was changed to "Vodafone 3G" (now "SoftBank 3G") in December 2004. Beginning in 2003,
Hutchison Whampoa Hutchison Whampoa Limited (HWL) was an investment holding company based in Hong Kong. It was a Fortune Global 500 company and one of the largest companies listed on the Hong Kong Stock Exchange. HWL was an international corporation with a dive ...
gradually launched their upstart UMTS networks. Most countries have, since the ITU approved of the 3G mobile service, either "auctioned" the radio frequencies to the company willing to pay the most, or conducted a "beauty contest" asking the various companies to present what they intend to commit to if awarded the licences. This strategy has been criticised for aiming to drain the cash of operators to the brink of bankruptcy in order to honour their bids or proposals. Most of them have a time constraint for the rollout of the service where a certain "coverage" must be achieved within a given date or the licence will be revoked. Vodafone launched several UMTS networks in Europe in February 2004.
MobileOne M1 Limited (commonly known as M1; formerly MobileOne) is a Singaporean telecommunications company and one of the major telcos operating in the country. M1 was founded in 1994 and traded on the Singapore Exchange from 2002 to 2019. M1 is a subsi ...
of
Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...
commercially launched its 3G (W-CDMA) services in February 2005.
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
in August 2005 and
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
in October 2005.
AT&T Mobility AT&T Mobility LLC, also known as AT&T Wireless and marketed as simply AT&T, is an American telecommunications company. It is a wholly owned subsidiary of AT&T Inc. and provides wireless services in the United States. AT&T Mobility is the thi ...
utilized a UMTS network, with HSPA+, from 2005 until its shutdown in February 2022. Rogers in
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
March 2007 has launched HSDPA in the Toronto Golden Horseshoe district on W-CDMA at 850/1900 MHz and plan the launch the service commercial in the top 25 cities October, 2007.
TeliaSonera Telia Company AB is a Swedish multinational telecommunications company and mobile network operator present in Sweden, Finland, Norway, Denmark, Estonia, Latvia and Lithuania. Telia also owns TV4 Media which includes TV4 in Sweden, MTV Oy in Fi ...
opened W-CDMA service in
Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
October 13, 2004, with speeds up to 384 kbit/s. Availability only in main cities. Pricing is approx. €2/MB.
SK Telecom SK Telecom Co., Ltd. ( or ) is a South Korean wireless telecommunications operator and former film distributor and is part of the SK Group, one of the country's largest chaebols. It leads the local market with 50.5 percent share as of 2008. S ...
and KTF, two largest mobile phone service providers in
South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...
, have each started offering W-CDMA service in December 2003. Due to poor coverage and lack of choice in handhelds, the W-CDMA service has barely made a dent in the Korean market which was dominated by CDMA2000. By October 2006 both companies are covering more than 90 cities while
SK Telecom SK Telecom Co., Ltd. ( or ) is a South Korean wireless telecommunications operator and former film distributor and is part of the SK Group, one of the country's largest chaebols. It leads the local market with 50.5 percent share as of 2008. S ...
has announced that it will provide nationwide coverage for its WCDMA network in order for it to offer SBSM (Single Band Single Mode) handsets by the first half of 2007. KT Freecel will thus cut funding to its CDMA2000 network development to the minimum. In
Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
,
Telenor Telenor ASA ( or ) is a Norwegian majority state-owned multinational telecommunications company headquartered at Fornebu in Bærum, close to Oslo. It is one of the world's largest mobile telecommunications companies with operations worldwide, ...
introduced W-CDMA in major cities by the end of 2004, while their competitor, NetCom, followed suit a few months later. Both operators have 98% national coverage on EDGE, but Telenor has parallel WLAN roaming networks on GSM, where the UMTS service is competing with this. For this reason Telenor is dropping support of their WLAN service in Austria (2006).
Maxis Communications Maxis Communications or Maxis Berhad is a communications service provider in Malaysia. It is one of the oldest and largest telecommunications companies in the country. Headquartered in Kuala Lumpur, Malaysia, it provides a variety of communica ...
and
Celcom Celcom Axiata Berhad, DBA Celcom, is the oldest mobile telecommunications provider in Malaysia. Celcom is a member of the Axiata group of companies. Being one of the very few companies in Malaysia to originally obtain a cellular phone licens ...
, two mobile phone service providers in
Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...
, started offering W-CDMA services in 2005. In
Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
, Telia introduced W-CDMA in March 2004.


UTRA-TDD

UMTS-TDD, an acronym for Universal Mobile Telecommunications System (UMTS) time-division duplexing (TDD), is a 3GPP standardized version of UMTS networks that use UTRA-TDD. UTRA-TDD is a UTRA that uses
time-division duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
ing for duplexing. While a full implementation of UMTS, it is mainly used to provide Internet access in circumstances similar to those where
WiMAX Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options. The WiMAX ...
might be used. UMTS-TDD is not directly compatible with UMTS-FDD: a device designed to use one standard cannot, unless specifically designed to, work on the other, because of the difference in air interface technologies and frequencies used. It is more formally as IMT-2000 CDMA-TDD or IMT 2000 Time-Division (IMT-TD). The two UMTS air interfaces (UTRAs) for UMTS-TDD are TD-CDMA and TD-SCDMA. Both air interfaces use a combination of two channel access methods,
code-division multiple access Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication ...
(CDMA) and time-division multiple access (TDMA): the frequency band is divided into time slots (TDMA), which are further divided into channels using CDMA spreading codes. These air interfaces are classified as TDD, because time slots can be allocated to either uplink or downlink traffic.


TD-CDMA (UTRA-TDD 3.84 Mcps High Chip Rate (HCR))

TD-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
, an acronym for Time-Division-
Code-Division Multiple Access Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication ...
, is a channel-access method based on using
spread-spectrum In telecommunication and radio communication, spread-spectrum techniques are methods by which a signal (e.g., an electrical, electromagnetic, or acoustic signal) generated with a particular bandwidth is deliberately spread in the frequency doma ...
multiple-access (CDMA) across multiple time slots ( TDMA). TD-CDMA is the channel access method for UTRA-TDD HCR, which is an acronym for UMTS Terrestrial Radio Access-Time Division Duplex High Chip Rate. UMTS-TDD's air interfaces that use the TD-CDMA channel access technique are standardized as UTRA-TDD HCR, which uses increments of 5 
MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that one he ...
of spectrum, each slice divided into 10 ms frames containing fifteen time slots (1500 per second). The time slots (TS) are allocated in fixed percentage for downlink and uplink. TD-CDMA is used to multiplex streams from or to multiple transceivers. Unlike W-CDMA, it does not need separate frequency bands for up- and downstream, allowing deployment in tight
frequency band A frequency band is an interval in the frequency domain, delimited by a lower frequency and an upper frequency. The term may refer to a radio band or an interval of some other spectrum. The frequency range of a system is the range over which i ...
s. TD-CDMA is a part of IMT-2000, defined as IMT-TD Time-Division (IMT CDMA TDD), and is one of the three UMTS air interfaces (UTRAs), as standardized by the 3GPP in UTRA-TDD HCR. UTRA-TDD HCR is closely related to W-CDMA, and provides the same types of channels where possible. UMTS's HSDPA/HSUPA enhancements are also implemented under TD-CDMA. In the United States, the technology has been used for public safety and government use in the
New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...
and a few other areas. In Japan, IPMobile planned to provide TD-CDMA service in year 2006, but it was delayed, changed to TD-SCDMA, and bankrupt before the service officially started.


TD-SCDMA (UTRA-TDD 1.28 Mcps Low Chip Rate (LCR))

Time-Division Synchronous Code-Division Multiple Access (TD-SCDMA) or UTRA TDD 1.28 Mcps low chip rate (UTRA-TDD LCR) is an air interface found in UMTS mobile telecommunications networks in China as an alternative to W-CDMA. TD-SCDMA uses the TDMA channel access method combined with an adaptive synchronous CDMA component on 1.6 MHz slices of spectrum, allowing deployment in even tighter frequency bands than TD-CDMA. It is standardized by the 3GPP and also referred to as "UTRA-TDD LCR". However, the main incentive for development of this Chinese-developed standard was avoiding or reducing the license fees that have to be paid to non-Chinese patent owners. Unlike the other air interfaces, TD-SCDMA was not part of UMTS from the beginning but has been added in Release 4 of the specification. Like TD-CDMA, TD-SCDMA is known as IMT CDMA TDD within IMT-2000. The term "TD-SCDMA" is misleading. While it suggests covering only a channel access method, it is actually the common name for the whole air interface specification. TD-SCDMA / UMTS-TDD (LCR) networks are incompatible with W-CDMA / UMTS-FDD and TD-CDMA / UMTS-TDD (HCR) networks.


= Objectives

= TD-SCDMA was developed in the People's Republic of China by the Chinese Academy of Telecommunications Technology (CATT),
Datang Telecom Datang Telecom Group (officially Datang Telecom Technology & Industry Group) is a Chinese state-owned telecommunications equipment group headquartered in Beijing, China. The group was founded in September 1998 by the China Academy of Telecommuni ...
, and
Siemens AG Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', '' ...
in an attempt to avoid dependence on Western technology. This is likely primarily for practical reasons, since other 3G formats require the payment of patent fees to a large number of Western patent holders. TD-SCDMA proponents also claim it is better suited for densely populated areas. Further, it is supposed to cover all usage scenarios, whereas W-CDMA is optimised for symmetric traffic and macro cells, while TD-CDMA is best used in low mobility scenarios within micro or pico cells. TD-SCDMA is based on spread-spectrum technology which makes it unlikely that it will be able to completely escape the payment of license fees to western patent holders. The launch of a national TD-SCDMA network was initially projected by 2005 but only reached large scale commercial trials with 60,000 users across eight cities in 2008. On January 7, 2009, China granted a TD-SCDMA 3G licence to
China Mobile China Mobile is the trade name of both China Mobile Limited () and its ultimate controlling shareholder, China Mobile Communications Group Co., Ltd. (, formerly known as China Mobile Communications Corporation, "CMCC"), a Chinese state-ownedSt ...
. On September 21, 2009, China Mobile officially announced that it had 1,327,000 TD-SCDMA subscribers as of the end of August, 2009. While TD is primarily a China-only system, it may well be exported to developing countries. It is likely to be replaced with a newer
TD-LTE In telecommunications, long-term evolution (LTE) is a Technical standard, standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/Enhanced Data Rates for GSM Evolution, EDGE and UMTS/High Speed Pac ...
system over the next 5 years.


= Technical highlights

= TD-SCDMA uses TDD, in contrast to the FDD scheme used by
W-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
. By dynamically adjusting the number of timeslots used for downlink and
uplink In a telecommunications network, a link is a communication channel that connects two or more devices for the purpose of data transmission. The link may be a dedicated physical link or a virtual circuit that uses one or more physical links or shar ...
, the system can more easily accommodate asymmetric traffic with different data rate requirements on downlink and uplink than FDD schemes. Since it does not require paired spectrum for downlink and uplink, spectrum allocation flexibility is also increased. Using the same carrier frequency for uplink and downlink also means that the channel condition is the same on both directions, and the
base station Base station (or base radio station) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service." The term is used in the context of mobile telephony, wireless com ...
can deduce the downlink channel information from uplink channel estimates, which is helpful to the application of
beamforming Beamforming or spatial filtering is a signal processing technique used in sensor arrays for directional signal transmission or reception. This is achieved by combining elements in an antenna array in such a way that signals at particular angles e ...
techniques. TD-SCDMA also uses TDMA in addition to the CDMA used in WCDMA. This reduces the number of users in each timeslot, which reduces the implementation complexity of
multiuser detection Multiuser detection deals with demodulation of the mutually interfering digital streams of information that occur in areas such as wireless communications, high-speed data transmission, DSL, satellite communication, digital television, and magneti ...
and beamforming schemes, but the non-continuous transmission also reduces
coverage Coverage may refer to: Filmmaking * Coverage (lens), the size of the image a lens can produce * Camera coverage, the amount of footage shot and different camera setups used in filming a scene * Script coverage, a short summary of a script, wri ...
(because of the higher peak power needed), mobility (because of lower
power control Power control, broadly speaking, is the intelligent selection of transmitter power output in a communication system to achieve good performance within the system.Guowang Miao, Jens Zander, Ki Won Sung, and Ben Slimane, Fundamentals of Mobile Data ...
frequency) and complicates
radio resource management Radio resource management (RRM) is the system level management of co-channel interference, radio resources, and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless local area networks, ...
algorithms. The "S" in TD-SCDMA stands for "synchronous", which means that uplink signals are synchronized at the base station receiver, achieved by continuous timing adjustments. This reduces the
interference Interference is the act of interfering, invading, or poaching. Interference may also refer to: Communications * Interference (communication), anything which alters, modifies, or disrupts a message * Adjacent-channel interference, caused by extr ...
between users of the same timeslot using different codes by improving the
orthogonality In mathematics, orthogonality is the generalization of the geometric notion of ''perpendicularity''. By extension, orthogonality is also used to refer to the separation of specific features of a system. The term also has specialized meanings in ...
between the codes, therefore increasing system capacity, at the cost of some hardware complexity in achieving uplink synchronization.


= History

= On January 20, 2006,
Ministry of Information Industry The Ministry of Industry and Information Technology of the Chinese government, established in March 2008, is the state agency of the People's Republic of China responsible for regulation and development of the postal service, Internet, wireless ...
of the People's Republic of China formally announced that TD-SCDMA is the country's standard of 3G mobile telecommunication. On February 15, 2006, a timeline for deployment of the network in China was announced, stating pre-commercial trials would take place starting after completion of a number of test networks in select cities. These trials ran from March to October, 2006, but the results were apparently unsatisfactory. In early 2007, the Chinese government instructed the dominant cellular carrier, China Mobile, to build commercial trial networks in eight cities, and the two fixed-line carriers,
China Telecom China Telecom Corp., Ltd. is a Chinese telecommunications company. It is one of the red chip listed companies of state-owned China Telecommunications Corporation. Its H shares have been traded on the Stock Exchange of Hong Kong since 15 Novembe ...
and
China Netcom China Netcom, full name China Netcom Group Corporation (Hong Kong) Limited (former stock codes: HKEX:0906, NYSE:CN), abbreviated CNC, was a telecommunication service provider in People's Republic of China. It was formed in August 1999 by the Chine ...
, to build one each in two other cities. Construction of these trial networks was scheduled to finish during the fourth quarter of 2007, but delays meant that construction was not complete until early 2008. The standard has been adopted by 3GPP since Rel-4, known as "UTRA TDD 1.28Mbps Option". On March 28, 2008, China Mobile Group announced TD-SCDMA "commercial trials" for 60,000 test users in eight cities from April 1, 2008. Networks using other 3G standards (WCDMA and CDMA2000 EV/DO) had still not been launched in China, as these were delayed until TD-SCDMA was ready for commercial launch. In January 2009, the
Ministry of Industry and Information Technology The Ministry of Industry and Information Technology of the Chinese government, established in March 2008, is the state agency of the People's Republic of China responsible for regulation and development of the postal service, Internet, wireless ...
(MIIT) in China took the unusual step of assigning licences for 3 different third-generation mobile phone standards to three carriers in a long-awaited step that is expected to prompt $41 billion in spending on new equipment. The Chinese-developed standard, TD-SCDMA, was assigned to China Mobile, the world's biggest phone carrier by subscribers. That appeared to be an effort to make sure the new system has the financial and technical backing to succeed. Licences for two existing 3G standards, W-CDMA and CDMA2000 1xEV-DO, were assigned to
China Unicom China United Network Communications Group Co., Ltd. () or China Unicom () (CUniq in short) is a Chinese state-owned telecommunications operator. Started as a wireless paging and GSM mobile operator, it currently provides a range of services in ...
and China Telecom, respectively. Third-generation, or 3G, technology supports Web surfing, wireless video and other services and the start of service is expected to spur new revenue growth. The technical split by MIIT has hampered the performance of China Mobile in the 3G market, with users and China Mobile engineers alike pointing to the lack of suitable handsets to use on the network. Deployment of base stations has also been slow, resulting in lack of improvement of service for users. The network connection itself has consistently been slower than that from the other two carriers, leading to a sharp decline in market share. By 2011 China Mobile has already moved its focus onto TD-LTE. Gradual closures of TD-SCDMA stations started in 2016.


= Frequency bands & Deployments

= The following is a list of
mobile telecommunications Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Telephony is supposed to specifically point to a voice-only service or connection, though sometimes the l ...
networks using third-generation TD-SCDMA / UMTS-TDD (LCR) technology.


Unlicensed UMTS-TDD

In Europe, CEPT allocated the 2010–2020 MHz range for a variant of UMTS-TDD designed for unlicensed, self-provided use. Some telecom groups and jurisdictions have proposed withdrawing this service in favour of licensed UMTS-TDD, due to lack of demand, and lack of development of a UMTS TDD air interface technology suitable for deployment in this band.


Comparison with UMTS-FDD

Ordinary UMTS uses UTRA-FDD as an air interface and is known as
UMTS-FDD The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
. UMTS-FDD uses W-CDMA for multiple access and
frequency-division duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ...
for duplexing, meaning that the up-link and down-link transmit on different frequencies. UMTS is usually transmitted on frequencies assigned for 1G, 2G, or 3G mobile telephone service in the countries of operation. UMTS-TDD uses time-division duplexing, allowing the up-link and down-link to share the same spectrum. This allows the operator to more flexibly divide the usage of available spectrum according to traffic patterns. For ordinary phone service, you would expect the up-link and down-link to carry approximately equal amounts of data (because every phone call needs a voice transmission in either direction), but Internet-oriented traffic is more frequently one-way. For example, when browsing a website, the user will send commands, which are short, to the server, but the server will send whole files, that are generally larger than those commands, in response. UMTS-TDD tends to be allocated frequency intended for mobile/wireless Internet services rather than used on existing cellular frequencies. This is, in part, because TDD duplexing is not normally allowed on
cellular Cellular may refer to: *Cellular automaton, a model in discrete mathematics * Cell biology, the evaluation of cells work and more * ''Cellular'' (film), a 2004 movie *Cellular frequencies, assigned to networks operating in cellular RF bands *Cell ...
,
PCS A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or techn ...
/PCN, and 3G frequencies. TDD technologies open up the usage of left-over unpaired spectrum. Europe-wide, several bands are provided either specifically for UMTS-TDD or for similar technologies. These are 1900 MHz and 1920 MHz and between 2010 MHz and 2025 MHz. In several countries the 2500-2690 MHz band (also known as MMDS in the USA) have been used for UMTS-TDD deployments. Additionally, spectrum around the 3.5 GHz range has been allocated in some countries, notably Britain, in a technology-neutral environment. In the Czech Republic UTMS-TDD is also used in a frequency range around 872 MHz.


Deployment

UMTS-TDD has been deployed for public and/or private networks in at least nineteen countries around the world, with live systems in, amongst other countries, Australia, Czech Republic, France, Germany, Japan, New Zealand, Botswana, South Africa, the UK, and the USA. Deployments in the US thus far have been limited. It has been selected for a public safety support network used by emergency responders in New York, but outside of some experimental systems, notably one from
Nextel Nextel Communications, Inc. was an American wireless service operator that merged with and ceased to exist as a subsidiary of Sprint Corporation, which would later be bought by T-Mobile, T-Mobile US and folded into that company. Nextel in Brazil, ...
, thus far the WiMAX standard appears to have gained greater traction as a general mobile Internet access system.


Competing standards

A variety of Internet-access systems exist which provide broadband speed access to the net. These include WiMAX and HIPERMAN. UMTS-TDD has the advantages of being able to use an operator's existing UMTS/GSM infrastructure, should it have one, and that it includes UMTS modes optimized for circuit switching should, for example, the operator want to offer telephone service. UMTS-TDD's performance is also more consistent. However, UMTS-TDD deployers often have regulatory problems with taking advantage of some of the services UMTS compatibility provides. For example, the UMTS-TDD spectrum in the UK cannot be used to provide telephone service, though the regulator
OFCOM The Office of Communications, commonly known as Ofcom, is the government-approved regulatory and competition authority for the broadcasting, telecommunications and postal industries of the United Kingdom. Ofcom has wide-ranging powers acros ...
is discussing the possibility of allowing it at some point in the future. Few operators considering UMTS-TDD have existing UMTS/GSM infrastructure. Additionally, the WiMAX and HIPERMAN systems provide significantly larger bandwidths when the mobile station is in close proximity to the tower. Like most mobile Internet access systems, many users who might otherwise choose UMTS-TDD will find their needs covered by the ad hoc collection of unconnected Wi-Fi access points at many restaurants and transportation hubs, and/or by Internet access already provided by their mobile phone operator. By comparison, UMTS-TDD (and systems like WiMAX) offers mobile, and more consistent, access than the former, and generally faster access than the latter.


Radio access network

UMTS also specifies the Universal Terrestrial Radio Access Network (UTRAN), which is composed of multiple base stations, possibly using different terrestrial air interface standards and frequency bands. UMTS and GSM/EDGE can share a Core Network (CN), making UTRAN an alternative radio access network to
GERAN GERAN is an abbreviation for GSM EDGE Radio Access Network. The standards for GERAN are maintained by the 3GPP (Third Generation Partnership Project). GERAN is a key part of GSM, and also of combined UMTS/GSM networks. GERAN is the radio part of ...
(GSM/EDGE RAN), and allowing (mostly) transparent switching between the RANs according to available coverage and service needs. Because of that, UMTS's and GSM/EDGE's radio access networks are sometimes collectively referred to as UTRAN/GERAN. UMTS networks are often combined with GSM/EDGE, the latter of which is also a part of IMT-2000. The UE (
User Equipment In the Universal Mobile Telecommunications System (UMTS) and 3GPP Long Term Evolution (LTE), user equipment (UE) is any device used directly by an end-user to communicate. It can be a hand-held telephone, a laptop computer equipped with a mobile bro ...
) interface of the
RAN Ran, RaN and ran may refer to: Arts and entertainment * ''Ran'' (film), a 1985 film directed by Akira Kurosawa * "Ran" (song), a 2013 Japanese song by Luna Sea * '' Ran Online'', a 2004 MMORPG (massively multiplayer online role playing game) * ...
(Radio Access Network) primarily consists of RRC (Radio Resource Control),
PDCP Packet Data Convergence Protocol (PDCP) is specified by 3GPP in TS 25.323 for UMTS, TS 36.323 for LTE and TS 38.323 for 5G. PDCP is located in the Radio Protocol Stack in the UMTS/LTE/5G air interface on top of the RLC layer. PDCP provides its ...
(Packet Data Convergence Protocol), RLC (Radio Link Control) and MAC (Media Access Control) protocols. RRC protocol handles connection establishment, measurements, radio bearer services, security and handover decisions. RLC protocol primarily divides into three Modes Transparent Mode (TM), Unacknowledge Mode (UM), Acknowledge Mode (AM). The functionality of AM entity resembles TCP operation whereas UM operation resembles UDP operation. In TM mode, data will be sent to lower layers without adding any header to SDU of higher layers. MAC handles the scheduling of data on air interface depending on higher layer (RRC) configured parameters. The set of properties related to data transmission is called Radio Bearer (RB). This set of properties decides the maximum allowed data in a TTI (Transmission Time Interval). RB includes RLC information and RB mapping. RB mapping decides the mapping between RB<->logical channel<->transport channel. Signaling messages are sent on Signaling Radio Bearers (SRBs) and data packets (either CS or PS) are sent on data RBs. RRC and
NAS Nas (born 1973) is the stage name of American rapper Nasir Jones. Nas, NaS, or NAS may also refer to: Aviation * Nasair, a low-cost airline carrier and subsidiary based in Eritrea * National Air Services, an airline in Saudi Arabia ** Nas Air ( ...
messages go on SRBs. Security includes two procedures: integrity and ciphering. Integrity validates the resource of messages and also makes sure that no one (third/unknown party) on the radio interface has modified the messages. Ciphering ensures that no one listens to your data on the air interface. Both integrity and ciphering are applied for SRBs whereas only ciphering is applied for data RBs.


Core network

With Mobile Application Part, UMTS uses the same core network standard as GSM/EDGE. This allows a simple migration for existing GSM operators. However, the migration path to UMTS is still costly: while much of the core infrastructure is shared with GSM, the cost of obtaining new spectrum licenses and overlaying UMTS at existing towers is high. The CN can be connected to various
backbone network A backbone or core network is a part of a computer network which interconnects networks, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building ...
s, such as the
Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...
or an
Integrated Services Digital Network Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. W ...
(ISDN) telephone network. UMTS (and GERAN) include the three lowest layers of
OSI model The Open Systems Interconnection model (OSI model) is a conceptual model that 'provides a common basis for the coordination of SOstandards development for the purpose of systems interconnection'. In the OSI reference model, the communications ...
. The network layer (OSI 3) includes the
Radio Resource Management Radio resource management (RRM) is the system level management of co-channel interference, radio resources, and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless local area networks, ...
protocol (RRM) that manages the bearer channels between the mobile terminals and the fixed network, including the handovers.


Frequency bands and channel bandwidths


UARFCN

A UARFCN (
abbreviation An abbreviation (from Latin ''brevis'', meaning ''short'') is a shortened form of a word or phrase, by any method. It may consist of a group of letters or words taken from the full version of the word or phrase; for example, the word ''abbrevia ...
for UTRA Absolute Radio Frequency Channel Number, where UTRA stands for UMTS Terrestrial Radio Access) is used to identify a frequency in the
UMTS frequency bands The UMTS frequency bands are radio frequencies used by third generation (3G) wireless Universal Mobile Telecommunications System networks. They were allocated by delegates to the World Administrative Radio Conference (WARC-92) held in Málaga-Tor ...
. Typically channel number is derived from the frequency in MHz through the formula Channel Number = Frequency * 5. However, this is only able to represent channels that are centered on a multiple of 200 kHz, which do not align with licensing in North America. 3GPP added several special values for the common North American channels.


Spectrum allocation

Over 130 licenses have already been awarded to operators worldwide (as of December 2004), specifying W-CDMA radio access technology that builds on GSM. In Europe, the license process occurred at the tail end of the technology bubble, and the auction mechanisms for allocation set up in some countries resulted in some extremely high prices being paid for the original 2100 MHz licenses, notably in the UK and Germany. In
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
, bidders paid a total €50.8 billion for six licenses, two of which were subsequently abandoned and written off by their purchasers (Mobilcom and the
Sonera Telia Company AB is a Swedish multinational telecommunications company and mobile network operator present in Sweden, Finland, Norway, Denmark, Estonia, Latvia and Lithuania. Telia also owns TV4 Media which includes TV4 in Sweden, MTV Oy in F ...
/
Telefónica Telefónica, S.A. () is a Spanish multinational telecommunications company headquartered in Madrid, Spain. It is one of the largest telephone operators and mobile network providers in the world. It provides fixed and mobile telephony, broadba ...
consortium). It has been suggested that these huge license fees have the character of a very large tax paid on future income expected many years down the road. In any event, the high prices paid put some European telecom operators close to bankruptcy (most notably
KPN KPN (in full Koninklijke KPN N.V., also Royal KPN N.V.) is a Dutch landline and mobile telecommunications company. KPN originated from a government-run postal, telegraph and telephone service and is based in Rotterdam, Netherlands. History Un ...
). Over the last few years some operators have written off some or all of the license costs. Between 2007 and 2009, all three Finnish carriers began to use 900 MHz UMTS in a shared arrangement with its surrounding 2G GSM base stations for rural area coverage, a trend that is expected to expand over Europe in the next 1–3 years. The 2100 MHz band (downlink around 2100 MHz and uplink around 1900 MHz) allocated for UMTS in Europe and most of Asia is already used in North America. The 1900 MHz range is used for 2G (
PCS A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or techn ...
) services, and 2100 MHz range is used for satellite communications. Regulators have, however, freed up some of the 2100 MHz range for 3G services, together with a different range around 1700 MHz for the uplink. AT&T Wireless launched UMTS services in the United States by the end of 2004 strictly using the existing 1900 MHz spectrum allocated for 2G PCS services. Cingular acquired AT&T Wireless in 2004 and has since then launched UMTS in select US cities. Cingular renamed itself AT&T Mobility and rolled out some cities with a UMTS network at 850 MHz to enhance its existing UMTS network at 1900 MHz and now offers subscribers a number of dual-band UMTS 850/1900 phones. T-Mobile's rollout of UMTS in the US was originally focused on the 1700 MHz band. However, T-Mobile has been moving users from 1700 MHz to 1900 MHz (PCS) in order to reallocate the spectrum to 4G LTE services. In Canada, UMTS coverage is being provided on the 850 MHz and 1900 MHz bands on the Rogers and Bell-Telus networks. Bell and Telus share the network. Recently, new providers
Wind Mobile Freedom Mobile Inc. is a Canadian wireless telecommunications provider owned by Shaw Communications. It has 6% market share of Canada, mostly in urban areas of Ontario, British Columbia and Alberta. Freedom Mobile is the fourth-largest wirele ...
,
Mobilicity Data and Audio-Visual Enterprises Wireless, d/b/a Mobilicity, was a Canadian mobile virtual network operator (MVNO) owned by Rogers Communications. Its name was a portmanteau of the words "mobility" and "simplicity". Mobilicity was one of several ...
and Videotron have begun operations in the 1700 MHz band. In 2008, Australian telco Telstra replaced its existing CDMA network with a national UMTS-based 3G network, branded as
NextG Telstra Group Limited is an Australian telecommunications company that builds and operates telecommunications networks and markets voice, mobile, internet access, pay television and other products and services. It is a member of the S&P/ASX 20 ...
, operating in the 850 MHz band. Telstra currently provides UMTS service on this network, and also on the 2100 MHz UMTS network, through a co-ownership of the owning and administrating company 3GIS. This company is also co-owned by Hutchison 3G Australia, and this is the primary network used by their customers.
Optus Singtel Optus Pty Limited (commonly referred to as Optus) is an Australian Telecommunications in Australia, telecommunications company headquartered in Macquarie Park, New South Wales, Australia. It is a wholly owned subsidiary of Singapore, Si ...
is currently rolling out a 3G network operating on the 2100 MHz band in cities and most large towns, and the 900 MHz band in regional areas.
Vodafone Vodafone Group Public limited company, plc () is a British Multinational corporation, multinational Telephone company, telecommunications company. Its registered office and Headquarters, global headquarters are in Newbury, Berkshire, England. It ...
is also building a 3G network using the 900 MHz band. In India, BSNL has started its 3G services since October 2009, beginning with the larger cities and then expanding over to smaller cities. The 850 MHz and 900 MHz bands provide greater coverage compared to equivalent 1700/1900/2100 MHz networks, and are best suited to regional areas where greater distances separate base station and subscriber. Carriers in South America are now also rolling out 850 MHz networks.


Interoperability and global roaming

UMTS phones (and data cards) are highly portable they have been designed to roam easily onto other UMTS networks (if the providers have roaming agreements in place). In addition, almost all UMTS phones are UMTS/GSM dual-mode devices, so if a UMTS phone travels outside of UMTS coverage during a call the call may be transparently handed off to available GSM coverage. Roaming charges are usually significantly higher than regular usage charges. Most UMTS licensees consider ubiquitous, transparent global
roaming Roaming is a wireless telecommunication term typically used with mobile devices, such as mobile phones. It refers to a mobile phone being used outside the range of its native network and connecting to another available cell network. Technical ...
an important issue. To enable a high degree of interoperability, UMTS phones usually support several different frequencies in addition to their GSM fallback. Different countries support different UMTS frequency bands Europe initially used 2100 MHz while the most carriers in the USA use 850 MHz and 1900 MHz. T-Mobile has launched a network in the US operating at 1700 MHz (uplink) /2100 MHz (downlink), and these bands also have been adopted elsewhere in the US and in Canada and Latin America. A UMTS phone and network must support a common frequency to work together. Because of the frequencies used, early models of UMTS phones designated for the United States will likely not be operable elsewhere and vice versa. There are now 11 different frequency combinations used around the world including frequencies formerly used solely for 2G services. UMTS phones can use a
Universal Subscriber Identity Module A typical SIM card (mini-SIM with micro-SIM cutout) A GSM mobile phone file:Simkarte NFC SecureElement.jpg, T-Mobile nano-SIM card with NFC capabilities in the SIM tray of an iPhone 6s file:Tf sim both sides.png, A TracFone Wireless SIM card ha ...
, USIM (based on GSM's
SIM card file:SIM-Karte von Telefónica O2 Europe - Standard und Micro.jpg, A typical SIM card (mini-SIM with micro-SIM cutout) file:Sim card.png, A smart card taken from a Global System for Mobile Communications, GSM mobile phone file:Simkarte NFC SecureE ...
) and also work (including UMTS services) with GSM SIM cards. This is a global standard of identification, and enables a network to identify and authenticate the (U)SIM in the phone. Roaming agreements between networks allow for calls to a customer to be redirected to them while roaming and determine the services (and prices) available to the user. In addition to user subscriber information and authentication information, the (U)SIM provides storage space for phone book contact. Handsets can store their data on their own memory or on the (U)SIM card (which is usually more limited in its phone book contact information). A (U)SIM can be moved to another UMTS or GSM phone, and the phone will take on the user details of the (U)SIM, meaning it is the (U)SIM (not the phone) which determines the phone number of the phone and the billing for calls made from the phone. Japan was the first country to adopt 3G technologies, and since they had not used GSM previously they had no need to build GSM compatibility into their handsets and their 3G handsets were smaller than those available elsewhere. In 2002, NTT DoCoMo's FOMA 3G network was the first commercial UMTS network using a pre-release specification, it was initially incompatible with the UMTS standard at the radio level but used standard USIM cards, meaning USIM card based roaming was possible (transferring the USIM card into a UMTS or GSM phone when travelling). Both NTT DoCoMo and SoftBank Mobile (which launched 3G in December 2002) now use standard UMTS.


Handsets and modems

All of the major 2G phone manufacturers (that are still in business) are now manufacturers of 3G phones. The early 3G handsets and modems were specific to the frequencies required in their country, which meant they could only roam to other countries on the same 3G frequency (though they can fall back to the older GSM standard). Canada and USA have a common share of frequencies, as do most European countries. The article UMTS frequency bands is an overview of UMTS network frequencies around the world. Using a
cellular router A mobile broadband modem, also known as wireless modem or cellular modem, is a type of modem that allows a personal computer or a router to receive wireless Internet access via a mobile broadband connection instead of using telephone or cable t ...
, PCMCIA or USB card, customers are able to access 3G broadband services, regardless of their choice of computer (such as a
tablet PC A tablet computer, commonly shortened to tablet, is a mobile device, typically with a mobile operating system and touchscreen display processing circuitry, and a rechargeable battery in a single, thin and flat package. Tablets, being comput ...
or a
PDA PDA may refer to: Science and technology * Patron-driven acquisition, a mechanism for libraries to purchase books *Personal digital assistant, a mobile device * Photodiode array, a type of detector * Polydiacetylenes, a family of conducting poly ...
). Some software installs itself from the modem, so that in some cases absolutely no knowledge of technology is required to get
online In computer technology and telecommunications, online indicates a state of connectivity and offline indicates a disconnected state. In modern terminology, this usually refers to an Internet connection, but (especially when expressed "on line" or ...
in moments. Using a phone that supports 3G and Bluetooth 2.0, multiple Bluetooth-capable laptops can be connected to the Internet. Some smartphones can also act as a mobile WLAN access point. There are very few 3G phones or modems available supporting all 3G frequencies (UMTS850/900/1700/1900/2100 MHz). In 2010, Nokia released a range of phones with Pentaband 3G coverage, including the N8 and E7. Many other phones are offering more than one band which still enables extensive roaming. For example, Apple's
iPhone 4 The iPhone 4 is a smartphone that was designed and marketed by Apple Inc. It is the fourth generation of the iPhone lineup, succeeding the iPhone 3GS and preceding the 4S. Following a number of notable leaks, the iPhone 4 was first unvei ...
contains a quadband chipset operating on 850/900/1900/2100 MHz, allowing usage in the majority of countries where UMTS-FDD is deployed.


Other competing standards

The main competitor to UMTS is CDMA2000 (IMT-MC), which is developed by the
3GPP2 The 3rd Generation Partnership Project 2 (3GPP2) is a collaboration between telecommunications associations to make a globally applicable third generation ( 3G) mobile phone system specification within the scope of the ITU's IMT-2000 project. In ...
. Unlike UMTS, CDMA2000 is an evolutionary upgrade to an existing 2G standard, cdmaOne, and is able to operate within the same frequency allocations. This and CDMA2000's narrower bandwidth requirements make it easier to deploy in existing spectra. In some, but not all, cases, existing GSM operators only have enough spectrum to implement either UMTS or GSM, not both. For example, in the US D, E, and F PCS spectrum blocks, the amount of spectrum available is 5 MHz in each direction. A standard UMTS system would saturate that spectrum. Where CDMA2000 is deployed, it usually co-exists with UMTS. In many markets however, the co-existence issue is of little relevance, as legislative hurdles exist to co-deploying two standards in the same licensed slice of spectrum. Another competitor to UMTS is
EDGE Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed by ...
(IMT-SC), which is an evolutionary upgrade to the 2G GSM system, leveraging existing GSM spectrums. It is also much easier, quicker, and considerably cheaper for wireless carriers to "bolt-on" EDGE functionality by upgrading their existing GSM transmission hardware to support EDGE rather than having to install almost all brand-new equipment to deliver UMTS. However, being developed by 3GPP just as UMTS, EDGE is not a true competitor. Instead, it is used as a temporary solution preceding UMTS roll-out or as a complement for rural areas. This is facilitated by the fact that GSM/EDGE and UMTS specifications are jointly developed and rely on the same core network, allowing dual-mode operation including
vertical handover Vertical handover or vertical handoff refers to a network node changing the type of connectivity it uses to access a supporting infrastructure, usually to support node mobility. For example, a suitably equipped laptop might be able to use both a hig ...
s. China's
TD-SCDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
standard is often seen as a competitor, too. TD-SCDMA has been added to UMTS' Release 4 as UTRA-TDD 1.28 Mcps Low Chip Rate (UTRA-TDD LCR). Unlike
TD-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
(UTRA-TDD 3.84 Mcps High Chip Rate, UTRA-TDD HCR) which complements W-CDMA (UTRA-FDD), it is suitable for both micro and macrocells. However, the lack of vendors' support is preventing it from being a real competitor. While DECT is technically capable of competing with UMTS and other cellular networks in densely populated, urban areas, it has only been deployed for domestic cordless phones and private in-house networks. All of these competitors have been accepted by ITU as part of the IMT-2000 family of 3G standards, along with UMTS-FDD. On the Internet access side, competing systems include WiMAX and
Flash-OFDM In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communi ...
.


Migrating from GSM/GPRS to UMTS

From a GSM/GPRS network, the following network elements can be reused: *
Home Location Register Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations. It is owned and deployed by mobile ...
(HLR) *
Visitor Location Register Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations. It is owned and deployed by mobile ...
(VLR) * Equipment Identity Register (EIR) *
Mobile Switching Center Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations. It is owned and deployed by mobi ...
(MSC) *
Gateway Mobile Switching Center Gateway often refers to: *A gate or portal (architecture), portal Gateway or The Gateway may also refer to: Arts and entertainment Films * Gateway (film), ''Gateway'' (film), a 1938 drama * The Gateway (2015 film), ''The Gateway'' (2015 film), ...
(GMSC) *
Authentication Center Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations. It is owned and deployed by mobile ...
(AUC) * Serving GPRS Support Node (
SGSN The GPRS core network is the central part of the general packet radio service (GPRS) which allows 2G, 3G and WCDMA mobile networks to transmit IP packets to external networks such as the Internet. The GPRS system is an integrated part of the G ...
) * Gateway GPRS Support Node (
GGSN The GPRS core network is the central part of the general packet radio service (GPRS) which allows 2G, 3G and WCDMA mobile networks to transmit IP packets to external networks such as the Internet. The GPRS system is an integrated part of the G ...
) From a GSM/GPRS communication radio network, the following elements cannot be reused: * Base transceiver station (BTS) * Base station controller (BSC) * Packet Control Unit (PCU) They can remain in the network and be used in dual network operation where 2G and 3G networks co-exist while network migration and new 3G terminals become available for use in the network. The UMTS network introduces new network elements that function as specified by 3GPP: *
Node B {{Unreferenced, date=May 2019, bot=noref (GreenC bot) Node B is the telecommunications node in particular mobile communication networks, namely those that adhere to the UMTS standard. The Node B provides the connection between mobile phones ( UEs) ...
(base transceiver station) *
Radio Network Controller The Radio Network Controller (RNC) is a governing element in the UMTS radio access network (UTRAN) and is responsible for controlling the Node Bs that are connected to it. The RNC carries out radio resource management, some of the mobility managem ...
(RNC) * Media Gateway (MGW) The functionality of MSC changes when going to UMTS. In a GSM system the MSC handles all the circuit switched operations like connecting A- and B-subscriber through the network. In UMTS the Media gateway (MGW) takes care of data transfer in circuit switched networks. MSC controls MGW operations.


Problems and issues

Some countries, including the United States, have allocated spectrum differently from the
ITU The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
recommendations, so that the standard bands most commonly used for UMTS (UMTS-2100) have not been available. In those countries, alternative bands are used, preventing the interoperability of existing UMTS-2100 equipment, and requiring the design and manufacture of different equipment for the use in these markets. As is the case with GSM900 today, standard UMTS 2100 MHz equipment will not work in those markets. However, it appears as though UMTS is not suffering as much from handset band compatibility issues as GSM did, as many UMTS handsets are multi-band in both UMTS and GSM modes. Penta-band (850, 900, 1700, 2100, and 1900 MHz bands), quad-band GSM (850, 900, 1800, and 1900 MHz bands) and tri-band UMTS (850, 1900, and 2100 MHz bands) handsets are becoming more commonplace. In its early days, UMTS had problems in many countries: Overweight handsets with poor battery life were first to arrive on a market highly sensitive to weight and form factor. The Motorola A830, a debut handset on Hutchison's 3 network, weighed more than 200 grams and even featured a detachable camera to reduce handset weight. Another significant issue involved call reliability, related to problems with handover from UMTS to GSM. Customers found their connections being dropped as handovers were possible only in one direction (UMTS → GSM), with the handset only changing back to UMTS after hanging up. In most networks around the world this is no longer an issue. Compared to GSM, UMTS networks initially required a higher
base station Base station (or base radio station) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service." The term is used in the context of mobile telephony, wireless com ...
density. For fully-fledged UMTS incorporating
video on demand Video on demand (VOD) is a media distribution system that allows users to access videos without a traditional video playback device and the constraints of a typical static broadcasting schedule. In the 20th century, broadcasting in the form of o ...
features, one base station needed to be set up every 1–1.5 km (0.62–0.93 mi). This was the case when only the 2100 MHz band was being used, however with the growing use of lower-frequency bands (such as 850 and 900 MHz) this is no longer so. This has led to increasing rollout of the lower-band networks by operators since 2006. Even with current technologies and low-band UMTS, telephony and data over UMTS requires more power than on comparable GSM networks.
Apple Inc. Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company b ...
cited UMTS power consumption as the reason that the first generation iPhone only supported EDGE. Their release of the iPhone 3G quotes talk time on UMTS as half that available when the handset is set to use GSM. Other manufacturers indicate different battery lifetime for UMTS mode compared to GSM mode as well. As battery and network technology improve, this issue is diminishing.


Security issues

As early as 2008, it was known that carrier networks can be used to surreptitiously gather user location information. In August 2014, the
Washington Post ''The Washington Post'' (also known as the ''Post'' and, informally, ''WaPo'') is an American daily newspaper published in Washington, D.C. It is the most widely circulated newspaper within the Washington metropolitan area and has a large nati ...
reported on widespread marketing of surveillance systems using
Signalling System No. 7 Signalling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down telephone calls in most parts of the world-wide public switched telephone network (PSTN). The protocol also perform ...
(SS7) protocols to locate callers anywhere in the world. In December 2014, news broke that SS7's very own functions can be repurposed for surveillance, because of its lax security, in order to listen to calls in real time or to record encrypted calls and texts for later decryption, or to defraud users and cellular carriers.
Deutsche Telekom Deutsche Telekom AG (; short form often just Telekom, DTAG or DT; stylised as ·T·) is a German telecommunications company that is headquartered in Bonn and is the largest telecommunications provider in Europe by revenue. Deutsche Telekom was ...
and Vodafone declared the same day that they had fixed gaps in their networks, but that the problem is global and can only be fixed with a telecommunication system-wide solution.


Releases

The evolution of UMTS progresses according to planned releases. Each release is designed to introduce new features and improve upon existing ones.


Release '99

* Bearer services * 64 kbit/s circuit switch * 384 kbit/s packet switched * Location services * Call service: compatible with Global System for Mobile Communications (
GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such as ...
), based on Universal Subscriber Identity Module (USIM) * Voice quality features
Tandem Free Operation Tandem Free Operation (TFO) is a part of ETSI's 3GPP standard specification, which has been included from R99 of the standards specifications onwards. Overview In traditional GSM networks, a call between two Mobile Stations (MS) involve a dual e ...
* Frequency 2.1 GHz


Release 4

* Edge radio * Multimedia messaging * MExE (Mobile Execution Environment) * Improved location services * IP Multimedia Services (IMS) * TD-SCDMA (UTRA-TDD 1.28 Mcps low chip rate)


Release 5

*
IP Multimedia Subsystem The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem (IMS) is a standardised architectural framework for delivering IP multimedia services. Historically, mobile phones have provided voice call services over a circuit-switched-styl ...
(IMS) *
IPv6 Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic ...
, IP transport in
UTRAN UTRAN (short for "UMTS Terrestrial Radio Access Network''") is a collective term for the network and equipment that connects mobile handsets to the public telephone network or the Internet. It contains the base stations, which are called Node B's ...
* Improvements in GERAN, MExE, etc. * HSDPA


Release 6

*
WLAN A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, or office building ...
integration * Multimedia broadcast and multicast * Improvements in IMS * HSUPA * Fractional DPCH


Release 7

* Enhanced L2 * 64 QAM, MIMO * Voice over
HSPA HSPA may refer to: * High Speed Packet Access, a mobile broadband technology * Hawaiian Sugar Planters' Association Education * High School Proficiency Assessment * Humphrey School of Public Affairs The Hubert H. Humphrey School of Public Aff ...
* CPC continuous packet connectivity * FRLC Flexible RLC


Release 8

*
Dual-Cell HSDPA Evolved High Speed Packet Access, HSPA+, HSPA (Plus) or HSPAP, is a technical standard for wireless broadband telecommunication. It is the second phase of HSPA which has been introduced in 3GPP release 7 and being further improved in later 3GPP ...


Release 9

* Dual-Cell HSUPA


See also

*
List of UMTS networks A ''list'' is any set of items in a row. List or lists may also refer to: People * List (surname) Organizations * List College, an undergraduate division of the Jewish Theological Seminary of America * SC Germania List, German rugby union ...
* 3GPP: the body that manages the UMTS standard. *
3GPP Long Term Evolution In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA standards. It improves on those standards' capacity and speed by usi ...
, the 3GPP project to evolve UMTS towards 4G capabilities. *
GAN The word Gan or the initials GAN may refer to: Places *Gan, a component of Hebrew placenames literally meaning "garden" China * Gan River (Jiangxi) * Gan River (Inner Mongolia), * Gan County, in Jiangxi province * Gansu, abbreviated ''Gā ...
/UMA: A standard for running GSM and UMTS over wireless LANs. *
Opportunity-Driven Multiple Access Opportunity-Driven Multiple Access (ODMA) is a UMTS communications relaying protocol standard first introduced by the European Telecommunication Standards Institute (ETSI) in 1996. ODMA has been adopted by the 3rd-Generation Partnership Project, 3 ...
,
ODMA The Open Document Management API is an API that simplifies the communication of desktop applications with document management systems (DMS). ODMA standardizes the access to the DMS, which makes getting to these files as easy as if the files were ...
: a UMTS TDD mode communications relaying protocol *
HSDPA High Speed Packet Access (HSPA) is an amalgamation of two mobile protocols—High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA)—that extends and improves the performance of existing 3G mobile telecommunicat ...
,
HSUPA High Speed Packet Access (HSPA) is an amalgamation of two mobile protocols—High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA)—that extends and improves the performance of existing 3G mobile telecommunicat ...
: updates to the W-CDMA air interface. *
PDCP Packet Data Convergence Protocol (PDCP) is specified by 3GPP in TS 25.323 for UMTS, TS 36.323 for LTE and TS 38.323 for 5G. PDCP is located in the Radio Protocol Stack in the UMTS/LTE/5G air interface on top of the RLC layer. PDCP provides its ...
*
Subscriber Identity Module A typical SIM card (mini-SIM with micro-SIM cutout) A GSM mobile phone file:Simkarte NFC SecureElement.jpg, T-Mobile nano-SIM card with NFC capabilities in the SIM tray of an iPhone 6s file:Tf sim both sides.png, A TracFone Wireless SIM card ha ...
*
UMTS-TDD The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
: a variant of UMTS largely used to provide wireless Internet service. *
UMTS frequency bands The UMTS frequency bands are radio frequencies used by third generation (3G) wireless Universal Mobile Telecommunications System networks. They were allocated by delegates to the World Administrative Radio Conference (WARC-92) held in Málaga-Tor ...
*
UMTS channels Sources 3GPP specification series 25Radio aspects of 3G, including UMTS TS 25.101 User Equipment (UE) radio transmission and reception (FDD)TS 25.201 DescriptionDescribes basic differences between FDD and TDD. TS 25.211_PHYSICAL channels and m ...
*
W-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...
: the primary air interface standard used by UMTS. *
TD-SCDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...


Other, non-UMTS, 3G and 4G standards

*
CDMA2000 CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatible ...
: evolved from
cdmaOne Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology. It was developed by Qualcomm and later adopted as a standard by the Telecommunications Industry Association in TIA/EIA/IS-95 release published in 1995. The ...
(also known as IS-95 or "CDMA"), managed by the
3GPP2 The 3rd Generation Partnership Project 2 (3GPP2) is a collaboration between telecommunications associations to make a globally applicable third generation ( 3G) mobile phone system specification within the scope of the ITU's IMT-2000 project. In ...
*
FOMA Freedom of Mobile Multimedia Access (FOMA) is the brand name of the W-CDMA-based 3G telecommunications services being offered by the Japanese telecommunications service provider NTT DoCoMo. It is an implementation of the Universal Mobile Tel ...
*
WiMAX Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options. The WiMAX ...
*
GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such as ...
*
GPRS General Packet Radio Service (GPRS) is a packet oriented mobile data standard on the 2G and 3G cellular communication network's global system for mobile communications (GSM). GPRS was established by European Telecommunications Standards Insti ...
*
EDGE Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed by ...
*
ETSI The European Telecommunications Standards Institute (ETSI) is an independent, not-for-profit, standardization organization in the field of information and communications. ETSI supports the development and testing of global technical standard ...


Other information

*
Cellular frequencies Cellular frequencies are the sets of frequency ranges within the ultra high frequency band that have been assigned for cellular-compatible mobile devices, such as mobile phones, to connect to cellular networks.Guowang Miao, Jens Zander, Ki Won ...
*
CDMA Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication ...
*
Comparison of wireless data standards A wide variety of different wireless data technologies exist, some in direct competition with one another, others designed for specific applications. Wireless technologies can be evaluated by a variety of different metrics of which some are describe ...
*
DECT Digital enhanced cordless telecommunications (Digital European cordless telecommunications), usually known by the acronym DECT, is a standard primarily used for creating cordless telephone systems. It originated in Europe, where it is the common ...
*
Dynamic TDMA Time-division multiple access (TDMA) is a channel access method for shared-medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, o ...
*
Evolution-Data Optimized Evolution-Data Optimized (EV-DO, EVDO, etc.) is a telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access. EV-DO is an evolution of the CDMA2000 (IS-2000) standard which su ...
/
CDMA2000 CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatible ...
*
FOMA Freedom of Mobile Multimedia Access (FOMA) is the brand name of the W-CDMA-based 3G telecommunications services being offered by the Japanese telecommunications service provider NTT DoCoMo. It is an implementation of the Universal Mobile Tel ...
*
GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such as ...
/
EDGE Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed by ...
*
HSPA HSPA may refer to: * High Speed Packet Access, a mobile broadband technology * Hawaiian Sugar Planters' Association Education * High School Proficiency Assessment * Humphrey School of Public Affairs The Hubert H. Humphrey School of Public Aff ...
*
PN sequences A pseudorandom number generator (PRNG), also known as a deterministic random bit generator (DRBG), is an algorithm for generating a sequence of numbers whose properties approximate the properties of sequences of random number generation, random n ...
*
Spectral efficiency comparison table Spectral efficiency, spectrum efficiency or bandwidth efficiency refers to the information rate that can be transmitted over a given bandwidth in a specific communication system. It is a measure of how efficiently a limited frequency spectrum is ut ...
*
UMTS frequency bands The UMTS frequency bands are radio frequencies used by third generation (3G) wireless Universal Mobile Telecommunications System networks. They were allocated by delegates to the World Administrative Radio Conference (WARC-92) held in Málaga-Tor ...
*
WiMAX Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options. The WiMAX ...
*
Telecommunications industry in China :''This article discusses the telecommunications industry in mainland China. For Hong Kong and Macau, see Communications in Hong Kong and Communications in Macau.'' The telecommunications industry in China is dominated by three state-run business ...
*
Communications in China The People's Republic of China possesses a diversified communications system that links all parts of the country by Internet, telephone, telegraph, radio, and television. The country is served by an extensive system of automatic telephone exchan ...
*
Standardization in China The Standardization Administration of China (SAC; ; abbr.: ) is the standards organization authorized by the State Council of China to exercise administrative responsibilities by undertaking unified management, supervision and overall coordinat ...
*
Mobile modem A mobile broadband modem, also known as wireless modem or cellular modem, is a type of modem that allows a personal computer or a router to receive wireless Internet access via a mobile broadband connection instead of using telephone or cable tel ...
*
Spectral efficiency comparison table Spectral efficiency, spectrum efficiency or bandwidth efficiency refers to the information rate that can be transmitted over a given bandwidth in a specific communication system. It is a measure of how efficiently a limited frequency spectrum is ut ...
* Code-Division Multiple Access (CDMA) *
Common pilot channel {{Technical, date=September 2010 CPICH stands for ''Common Pilot Channel'' in UMTS and some other CDMA communications systems. In WCDMA FDD cellular systems, CPICH is a downlink channel broadcast by Node Bs with constant power and of a known bit ...
or CPICH, a simple synchronisation channel in WCDMA. * Multiple-input multiple-output (MIMO) is the major issue of
multiple antenna research In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
. *
Wi-Fi Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio wave ...
: a local area wireless technology that is complementary to UMTS. *
List of device bandwidths This is a list of interface bit rates, is a measure of information transfer rates, or digital bandwidth capacity, at which digital interfaces in a computer or network can communicate over various kinds of buses and channels. The distinction can ...
* Operations and Maintenance Centre *
Radio Network Controller The Radio Network Controller (RNC) is a governing element in the UMTS radio access network (UTRAN) and is responsible for controlling the Node Bs that are connected to it. The RNC carries out radio resource management, some of the mobility managem ...
*
UMTS security {{unreferenced, date=January 2010 The Universal Mobile Telecommunications System (UMTS) is one of the new ‘third generation’ 3G mobile cellular communication systems. UMTS builds on the success of the ‘second generation’ GSM system. One o ...
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Huawei SingleRAN Huawei SingleRAN is a radio access network (RAN) technology offered by Huawei that allows mobile telecommunications operators to support multiple mobile communications standards and wireless telephone services on a single network. The technology i ...
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RAN Ran, RaN and ran may refer to: Arts and entertainment * ''Ran'' (film), a 1985 film directed by Akira Kurosawa * "Ran" (song), a 2013 Japanese song by Luna Sea * '' Ran Online'', a 2004 MMORPG (massively multiplayer online role playing game) * ...
technology allowing migration from GSM to UMTS or simultaneous use of both


References


Citations


Bibliography

* Martin Sauter: ''Communication Systems for the Mobile Information Society'', John Wiley, September 2006, . * Ahonen and Barrett (editors), ''Services for UMTS'' (Wiley, 2002) first book on the services for 3G, . * Holma and Toskala (editors), ''WCDMA for UMTS'', (Wiley, 2000) first book dedicated to 3G technology, . * Kreher and Ruedebusch, ''UMTS Signaling: UMTS Interfaces, Protocols, Message Flows and Procedures Analyzed and Explained'' (Wiley 2007), . * Laiho, Wacker and Novosad, ''Radio Network Planning and Optimization for UMTS'' (Wiley, 2002) first book on radio network planning for 3G, . * Muratore, Flavio. UMTS: mobile communications for the future. John Wiley & Sons, Inc., 2000. .


Documentation


3GPP specification series 25
Radio aspects of 3G, including UMTS
TS 25.201 Physical Layer General Description
Describes basic differences between FDD and TDD.
TS 25.211 Physical channels and mapping of transport channels onto physical channels (FDD)

TS 25.221 Physical channels and mapping of transport channels onto physical channels (TDD)

TS 25.212 Multiplexing and channel coding (FDD)

TS 25.222 Multiplexing and channel coding (TDD)

TS 25.213 Spreading and modulation (FDD)

TS 25.223 Spreading and modulation (TDD)

TS 25.214 Physical layer procedures (FDD)

TS 25.224 Physical layer procedures (TDD)

TS 25.215 Physical layer Measurements (FDD)

TS 25.225 Physical layer Measurements (TDD)


External links



3rd Generation Partnership Project Standard
3GPP Specifications Numbering Schemes



UMTS LTE Link Budget Comparison


on UMTS World

on UMTS World
UMTS TDD Alliance
The Global UMTS TDD Alliance
3GSM World Congress

UMTS Provider Chart

LTE Encyclopedia

TD-SCDMA Forum

TD-SCDMA Industry Alliance

UMTS FAQ
{{Authority control Telecommunications-related introductions in 2002 3GPP standards Bandplans Metropolitan area networks Mobile telecommunications Mobile telecommunications standards Network access UMTS Videotelephony Wireless networking