The Type Allocation Code (TAC) is the initial eight- digit portion of the 15-digit IMEI and 16-digit IMEISV codes used to uniquely identify wireless devices.
85-640: The Type Allocation Code identifies a particular model (and often revision) of wireless telephone for use on a GSM , UMTS , LTE , 5G NR , iDEN , Iridium or other IMEI-employing wireless network. The first two digits of the TAC are the Reporting Body Identifier . This indicates the GSMA -approved group that allocated the TAC. Prior to January 1, 2003, the global standard for the IMEI started with
170-518: A broadband-internet connection. Umbrella cells are used to cover shadowed regions of smaller cells and to fill in gaps in coverage between those cells. Cell horizontal radius varies – depending on antenna height, antenna gain , and propagation conditions – from a couple of hundred meters to several tens of kilometers. The longest distance the GSM specification supports in practical use is 35 kilometres (22 mi). There are also several implementations of
255-559: A memorandum of understanding in Copenhagen to develop and deploy a common cellular telephone system across Europe, and EU rules were passed to make GSM a mandatory standard. The decision to develop a continental standard eventually resulted in a unified, open, standard-based network which was larger than that in the United States. In February 1987 Europe produced the first agreed GSM Technical Specification. Ministers from
340-679: A UMTS network, with HSPA+, from 2005 until its shutdown in February 2022. Rogers in Canada 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 opened W-CDMA service in Finland October 13, 2004, with speeds up to 384 kbit/s. Availability only in main cities. Pricing
425-402: 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 of patents between Qualcomm and W-CDMA vendors has not eliminated possible patent issues due to
510-664: A generic term for the plethora of G mobile phone technologies evolved from it. In 1983, work began to develop a European standard for digital cellular voice telecommunications when the European Conference of Postal and Telecommunications Administrations (CEPT) set up the Groupe Spécial Mobile (GSM) committee and later provided a permanent technical-support group based in Paris . Five years later, in 1987, 15 representatives from 13 European countries signed
595-426: A mast or a building above average rooftop level. Micro cells are cells whose antenna height is under average rooftop level; they are typically deployed in urban areas. Picocells are small cells whose coverage diameter is a few dozen meters; they are mainly used indoors. Femtocells are cells designed for use in residential or small-business environments and connect to a telecommunications service provider 's network via
680-466: A next generation air interface technology based upon orthogonal frequency-division multiplexing . 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 . 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
765-453: A number of companies over the years, but development of cell-phone networks based on CDMA (prior to W-CDMA) was dominated by Qualcomm , the first company to succeed in developing a practical and cost-effective CDMA implementation for consumer cell phones and its early IS-95 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
850-456: A problem for any open-source GSM implementation, because it is not possible for GNU or any other free software distributor to guarantee immunity from all lawsuits by the patent holders against the users. Furthermore, new features are being added to the standard all the time which means they have patent protection for a number of years. The original GSM implementations from 1991 may now be entirely free of patent encumbrances, however patent freedom
935-658: A rare unity and speed guided by four public officials: Armin Silberhorn (Germany), Stephen Temple (UK), Philippe Dupuis (France), and Renzo Failli (Italy). In 1989 the Groupe Spécial Mobile committee was transferred from CEPT to the European Telecommunications Standards Institute (ETSI). The IEEE/RSE awarded to Thomas Haug and Philippe Dupuis the 2018 James Clerk Maxwell medal for their "leadership in
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#17327983124411020-481: A relationship between two parts of the algorithm. The researchers found that this relationship was very unlikely to have happened if it was not intentional. This may have been done in order to satisfy European controls on export of cryptographic programs. The GSM systems and services are described in a set of standards governed by ETSI , where a full list is maintained. Several open-source software projects exist that provide certain GSM features: Patents remain
1105-426: A replacement for first generation ( 1G ) analog cellular networks. The GSM standard originally described a digital, circuit-switched network optimized for full duplex voice telephony . This expanded over time to include data communications, first by circuit-switched transport , then by packet data transport via General Packet Radio Service (GPRS), and Enhanced Data Rates for GSM Evolution (EDGE). Subsequently,
1190-566: A six-digit Type Approval Code followed by a two-digit Final Assembly Code (FAC). The Type Approval Code (also known as TAC) indicated that the particular device was approved by a national GSM approval body and the FAC identified the company that had built and assembled the device (which is not always the same as the brand name stamped on the device). Effective on that date, many GSM member nations and entities (mainly Europe) moved away from requiring that devices be approved by national bodies, and towards
1275-481: A stronger one. Since 2000, different efforts have been made in order to crack the A5 encryption algorithms. Both A5/1 and A5/2 algorithms have been broken, and their cryptanalysis has been revealed in the literature. As an example, Karsten Nohl developed a number of rainbow tables (static values which reduce the time needed to carry out an attack) and have found new sources for known plaintext attacks . He said that it
1360-515: A system where device manufacturers self-regulate the device market. As a result, a manufacturer now simply requests an eight-digit Type Allocation Code for a new phone model from the international GSM standards body, instead of submitting a device for approval to a national review body. Both the old and new TAC uniquely identify a model of phone, although some models may have more than one code, depending on revision, manufacturing location, and other factors. The authoritative database maintained by GSMA
1445-443: A term referring to inexperienced individuals utilizing readily available hardware and software. The vulnerability arises from the accessibility of tools such as a DVB-T TV tuner, posing a threat to both mobile and network users. Despite the term "script kiddies" implying a lack of sophisticated skills, the consequences of their attacks on GSM can be severe, impacting the functionality of cellular networks . Given that GSM continues to be
1530-479: A way was required to prevent users inserting the rural broadband SIM cards in an unauthorized devices to get subsidized data rates. The use of a TAC lock by the use of a customized SIM card with embedded TAC codes was devised. Several Type allocation codes can be stored in the SIM cards of the device to allow a group of provider-supplied Huawei branded 4G modems and block the use of unauthorized and third-party devices on
1615-447: Is 4.615 ms. TDMA noise is interference that can be heard on speakers near a GSM phone using TDMA, audible as a buzzing sound. The transmission power in the handset is limited to a maximum of 2 watts in GSM 850/900 and 1 watt in GSM 1800/1900 . GSM has used a variety of voice codecs to squeeze 3.1 kHz audio into between 7 and 13 kbit/s. Originally, two codecs, named after
1700-438: Is a UTRA that uses time-division duplexing for duplexing. While a full implementation of UMTS, it is mainly used to provide Internet access in circumstances similar to those where 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
1785-659: Is a channel-access method based on using spread-spectrum 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 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
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#17327983124411870-401: Is an acronym for Universal Mobile Telecommunications System (UMTS) – frequency-division duplexing (FDD) and a 3GPP standardized version of UMTS networks that makes use of frequency-division duplexing for duplexing over an UMTS Terrestrial Radio Access ( UTRA ) air interface. W-CDMA is the basis of Japan's NTT DoCoMo 's FOMA service and the most-commonly used member of
1955-616: 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
2040-764: Is approx. €2/MB. SK Telecom and KTF , two largest mobile phone service providers in South Korea , 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 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
2125-426: Is called SIM locking and is implemented by a software feature of the phone. A subscriber may usually contact the provider to remove the lock for a fee, utilize private services to remove the lock, or use software and websites to unlock the handset themselves. It is possible to hack past a phone locked by a network operator. In some countries and regions (e.g. Brazil and Germany ) all phones are sold unlocked due to
2210-612: Is dropping support of their WLAN service in Austria (2006). Maxis Communications and Celcom , two mobile phone service providers in Malaysia , started offering W-CDMA services in 2005. In Sweden , Telia introduced W-CDMA in March 2004. 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
2295-677: 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 (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 (HSCSD) and 14.4 kbit/s for CDMAOne channels. Since 2006, UMTS networks in many countries have been or are in
2380-617: 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 (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 , an acronym for Time-Division- Code-Division Multiple Access ,
2465-416: Is named GSMA Device Database and is only made available to partners. However, there are many public alternatives, though they will not be fully up to date. The Osmocom project maintains a crowdsourced TAC database , which is CC-BY-SA v3.0 licensed and fully downloadable. Some OEMs publish TAC data for their products: In New Zealand with the rollout of the government subsidized rural broadband initiative
2550-477: Is needed indoors, as in shopping centers or airports. However, this is not a prerequisite, since indoor coverage is also provided by in-building penetration of radio signals from any nearby cell. GSM networks operate in a number of different carrier frequency ranges (separated into GSM frequency ranges for 2G and UMTS frequency bands for 3G), with most 2G GSM networks operating in the 900 MHz or 1800 MHz bands. Where these bands were already allocated,
2635-443: Is not certain due to the United States' "first to invent" system that was in place until 2012. The "first to invent" system, coupled with "patent term adjustment" can extend the life of a U.S. patent far beyond 20 years from its priority date. It is unclear at this time whether OpenBTS will be able to implement features of that initial specification without limit. As patents subsequently expire, however, those features can be added into
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2720-591: 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 , Bluetooth or USB . UMTS combines three different terrestrial air interfaces , GSM 's Mobile Application Part (MAP) core, and the GSM family of speech codecs . The air interfaces are called UMTS Terrestrial Radio Access (UTRA). All air interface options are part of ITU 's IMT-2000 . In
2805-486: Is possible to build "a full GSM interceptor ... from open-source components" but that they had not done so because of legal concerns. Nohl claimed that he was able to intercept voice and text conversations by impersonating another user to listen to voicemail , make calls, or send text messages using a seven-year-old Motorola cellphone and decryption software available for free online. GSM uses General Packet Radio Service (GPRS) for data transmissions like browsing
2890-511: Is said to be in use on some more modern networks. If used with USIM to prevent connections to fake base stations and downgrade attacks , users will be protected in the medium term, though migration to 128-bit GEA/4 is still recommended. The first public cryptanalysis of GEA/1 and GEA/2 (also written GEA-1 and GEA-2) was done in 2021. It concluded that although using a 64-bit key, the GEA-1 algorithm actually provides only 40 bits of security, due to
2975-400: Is structured into several discrete sections: GSM utilizes a cellular network , meaning that cell phones connect to it by searching for cells in the immediate vicinity. There are five different cell sizes in a GSM network: The coverage area of each cell varies according to the implementation environment. Macro cells can be regarded as cells where the base-station antenna is installed on
3060-488: 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 bands . 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
3145-573: The 2G GSM networks deployed worldwide, allowing dual-mode mobile operation along with GSM/ EDGE ; a feature it shares with other members of the UMTS family. In the late 1990s, W-CDMA was developed by NTT DoCoMo as the air interface for their 3G network FOMA . Later NTT DoCoMo submitted the specification to the International Telecommunication Union (ITU) as a candidate for the international 3G standard known as IMT-2000. The ITU eventually accepted W-CDMA as part of
3230-457: The 3GPP developed third-generation ( 3G ) UMTS standards, followed by the fourth-generation ( 4G ) LTE Advanced and the fifth-generation 5G standards, which do not form part of the ETSI GSM standard. Beginning in the late 2010s, various carriers worldwide started to shut down their GSM networks . Nevertheless, as a result of the network's widespread use, the acronym "GSM" is still used as
3315-504: The CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code-division multiple access ( W-CDMA ) 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 ( UMTS Terrestrial Radio Access Network , or UTRAN), the core network ( Mobile Application Part , or MAP) and
3400-466: The DS-CDMA channel access method with a pair of 5 MHz wide channels. In contrast, the competing CDMA2000 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
3485-529: The 3GPP. GSM, for the first time, set a common standard for Europe for wireless networks. It was also adopted by many countries outside Europe. This allowed subscribers to use other GSM networks that have roaming agreements with each other. The common standard reduced research and development costs, since hardware and software could be sold with only minor adaptations for the local market. Telstra in Australia shut down its 2G GSM network on 1 December 2016,
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3570-764: 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 , New Zealand by Telecom New Zealand on the XT Mobile Network and in Australia by Telstra on the Next G network. Some carriers such as 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
3655-614: The 850 MHz and 1900 MHz bands were used instead (for example in Canada and the United States). In rare cases the 400 and 450 MHz frequency bands are assigned in some countries because they were previously used for first-generation systems. For comparison, most 3G networks in Europe operate in the 2100 MHz frequency band. For more information on worldwide GSM frequency usage, see GSM frequency bands . Regardless of
3740-510: The IMT-2000 family of 3G standards, as an alternative to CDMA2000, EDGE, and the short range DECT system. Later, W-CDMA was selected as an air interface for UMTS . 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
3825-508: The UK by 1993, called the DCS 1800. Also that year, Telstra became the first network operator to deploy a GSM network outside Europe and the first practical hand-held GSM mobile phone became available. In 1995 fax, data and SMS messaging services were launched commercially, the first 1900 MHz GSM network became operational in the United States and GSM subscribers worldwide exceeded 10 million. In
3910-410: 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
3995-542: The United States; A5/2 is weaker and used in other countries. Serious weaknesses have been found in both algorithms: it is possible to break A5/2 in real-time with a ciphertext-only attack , and in January 2007, The Hacker's Choice started the A5/1 cracking project with plans to use FPGAs that allow A5/1 to be broken with a rainbow table attack. The system supports multiple algorithms so operators may replace that cipher with
4080-628: 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 (TDMA) and time-division duplex (TDD) schemes. While not an evolutionary upgrade on the airside, it uses the same core network as
4165-533: The W-CDMA ( 3GPP ) and CDMA2000 ( 3GPP2 ) 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 as of 2006 . However, divergent requirements resulted in the W-CDMA standard being retained and deployed globally. W-CDMA has then become
4250-427: The abundance of dual-SIM handsets and operators. GSM was intended to be a secure wireless system. It has considered the user authentication using a pre-shared key and challenge–response , and over-the-air encryption. However, GSM is vulnerable to different types of attack, each of them aimed at a different part of the network. Research findings indicate that GSM faces susceptibility to hacking by script kiddies ,
4335-450: The authentication of users via SIM ( subscriber identity module ) cards. The technology described in UMTS is sometimes also referred to as Freedom of Mobile Multimedia Access (FOMA) or 3GSM. Unlike EDGE (IMT Single-Carrier, based on GSM) and CDMA2000 (IMT Multi-Carrier), UMTS requires new base stations and new frequency allocations. UMTS supports theoretical maximum data transfer rates of 42 Mbit/s when Evolved HSPA (HSPA+)
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#17327983124414420-587: 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. TD-SCDMA was developed in the People's Republic of China by the Chinese Academy of Telecommunications Technology (CATT), Datang Telecom , and Siemens AG in an attempt to avoid dependence on Western technology. This is likely primarily for practical reasons, since other 3G formats require
4505-507: The concept of an extended cell, where the cell radius could be double or even more, depending on the antenna system, the type of terrain, and the timing advance . GSM supports indoor coverage – achievable by using an indoor picocell base station, or an indoor repeater with distributed indoor antennas fed through power splitters – to deliver the radio signals from an antenna outdoors to the separate indoor distributed antenna system. Picocells are typically deployed when significant call capacity
4590-512: 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 , TD-CDMA and TD-SCDMA are misleading. While they suggest covering just a channel access method (namely a variant of CDMA ), they are actually the common names for
4675-537: The development of the first international mobile communications standard with subsequent evolution into worldwide smartphone data communication". The GSM (2G) has evolved into 3G, 4G and 5G. In parallel France and Germany signed a joint development agreement in 1984 and were joined by Italy and the UK in 1986. In 1986, the European Commission proposed reserving the 900 MHz spectrum band for GSM. It
4760-400: The dominant standard. 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
4845-409: 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
4930-409: 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. The world's first commercial W-CDMA service, FOMA,
5015-492: The first HSDPA -capable network also became operational. The first HSUPA network launched in 2007. ( High Speed Packet Access (HSPA) and its uplink and downlink versions are 3G technologies, not part of GSM.) Worldwide GSM subscribers exceeded three billion in 2008. The GSM Association estimated in 2011 that technologies defined in the GSM standard served 80% of the mobile market, encompassing more than 5 billion people across more than 212 countries and territories, making GSM
5100-453: The first Multimedia Messaging Service (MMS) was introduced and the first GSM network in the 800 MHz frequency band became operational. Enhanced Data rates for GSM Evolution (EDGE) services first became operational in a network in 2003, and the number of worldwide GSM subscribers exceeded 1 billion in 2004. By 2005 GSM networks accounted for more than 75% of the worldwide cellular network market, serving 1.5 billion subscribers. In 2005,
5185-434: The first half of 2007. KT Freecel will thus cut funding to its CDMA2000 network development to the minimum. In Norway , Telenor 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
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#17327983124415270-735: The first mobile network operator to decommission a GSM network. The second mobile provider to shut down its GSM network (on 1 January 2017) was AT&T Mobility from the United States . Optus in Australia completed the shut down of its 2G GSM network on 1 August 2017, part of the Optus GSM network covering Western Australia and the Northern Territory had earlier in the year been shut down in April 2017. Singapore shut down 2G services entirely in April 2017. The network
5355-645: The four big EU countries cemented their political support for GSM with the Bonn Declaration on Global Information Networks in May and the GSM MoU was tabled for signature in September. The MoU drew in mobile operators from across Europe to pledge to invest in new GSM networks to an ambitious common date. In this short 38-week period the whole of Europe (countries and industries) had been brought behind GSM in
5440-416: The frequency selected by an operator, it is divided into timeslots for individual phones. This allows eight full-rate or sixteen half-rate speech channels per radio frequency . These eight radio timeslots (or burst periods) are grouped into a TDMA frame. Half-rate channels use alternate frames in the same timeslot. The channel data rate for all 8 channels is 270.833 kbit/s, and the frame duration
5525-579: The key features of GSM is the Subscriber Identity Module , commonly known as a SIM card . The SIM is a detachable smart card containing a user's subscription information and phone book. This allows users to retain their information after switching handsets. Alternatively, users can change networks or network identities without switching handsets - simply by changing the SIM. Sometimes mobile network operators restrict handsets that they sell for exclusive use in their own network. This
5610-704: 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 of Singapore commercially launched its 3G (W-CDMA) services in February 2005. New Zealand in August 2005 and Australia in October 2005. AT&T Mobility utilized
5695-414: The main source of cellular technology in numerous countries, its susceptibility to potential threats from malicious attacks is one that needs to be addressed. The development of UMTS introduced an optional Universal Subscriber Identity Module (USIM), that uses a longer authentication key to give greater security, as well as mutually authenticating the network and the user, whereas GSM only authenticates
5780-598: The most ubiquitous of the many standards for cellular networks. GSM is a second-generation (2G) standard employing time-division multiple-access (TDMA) spectrum-sharing, issued by the European Telecommunications Standards Institute (ETSI). The GSM standard does not include the 3G Universal Mobile Telecommunications System (UMTS), code-division multiple access (CDMA) technology, nor the 4G LTE orthogonal frequency-division multiple access (OFDMA) technology standards issued by
5865-463: The network. A company wishing to resell Vodafone RBI is required to supply a device for the approval process and certification, and to supply One NZ with the TAC details of this device to embed into the SIM cards at the point of manufacture. A minimum order of 500 SIM cards is required. GSM The Global System for Mobile Communications ( GSM ) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe
5950-546: The open-source version. As of 2011 , there have been no lawsuits against users of OpenBTS over GSM use. UMTS The Universal Mobile Telecommunications System ( UMTS ) is a 3G 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 International Telecommunication Union IMT-2000 standard set and compares with
6035-473: 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
6120-543: The process of being upgraded with High-Speed Downlink Packet Access (HSDPA), sometimes known as 3.5G . Currently, HSDPA enables downlink 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 (HSUPA). The 3GPP LTE standard succeeds UMTS and initially provided 4G speeds of 100 Mbit/s down and 50 Mbit/s up, with scalability up to 3 Gbps, using
6205-617: The protocols for second-generation ( 2G ) digital cellular networks used by mobile devices such as mobile phones and tablets. GSM is also a trade mark owned by the GSM Association . " GSM " may also refer to the voice codec initially used in GSM. It was first implemented in Finland in December 1991. By the mid-2010s, it became a global standard for mobile communications achieving over 90% market share, and operating in over 193 countries and territories. 2G networks developed as
6290-596: 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 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. Time-Division Synchronous Code-Division Multiple Access (TD-SCDMA) or UTRA TDD 1.28 Mcps low chip rate (UTRA-TDD LCR)
6375-459: The same year, the GSM Association formed. Pre-paid GSM SIM cards were launched in 1996 and worldwide GSM subscribers passed 100 million in 1998. In 2000 the first commercial General Packet Radio Service (GPRS) services were launched and the first GPRS-compatible handsets became available for sale. In 2001, the first UMTS (W-CDMA) network was launched, a 3G technology that is not part of GSM. Worldwide GSM subscribers exceeded 500 million. In 2002,
6460-500: The service was changed to "Vodafone 3G" (now "SoftBank 3G") in December 2004. Beginning in 2003, Hutchison Whampoa 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
6545-458: The signal. GSM was further enhanced in 1997 with the enhanced full rate (EFR) codec, a 12.2 kbit/s codec that uses a full-rate channel. Finally, with the development of UMTS , EFR was refactored into a variable-rate codec called AMR-Narrowband , which is high quality and robust against interference when used on full-rate channels, or less robust but still relatively high quality when used in good radio conditions on half-rate channel. One of
6630-400: The types of data channel they were allocated, were used, called Half Rate (6.5 kbit/s) and Full Rate (13 kbit/s). These used a system based on linear predictive coding (LPC). In addition to being efficient with bitrates , these codecs also made it easier to identify more important parts of the audio, allowing the air interface layer to prioritize and better protect these parts of
6715-415: The user to the network (and not vice versa). The security model therefore offers confidentiality and authentication, but limited authorization capabilities, and no non-repudiation . GSM uses several cryptographic algorithms for security. The A5/1 , A5/2 , and A5/3 stream ciphers are used for ensuring over-the-air voice privacy. A5/1 was developed first and is a stronger algorithm used within Europe and
6800-535: The web. The most commonly deployed GPRS ciphers were publicly broken in 2011. The researchers revealed flaws in the commonly used GEA/1 and GEA/2 (standing for GPRS Encryption Algorithms 1 and 2) ciphers and published the open-source "gprsdecode" software for sniffing GPRS networks. They also noted that some carriers do not encrypt the data (i.e., using GEA/0) in order to detect the use of traffic or protocols they do not like (e.g., Skype ), leaving customers unprotected. GEA/3 seems to remain relatively hard to break and
6885-477: The whole air interface standards. W-CDMA (WCDMA; Wideband Code-Division Multiple Access ), along with UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface standard found in 3G mobile telecommunications networks. It supports conventional cellular voice, text and MMS 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
6970-467: Was actually made by me. I called Marjo Jousinen, in Salo.", Lonka informed. The following year saw the sending of the first short messaging service (SMS or "text message") message, and Vodafone UK and Telecom Finland signed the first international roaming agreement. Work began in 1991 to expand the GSM standard to the 1800 MHz frequency band and the first 1800 MHz network became operational in
7055-459: 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
7140-551: Was launched by NTT DoCoMo in Japan 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 using geosynchronous satellites in place of cell towers. J-Phone Japan (once Vodafone and now SoftBank Mobile ) soon followed by launching their own W-CDMA based service, originally branded "Vodafone Global Standard" and claiming UMTS compatibility. The name of
7225-478: Was long believed that the former Finnish prime minister Harri Holkeri made the world's first GSM call on 1 July 1991, calling Kaarina Suonio (deputy mayor of the city of Tampere ) using a network built by Nokia and Siemens and operated by Radiolinja . In 2021 a former Nokia engineer Pekka Lonka revealed to Helsingin Sanomat making a test call just a couple of hours earlier. "World's first GSM call
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