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131-505: IMS was originally designed by the wireless standards body 3rd Generation Partnership Project (3GPP), as a part of the vision for evolving mobile networks beyond GSM . Its original formulation (3GPP Rel-5) represented an approach for delivering Internet services over GPRS . This vision was later updated by 3GPP, 3GPP2 and ETSI TISPAN by requiring support of networks other than GPRS , such as Wireless LAN , CDMA2000 and fixed lines. IMS uses IETF protocols wherever possible, e.g.,

262-412: A thermionic tube or thermionic valve uses thermionic emission of electrons from a heated cathode for a number of fundamental electronic functions such as signal amplification and current rectification . The simplest vacuum tube, the diode invented in 1904 by John Ambrose Fleming , contains only a heated electron-emitting cathode and an anode. Electrons can only flow in one direction through

393-580: A business card ). Also known as Address of Record (AOR). There can be multiple IMPU per IMPI. The IMPU can also be shared with another phone, so that both can be reached with the same identity (for example, a single phone-number for an entire family). Globally Routable User Agent URI: Globally Routable User Agent URI (GRUU) is an identity that identifies a unique combination of IMPU and UE instance. There are two types of GRUU: Public-GRUU (P-GRUU) and Temporary GRUU (T-GRUU). Wildcarded Public User Identity: A wildcarded Public User Identity expresses

524-411: A radio broadcasting station , the station's large power amplifier is the transmitter and the broadcasting antenna is the interface between the power amplifier and the free space channel. The free space channel is the transmission medium and the receiver's antenna is the interface between the free space channel and the receiver. Next, the radio receiver is the destination of the radio signal, where it

655-745: A 55° thread angle and a thread depth of 0.640327 p and a radius of 0.137329 p , where p is the pitch. The thread pitch increased with diameter in steps specified on a chart. An example of the use of the Whitworth thread is the Royal Navy 's Crimean War gunboats. These were the first instance of "mass-production" techniques being applied to marine engineering. With the adoption of BSW by British railway lines, many of which had previously used their own standard both for threads and for bolt head and nut profiles, and improving manufacturing techniques, it came to dominate British manufacturing. American Unified Coarse

786-411: A better price for their goods. In Côte d'Ivoire , coffee growers share mobile phones to follow hourly variations in coffee prices and sell at the best price. On the macroeconomic scale, Lars-Hendrik Röller and Leonard Waverman suggested a causal link between good telecommunication infrastructure and economic growth. Few dispute the existence of a correlation although some argue it is wrong to view

917-438: A caveat for it in 1876. Gray abandoned his caveat and because he did not contest Bell's priority, the examiner approved Bell's patent on March 3, 1876. Gray had filed his caveat for the variable resistance telephone, but Bell was the first to document the idea and test it in a telephone.[88] Antonio Meucci invented a device that allowed the electrical transmission of voice over a line nearly 30 years before in 1849, but his device

1048-441: A connection between two or more users. For both types of networks, repeaters may be necessary to amplify or recreate the signal when it is being transmitted over long distances. This is to combat attenuation that can render the signal indistinguishable from the noise. Another advantage of digital systems over analogue is that their output is easier to store in memory, i.e., two voltage states (high and low) are easier to store than

1179-495: A continuous range of states. Telecommunication has a significant social, cultural and economic impact on modern society. In 2008, estimates placed the telecommunication industry 's revenue at US$ 4.7 trillion or just under three per cent of the gross world product (official exchange rate). Several following sections discuss the impact of telecommunication on society. On the microeconomic scale, companies have used telecommunications to help build global business empires. This

1310-406: A higher-frequency signal (known as the " carrier wave ") before transmission. There are several different modulation schemes available to achieve this [two of the most basic being amplitude modulation (AM) and frequency modulation (FM)]. An example of this process is a disc jockey's voice being impressed into a 96 MHz carrier wave using frequency modulation (the voice would then be received on

1441-450: A key advantage of digital signals over analogue signals. However, digital systems fail catastrophically when noise exceeds the system's ability to autocorrect. On the other hand, analogue systems fail gracefully: as noise increases, the signal becomes progressively more degraded but still usable. Also, digital transmission of continuous data unavoidably adds quantization noise to the output. This can be reduced, but not eliminated, only at

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1572-404: A larger network and attracting more consumers to use the new technology, further enhancing network effects. Other benefits of standardization to consumers are reduced uncertainty, because consumers can be more certain that they are not choosing the wrong product, and reduced lock-in, because the standard makes it more likely that there will be competing products in the space. Consumers may also get

1703-441: A measuring instrument or procedure is similar to every subjects or patients. For example, educational psychologist may adopt structured interview to systematically interview the people in concern. By delivering the same procedures, all subjects is evaluated using same criteria and minimising any confounding variable that reduce the validity . Some other example includes mental status examination and personality test . In

1834-501: A merger of two predecessor organizations (Bern and Paris treaties) that had similar objectives, but in more limited territories. With the advent of radiocommunication soon after the creation, the work of the ITU quickly expanded from the standardization of Telegraph communications, to developing standards for telecommunications in general. By the mid to late 19th century, efforts were being made to standardize electrical measurement. Lord Kelvin

1965-448: A metal fastening on the other side were usually fastened in non-threaded ways (such as clinching or upsetting against a washer). Maudslay standardized the screw threads used in his workshop and produced sets of taps and dies that would make nuts and bolts consistently to those standards, so that any bolt of the appropriate size would fit any nut of the same size. This was a major advance in workshop technology. Maudslay's work, as well as

2096-746: A new international frequency list and used in conformity with the Radio Regulation". According to the ITU's Radio Regulations adopted in Atlantic City, all frequencies referenced in the International Frequency Registration Board , examined by the board and registered on the International Frequency List "shall have the right to international protection from harmful interference". From a global perspective, there have been political debates and legislation regarding

2227-443: A normalization of formerly custom processes. In social sciences , including economics , the idea of standardization is close to the solution for a coordination problem , a situation in which all parties can realize mutual gains, but only by making mutually consistent decisions. Divergent national standards impose costs on consumers and can be a form of non-tariff trade barrier . Standard weights and measures were developed by

2358-437: A person's age, interests, sexual preference and relationship status. In this way, these sites can play important role in everything from organising social engagements to courtship . Prior to social networking sites, technologies like short message service (SMS) and the telephone also had a significant impact on social interactions. In 2000, market research group Ipsos MORI reported that 81% of 15- to 24-year-old SMS users in

2489-640: A provisioned subscription of a user to an application. They are stored in the HSS as part of the IMS Subscription Profile and are downloaded to the S-CSCF upon user registration (for registered users) or on processing demand (for services, acting as unregistered users). iFCs are valid throughout the registration lifetime or until the User Profile is changed. The iFC is composed of: There are two types of iFCs: It

2620-491: A radio as the channel "96 FM"). In addition, modulation has the advantage that it may use frequency division multiplexing (FDM). A telecommunications network is a collection of transmitters, receivers, and communications channels that send messages to one another. Some digital communications networks contain one or more routers that work together to transmit information to the correct user. An analogue communications network consists of one or more switches that establish

2751-1012: A regional level (e.g. Europa, the Americas, Africa, etc) or at subregional level (e.g. Mercosur, Andean Community, South East Asia, South East Africa, etc), several Regional Standardization Organizations exist (see also Standards Organization ). The three regional standards organizations in Europe – European Standardization Organizations (ESOs), recognised by the EU Regulation on Standardization (Regulation (EU) 1025/2012) – are CEN , CENELEC and ETSI . CEN develops standards for numerous kinds of products, materials, services and processes. Some sectors covered by CEN include transport equipment and services, chemicals, construction, consumer products, defence and security, energy, food and feed, health and safety, healthcare, digital sector, machinery or services. The European Committee for Electrotechnical Standardization (CENELEC)

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2882-507: A scientific basis, the robustness and applicability of a scientific basis, whether adoption of the certifications is voluntary, and the socioeconomic context (systems of governance and the economy ), with possibly most certifications being so far mostly largely ineffective. Moreover, standardized scientific frameworks can enable evaluation of levels of environmental protection, such as of marine protected areas , and serve as, potentially evolving, guides for improving, planning and monitoring

3013-469: A service that operated for a year until the gap in the telegraph link was closed. In the Middle Ages, chains of beacons were commonly used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could only pass a single bit of information, so the meaning of the message such as "the enemy has been sighted" had to be agreed upon in advance. One notable instance of their use

3144-503: A set of IMPU grouped together. The HSS subscriber database contains the IMPU, IMPI, IMSI , MSISDN , subscriber service profiles, service triggers, and other information. Several roles of SIP servers or proxies, collectively called Call Session Control Function (CSCF), are used to process SIP signaling packets in the IMS. SIP Application servers (AS) host and execute services , and interface with

3275-442: A single medium to transmit several concurrent communication sessions . Several methods of long-distance communication before the modern era used sounds like coded drumbeats , the blowing of horns , and whistles . Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the telegraph , telephone , television , and radio . Early telecommunication networks used metal wires as

3406-411: A telephone network, the caller is connected to the person to whom they wish to talk by switches at various telephone exchanges . The switches form an electrical connection between the two users and the setting of these switches is determined electronically when the caller dials the number. Once the connection is made, the caller's voice is transformed to an electrical signal using a small microphone in

3537-520: A variety of benefits and drawbacks for firms and consumers participating in the market, and on technology and innovation. The primary effect of standardization on firms is that the basis of competition is shifted from integrated systems to individual components within the system. Prior to standardization a company's product must span the entire system because individual components from different competitors are incompatible, but after standardization each company can focus on providing an individual component of

3668-412: A version of the electrical telegraph that he unsuccessfully demonstrated on September 2, 1837. His code was an important advance over Wheatstone's signaling method. The first transatlantic telegraph cable was successfully completed on July 27, 1866, allowing transatlantic telecommunication for the first time. The conventional telephone was patented by Alexander Bell in 1876. Elisha Gray also filed

3799-489: Is a Canadian Crown Corporation , DGN is a governmental agency within the Mexican Ministry of Economy, and ANSI and AENOR are a 501(c)(3) non-profit organization with members from both the private and public sectors. The determinants of whether an NSB for a particular economy is a public or private sector body may include the historical and traditional roles that the private sector fills in public affairs in that economy or

3930-592: Is a SIP proxy which processes requests for routing from an S-CSCF when the S-CSCF has determined that the session cannot be routed using DNS or ENUM/DNS. It includes routing functionality based on telephone numbers. A PSTN/CS gateway interfaces with PSTN circuit switched (CS) networks. For signalling, CS networks use ISDN User Part (ISUP) (or BICC ) over Message Transfer Part (MTP), while IMS uses SIP over IP. For media, CS networks use Pulse-code modulation (PCM), while IMS uses Real-time Transport Protocol (RTP). Media Resources are those components that operate on

4061-471: Is a collection of different functions, linked by standardized interfaces, which grouped form one IMS administrative network. A function is not a node (hardware box): An implementer is free to combine two functions in one node, or to split a single function into two or more nodes. Each node can also be present multiple times in a single network, for dimensioning, load balancing or organizational issues. The user can connect to IMS in various ways, most of which use

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4192-487: Is a master user database that supports the IMS network entities that actually handle calls . It contains the subscription-related information (subscriber profiles ), performs authentication and authorization of the user, and can provide information about the subscriber's location and IP information. It is similar to the GSM home location register (HLR) and Authentication centre (AuC). A subscriber location function (SLF)

4323-477: Is a unique permanently allocated global identity assigned by the home network operator. It has the form of a Network Access Identifier(NAI) i.e. user.name@domain, and is used, for example, for Registration, Authorization, Administration, and Accounting purposes. Every IMS user shall have one IMPI. IP Multimedia Public Identity: The IP Multimedia Public Identity (IMPU) is used by any user for requesting communications to other users (e.g. this might be included on

4454-577: Is adapted from the French, because its written use was recorded in 1904 by the French engineer and novelist Édouard Estaunié . Communication was first used as an English word in the late 14th century. It comes from Old French comunicacion (14c., Modern French communication), from Latin communicationem (nominative communication), noun of action from past participle stem of communicare, "to share, divide out; communicate, impart, inform; join, unite, participate in," literally, "to make common", from communis". At

4585-671: Is called point-to-point communication because it occurs between a transmitter and a receiver. Telecommunication through radio broadcasts is called broadcast communication because it occurs between a powerful transmitter and numerous low-power but sensitive radio receivers. Telecommunications in which multiple transmitters and multiple receivers have been designed to cooperate and share the same physical channel are called multiplex systems . The sharing of physical channels using multiplexing often results in significant cost reduction. Multiplexed systems are laid out in telecommunication networks and multiplexed signals are switched at nodes through to

4716-451: Is called (in the jargon of the field) " quadrature amplitude modulation " (QAM) that are used in high-capacity digital radio communication systems. Modulation can also be used to transmit the information of low-frequency analogue signals at higher frequencies. This is helpful because low-frequency analogue signals cannot be effectively transmitted over free space. Hence the information from a low-frequency analogue signal must be impressed into

4847-434: Is commonly called "keying" —a term derived from the older use of Morse Code in telecommunications—and several keying techniques exist (these include phase-shift keying , frequency-shift keying , and amplitude-shift keying ). The " Bluetooth " system, for example, uses phase-shift keying to exchange information between various devices. In addition, there are combinations of phase-shift keying and amplitude-shift keying which

4978-794: Is converted from electricity to sound. Telecommunication systems are occasionally "duplex" (two-way systems) with a single box of electronics working as both the transmitter and a receiver, or a transceiver (e.g., a mobile phone ). The transmission electronics and the receiver electronics within a transceiver are quite independent of one another. This can be explained by the fact that radio transmitters contain power amplifiers that operate with electrical powers measured in watts or kilowatts, but radio receivers deal with radio powers measured in microwatts or nanowatts . Hence, transceivers have to be carefully designed and built to isolate their high-power circuitry and their low-power circuitry from each other to avoid interference. Telecommunication over fixed lines

5109-481: Is degraded by undesirable noise . Commonly, the noise in a communication system can be expressed as adding or subtracting from the desirable signal via a random process . This form of noise is called additive noise , with the understanding that the noise can be negative or positive at different instances. Unless the additive noise disturbance exceeds a certain threshold, the information contained in digital signals will remain intact. Their resistance to noise represents

5240-492: Is envisaged that security defined in TS 33.203 may not be available for a while especially because of the lack of USIM / ISIM interfaces and prevalence of devices that support IPv4 . For this situation, to provide some protection against the most significant threats, 3GPP defines some security mechanisms, which are informally known as "early IMS security," in TR33.978. This mechanism relies on

5371-464: Is further divided into a media resource function controller (MRFC) and a media resource function processor (MRFP). The Media Resource Broker (MRB) is a functional entity that is responsible for both collection of appropriate published MRF information and supplying of appropriate MRF information to consuming entities such as the AS. MRB can be used in two modes: A Breakout Gateway Control Function (BGCF)

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5502-697: Is likely the sole member from that economy in ISO. NSBs may be either public or private sector organizations, or combinations of the two. For example, the three NSBs of Canada, Mexico and the United States are respectively the Standards Council of Canada ( SCC ), the General Bureau of Standards ( Dirección General de Normas , DGN), and the American National Standards Institute (ANSI). SCC

5633-619: Is needed to map user addresses when multiple HSSs are used. User identities: Various identities may be associated with IMS: IP multimedia private identity (IMPI), IP multimedia public identity (IMPU), globally routable user agent URI (GRUU), wildcarded public user identity. Both IMPI and IMPU are not phone numbers or other series of digits, but uniform resource identifier (URIs), that can be digits (a Tel URI, such as tel:+1-555-123-4567 ) or alphanumeric identifiers (a SIP URI, such as sip:john.doe@example.com " ). IP Multimedia Private Identity: The IP Multimedia Private Identity (IMPI)

5764-573: Is not limited to the domain of electronic devices like smartphones and phone chargers but could also be applied to e.g. the energy infrastructure. Policy-makers could develop policies "fostering standard design and interfaces, and promoting the re-use of modules and components across plants to develop more sustainable energy infrastructure ". Computers and the Internet are some of the tools that could be used to increase practicability and reduce suboptimal results, detrimental standards and bureaucracy , which

5895-666: Is often associated with traditional processes and results of standardization. Taxes and subsidies, and funding of research and development could be used complementarily. Standardized measurement is used in monitoring, reporting and verification frameworks of environmental impacts, usually of companies, for example to prevent underreporting of greenhouse gas emissions by firms. In routine product testing and product analysis results can be reported using official or informal standards. It can be done to increase consumer protection , to ensure safety or healthiness or efficiency or performance or sustainability of products. It can be carried out by

6026-492: Is operator's implementation. RCS also further added Presence/EAB (enhanced address book) functionality. Some operators opposed IMS because it was seen as complex and expensive. In response, a cut-down version of IMS—enough of IMS to support voice and SMS over the LTE network—was defined and standardized in 2010 as Voice over LTE (VoLTE). Each of the functions in the diagram is explained below. The IP multimedia core network subsystem

6157-609: Is self-evident in the case of online retailer Amazon.com but, according to academic Edward Lenert, even the conventional retailer Walmart has benefited from better telecommunication infrastructure compared to its competitors. In cities throughout the world, home owners use their telephones to order and arrange a variety of home services ranging from pizza deliveries to electricians. Even relatively poor communities have been noted to use telecommunication to their advantage. In Bangladesh 's Narsingdi District , isolated villagers use cellular phones to speak directly to wholesalers and arrange

6288-448: Is separated from its adjacent stations by 200 kHz, and the difference between 200 kHz and 180 kHz (20 kHz) is an engineering allowance for the imperfections in the communication system. In the example above, the "free space channel" has been divided into communications channels according to frequencies , and each channel is assigned a separate frequency bandwidth in which to broadcast radio waves. This system of dividing

6419-669: Is the European Standardization organization developing standards in the electrotechnical area and corresponding to the International Electrotechnical Commission (IEC) in Europe. The first modern International Organization ( Intergovernmental Organization ) the International Telegraph Union (now International Telecommunication Union ) was created in 1865 to set international standards in order to connect national telegraph networks, as

6550-449: Is the informational equivalent of two newspaper pages per person per day in 1986, and six entire newspapers per person per day by 2007. Given this growth, telecommunications play an increasingly important role in the world economy and the global telecommunications industry was about a $ 4.7 trillion sector in 2012. The service revenue of the global telecommunications industry was estimated to be $ 1.5 trillion in 2010, corresponding to 2.4% of

6681-569: Is the transmission of information with an immediacy comparable to face-to-face communication. As such, slow communications technologies like postal mail and pneumatic tubes are excluded from the definition. Many transmission media have been used for telecommunications throughout history, from smoke signals , beacons , semaphore telegraphs , signal flags , and optical heliographs to wires and empty space made to carry electromagnetic signals. These paths of transmission may be divided into communication channels for multiplexing , allowing for

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6812-570: The Indus Valley civilization . The centralized weight and measure system served the commercial interest of Indus merchants as smaller weight measures were used to measure luxury goods while larger weights were employed for buying bulkier items, such as food grains etc. Weights existed in multiples of a standard weight and in categories. Technical standardisation enabled gauging devices to be effectively used in angular measurement and measurement for construction. Uniform units of length were used in

6943-756: The Nipkow disk by Paul Nipkow and thus became known as the mechanical television . It formed the basis of experimental broadcasts done by the British Broadcasting Corporation beginning on 30 September 1929. However, for most of the 20th century, televisions depended on the cathode ray tube invented by Karl Ferdinand Braun . The first version of such a television to show promise was produced by Philo Farnsworth and demonstrated to his family on 7 September 1927. After World War II, interrupted experiments resumed and television became an important home entertainment broadcast medium. The type of device known as

7074-550: The Session Initiation Protocol (SIP). According to the 3GPP, IMS is not intended to standardize applications, but rather to aid the access of multimedia and voice applications from wireless and wireline terminals, i.e., to create a form of fixed-mobile convergence (FMC). This is done by having a horizontal control layer that isolates the access network from the service layer . From a logical architecture perspective, services need not have their own control functions, as

7205-440: The spark gap transmitter for radio or mechanical computers for computing, it was the invention of the thermionic vacuum tube that made these technologies widespread and practical, leading to the creation of electronics . In the 1940s, the invention of semiconductor devices made it possible to produce solid-state devices, which are smaller, cheaper, and more efficient, reliable, and durable than thermionic tubes. Starting in

7336-543: The standard unit of electric current . R. E. B. Crompton became concerned by the large range of different standards and systems used by electrical engineering companies and scientists in the early 20th century. Many companies had entered the market in the 1890s and all chose their own settings for voltage , frequency , current and even the symbols used on circuit diagrams. Adjacent buildings would have totally incompatible electrical systems simply because they had been fitted out by different companies. Crompton could see

7467-671: The 1932 Plenipotentiary Telegraph Conference and the International Radiotelegraph Conference in Madrid, the two organizations merged to form the International Telecommunication Union (ITU). They defined telecommunication as "any telegraphic or telephonic communication of signs, signals, writing, facsimiles and sounds of any kind, by wire, wireless or other systems or processes of electric signaling or visual signaling (semaphores)." The definition

7598-492: The 1970s. In the 1960s, Paul Baran and, independently, Donald Davies started to investigate packet switching , a technology that sends a message in portions to its destination asynchronously without passing it through a centralized mainframe . A four-node network emerged on 5 December 1969, constituting the beginnings of the ARPANET , which by 1981 had grown to 213 nodes . ARPANET eventually merged with other networks to form

7729-553: The Diameter Sh or Si interfaces (for a SIP-AS). The AS-ILCM (Application Server - Incoming Leg Control Model) and AS-OLCM (Application Server - Outgoing Leg Control Model) store transaction state, and may optionally store session state depending on the specific service being executed. The AS-ILCM interfaces to the S-CSCF (ILCM) for an incoming leg and the AS-OLCM interfaces to the S-CSCF (OLCM) for an outgoing leg. Application Logic provides

7860-569: The Digest-MD5 is a valid authentication option. Later on, TISPAN also did a similar effort given their fixed networks scopes, although the procedures are different. To compensate for the lack of IPsec capabilities, TLS has been added as an option for securing the Gm interface. Later 3GPP Releases have included the Digest-MD5 method, towards a Common-IMS platform, yet in its own and again different approach. Although all 3 variants of Digest-MD5 authentication have

7991-461: The ITU was able to compile an index that measures the overall ability of citizens to access and use information and communication technologies. Using this measure, Sweden, Denmark and Iceland received the highest ranking while the African countries Niger , Burkina Faso and Mali received the lowest. Telecommunication has played a significant role in social relationships. Nevertheless, devices like

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8122-675: The Internet. While Internet development was a focus of the Internet Engineering Task Force (IETF) who published a series of Request for Comments documents, other networking advancements occurred in industrial laboratories , such as the local area network (LAN) developments of Ethernet (1983), Token Ring (1984) and Star network topology. The effective capacity to exchange information worldwide through two-way telecommunication networks grew from 281 petabytes (PB) of optimally compressed information in 1986 to 471 PB in 1993 to 2.2 exabytes (EB) in 2000 to 65 EB in 2007. This

8253-636: The National Standardizing Associations (ISA) was founded in 1926 with a broader remit to enhance international cooperation for all technical standards and specifications. The body was suspended in 1942 during World War II . After the war, ISA was approached by the recently formed United Nations Standards Coordinating Committee (UNSCC) with a proposal to form a new global standards body. In October 1946, ISA and UNSCC delegates from 25 countries met in London and agreed to join forces to create

8384-660: The Organization for the Advancement of Structured Information Standards ( OASIS ). There are many specifications that govern the operation and interaction of devices and software on the Internet , which do not use the term "standard" in their names. The W3C , for example, publishes "Recommendations", and the IETF publishes " Requests for Comments " (RFCs). Nevertheless, these publications are often referred to as "standards", because they are

8515-493: The S-CSCF using SIP. An example of an application server that is being developed in 3GPP is the Voice call continuity Function (VCC Server). Depending on the actual service, the AS can operate in SIP proxy mode, SIP UA ( user agent ) mode or SIP B2BUA mode. An AS can be located in the home network or in an external third-party network. If located in the home network, it can query the HSS with

8646-445: The S-CSCF. The S-CSCF might apply filter criteria to determine the need to forward SIP requests to AS. It is important to note that services for the originating party will be applied in the originating network, while the services for the terminating party will be applied in the terminating network, all in the respective S-CSCFs. An initial filter criteria (iFC) is an XML -based format used for describing control logic. iFCs represent

8777-499: The United Kingdom had used the service to coordinate social arrangements and 42% to flirt. In cultural terms, telecommunication has increased the public's ability to access music and film. With television, people can watch films they have not seen before in their own home without having to travel to the video store or cinema. With radio and the Internet, people can listen to music they have not heard before without having to travel to

8908-692: The United States was spent on media that depend upon telecommunication. Many countries have enacted legislation which conforms to the International Telecommunication Regulations established by the International Telecommunication Union (ITU), which is the "leading UN agency for information and communication technology issues". In 1947, at the Atlantic City Conference, the ITU decided to "afford international protection to all frequencies registered in

9039-462: The authentication performed during the network attachment procedures, which binds between the user's profile and its IP address. This mechanism is also weak because the signaling is not protected on the user–network interface . CableLabs in PacketCable 2.0 , which adopted also the IMS architecture but has no USIM/ISIM capabilities in their terminals, published deltas to the 3GPP specifications where

9170-437: The benefit of being able to mix and match components of a system to align with their specific preferences. Once these initial benefits of standardization are realized, further benefits that accrue to consumers as a result of using the standard are driven mostly by the quality of the technologies underlying that standard. Telecommunication Telecommunication , often used in its plural form or abbreviated as telecom ,

9301-479: The context of customer service , standardization refers to the process of developing an international standard that enables organizations to focus on customer service, while at the same time providing recognition of success through a third party organization, such as the British Standards Institution . An international standard has been developed by The International Customer Service Institute . In

9432-635: The context of supply chain management and materials management , standardization covers the process of specification and use of any item the company must buy in or make, allowable substitutions, and build or buy decisions. The process of standardization can itself be standardized. There are at least four levels of standardization: compatibility, interchangeability , commonality and reference . These standardization processes create compatibility, similarity, measurement, and symbol standards. There are typically four different techniques for standardization Types of standardization process: Standardization has

9563-648: The context of information exchange, standardization refers to the process of developing standards for specific business processes using specific formal languages . These standards are usually developed in voluntary consensus standards bodies such as the United Nations Center for Trade Facilitation and Electronic Business ( UN/CEFACT ), the World Wide Web Consortium ( W3C ), the Telecommunications Industry Association (TIA), and

9694-550: The context of social criticism and social science , standardization often means the process of establishing standards of various kinds and improving efficiency to handle people, their interactions, cases, and so forth. Examples include formalization of judicial procedure in court, and establishing uniform criteria for diagnosing mental disease. Standardization in this sense is often discussed along with (or synonymously to) such large-scale social changes as modernization, bureaucratization, homogenization, and centralization of society. In

9825-515: The contributions of other engineers, accomplished a modest amount of industry standardization; some companies' in-house standards spread a bit within their industries. Joseph Whitworth 's screw thread measurements were adopted as the first (unofficial) national standard by companies around the country in 1841. It came to be known as the British Standard Whitworth , and was widely adopted in other countries. This new standard specified

9956-445: The control layer is a common horizontal layer. However, in implementation this does not necessarily map into greater reduced cost and complexity. Alternative and overlapping technologies for access and provisioning of services across wired and wireless networks include combinations of Generic Access Network , softswitches and "naked" SIP. Since it is becoming increasingly easier to access content and contacts using mechanisms outside

10087-440: The control of traditional wireless/fixed operators, the interest of IMS is being challenged. Examples of global standards based on IMS are MMTel which is the basis for Voice over LTE ( VoLTE ), Wi-Fi Calling (VoWIFI), Video over LTE (ViLTE), SMS/MMS over WiFi and LTE, Unstructured Supplementary Service Data (USSD) over LTE, and Rich Communication Services (RCS), which is also known as joyn or Advanced Messaging, and now RCS

10218-437: The correct destination terminal receiver. Communications can be encoded as analogue or digital signals , which may in turn be carried by analogue or digital communication systems. Analogue signals vary continuously with respect to the information, while digital signals encode information as a set of discrete values (e.g., a set of ones and zeroes). During propagation and reception, information contained in analogue signals

10349-689: The country, and enabled the markets to act more rationally and efficiently, with an increased level of cooperation. After the First World War , similar national bodies were established in other countries. The Deutsches Institut für Normung was set up in Germany in 1917, followed by its counterparts, the American National Standard Institute and the French Commission Permanente de Standardisation , both in 1918. At

10480-511: The development of optical fibre. The Internet , a technology independent of any given medium, has provided global access to services for individual users and further reduced location and time limitations on communications. Telecommunication is a compound noun of the Greek prefix tele- (τῆλε), meaning distant , far off , or afar , and the Latin verb communicare , meaning to share . Its modern use

10611-420: The development stage of that economy. Standards can be: The existence of a published standard does not necessarily imply that it is useful or correct. Just because an item is stamped with a standard number does not, by itself, indicate that the item is fit for any particular use. The people who use the item or service (engineers, trade unions, etc.) or specify it (building codes, government, industry, etc.) have

10742-537: The device—from the cathode to the anode. Adding one or more control grids within the tube enables the current between the cathode and anode to be controlled by the voltage on the grid or grids. These devices became a key component of electronic circuits for the first half of the 20th century and were crucial to the development of radio, television, radar, sound recording and reproduction , long-distance telephone networks, and analogue and early digital computers . While some applications had used earlier technologies such as

10873-422: The electrical telegraph, the last commercial line was abandoned in 1880. On July 25, 1837, the first commercial electrical telegraph was demonstrated by English inventor Sir William Fothergill Cooke and English scientist Sir Charles Wheatstone . Both inventors viewed their device as "an improvement to the [existing] electromagnetic telegraph" and not as a new device. Samuel Morse independently developed

11004-774: The end of the month). Online charging , also known as credit-based charging, is used for prepaid services, or real-time credit control of postpaid services. Both may be applied to the same session. Charging function addresses are addresses distributed to each IMS entities and provide a common location for each entity to send charging information. charging data function (CDF) addresses are used for offline billing and Online Charging Function (OCF) for online billing. IMS-based PES (PSTN Emulation System) provides IP networks services to analog devices. IMS-based PES allows non-IMS devices to appear to IMS as normal SIP users. Analog terminal using standard analog interfaces can connect to IMS-based PES in two ways: Both A-MGW and VGW are unaware of

11135-403: The expense of increasing the channel bandwidth requirement. The term "channel" has two different meanings. In one meaning, a channel is the physical medium that carries a signal between the transmitter and the receiver. Examples of this include the atmosphere for sound communications, glass optical fibres for some kinds of optical communications , coaxial cables for communications by way of

11266-431: The importance of social conversations and staying connected to family and friends. Since then the role that telecommunications has played in social relations has become increasingly important. In recent years, the popularity of social networking sites has increased dramatically. These sites allow users to communicate with each other as well as post photographs, events and profiles for others to see. The profiles can list

11397-420: The interconnection between two network domains with one or more intermediate network domain(s) acting as transit networks . The intermediate network domain(s) provide(s) transit functionality to the two other network domains. Different interconnection modes may be used for carrying service layer signalling and media traffic. Offline charging is applied to users who pay for their services periodically (e.g., at

11528-471: The international level . Standardization is also used to ensure safe design and operation of laboratories and similar potentially dangerous workplaces, e.g. to ensure biosafety levels . There is research into microbiology safety standards used in clinical and research laboratories. In the context of defense, standardization has been defined by NATO as The development and implementation of concepts, doctrines, procedures and designs to achieve and maintain

11659-606: The lack of efficiency in this system and began to consider proposals for an international standard for electric engineering. In 1904, Crompton represented Britain at the International Electrical Congress , held in connection with Louisiana Purchase Exposition in Saint Louis as part of a delegation by the Institute of Electrical Engineers . He presented a paper on standardisation, which was so well received that he

11790-552: The management of telecommunication and broadcasting. The history of broadcasting discusses some debates in relation to balancing conventional communication such as printing and telecommunication such as radio broadcasting. The onset of World War II brought on the first explosion of international broadcasting propaganda. Countries, their governments, insurgents, terrorists, and militiamen have all used telecommunication and broadcasting techniques to promote propaganda. Patriotic propaganda for political movements and colonization started

11921-645: The manufacturer, an independent laboratory, a government agency, a magazine or others on a voluntary or commissioned/mandated basis. Estimating the environmental impacts of food products in a standardized way – as has been done with a dataset of >57,000 food products in supermarkets – could e.g. be used to inform consumers or in policy . For example, such may be useful for approaches using personal carbon allowances (or similar quota) or for targeted alteration of (ultimate overall) costs . Public information symbols (e.g. hazard symbols ), especially when related to safety, are often standardized, sometimes on

12052-426: The media plane and are under the control of IMS core functions. Specifically, Media Server (MS) and Media gateway (MGW) There are two types of next-generation networking interconnection: An NGN interconnection mode can be direct or indirect. Direct interconnection refers to the interconnection between two network domains without any intermediate network domain. Indirect interconnection at one layer refers to

12183-474: The medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi , who won the 1909 Nobel Prize in Physics . Other early pioneers in electrical and electronic telecommunications include co-inventors of

12314-567: The medium into channels according to frequency is called " frequency-division multiplexing ". Another term for the same concept is " wavelength-division multiplexing ", which is more commonly used in optical communications when multiple transmitters share the same physical medium. Another way of dividing a communications medium into channels is to allocate each sender a recurring segment of time (a "time slot", for example, 20 milliseconds out of each second), and to allow each sender to send messages only within its own time slot. This method of dividing

12445-414: The medium into communication channels is called " time-division multiplexing " ( TDM ), and is used in optical fibre communication. Some radio communication systems use TDM within an allocated FDM channel. Hence, these systems use a hybrid of TDM and FDM. The shaping of a signal to convey information is known as modulation . Modulation can be used to represent a digital message as an analogue waveform. This

12576-727: The mid-1930s. In 1936, the BBC broadcast propaganda to the Arab World to partly counter similar broadcasts from Italy, which also had colonial interests in North Africa. Modern political debates in telecommunication include the reclassification of broadband Internet service as a telecommunications service (also called net neutrality ), regulation of phone spam , and expanding affordable broadband access. According to data collected by Gartner and Ars Technica sales of main consumer's telecommunication equipment worldwide in millions of units was: In

12707-584: The mid-1960s, thermionic tubes were replaced with the transistor . Thermionic tubes still have some applications for certain high-frequency amplifiers. On 11 September 1940, George Stibitz transmitted problems for his Complex Number Calculator in New York using a teletype and received the computed results back at Dartmouth College in New Hampshire . This configuration of a centralized computer ( mainframe ) with remote dumb terminals remained popular well into

12838-452: The music store. Telecommunication has also transformed the way people receive their news. A 2006 survey (right table) of slightly more than 3,000 Americans by the non-profit Pew Internet and American Life Project in the United States the majority specified television or radio over newspapers. Telecommunication has had an equally significant impact on advertising. TNS Media Intelligence reported that in 2007, 58% of advertising expenditure in

12969-400: The neighbourhood of 94.5  MHz (megahertz) while another radio station can simultaneously broadcast radio waves at frequencies in the neighbourhood of 96.1 MHz. Each radio station would transmit radio waves over a frequency bandwidth of about 180  kHz (kilohertz), centred at frequencies such as the above, which are called the "carrier frequencies" . Each station in this example

13100-477: The new International Organization for Standardization (ISO); the new organization officially began operations in February ;1947. In general, each country or economy has a single recognized National Standards Body (NSB). Examples include ABNT , AENOR (now called UNE, Spanish Association for Standardization ) , AFNOR , ANSI , BSI , DGN , DIN , IRAM , JISC , KATS , SABS , SAC , SCC , SIS . An NSB

13231-745: The onset of the Industrial Revolution and the need for high-precision machine tools and interchangeable parts . Henry Maudslay developed the first industrially practical screw-cutting lathe in 1800. This allowed for the standardization of screw thread sizes for the first time and paved the way for the practical application of interchangeability (an idea that was already taking hold) to nuts and bolts . Before this, screw threads were usually made by chipping and filing (that is, with skilled freehand use of chisels and files ). Nuts were rare; metal screws, when made at all, were usually for use in wood. Metal bolts passing through wood framing to

13362-656: The planning of towns such as Lothal , Surkotada , Kalibangan , Dolavira , Harappa , and Mohenjo-daro . The weights and measures of the Indus civilization also reached Persia and Central Asia , where they were further modified. Shigeo Iwata describes the excavated weights unearthed from the Indus civilization: A total of 558 weights were excavated from Mohenjodaro, Harappa, and Chanhu-daro , not including defective weights. They did not find statistically significant differences between weights that were excavated from five different layers, each measuring about 1.5 m in depth. This

13493-515: The presence or absence of an atmosphere between the two. Radio waves travel through a perfect vacuum just as easily as they travel through air, fog, clouds, or any other kind of gas. The other meaning of the term "channel" in telecommunications is seen in the phrase communications channel , which is a subdivision of a transmission medium so that it can be used to send multiple streams of information simultaneously. For example, one radio station can broadcast radio waves into free space at frequencies in

13624-497: The products of regular standardization processes. Standardized product certifications such as of organic food , buildings or possibly sustainable seafood as well as standardized product safety evaluation and dis/approval procedures (e.g. regulation of chemicals , cosmetics and food safety ) can protect the environment. This effect may depend on associated modified consumer choices , strategic product support/obstruction, requirements and bans as well as their accordance with

13755-457: The protection-quality, -scopes and -extents. Moreover, technical standards could decrease electronic waste and reduce resource-needs such as by thereby requiring (or enabling) products to be interoperable , compatible (with other products, infrastructures, environments, etc), durable , energy-efficient , modular , upgradeable / repairable and recyclable and conform to versatile, optimal standards and protocols. Such standardization

13886-709: The relationship as causal. Because of the economic benefits of good telecommunication infrastructure, there is increasing worry about the inequitable access to telecommunication services amongst various countries of the world—this is known as the digital divide . A 2003 survey by the International Telecommunication Union (ITU) revealed that roughly a third of countries have fewer than one mobile subscription for every 20 people and one-third of countries have fewer than one land-line telephone subscription for every 20 people. In terms of Internet access, roughly half of all countries have fewer than one out of 20 people with Internet access. From this information, as well as educational data,

14017-627: The required levels of compatibility , interchangeability or commonality in the operational, procedural, material, technical and administrative fields to attain interoperability. In some cases, standards are being used in the design and operation of workplaces and products that can impact consumers' health. Some of such standards seek to ensure occupational safety and health and ergonomics . For example, chairs (see e.g. active sitting and steps of research ) could be potentially be designed and chosen using standards that may or may not be based on adequate scientific data. Standards could reduce

14148-591: The responsibility to consider the available standards, specify the correct one, enforce compliance, and use the item correctly: validation and verification . To avoid the proliferation of industry standards, also referred to as private standards , regulators in the United States are instructed by their government offices to adopt "voluntary consensus standards" before relying upon "industry standards" or developing "government standards". Regulatory authorities can reference voluntary consensus standards to translate internationally accepted criteria into public policy . In

14279-648: The same functionality and are the same from the IMS terminal's perspective, the implementations on the Cx interface between the S-CSCF and the HSS are different. Standardization Standardization ( American English ) or standardisation ( British English ) 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 can help maximize compatibility , interoperability , safety , repeatability , or quality . It can also facilitate

14410-546: The service(s) and interacts between the AS-ILCM and AS-OLCM. Public Service Identities (PSI) are identities that identify services, which are hosted by application servers. As user identities, PSI takes the form of either a SIP or Tel URI. PSIs are stored in the HSS either as a distinct PSI or as a wildcarded PSI: The Media Resource Function (MRF) provides media related functions such as media manipulation (e.g. voice stream mixing) and playing of tones and announcements. Each MRF

14541-500: The services. They only relay call control signalling to and from the PSTN terminal. Session control and handling is done by IMS components. Replacement for the Gq reference point. One of the most important features of IMS, that of allowing for a SIP application to be dynamically and differentially (based on the user's profile) triggered, is implemented as a filter-and-redirect signalling mechanism in

14672-587: The size and weight of a girder to employ for given work." The Engineering Standards Committee was established in London in 1901 as the world's first national standards body. It subsequently extended its standardization work and became the British Engineering Standards Association in 1918, adopting the name British Standards Institution in 1931 after receiving its Royal Charter in 1929. The national standards were adopted universally throughout

14803-797: The standard IP. IMS terminals (such as mobile phones , personal digital assistants (PDAs) and computers) can register directly on IMS, even when they are roaming in another network or country (the visited network). The only requirement is that they can use IP and run SIP user agents. Fixed access (e.g., digital subscriber line (DSL), cable modems , Ethernet , FTTx ), mobile access (e.g. 5G NR , LTE , W-CDMA , CDMA2000 , GSM , GPRS ) and wireless access (e.g., WLAN , WiMAX ) are all supported. Other phone systems like plain old telephone service (POTS—the old analogue telephones), H.323 and non IMS-compatible systems, are supported through gateways . HSS – Home subscriber server: The home subscriber server (HSS), or user profile server function (UPSF),

14934-465: The system. When the shift toward competition based on individual components takes place, firms selling tightly integrated systems must quickly shift to a modular approach, supplying other companies with subsystems or components. Standardization has a variety of benefits for consumers, but one of the greatest benefits is enhanced network effects. Standards increase compatibility and interoperability between products, allowing information to be shared within

15065-604: The telegraph Charles Wheatstone and Samuel Morse , numerous inventors and developers of the telephone including Antonio Meucci , Philipp Reis , Elisha Gray and Alexander Graham Bell , inventors of radio Edwin Armstrong and Lee de Forest , as well as inventors of television like Vladimir K. Zworykin , John Logie Baird and Philo Farnsworth . Since the 1960s, the proliferation of digital technologies has meant that voice communications have gradually been supplemented by data. The physical limitations of metallic media prompted

15196-412: The telephone system were originally advertised with an emphasis on the practical dimensions of the device (such as the ability to conduct business or order home services) as opposed to the social dimensions. It was not until the late 1920s and 1930s that the social dimensions of the device became a prominent theme in telephone advertisements. New promotions started appealing to consumers' emotions, stressing

15327-609: The then-newly discovered phenomenon of radio waves , demonstrating, by 1901, that they could be transmitted across the Atlantic Ocean. This was the start of wireless telegraphy by radio. On 17 December 1902, a transmission from the Marconi station in Glace Bay, Nova Scotia, Canada , became the world's first radio message to cross the Atlantic from North America. In 1904, a commercial service

15458-411: The variety of products and lead to convergence on fewer broad designs – which can often be efficiently mass-produced via common shared automated procedures and instruments – or formulations deemed to be the most healthy, most efficient or best compromise between healthiness and other factors. Standardization is sometimes or could also be used to ensure or increase or enable consumer health protection beyond

15589-490: The voltages and electric currents in them, and free space for communications using visible light , infrared waves, ultraviolet light , and radio waves . Coaxial cable types are classified by RG type or "radio guide", terminology derived from World War II. The various RG designations are used to classify the specific signal transmission applications. This last channel is called the "free space channel". The sending of radio waves from one place to another has nothing to do with

15720-439: The wartime purposes of aircraft and land communication, radio navigation, and radar. Development of stereo FM broadcasting of radio began in the 1930s in the United States and the 1940s in the United Kingdom, displacing AM as the dominant commercial standard in the 1970s. On March 25, 1925, John Logie Baird demonstrated the transmission of moving pictures at the London department store Selfridges . Baird's device relied upon

15851-420: The workplace and ergonomics such as standards in food, food production, hygiene products, tab water, cosmetics, drugs/medicine, drink and dietary supplements, especially in cases where there is robust scientific data that suggests detrimental impacts on health (e.g. of ingredients) despite being substitutable and not necessarily of consumer interest. In the context of assessment, standardization may define how

15982-418: The world's gross domestic product (GDP). Modern telecommunication is founded on a series of key concepts that experienced progressive development and refinement in a period of well over a century: Telecommunication technologies may primarily be divided into wired and wireless methods. Overall, a basic telecommunication system consists of three main parts that are always present in some form or another: In

16113-460: Was an important figure in this process, introducing accurate methods and apparatus for measuring electricity. In 1857, he introduced a series of effective instruments, including the quadrant electrometer, which cover the entire field of electrostatic measurement. He invented the current balance , also known as the Kelvin balance or Ampere balance ( SiC ), for the precise specification of the ampere ,

16244-529: Was asked to look into the formation of a commission to oversee the process. By 1906 his work was complete and he drew up a permanent constitution for the International Electrotechnical Commission . The body held its first meeting that year in London, with representatives from 14 countries. In honour of his contribution to electrical standardisation, Lord Kelvin was elected as the body's first President. The International Federation of

16375-483: Was during the Spanish Armada , when a beacon chain relayed a signal from Plymouth to London . In 1792, Claude Chappe , a French engineer, built the first fixed visual telegraphy system (or semaphore line ) between Lille and Paris. However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres (six to nineteen miles). As a result of competition from

16506-407: Was established to transmit nightly news summaries to subscribing ships, which incorporated them into their onboard newspapers. World War I accelerated the development of radio for military communications . After the war, commercial radio AM broadcasting began in the 1920s and became an important mass medium for entertainment and news. World War II again accelerated the development of radio for

16637-405: Was evidence that strong control existed for at least a 500-year period. The 13.7-g weight seems to be one of the units used in the Indus valley. The notation was based on the binary and decimal systems. 83% of the weights which were excavated from the above three cities were cubic, and 68% were made of chert . The implementation of standards in industry and commerce became highly important with

16768-462: Was later reconfirmed, according to Article 1.3 of the ITU Radio Regulations , which defined it as "Any transmission , emission or reception of signs, signals, writings, images and sounds or intelligence of any nature by wire , radio, optical, or other electromagnetic systems". Homing pigeons have been used throughout history by different cultures. Pigeon post had Persian roots and

16899-657: Was later used by the Romans to aid their military. Frontinus claimed Julius Caesar used pigeons as messengers in his conquest of Gaul . The Greeks also conveyed the names of the victors at the Olympic Games to various cities using homing pigeons. In the early 19th century, the Dutch government used the system in Java and Sumatra . And in 1849, Paul Julius Reuter started a pigeon service to fly stock prices between Aachen and Brussels ,

17030-476: Was of little practical value because it relied on the electrophonic effect requiring users to place the receiver in their mouths to "hear". The first commercial telephone services were set up by the Bell Telephone Company in 1878 and 1879 on both sides of the Atlantic in the cities of New Haven and London. In 1894, Italian inventor Guglielmo Marconi began developing a wireless communication using

17161-927: Was originally based on almost the same imperial fractions. The Unified thread angle is 60° and has flattened crests (Whitworth crests are rounded). Thread pitch is the same in both systems except that the thread pitch for the 1 ⁄ 2  in. (inch) bolt is 12 threads per inch (tpi) in BSW versus 13 tpi in the UNC. By the end of the 19th century, differences in standards between companies were making trade increasingly difficult and strained. For instance, an iron and steel dealer recorded his displeasure in The Times : "Architects and engineers generally specify such unnecessarily diverse types of sectional material or given work that anything like economical and continuous manufacture becomes impossible. In this country no two professional men are agreed upon

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