GSM is a standard developed by the European Telecommunications Standards Institute to describe the protocols for second-generation digital cellular networks used by mobile devices such as mobile phones and tablets. It was first deployed in Finland in December 1991; as of 2014, it has become the global standard for mobile communications – with over 90% market share, operating in over 193 countries and territories.2G networks developed as a replacement for first generation analog cellular networks, the GSM standard 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 by packet data transport via GPRS and EDGE. Subsequently, the 3GPP developed third-generation UMTS standards, followed by fourth-generation LTE Advanced standards, which do not form part of the ETSI GSM standard. "GSM" is a trademark owned by the GSM Association. It may refer to the most common voice codec used, Full Rate.
In 1983, work began to develop a European standard for digital cellular voice telecommunications when the European Conference of Postal and Telecommunications Administrations set up the Groupe Spécial Mobile committee and provided a permanent technical-support group based in Paris. Five years in 1987, 15 representatives from 13 European countries signed a memorandum of understanding in Copenhagen to develop and deploy a common cellular telephone system across Europe, EU rules were passed to make GSM a mandatory standard; the decision to develop a continental standard resulted in a unified, standard-based network, larger than that in the United States. In February 1987 Europe produced the first agreed GSM Technical Specification. Ministers from 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 had been brought behind GSM in a rare unity and speed guided by four public officials: Armin Silberhorn, Stephen Temple, Philippe Dupuis, Renzo Failli. In 1989 the Groupe Spécial Mobile committee was transferred from CEPT to the European Telecommunications Standards Institute. 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; the former Finnish prime minister Harri Holkeri made the world's first GSM call on July 1, 1991, calling Kaarina Suonio using a network built by Telenokia and Siemens and operated by Radiolinja. The following year saw the sending of the first short messaging service message, 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 the UK by 1993, called and DCS 1800.
That year, Telecom Australia 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 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 GPRS services were launched and the first GPRS-compatible handsets became available for sale. In 2001, the first UMTS network was launched, a 3G technology, not part of GSM. Worldwide GSM subscribers exceeded 500 million. In 2002, the first Multimedia Messaging Service was introduced and the first GSM network in the 800 MHz frequency band became operational. EDGE services first became operational in a network in 2003, 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, the first HSDPA-capable network became operational; the first HSUPA network launched in 2007. Worldwide GSM subscribers exceeded three billion in 2008; the GSM Association estimated in 2010 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 the most ubiquitous of the many standards for cellular networks. GSM is a second-generation standard employing time-division multiple-Access spectrum-sharing, issued by the European Telecommunications Standards Institute; the GSM standard does not include the 3G Universal Mobile Telecommunications System code division multiple access technology nor the 4G LTE orthogonal frequency-division multiple access technology standards issued by the 3GPP. GSM, for the first time, set a common standard for Europe for wireless networks.
It was adopted by many countries outside Europe. This allowed subscribers to use other GSM networks; the common standard reduced research and development costs, since ha
The next-generation network is a body of key architectural changes in telecommunication core and access networks. The general idea behind the NGN is that one network transports all information and services by encapsulating these into IP packets, similar to those used on the Internet. NGNs are built around the Internet Protocol, therefore the term all IP is sometimes used to describe the transformation of telephone-centric networks toward NGN. NGN is a different concept from Future Internet, more focused on the evolution of Internet in terms of the variety and interactions of services offered. According to ITU-T, the definition is: A next-generation network is a packet-based network which can provide services including Telecommunication Services and is able to make use of multiple broadband, quality of Service-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies, it offers unrestricted access by users to different service providers.
It supports generalized mobility which will allow consistent and ubiquitous provision of services to users. From a practical perspective, NGN involves three main architectural changes that need to be looked at separately: In the core network, NGN implies a consolidation of several transport networks each built for a different service into one core transport network, it implies amongst others the migration of voice from a circuit-switched architecture to VoIP, migration of legacy services such as X.25, frame relay. In the wired access network, NGN implies the migration from the dual system of legacy voice next to xDSL setup in local exchanges to a converged setup in which the DSLAMs integrate voice ports or VoIP, making it possible to remove the voice switching infrastructure from the exchange. In the cable access network, NGN convergence implies migration of constant bit rate voice to CableLabs PacketCable standards that provide VoIP and SIP services. Both services ride over DOCSIS as the cable data layer standard.
In an NGN, there is a more defined separation between the transport portion of the network and the services that run on top of that transport. This means that whenever a provider wants to enable a new service, they can do so by defining it directly at the service layer without considering the transport layer – i.e. services are independent of transport details. Applications, including voice, tend to be independent of the access network and will reside more on end-user devices. Next-generation networks are based on Internet technologies including Internet Protocol and multiprotocol label switching. At the application level, Session Initiation Protocol seems to be taking over from ITU-T H.323. H.323 was the most popular protocol, though its popularity decreased in the "local loop" due to its original poor traversal of network address translation and firewalls. For this reason as domestic VoIP services have been developed, SIP has been more adopted. However, in voice networks where everything is under the control of the network operator or telco, many of the largest carriers use H.323 as the protocol of choice in their core backbones.
With the most recent changes introduced for H.323, it is now possible for H.323 devices to and traverse NAT and firewall devices, opening up the possibility that H.323 may again be looked upon more favorably in cases where such devices encumbered its use previously. Nonetheless, most of the telcos are extensively researching and supporting IP Multimedia Subsystem, which gives SIP a major chance of being the most adopted protocol. For voice applications one of the most important devices in NGN is a Softswitch – a programmable device that controls Voice over IP calls, it enables correct integration of different protocols within NGN. The most important function of the Softswitch is creating the interface to the existing telephone network, PSTN, through Signalling Gateways and Media Gateways. However, the Softswitch as a term may be defined differently by the different equipment manufacturers and have somewhat different functions. One may quite find the term Gatekeeper in NGN literature; this was a VoIP device, which converted voice and data from their analog or digital switched-circuit form to the packet-based one.
It controlled one or more gateways. As soon as this kind of device started using the Media Gateway Control Protocol, the name was changed to Media Gateway Controller. A Call Agent is a general name for devices/systems controlling calls; the IP Multimedia Subsystem is a standardised NGN architecture for an Internet media-services capability defined by the European Telecommunications Standards Institute and the 3rd Generation Partnership Project. In the UK another popular acronym was introduced by BT as 21CN — this is another loose term for NGN and denotes BT's initiative to deploy and operate NGN switches and networks in the period 2006–2008; the concept was abandoned, however, in favor of maintaining current-generation equipment. The first company in the UK to roll out a NGN was THUS plc which started deployment back in 1999. THUS' NGN contains 10,600 km of fibre optic cable with more than 190 points of presence t
A voicemail system is a computer-based system that allows users and subscribers to exchange personal voice messages. The term is used more broadly to denote any system of conveying a stored telecommunications voice messages, including using an answering machine. Most cell phone services offer voice-mail as a basic feature; the term Voicemail was coined by Televoice International for their introduction of the first US-wide Voicemail service in 1980. Although VMI trademarked the term, it became a generic term used for referring to all automated voice services employing a telephone. Voicemail popularity continues today with Internet telephone services such as Skype, Google Voice and ATT that integrate voice and text services for tablets and smartphones Voicemail systems were developed in the late 1970s by Voice Message Exchange, they became popular in the early 1980s. In September 2012 a report from USA Today and Vonage claimed; the report said that the number of voicemail messages declined 8 percent compared to 2011.
Voicemail systems are designed to convey a caller's recorded audio message to a recipient. To do so they contain a user interface to select and manage messages. Most systems use phone networks, either cellular- or landline-based, as the conduit for all of these functions; some systems may use multiple telecommunications methods, permitting recipients and callers to retrieve or leave messages through multiple methods such as PCs, PDA, Cellphones or Smartphones. Simple voicemail systems function as a remote answering machine using touch-tones as the user interface. More complicated systems may use other input devices such as a computer interface. Simpler voice-mail systems may play the audio message through the phone, while more advanced systems may have alternative delivery methods, including email or text message delivery, message transfer and forwarding options, multiple mailboxes. All modern voicemail systems use digital storage and are stored on computer data storage. Notification methods vary based on the voice-mail system.
Simple systems may not provide active notification at all, instead requiring the recipient to check with the system, while others may provide an indication that messages are waiting. More advanced systems may be integrated with a company’s PABX, with a call center ACD for automatic call distribution. Interactive Voice Response systems may use digital information stored in a corporate data base to select pre-recorded words and phrases stored in a voice-mail vocabulary to form sentences that are delivered to the caller; the conventional solution to efficient handling of telephone communication in businesses was the "message center." A message center or "message desk" was a centralized, manual answering service inside a company staffed by a few operators who answered all incoming phone calls. Extensions that were busy or rang "no answer" would forward to the message center using a device called a "call director"; the call director had a button for each extension in the company which would flash when that person's extension forwarded to the message center.
A little label next to the button told the operator the person being called. While it was an improvement over basic multi-line systems, the message center had many disadvantages. Many calls would come in at peak periods, such as lunch time, operators were busy; this left message attendants with little time to take each message accurately. They were not familiar with employees' names and "buzzwords" and how to spell or pronounce them. Messages were scribbled on pink slips and distributed by the internal mail system and messages arrived at people's desks after lengthy delays, contained little content other than the caller's name and number, were inaccurate, with misspelled names and wrong phone numbers. Tape-based telephone answering machines had come into the residential telephone market, but they weren't used much in the corporate environment due to physical limitations of the technology. One answering machine was needed for each telephone. Further, the manufacturers of PBXs used proprietary digital phone sets in order to increase the functionality and value of the PBX.
These phone sets were, by design, incompatible with answering machines. In the 1970s and early 1980s, the cost of long distance calling decreased and more business communications were conducted by telephone; as corporations grew and labor rates increased, the ratio of secretaries to employees decreased. With more communication by phone, multiple time zones, fewer secretaries, real-time phone communications were hampered by callers being unable to reach people; some early studies showed that only 1 in 4 phone calls resulted in a completed call and ha
A mobile phone, cell phone, cellphone, or hand phone, sometimes shortened to mobile, cell or just phone, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network. Modern mobile telephone services use a cellular network architecture, therefore, mobile telephones are called cellular telephones or cell phones, in North America. In addition to telephony, 2000s-era mobile phones support a variety of other services, such as text messaging, MMS, Internet access, short-range wireless communications, business applications, video games, digital photography. Mobile phones offering only those capabilities are known as feature phones; the first handheld mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola in 1973, using a handset weighing c. 2 kilograms.
In 1979, Nippon Telegraph and Telephone launched the world's first cellular network in Japan. In 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone. From 1983 to 2014, worldwide mobile phone subscriptions grew to over seven billion—enough to provide one for every person on Earth. In first quarter of 2016, the top smartphone developers worldwide were Samsung and Huawei, smartphone sales represented 78 percent of total mobile phone sales. For feature phones as of 2016, the largest were Samsung and Alcatel. A handheld mobile radio telephone service was envisioned in the early stages of radio engineering. In 1917, Finnish inventor Eric Tigerstedt filed a patent for a "pocket-size folding telephone with a thin carbon microphone". Early predecessors of cellular phones included analog radio communications from trains; the race to create portable telephone devices began after World War II, with developments taking place in many countries. The advances in mobile telephony have been traced in successive "generations", starting with the early zeroth-generation services, such as Bell System's Mobile Telephone Service and its successor, the Improved Mobile Telephone Service.
These 0G systems were not cellular, supported few simultaneous calls, were expensive. The first handheld cellular mobile phone was demonstrated by John F. Mitchell and Martin Cooper of Motorola in 1973, using a handset weighing 2 kilograms; the first commercial automated cellular network analog was launched in Japan by Nippon Telegraph and Telephone in 1979. This was followed in 1981 by the simultaneous launch of the Nordic Mobile Telephone system in Denmark, Finland and Sweden. Several other countries followed in the early to mid-1980s; these first-generation systems could support far more simultaneous calls but still used analog cellular technology. In 1983, the DynaTAC 8000x was the first commercially available handheld mobile phone. In 1991, the second-generation digital cellular technology was launched in Finland by Radiolinja on the GSM standard; this sparked competition in the sector as the new operators challenged the incumbent 1G network operators. Ten years in 2001, the third generation was launched in Japan by NTT DoCoMo on the WCDMA standard.
This was followed by 3.5G, 3G+ or turbo 3G enhancements based on the high-speed packet access family, allowing UMTS networks to have higher data transfer speeds and capacity. By 2009, it had become clear that, at some point, 3G networks would be overwhelmed by the growth of bandwidth-intensive applications, such as streaming media; the industry began looking to data-optimized fourth-generation technologies, with the promise of speed improvements up to ten-fold over existing 3G technologies. The first two commercially available technologies billed as 4G were the WiMAX standard, offered in North America by Sprint, the LTE standard, first offered in Scandinavia by TeliaSonera. 5G is a technology and term used in research papers and projects to denote the next major phase in mobile telecommunication standards beyond the 4G/IMT-Advanced standards. The term 5G is not used in any specification or official document yet made public by telecommunication companies or standardization bodies such as 3GPP, WiMAX Forum or ITU-R.
New standards beyond 4G are being developed by standardization bodies, but they are at this time seen as under the 4G umbrella, not for a new mobile generation. Smartphones have a number of distinguishing features; the International Telecommunication Union measures those with Internet connection, which it calls Active Mobile-Broadband subscriptions. In the developed world, smartphones have now overtaken the usage of earlier mobile systems. However, in the developing world, they account for around 50% of mobile telephony. Feature phone is a term used as a retronym to describe mobile phones which are limited in capabilities in contrast to a modern smartphone. Feature phones provide voice calling and text messaging functionality, in addition to basic multimedia and Internet capabilities, other services offered by the user's wireless service provider. A feature phone has additional functions over and above a basic mobile phone, only capable of voice calling and text messaging. Feature phones and basic mobile phones tend to use a proprietary, custom-designed software and user interface.
By contrast, smartphones use a mobile operating system that shares common traits across devices. There are Orthodox Jewish religious re
Mobile switching centre server
The mobile switching station, abbreviated as MSC Server or MSS, is a 2G core network element which controls the network switching subsystem elements. Alternatively or adaptively, MSS can be used in GSM networks as well, if the manufacturer has implemented support for GSM networks in the MSS. Since an immediate upgrade of existing GSM network to 3G is not viable due to various issues like handset incompatibilities and high expenditure, most manufacturers do implement GSM support in MSS. In fact, MSS along with other 3G network elements such as media gateway, can be configured to support GSM network and can be considered as an upgraded version of existing GSM mobile switching centres; the MSC Server is standards-based and communicates with other distributed elements using industry open standards such as media gateway control protocol, megaco/H.248, session initiation protocol, M2UA and M3UA. The MSC server incorporates industry standards as defined by ETSI, ITU, GSM, 3GPP and 3GPP2 and other leading standard bodies.
The MSS supports the regulatory environment set by governing bodies via its support for E911, CALEA/legal intercept and local number portability, TTY/TTD, Number Pooling requirements. Alternatively MSS is called an MTS-U in Motorola terminology, as MSC-S in Ericsson terminology. MSC server functionality enables split between control plane and user plane, which guarantees better placement of network elements within the network. MSC server and MGW makes it possible to cross-connect circuit switched calls switched by using IP, ATM AAL2 as well as TDM. 3GPP TS 23.205 "3GPP TS 23.205". 3GPP. Retrieved 2007-11-20
The Internet is the global system of interconnected computer networks that use the Internet protocol suite to link devices worldwide. It is a network of networks that consists of private, academic and government networks of local to global scope, linked by a broad array of electronic and optical networking technologies; the Internet carries a vast range of information resources and services, such as the inter-linked hypertext documents and applications of the World Wide Web, electronic mail and file sharing. Some publications no longer capitalize "internet"; the origins of the Internet date back to research commissioned by the federal government of the United States in the 1960s to build robust, fault-tolerant communication with computer networks. The primary precursor network, the ARPANET served as a backbone for interconnection of regional academic and military networks in the 1980s; the funding of the National Science Foundation Network as a new backbone in the 1980s, as well as private funding for other commercial extensions, led to worldwide participation in the development of new networking technologies, the merger of many networks.
The linking of commercial networks and enterprises by the early 1990s marked the beginning of the transition to the modern Internet, generated a sustained exponential growth as generations of institutional and mobile computers were connected to the network. Although the Internet was used by academia since the 1980s, commercialization incorporated its services and technologies into every aspect of modern life. Most traditional communication media, including telephony, television, paper mail and newspapers are reshaped, redefined, or bypassed by the Internet, giving birth to new services such as email, Internet telephony, Internet television, online music, digital newspapers, video streaming websites. Newspaper and other print publishing are adapting to website technology, or are reshaped into blogging, web feeds and online news aggregators; the Internet has enabled and accelerated new forms of personal interactions through instant messaging, Internet forums, social networking. Online shopping has grown exponentially both for major retailers and small businesses and entrepreneurs, as it enables firms to extend their "brick and mortar" presence to serve a larger market or sell goods and services online.
Business-to-business and financial services on the Internet affect supply chains across entire industries. The Internet has no single centralized governance in either technological implementation or policies for access and usage; the overreaching definitions of the two principal name spaces in the Internet, the Internet Protocol address space and the Domain Name System, are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers. The technical underpinning and standardization of the core protocols is an activity of the Internet Engineering Task Force, a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise. In November 2006, the Internet was included on USA Today's list of New Seven Wonders; when the term Internet is used to refer to the specific global system of interconnected Internet Protocol networks, the word is a proper noun that should be written with an initial capital letter.
In common use and the media, it is erroneously not capitalized, viz. the internet. Some guides specify that the word should be capitalized when used as a noun, but not capitalized when used as an adjective; the Internet is often referred to as the Net, as a short form of network. As early as 1849, the word internetted was used uncapitalized as an adjective, meaning interconnected or interwoven; the designers of early computer networks used internet both as a noun and as a verb in shorthand form of internetwork or internetworking, meaning interconnecting computer networks. The terms Internet and World Wide Web are used interchangeably in everyday speech. However, the World Wide Web or the Web is only one of a large number of Internet services; the Web is a collection of interconnected documents and other web resources, linked by hyperlinks and URLs. As another point of comparison, Hypertext Transfer Protocol, or HTTP, is the language used on the Web for information transfer, yet it is just one of many languages or protocols that can be used for communication on the Internet.
The term Interweb is a portmanteau of Internet and World Wide Web used sarcastically to parody a technically unsavvy user. Research into packet switching, one of the fundamental Internet technologies, started in the early 1960s in the work of Paul Baran and Donald Davies. Packet-switched networks such as the NPL network, ARPANET, the Merit Network, CYCLADES, Telenet were developed in the late 1960s and early 1970s; the ARPANET project led to the development of protocols for internetworking, by which multiple separate networks could be joined into a network of networks. ARPANET development began with two network nodes which were interconnected between the Network Measurement Center at the University of California, Los Angeles Henry Samueli School of Engineering and Applied Science directed by Leonard Kleinrock, the NLS system at SRI International by Douglas Engelbart in Menlo Park, California, on 29 October 1969; the third site was the Culler-Fried Interactive Mathematics Center at the University of California, Santa Barbara, followed by the University of
A backbone is a part of computer network that interconnects various pieces of network, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building, in different buildings in a campus environment, or over wide areas; the backbone's capacity is greater than the networks connected to it. A large corporation that has many locations may have a backbone network that ties all of the locations together, for example, if a server cluster needs to be accessed by different departments of a company that are located at different geographical locations; the pieces of the network connections that bring these departments together is mentioned as network backbone. Network congestion is taken into consideration while designing backbones. One example of a backbone network is the Internet backbone; the theory, design principles, first instantiation of the backbone network came from the telephone core network, when traffic was purely voice.
The core network was the central part of a telecommunications network that provided various services to customers who were connected by the access network. One of the main functions was to route telephone calls across the PSTN; the term referred to the high capacity communication facilities that connect primary nodes. A core network provided paths for the exchange of information between different sub-networks. In the United States, local exchange core networks were linked by several competing interexchange networks. Core networks had a mesh topology that provided any-to-any connections among devices on the network. Many main service providers would have their own core/backbone networks; some large enterprises have their own core/backbone network, which are connected to the public networks. Core networks provided the following functionality: Aggregation: The highest level of aggregation in a service provider network; the next level in the hierarchy under the core nodes is the distribution networks and the edge networks.
Customer-premises equipment do not connect to the core networks of a large service provider. Authentication: The function to decide whether the user requesting a service from the telecom network is authorized to do so within this network or not. Call Control/Switching: call control or switching functionality decides the future course of call based on the call signalling processing. E.g. switching functionality may decide based on the "called number" that the call be routed towards a subscriber within this operator's network or with number portability more prevalent to another operator's network. Charging: This functionality of the collation and processing of charging data generated by various network nodes. Two common types of charging mechanisms found in present-day networks are prepaid charging and postpaid charging. See Automatic Message Accounting Service Invocation: Core network performs the task of service invocation for its subscribers. Service invocation may happen based on some explicit action by user or implicitly.
It's important to note however that service "execution" may or may not be a core network functionality as third party network/nodes may take part in actual service execution. Gateways: Gateways shall be present in the core network to access other networks. Gateway functionality is dependent on the type of network. Physically, one or more of these logical functionalities may exist in a given core network node. Besides above mentioned functionalities, the following formed part of a telecommunications core network: O&M: Operations & Maintenance centre or Operations Support Systems to configure and provision the core network nodes. Number of subscribers, peak hour call rate, nature of services, geographical preferences are some of the factors which impact the configuration. Network statistics collection, alarm monitoring and logging of various network nodes actions happens in the O&M centre; these stats and traces form important tools for a network operator to monitor the network health and performance and improvise on the same.
Subscriber Database: Core network hosts the subscribers database. Subscriber database is accessed by core network nodes for functions like authentication, service invocation etc. A distributed backbone is a backbone network that consists of a number of connectivity devices connected to a series of central connectivity devices, such as hubs, switches, or routers, in a hierarchy; this kind of topology allows for simple expansion and limited capital outlay for growth, because more layers of devices can be added to existing layers. In a distributed backbone network, all of the devices that access the backbone share the transmission media, as every device connected to this network is sent all transmissions placed on that network. Distributed backbones, in all practicality, are in use by all large-scale networks. Applications in enterprise-wide scenarios confined to a single building are practical, as certain connectivity devices can be assigned to certain floors or departments; each floor or department possesses a LAN and a wiring closet with that workgroup's main hub or router connected to a bus-style network using backbone cabling.
Another advantage of using a distributed backbone is the ability for network administrator to segregate workgroups for ease of management. There is the possibility of single points of failure, referring to connectivity devices high in the series hierarchy; the distributed backbo