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Service Evaluation System
The Service Evaluation System (SES) was an operations support system developed by Bell Laboratories and used by telephone companies beginning in the late 1960s. Many local, long distance, and operator circuit-switching systems provided special dedicated circuits to the SES to monitor the quality of customer connections during the call setup process. Calls were selected at random by switching systems and one-way voice connections were established to the SES monitoring center. During this era, most voice connections used analog trunk circuits that were designed to conform with the Via Net Loss plan established by Bell Laboratories. The purpose of the VNL plan and five-level long distance switching hierarchy was to minimize the number of trunk circuits in a call and maximize the voice quality of the connections. Excessive loss in a voice connection meant that subscribers may have difficulty hearing each other. This was particularly important in the 1960s when dial up data connectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operations Support System
Operations support systems (OSS), operational support systems in British usage, or Operation System (OpS) in NTT, are computer systems used by telecommunications service providers to manage their networks (e.g., telephone networks). They support management functions such as network inventory, service provisioning, network configuration and fault management. Together with business support systems (BSS), they are used to support various end-to-end telecommunication services. BSS and OSS have their own data and service responsibilities. The two systems together are often abbreviated OSS/BSS, BSS/OSS or simply B/OSS. The acronym OSS is also used in a singular form to refer to all the Operations Support Systems viewed as a whole system. Different subdivisions of OSS have been proposed by the TM Forum, industrial research labs, or OSS vendors. In general, an OSS covers at least the following five functions: * Network management systems *Service delivery * Service fulfillment, inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Laboratories
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by multinational company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. Researchers working at Bell Laboratories are credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others. Nine Nobel Prizes have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. In the late 19th century, the laboratory began as the Western Electric Engineering Department, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Companies
A telephone company, also known as a telco, telephone service provider, or telecommunications operator, is a kind of communications service provider (CSP), more precisely a telecommunications service provider (TSP), that provides telecommunications services such as telephony and data communications access. Many telephone companies were at one time government agencies or privately owned but state-regulated monopolies. The government agencies are often referred to, primarily in Europe, as PTTs (postal, telegraph and telephone services). Telephone companies are common carriers, and in the United States are also called local exchange carriers. With the advent of mobile telephony, telephone companies now include wireless carriers, or mobile network operators. Most telephone companies now also function as internet service providers (ISPs), and the distinction between a telephone company and an ISP may disappear completely over time, as the current trend for supplier convergence in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Distance Calling
In telecommunications, a long-distance call (U.S.) or trunk call (also known as a toll call in the U.K. ) is a telephone call made to a location outside a defined local calling area. Long-distance calls are typically charged a higher billing rate than local calls. The term is not necessarily synonymous with placing calls to another telephone area code. Long-distance calls are classified into two categories: national or domestic calls which connect two points within the same country, and international calls which connect two points in different countries. Within the United States there is a further division into long-distance calls within a single state (intrastate) and interstate calls, which are subject to different regulations (counter-intuitively, calls within states are usually more expensive than interstate calls). Not all interstate calls are long-distance calls. Since 1984 there has also been a distinction between intra-local access and transport area (LATA) calls and those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Via Net Loss
{{unreferenced, date=April 2019 Via Net Loss (VNL) is a network architecture of telephone systems using circuit switching technologies deployed in the 1950s with Direct Distance Dialing and used until the late 1980s. The purpose of the VNL plan and a five-level long-distance switching hierarchy was to minimize the number of trunk circuits used during a call and maximize the voice quality achieved on each circuit. Excessive noise or loss meant that subscribers may have difficulty hearing each other. This was particularly important in the 1960s when dial-up data applications were developed using analog modems. The five levels of PSTN switching systems used with VNL were: * Class 1 - Regional long-distance switching system * Class 2 - Sectional long-distance switching system * Class 3 - Primary long-distance switching system * Class 4 - Toll-access switching system * Class 5 - End-office switching system Class 5 end-office switches provide local telephone service and dialtone to res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modems
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulation methods, modulating one or more carrier wave signals to encode digital information, while the receiver Demodulation, demodulates the signal to recreate the original digital information. The goal is to produce a Signal (electronics), signal that can be transmitted easily and decoded reliably. Modems can be used with almost any means of transmitting analog signals, from light-emitting diodes to radio. Early modems were devices that used audible sounds suitable for transmission over traditional telephone systems and leased lines. These generally operated at 110 or 300 bits per second (bit/s), and the connection between devices was normally manual, using an attached telephone handset. By the 1970s, higher speeds of 1,200 and 2,400 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-frequency
In telephony, multi-frequency signaling (MF) is a type of signaling that was introduced by the Bell System after World War II. It uses a combination of audible tones for address (telephone number) transport and supervision signaling on trunk lines between central offices. The signaling is sent ''in-band'' over the same channel as the bearer channel used for voice traffic. Multi-frequency signaling defines electronic signals that consist of a combination of two audible frequencies, usually selected from a set of six frequencies. Over several decades, various types of MF signaling were developed, including national and international varieties. The CCITT standardization process specified the American Bell System version as ''Regional Standard No. 1'', or Signalling System R1, and a corresponding European standard as Signalling System R2. Both were largely replaced by digital systems, such as Signalling System 7, which operate out-of-band on a separate data network. Because of the in-ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common-channel Signaling
In telecommunication, common-channel signaling (CCS), or common-channel interoffice signaling (CCIS), is the transmission of control information ''(signaling)'' via a separate channel than that used for the messages, The signaling channel usually controls multiple message channels. In the public switched telephone network (PSTN) one channel of a communications link is typically used for the sole purpose of carrying signaling for establishment and tear down of telephone calls. The remaining channels are used entirely for the transmission of voice messages. In most cases, a single channel is sufficient to handle the call setup and call clear-down traffic for numerous bearer (voice and data) channels. The technical alternative to CCS is channel-associated signaling (CAS), in which each bearer channel has a dedicated signaling channel. CCS offers the following advantages over CAS, in the context of the PSTN: * Faster call set-up time * Greater trunking efficiency due to the quicker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signaling System
Signalling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down telephone calls in most parts of the world-wide public switched telephone network (PSTN). The protocol also performs number translation, local number portability, prepaid billing, Short Message Service (SMS), and other services. The protocol was introduced in the Bell System in the United States by the name ''Common Channel Interoffice Signaling'' in the 1970s for signalling between No. 4ESS switch and No. 4A crossbar toll offices. In North America SS7 is also often referred to as ''Common Channel Signaling System 7'' (CCSS7). In the United Kingdom, it is called ''C7'' (CCITT number 7), ''number 7'' and ''Common Channel Interoffice Signaling 7'' (CCIS7). In Germany, it is often called ''Zentraler Zeichengabekanal Nummer 7'' (ZZK-7). The SS7 protocol is defined for international use by the Q.700-series recommendations of 1988 by the ITU-T. Of the many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notes On The Network
''Notes on the Network'' is a publication of the American Telephone & Telegraph Company (AT&T) that outlines the state, technology, and operating principles of the public switched telephone network in the United States and Canada, and the other member regions of the North American Numbering Plan. The origins of publication date back to the 1945 communications about ''Nationwide Operator Toll Dialing'' disseminated by AT&T to the Bell System companies and to the independent telephone operators via the ''Dial interexchange Committee'' of the ''United States Independent Telephone Association'' (USITA). In 1955, AT&T published the first extensive edition under the title ''Notes on Nationwide Dialing'', which was updated the following year (1956) under the title ''Notes on Distance Dialing''. Additional editions were issued in 1961, 1968, and 1975. The first use of the title ''Notes on the Network'' was for the 1980 edition. After the breakup of AT&T and the Bell System, the documen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Telephone & Telegraph
AT&T Corporation, originally the American Telephone and Telegraph Company, is the subsidiary of AT&T Inc. that provides voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agencies. During the Bell System's long history, AT&T was at times the world's largest telephone company, the world's largest cable television operator, and a regulated monopoly. At its peak in the 1950s and 1960s, it employed one million people and its revenue ranged between US$3 billion in 1950 ($ in present-day terms) and $12 billion in 1966 ($ in present-day terms). In 2005, AT&T was purchased by Baby Bell and former subsidiary SBC Communications for more than $16 billion ($ in present-day terms). SBC then changed its name to AT&T Inc. Today, AT&T Corporation continues to exist as the long distance subsidiary of AT&T Inc., and its name occasionally shows up in AT&T press releases. Buildings with AT&T logo * AT&T Huro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telcordia Technologies
iconectiv is a supplier of network planning and network management services to telecommunications providers. Known as Bellcore after its establishment in the United States in 1983 as part of the break-up of the Bell System, the company's name changed to Telcordia Technologies after a change of ownership in 1996. The business was acquired by Ericsson in 2012, then restructured and rebranded as iconectiv in 2013. A major architect of the United States telecommunications system, the company pioneered many services, including caller ID, call waiting, mobile number portability and toll-free telephone number (800) service. It also pioneered the prepaid charging system and the Intelligent Network. Headquartered in Bridgewater, New Jersey (U.S.), iconectiv provides network and operations management, numbering, registry and fraud prevention services for the global telecommunications industry. It provides numbering services in more than a dozen countries, including serving as the Local ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
