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Personal Handyphone System
The Personal Handy-phone System (PHS), also marketed as the Personal Communication Telephone (PCT) in Thailand, and the Personal Access System (PAS) and commercially branded as ''Xiaolingtong'' () in Mainland China, was a mobile network system operating in the 1880–1930 MHz frequency band, used mainly in Japan, China, Taiwan, and some other Asian countries and regions. Outline Technology PHS is essentially a cordless telephone like DECT, with the capability to handover from one cell to another. PHS cells are small, with transmission power of base station a maximum of 500 mW and range typically measures in tens or at most hundreds of metres (some can range up to about 2 kilometres in line-of-sight), contrary to the multi-kilometre ranges of CDMA and GSM. This makes PHS suitable for dense urban areas, but impractical for rural areas, and the small cell size also makes it difficult if not impossible to make calls from rapidly moving vehicles. PHS uses TDMA/ T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mainland China
"Mainland China" is a geopolitical term defined as the territory governed by the People's Republic of China (including islands like Hainan or Chongming), excluding dependent territories of the PRC, and other territories within Greater China. By convention, the territories that fall outside of the Chinese mainland include: * Hong Kong, a quasi-dependent territory under PRC rule that is officially designated a " Special Administrative Region of the PRC" (formerly a British colony) * Macau, a quasi-dependent territory under PRC rule that is officially designated a "Special Administrative Region of the PRC" (formerly a Portuguese colony) * Territories ruled by the Republic of China (ROC, commonly referred to as Taiwan), including the island of Taiwan, the Penghu (Pescadores) islands in the Taiwan Strait, and the islands Kinmen, Matsu, and Wuqiu (Kinmen) offshore of Fujian. Overseas Chinese, especially Malaysian Chinese and Chinese Singaporeans, use this term to describe people ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, public, academic, business, and government networks of local to global scope, linked by a broad array of electronic, wireless, 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 (WWW), electronic mail, telephony, and file sharing. The origins of the Internet date back to the development of packet switching and research commissioned by the United States Department of Defense in the 1960s to enable time-sharing of computers. The primary precursor network, the ARPANET, initially served as a backbone for interconnection of regional academic and military networks in the 1970s to enable resource shari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass ( silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber laser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular Telephone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply 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 (PSTN). Modern mobile telephone services use a cellular network architecture and, therefore, mobile telephones are called ''cellular telephones'' or ''cell phones'' in North America. In addition to telephony, digital mobile phones ( 2G) support a variety of other services, such as text messaging, multimedia messagIng, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, video games and digital photography. Mobile phones offering only those capabilities are known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IMT-2000
IMT-2000 (International Mobile Telecommunications-2000) is the global standard for third generation ( 3G) wireless communications as defined by the International Telecommunication Union. In 1999 ITU approved five radio interfaces for IMT-2000 as a part of the ITU-R M.1457 Recommendation. The five standards are: * ''IMT-2000 CDMA Direct Spread'' ** also known as W-CDMA, used in UMTS, the successor to GSM * ''IMT-2000 CDMA Multi-Carrier'' ** also known as CDMA2000, the successor to 2G CDMA ( IS-95) * ''IMT-2000 CDMA TDD'' ** also known as TD-SCDMA * ''IMT-2000 TDMA Single Carrier'' ** also known as EDGE Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed ..., an intermediate 2.5G technology * ''IMT-2000 FDMA/TDMA'' ** also known as DECT To meet the IMT-2000 standards, a system must pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcell
A microcell is a cell in a mobile phone network served by a low power cellular base station (tower), covering a limited area such as a mall, a hotel, or a transportation hub. A microcell is usually larger than a picocell, though the distinction is not always clear. A microcell uses power control to limit the radius of its coverage area. Typically the range of a microcell is less than two kilometers wide, whereas standard base stations may have ranges of up to 35 kilometres (22 mi). A picocell, on the other hand, is 200 meters or less, and a femtocell is on the order of 10 meters, although AT&T calls its femtocell that has a range of , a "microcell". AT&T uses "AT&T 3G MicroCell" as a trade mark and not necessarily the "microcell" technology, however. A microcellular network is a radio network composed of microcells. Rationale Like picocells, microcells are usually used to add network capacity in areas with very dense phone usage, such as train stations. Microcells are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Exchange
telephone exchange, telephone switch, or central office is a telecommunications system used in the public switched telephone network (PSTN) or in large enterprises. It interconnects telephone subscriber lines or virtual circuits of digital systems to establish telephone calls between subscribers. In historical perspective, telecommunication terms have been used with different semantics over time. The term ''telephone exchange'' is often used synonymously with ''central office'', a Bell System term. Often, a ''central office'' is defined as a building used to house the inside plant equipment of potentially several telephone exchanges, each serving a certain geographical area. Such an area has also been referred to as the exchange or exchange area. In North America, a central office location may also be identified as a ''wire center'', designating a facility to which a telephone is connected and obtains dial tone. For business and billing purposes, telecommunication carriers def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Services Digital Network
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work on the standard began in 1980 at Bell Labs and was formally standardized in 1988 in the CCITT "Red Book". By the time the standard was released, newer networking systems with much greater speeds were available, and ISDN saw relatively little uptake in the wider market. One estimate suggests ISDN use peaked at a worldwide total of 25 million subscribers at a time when 1.3 billion analog lines were in use. ISDN has largely been replaced with digital subscriber line (DSL) systems of much higher performance. Prior to ISDN, the telephone system consisted of digital links like T1/ E1 on the long-distance lines between telephone company offices and analog signals on copper telephone wires to the customers, the " last mile". At the time, the ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Front And Back Ends
In software engineering, the terms frontend and backend (or sometimes referred to as back end or back-end) refer to the separation of concerns between the presentation layer (''frontend''), and the data access layer (''backend'') of a piece of software, or the physical infrastructure or hardware. In the client–server model, the client is usually considered the frontend and the server is usually considered the backend, even when some presentation work is actually done on the server itself. Introduction In software architecture, there may be many layers between the hardware and end user. The ''front'' is an abstraction, simplifying the underlying component by providing a user-friendly interface, while the ''back'' usually handles data storage and business logic. In telecommunication, the ''front'' can be considered a device or service, while the ''back'' is the infrastructure that supports provision of service. A rule of thumb is that the client-side (or "frontend") is any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plain Old Telephone Service
Plain old telephone service (POTS), or plain ordinary telephone system, is a retronym for voice-grade telephone service employing analog signal transmission over copper loops. POTS was the standard service offering from telephone companies from 1876 until 1988 in the United States when the Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI) was introduced, followed by cellular telephone systems, and voice over IP (VoIP). POTS remains the basic form of residential and small business service connection to the telephone network in many parts of the world. The term reflects the technology that has been available since the introduction of the public telephone system in the late 19th century, in a form mostly unchanged despite the introduction of Touch-Tone dialing, electronic telephone exchanges and fiber-optic communication into the public switched telephone network (PSTN). Characteristics POTS is characterized by several aspects: *Bi-directional ( full duplex) co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last Mile (telecommunications)
The last mile or last kilometer is a phrase widely used in the telecommunications, cable television and internet industries to refer to the final leg of the telecommunications networks that deliver telecommunication services to retail end-users (customers). More specifically, the ''last mile'' describes the portion of the telecommunications network chain that physically reaches the end-user's premises. Examples are the copper wire subscriber lines connecting landline telephones to the local telephone exchange; coaxial cable service drops carrying cable television signals from utility poles to subscribers' homes, and cell towers linking local cell phones to the cellular network. The word "mile" is used metaphorically; the length of the last mile link may be more or less than a mile. Because the last mile of a network to the user is conversely the first mile from the user's premises to the outside world when the user is sending data, the term first mile is also alternatively us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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