Mobility Management
Mobility management is one of the major functions of a GSM or a UMTS network that allows mobile phones to work. The aim of mobility management is to track where the subscribers are, allowing calls, SMS and other mobile phone services to be delivered to them. Location update procedure A GSM or UMTS network, like all cellular networks, is basically a radio network of individual cells, known as base stations. Each base station covers a small geographical area which is part of a uniquely identified location area. By integrating the coverage of each of these base stations, a cellular network provides a radio coverage over a much wider area. For GSM, a base station is called a base transceiver station (BTS), and for UMTS it is called a Node B. A group of base stations is named a location area, or a routing area. The location update procedure allows a mobile device to inform the cellular network whenever it moves from one location area to the next. Mobiles are responsible for dete ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Broadcasting
Broadcasting is the data distribution, distribution of sound, audio audiovisual content to dispersed audiences via a electronic medium (communication), mass communications medium, typically one using the electromagnetic spectrum (radio waves), in a :wikt:one-to-many, one-to-many model. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and radio receiver, receivers. Before this, most implementations of electronic communication (early radio, telephone, and telegraph) were wikt:one-to-one, one-to-one, with the message intended for a single recipient. The term ''broadcasting'' evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. IP has the task of delivering Packet (information technology), packets from the source Host (network), host to the destination host solely based on the IP addresses in the packet Header (computing), headers. For this purpose, IP defines packet structures that encapsulation (networking), encapsulate the data to be delivered. It also defines addressing methods that are used to label the datagram with source and destination information. IP was the connectionless datagram service in the original ''Transmission Control Program'' introduced by Vint Cerf and Bob Kahn in 1974, which was complemented by a connection-oriented service that became the basis for the Transmission Control Protocol (TCP). The Internet protocol suite is therefore often referre ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Data Communication
Data communication, including data transmission and data reception, is the transfer of data, transmitted and received over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical fibers, wireless communication using radio spectrum, storage media and computer buses. The data are represented as an electromagnetic signal, such as an electrical voltage, radiowave, microwave, or infrared signal. '' Analog transmission'' is a method of conveying voice, data, image, signal or video information using a continuous signal that varies in amplitude, phase, or some other property in proportion to that of a variable. The messages are either represented by a sequence of pulses by means of a line code ('' baseband transmission''), or by a limited set of continuously varying waveforms ('' passband transmission''), using a digital modulation method. The passband modulation and corresponding demodulation is carried out by ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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GPRS
General Packet Radio Service (GPRS), also called 2.5G, is a mobile data standard on the 2G cellular communication network's Global System for Mobile Communications, global system for mobile communications (GSM). Networks and mobile devices with GPRS started to roll out around the year 2001; it offered, for the first time on GSM networks, seamless data transmission using Packet switching, packet data for an "always-on" connection (eliminating the need to "dial-up"), so providing improved Internet access for World Wide Web, web, email, Wireless Application Protocol, WAP services, Multimedia Messaging Service (MMS) and others. Up until the rollout of GPRS, only circuit switched data was used in cellular networks, meaning that one or more radio channels were occupied for the entire duration of a data connection. On the other hand, on GPRS networks, data is broken into small packets and transmitted through available channels. This increased efficiency also gives it theoretical data ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Bandwidth (signal Processing)
Bandwidth is the difference between the upper and lower Frequency, frequencies in a continuous Frequency band, band of frequencies. It is typically measured in unit of measurement, unit of hertz (symbol Hz). It may refer more specifically to two subcategories: ''Passband bandwidth'' is the difference between the upper and lower cutoff frequencies of, for example, a band-pass filter, a communication channel, or a signal spectrum. ''Baseband bandwidth'' is equal to the upper cutoff frequency of a low-pass filter or baseband signal, which includes a zero frequency. Bandwidth in hertz is a central concept in many fields, including electronics, information theory, digital communications, radio communications, signal processing, and spectroscopy and is one of the determinants of the capacity of a given communication channel. A key characteristic of bandwidth is that any band of a given width can carry the same amount of information, regardless of where that band is located in the f ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cell Global Identity
Cell Global Identity (CGI) is a globally unique identifier for a Base Transceiver Station in mobile phone networks. It consists of four parts: Mobile Country Code (MCC), Mobile Network Code (MNC), Location Area Code (LAC) and Cell Identification (CI). It is an integral part of 3GPP specifications for mobile networks, for example, for identifying individual base stations to "handover" ongoing phone calls between separately controlled base stations, or between different mobile technologies. MCC and MNC make up a PLMN identifier, and PLMN and LAC make up a location area identity (LAI), which uniquely identifies a Location Area of a given operator's network. So a CGI can be seen as a LAI with added Cell Identification, to further identify the individual base station of that Location Area. Overview * a CGI (e.g. 001-02-3-4) consists of: ** a LAI (001-02-3), which consists of: *** a PLMN (001-02), which consists of: **** MCC (001) **** MNC (02) *** and a LAC (03), ** and a CI (4) E ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Radio Network Controller
The Radio Network Controller (RNC) is a governing element in the UMTS radio access network (UTRAN) and is responsible for controlling the Node Bs that are connected to it. The RNC carries out radio resource management, some of the mobility management functions and is the point where encryption is done before user data is sent to and from the mobile. The RNC connects to the Circuit Switched Core Network through Media Gateway (Media gateway, MGW) and to the SGSN (Serving GPRS Support Node) in the Packet Switched Core Network. Interfaces The logical connections between the network elements are known as interfaces. The interface between the RNC and the Circuit Switched Core Network (CS-CN) is called Iu-CS and between the RNC and the Packet Switched Core Network is called Iu-PS. Other interfaces include Iub (between the RNC and the Node B) and Iur (between RNCs in the same network). Iu interfaces carry user traffic (such as voice or data) as well as control information (see ), and Iur ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Engineering Optimization
Engineering optimization is the subject which uses optimization techniques to achieve design goals in engineering. It is sometimes referred to as design optimization. Topics * structural design (including pressure vessel design and welded beam design) * shape optimization * topology optimization (including airfoils) * inverse optimization (a subset of the inverse problem An inverse problem in science is the process of calculating from a set of observations the causal factors that produced them: for example, calculating an image in X-ray computed tomography, sound source reconstruction, source reconstruction in ac ...) * processing planning * product designs * electromagnetic optimization * space mapping * aggressive space mappingJ.E. Rayas-Sanche"Power in simplicity with ASM: tracing the aggressive space mapping algorithm over two decades of development and engineering applications" IEEE Microwave Magazine, vol. 17, no. 4, pp. 64-76, April 2016. * yield-driven design * o ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Invoice
An invoice, bill, tab, or bill of costs is a commercial document that includes an itemized list of goods or services furnished by a seller to a buyer relating to a sale transaction, that usually specifies the price and terms of sale, quantities, and agreed-upon prices and terms of sale for products or services the seller had provided the buyer. Payment terms are usually stated on the invoice. These may specify that the buyer has a maximum number of days to pay and is sometimes offered a discount if paid before the due date. The buyer could have already paid for the products or services listed on the invoice. To avoid confusion and consequent unnecessary communications from buyer to seller, some sellers clearly state in large and capital letters on an invoice whether it has already been paid. From a seller's point of view, an invoice is a ''sales invoice''. From a buyer's point of view, an invoice is a ''purchase invoice''. The document indicates the buyer and seller, but ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Authorization
Authorization or authorisation (see American and British English spelling differences#-ise, -ize (-isation, -ization), spelling differences), in information security, computer security and identity management, IAM (Identity and Access Management), is the function of specifying rights/privileges for accessing resources, in most cases through an access policy, and then deciding whether a particular ''subject'' has privilege to access a particular ''resource''. Examples of ''subjects'' include human users, computer software and other Computer hardware, hardware on the computer. Examples of ''resources'' include individual files or an item's data, computer programs, computer Computer hardware, devices and functionality provided by computer applications. For example, user accounts for human resources staff are typically configured with authorization for accessing employee records. Authorization is closely related to access control, which is what enforces the authorization policy by d ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |