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RSCP
In the UMTS cellular communication system, received signal code power (RSCP) denotes the power measured by a receiver on a particular physical communication channel. It is used as an indication of signal strength, as a handover criterion, in downlink power control, and to calculate path loss. In CDMA systems, a physical channel corresponds to a particular spreading code, hence the name (Received signal code power). RSCP is also called Receiver Side Call Power. While RSCP can be defined generally for any CDMA system, it is more specifically used in UMTS. Also, while RSCP can be measured in principle on the downlink as well as on the uplink In a telecommunications network, a link is a communication channel that connects two or more devices for the purpose of data transmission. The link may be a dedicated physical link or a virtual circuit that uses one or more physical links or shar ..., it is only defined for the downlink and thus presumed to be measured by the UE and repo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handoff
In cellular telecommunications, handover, or handoff, is the process of transferring an ongoing call or data session from one channel connected to the core network to another channel. In satellite communications it is the process of transferring satellite control responsibility from one earth station to another without loss or interruption of service. Terminology American English uses the term ''handoff'', and this is most commonly used within some American organizations such as 3GPP2 and in American originated technologies such as CDMA2000. In British English the term ''handover'' is more common, and is used within international and European organisations such as ITU-T, IETF, ETSI and 3GPP, and standardised within European originated standards such as GSM and UMTS. The term handover is more common in academic research publications and literature, while handoff is slightly more common within the IEEE and ANSI organisations. Purpose In telecommunications there may be differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UMTS
The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. UMTS uses Wideband Code Division Multiple Access, wideband code-division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators compared to previous 2G systems like GPRS and Circuit Switched Data, CSD. UMTS on its provides a peak theoretical data rate of 2 Data-rate units, Mbit/s. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the International Telecommunication Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing IS-95, cdmaOne technology. The technology described in UMTS is sometimes also referred to as Freedom of Mobile Multimedia Access (FOMA) or 3GSM. UMTS specifies a complete network system, which includes the radio access network (UMTS Terrestrial Radio Access Network, or U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power (physics)
Power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second. Power is a Scalar (physics), scalar quantity. Specifying power in particular systems may require attention to other quantities; for example, the power involved in moving a ground vehicle is the product of the aerodynamic drag plus traction (engineering), traction force on the wheels, and the velocity of the vehicle. The output power of a Engine, motor is the product of the torque that the motor generates and the angular velocity of its output shaft. Likewise, the power dissipated in an electrical element of a electrical circuit, circuit is the product of the electric current, current flowing through the element and of the voltage across the element. Definition Power is the Rate (mathematics), rate with respect to time at which work is done or, more generally, the rate of change of total mechanical energy. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receiver (radio)
In radio, radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna (radio), antenna. The antenna intercepts radio waves (electromagnetic waves of radio frequency) and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation. Radio receivers are essential components of all systems based on radio technology. The information produced by the receiver may be in the form of sound, video (television), or digital signal, digital data. A radio receiver may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Received Signal Strength Indication
In telecommunications, received signal strength indicator or received signal strength indication (RSSI) is a measurement of the power present in a received radio signal. RSSI is usually invisible to a user of a receiving device. However, because signal strength can vary greatly and affect functionality in wireless networking, IEEE 802.11 devices often make the measurement available to users. RSSI is often derived in the intermediate frequency (IF) stage before the IF amplifier. In zero-IF systems, it is derived in the baseband signal chain, before the baseband amplifier. RSSI output is often a DC analog level. It can also be sampled by an internal analog-to-digital converter (ADC) and the resulting values made available directly or via peripheral or internal processor bus. In 802.11 implementations In an IEEE 802.11 system, RSSI is the relative received signal strength in a wireless environment, in arbitrary units. RSSI is an indication of the power level being received by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Control
Power control, broadly speaking, is the intelligent selection of transmitter power output in a communication system to achieve good performance within the system. Guowang Miao, Jens Zander, Ki Won Sung, and Ben Slimane, Fundamentals of Mobile Data Networks, Cambridge University Press, , 2016. The notion of "good performance" can depend on context and may include optimizing metrics such as link data rate, network capacity, outage probability, geographic coverage and range, and life of the network and network devices. Power control algorithms are used in many contexts, including cellular networks, sensor networks, wireless LANs, and DSL modems. Transmit power control Transmit power control is a technical mechanism used within some networking devices in order to prevent too much unwanted interference between different wireless networks (e.g. the owner's network and the neighbour's network). It is also essential component in case of cognitive radio networks deployed in a distribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Path Loss
Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. Path loss is a major component in the analysis and design of the link budget of a telecommunication system. This term is commonly used in wireless communications and signal propagation. Path loss may be due to many effects, such as free-space loss, refraction, diffraction, reflection, aperture- medium coupling loss, and absorption. Path loss is also influenced by terrain contours, environment (urban or rural, vegetation and foliage), propagation medium (dry or moist air), the distance between the transmitter and the receiver, and the height and location of antennas. Overview In wireless communications, path loss is the reduction in signal strength as the signal travels from a transmitter to a receiver, and is an application for verifying the loss. There are several factors that affect this: *Free-space path loss: This is the fundame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDMA
Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel. This allows several users to share a band of frequencies (see bandwidth). To permit this without undue interference between the users, CDMA employs spread spectrum technology and a special coding scheme (where each transmitter is assigned a code). CDMA optimizes the use of available bandwidth as it transmits over the entire frequency range and does not limit the user's frequency range. It is used as the access method in many mobile phone standards. IS-95, also called "cdmaOne", and its 3G evolution CDMA2000, are often simply referred to as "CDMA", but UMTS, the 3G standard used by GSM carriers, also uses "wideband CDMA", or W-CDMA, as well as TD-CDMA and TD-SCDMA, as its radio technologies. Many carriers (such as AT&T, U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct-sequence Spread Spectrum
In telecommunications, direct-sequence spread spectrum (DSSS) is a spread-spectrum modulation technique primarily used to reduce overall signal interference. The direct-sequence modulation makes the transmitted signal wider in bandwidth than the information bandwidth. After the despreading or removal of the direct-sequence modulation in the receiver, the information bandwidth is restored, while the unintentional and intentional interference is substantially reduced. Swiss inventor, Gustav Guanella proposed a "means for and method of secret signals". With DSSS, the message symbols are modulated by a sequence of complex values known as ''spreading sequence''. Each element of the spreading sequence, a so-called ''chip'', has a shorter duration than the original message symbols. The modulation of the message symbols scrambles and spreads the signal in the spectrum, and thereby results in a bandwidth of the spreading sequence. The smaller the chip duration, the larger the bandw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downlink
In a telecommunications network, a link is a communication channel that connects two or more devices for the purpose of data transmission. The link may be a dedicated physical link or a virtual circuit that uses one or more physical links or shares a physical link with other telecommunications links. A telecommunications link is generally based on one of several types of information transmission paths such as those provided by communication satellites, terrestrial radio communications infrastructure and computer networks to connect two or more points. The term ''link'' is widely used in computer networking to refer to the communications facilities that connect nodes of a network. Sometimes the communications facilities that provide the communication channel that constitutes a link are also included in the definition of ''link''. Types Point-to-point A point-to-point link is a dedicated link that connects exactly two communication facilities (e.g., two nodes of a network, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UE (wireless Telephone)
In the Universal Mobile Telecommunications System (UMTS) and 3GPP Long Term Evolution (LTE), user equipment (UE) is any device used directly by an end-user to communicate. It can be a hand-held telephone, a laptop computer equipped with a mobile broadband adapter, or any other device. It connects to the base station Node B/eNodeB as specified in the ETSI 125/136-series and 3GPP 25/36-series of specifications. It roughly corresponds to the mobile station (MS) in GSM systems. The radio interface between the UE and the Node B is called ''Uu''. In the context of UMTS (Universal Mobile Telecommunications System), Uu stands for the interface between UTRAN (UMTS Terrestrial Radio Access Network) and the UE (User Equipment). Functionality UE handles the following tasks towards the core network: * 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 sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
