- What is D/A (digital-to-analog converter?
A D/A Converter is utilized to convert the binary output from a digital system into its equivalent analog voltage or current. Digital and analog converters convert digital signals to analog signals by performing the reverse function. DAC converts an abstract finite-precision numerical value into the physical value. DAC is used in television, mobile phones, and music players to convert digital data into analog.
- What is D2D (Device-to-Device)?
Device-to-Device (D2D) communication in cellular networks is characterized as direct communication between two cell phone subscribers without traversing the Base Station. D2D communication is non-transparent to the cellular network. It can happen at cellular frequencies. D2D communications can greatly enhance the spectral efficiency of the network. D2D communications are used for spectral capability. It can enhance throughput, energy efficiency, delay, and fairness.
- What is DA (Destination address)?
The destination address is that, in which a packet of information is transmitted over a network. The destination address is utilized in the network to signify the recipient of a piece of data. Destination address determines the network interference card of the intended recipient of layer 2 medium access control. The destination address is utilized by hosts on the network to examine whether the packet is deliberated for them or for other hosts. The destination address is utilized by routers to examine how to forward the packet through internetwork.
- What is DAB (digital audio broadcasting)?
Digital audio broadcasting (DAB) is an advanced radio standard for broadcasting digital audio radio administrations in numerous nations, characterized by the WorldDAB forum. The DAB standard was a European research project called Eureka-147 in the 1980s.
DAB is more efficient in its utilization of spectrum than analog FM radio and thus can provide more radio frameworks for the similarly provided bandwidth. DAB provides compact disc-quality audio on the frequency modulation broadcast band and provides FM-quality audio on the amplitude modulation broadcast band.
- What is DAD (Duplicate Address Detection)?
Duplicate address detection (DAD) is utilized to confirm that an IPv6 address is extraordinary on the LAN before the address is allocated to a physical interface. DAD is empowered in the default IPv6 design and can be reconfigured, debilitated. DAD can be valuable in assisting to troubleshoot erroneous answers to DAD requests. If DAD confirms that a unicast IPv6 address is a copy, the address is not utilized. If the link-local address of the VLAN interface is discovered to be a copy of an address for another device on the interface, the interface stops processing IPv6 traffic.
- What is DAMA (Demand Assigned Multiple Access)?
Demand Assigned Multiple Access (DAMA) is an innovation utilized to appoint a channel to users that don’t require to utilize it constantly. DAMA frameworks assign communication channels to a network security system depending on the news by subscriber’s terminals. The channels are returned to the central pool for reassignment to different subscribers at the point when the circuit is not used. DAMA is broadly utilized in satellite communications, especially in VSAT frameworks. It is exceptionally effective in environments involving various users. DAMA is frequently utilized in the military.
- What is DARP (Downlink Advanced Receiver Performance)?
DARP enhances network limits by utilizing lower reuse factors It permits network ability to be extended and the base station sends power to be diminished simultaneously. DARP is utilized equivalently with the term single antenna interference cancelation. The DARP method works with the antenna integrated into the cell phone and it depends on the information of GSM modulation, which makes it conceivable to suppress as viable as possible adjacent-channel interference that varies from general noise.
- What is DARPA (Defense Advanced Research Projects Agency)?
The Defense Advanced Research Projects Agency (DARPA) is an innovative work and development office of the United States Department of Defense liable for the improvement of technologies utilized by the military, the agency was set up on February 7, 1958, by President Dwight D. Eisenhower. It is Initially known as the Advanced Research Projects Agency (ARPA). DARPA is autonomous of other military innovative work and development. DARPA contains roughly 220 government workers in six specialized offices.
- What is DARS (Digital Audio Radio Satellite)?
Digital audio radio service (DARS) alludes to the kind of digital radio program service. The most well-known sort of DARS in the U.S. and Canada is Satellite Digital Audio Radio Service. WorldSpace additionally worked a DARS network outside the United States and Canada with an impression covering Europe, Asia, the Middle East and Africa.
- What is DAS (distributed antenna system)?
A DAS is an antennas network that conveys and receives cellular signals on a transporter’s authorized frequencies. It develops voice and data connectivity for end-users. In DAS network of spatially isolated antenna nodes associated with a common source through a transport medium that offers wireless support inside a geographic design. A distributed antenna system may be conveyed indoors (an iDAS) or outdoors.
- What is DBN (Deep Belief Network)?
Deep belief network (DBN) is a generative graphical model, made out of numerous layers of latent variables, with associations between the layers however not between units inside each layer. DBN are pre-prepared utilizing the Greedy learning algorithm. Greedy learning algorithm utilizes a layer-by-layer method for learning the hierarchical, generative weights. These generative weights decide how factors in one layer rely upon the factors in the layer above.
- What is DBPSK (Differential Binary Phase Shift Keying)?
The DPSK means “Differential phase-shift keying”. It is one sort of phase modulation utilized to send information by modifying the carrier wave’s phase. The signal phase follows the high or low state of the previous component. This DPSK strategy doesn’t require a reference oscillator. DPSK modulation doesn’t require the carrier signals toward the end of the receiver circuit. Hence compound circuits are not needed.
- What is DBSCAN (Density‐Based Spatial Clustering of Applications with Noise)?
Density-based spatial clustering of applications with noise is an information clustering algorithm. It was proposed by Martin Ester, Hans-Peter Kriegel, Jörg Sander, and Xiaowei Xu in 1996. The DBSCAN algorithm should be utilized to discover connections and designs in the information that is difficult to examine manually yet that can be significant and utilized to examine patterns and predict trends. Clustering techniques are normally utilized in biology, medicine, social sciences, marketing, character recognition, management systems, and so on.
- What is DC (Direct Current)?
Direct current (DC) is an electrochemical cell that is a great representation of DC power. Direct current may move through a conductor like a wire, but can also move through semiconductors, insulators, through a vacuum as in electrons. Direct current has many utilizations, from the charging of batteries to huge power supplies for electronic systems, motors.
The direct current might be changed over from an alternating current supply by utilization of a rectifier, which contains electronic components that permit current to move only in one direction.
- What is DC (Dual Connectivity)?
Dual connectivity (DC) is a 3GPP feature for small cell upgrades. It expects to use the radio asset within various carriers to develop UE throughput. Dual Connectivity (DC) permits a UE to simultaneously convey and receive information on numerous segment carriers from two cell bunches by means of master eNodeB (MN) and secondary eNodeB (SN). DC can enhance user throughput, give mobility robustness, and support load-balancing among eNodeBs.
- What is DC-HSPA (Dual Cell HSDPA)?
DC-HSPA is Dual cell rapid downlink packet access. DC-HSPA works on the use of the accessible assets by multiplexing carriers in the CELL DCH state.
The DC-HSPA configuration utilizes the accessible assets and gives altogether further developed execution under low signal conditions where ordinarily it is important to diminish the information rate by expanding the error correction and decreasing the modulation order.
DC-HSPA / DC-HSDPA is to give the most extreme productivity and execution for information conveys, using high levels of capacity for a short time.
- What is DCC (Decentralized Congestion Control)?
Decentralized Congestion Control in C-ITS is an obligatory segment of the 5.9 GHz ITS-G5 vehicular communication protocol stack that decreases radio channel overload, range degradation, and self-impedance.
- What is DCCH (Dedicated Control Channel)?
Dedicated Control Channel is a highlight point bi-directional channel that sends devoted control data between a UE and the network. It is utilized by UEs that have effectively settled the RRC association. These channels are utilized for signaling between the organization and the versatile. They include the Standalone Dedicated Control Channel, the Slow Associated Control Channel, and the FACCH (Fast Associated Control Channel).
- What is DCCP (Datagram Congestion Control Protocol)?
Datagram Congestion Control Protocol (DCCP) is a message-arranged transport layer protocol. DCCP gives an approach to gain access to congestion-control mechanisms without carrying out them at the application layer. A DCCP association contains affirmation traffic as well as information traffic. DCCP has the alternative for extremely long sequence numbers compared to a packet ID, rather than a byte ID as in TCP.
- What is DCF (Distributed coordination function)?
Distributed coordination function is the medium access control (MAC) procedure. DCF utilizes carrier-sense multiple access with collision avoidance (CSMA/CA) with binary exponential backoff algorithm.
The Distributed Coordination Function frames the premise of standard Carrier Sensing Multiple Access / Collision Avoidance access within an 802.11 network. The DCF first verifies whether the radio connection is free prior to sending and to avoid contention, starts an irregular backoff. The DCF might utilize the Request To Send and Clear To Send strategy to additionally prevent collisions.
- What is DCN (Dedicated Core Network)?
DCNs are deployed by portable services suppliers to serve explicit subsets of endorsers, for example, in the assistance of a wide scale IoT arrangement. The DCN might uphold different RAN sorts and will comprise standard core network nodes, like the MME (Mobility Management Entity), S-GW (Serving Gateway), and P-GW (PDN Gateway)
- What is DC (Direct Current)?/
Direct current is characterized by the consistent progression of electrons from an area of high electron density to an area of low electron density. An electrochemical cell is a great representation of DC power. Direct current might course through a channel like a wire and also flow through semiconductors, insulators. The electric current flows in a constant direction, distinguishing it from alternating current. A term utilized for this kind of current was galvanic current. Direct current is utilized in any electronic gadget with a battery for a force source. It is likewise used to charge batteries, so battery-powered gadgets like workstations and cells accompany an AC connector that converts substituting current to coordinate current.
- DCR (Drop Call Rate)
The dropped-call rate (DCR) is the fraction of the phone calls which were cut off before the talking parties had completed their conversational tone and before one of them had hung up because of some reasons. This division is normally estimated as a level of all calls. In versatile communication frameworks utilizing radio channels the dropped-call rate is higher and may range for commercial networks between 0.1% and a few percent. The fundamental purposes behind dropped calls in mobile networks are lack of radio coverage, radio interference between different subscribers.
- DCS (Digital Communication System)?
A digital communication system comprises six fundamental blocks. The functional blocks at the transmitter are liable for processing the input message, encoding, and sending over the communication channel. The functional blocks at the receiver execute the reverse process to retrieve the original message. The main goal of a digital communication system is to send the message proficiently over the communication channel by joining different information compressions, encoding and modulation techniques, in order to reproduce the message in the receiver with the least errors.
- DCR (Direct Conversion Receiver)?
DCR is a radio receiver design,it demodulates the approaching radio signal utilizing simultaneous identification driven by a local oscillator whose frequency is indistinguishable to the carrier frequency of the intended signal.
Direct conversion receiver (DCR) architecture, which has introduced the zero intermediate frequency (IF) approach, upholds productive wireless handset plans with a high level of integration
- What is a DDC (Digital Down Converter)?
Digital down-converter (DDC) changes a digitized, band-restricted signal to a lower frequency signal at a lower sampling rate to work on the resulting radio stages. The process can protect all the data in the frequency band of interest of the original signal. The input and output signals can be genuine samples. Frequently the DDC changes over from the raw radio recurrence or middle of the road recurrence down to a complex baseband signal.
- What is DDoS (Distributed Denial of service)?
A distributed denial-of-service (DDoS) attack implies that hackers have endeavored to create a website unavailable by crashing the website with an excessive amount of traffic.
Distributed denial-of-service attacks target sites and online services. The objective is to overwhelm them with more traffic than the network can administer. The objective is to render the website inoperable.
The traffic can comprise incoming messages, demands for associations, fake packets.
- What is DECOR (Dedicated Core Network)?
A DCN includes at least one MME/SGSN and it might involve at least one SGW/PDN GW/PCRF. This component empowers supporters to be assigned to and served by a DCN is a standard basically utilized for making cordless phone frameworks. DCN depends on subscription data. DCNs may assist one RAT only, to assist multiple RATs. Networks deploying DCNs might have a default DCN, which is overseeing UEs for which a DCN isn’t accessible or then again if adequate data isn’t accessible to allot a UE to a DCN. One or various DCNs might be conveyed along with a default DCN that all offer a similar RAN.
- What is DES (Data Encryption Standard)?
The Data Encryption Standard is used for the encryption of digital information. Data Encryption Standard (DES) is a symmetric block cipher that was once the US Government’s best standard in strategies it and others utilize to encrypt sensitive information. DES was prevailed by the Advanced Encryption Standard (AES) when, in the face of adversaries’ more potent brute-force capability, DES was censured.
- What is DFCA (Dynamic Frequency and Channel Allocation)?
Dynamic channel allocation (DCA) is used to enhance the use of radio assets by applying intelligence to the channel selection process. DCA methods can be dependent on a wide range of factors and various applications give fluctuating degrees of freedom in the channel selection. The DCA methods are regularly sorted as traffic adaptive (TA-DCA) or interference adaptive.
- What is DFE (Decision-Feedback Equalization)?
The Decision Feedback Equalizer (DFE) depends on choices about the degrees of previous symbols to address the current symbol. This permits the DFE to represent distortion in the current symbol that is brought about by the previous symbols. Its fundamental benefit over linear equalizers is the capacity to cancel inter-symbol interference (ISI) without intensifying the noise. The DFE administrator permits to approve hardware DFE designs and examine their impacts on eye openings.
- What is DFI (Deep flow inspection)?
Deep flow inspection is a packet filtering procedure that examines statistical attributes such as packet lengths, ratio of large packets and connection behavior of flows, to decide the procedures to be applied to session packets.
- What is DFS (Dynamic frequency selection)?
DFS was normalized in 2003 as a component of IEEE 802.11h. Dynamic Frequency Selection (DFS) is a channel allocation method indicated for wireless LAN, generally called Wi-Fi. It is intended to restrict electromagnetic interference with different usages of the C band recurrence band that had originated before Wi-Fi, like military radar, satellite communication, and weather radar.
- What is DFT (Discrete Fourier Transform)?
The discrete Fourier transform (DFT) converts a limited arrangement of same spaced samples of a function into a similar length sequence of same spaced samples of the discrete-time Fourier transform (DTFT), which is a complex-esteemed function of frequency. The span at which the DTFT is sampled is the reciprocal of the duration of the input sequence. The DFT is the most significant discrete transform, utilized to execute Fourier analysis in various practical applications.
- What is DFT-S-OFDM (DFT spread OFDM)?
The Discrete Fourier Transform – spread-OFDM (DFT-s-OFDM) waveform, normalized in LTE uplink. It gives the benefit of a lower PAPR, however it doesn’t defeat the other OFDM negative marks.
In basic DFT-s-OFDM, the information symbols are first distributed with a DFT block, and afterward mapped to the input of an IDFT block. OFDM does not utilize a DFT-spread block and the symbols are mapped to the subcarriers. Hence, while the RSs are distributed in frequency for OFDM, they are multiplexed in time for DFT-s-OFDM. Therefore, the coexistence of DFT-s-OFDM and OFDM leads to inconsistent overlapping on the equivalent resources.
- What is DGNA (dynamic group number assignment)?
DGNA gives the capacity for a network administrator or approved client to dynamically allocate new to selected terminals over the air interface. Utilizing supplementary services messages (SS-DGNA), the network administrator can command the terminal to add talkgroups or to update the existing talkgroups. At the point when a DGNA message is received and DGNA warning was designed by the Service Provider, then individuals will get a notice message and afterward show the new tasks.
- What is DGPS (differential GPS)?
A Differential Global Positioning System (DGPS) is an upgrade to the Global Positioning System (GPS) which gives further developed area precision, in the range of operations of each framework, from the 15-metre nominal GPS accuracy to about 1–3 centimetres in case of the best executions. Differential GPS includes the collaboration of two receivers, one that’s stationary and another that’s roving around making position estimations.
- What is DHCP (Dynamic Host Configuration Protocol)?
Dynamic Host Configuration Protocol (DHCP) offers an Internet Protocol (IP) host with its IP address and other related configuration data for example, the subnet mask and default gateway. DHCP limits configuration errors brought about by manual IP address configuration, for example, typographical mistakes caused by the assignment of an IP address to more than one computer simultaneously. A DHCP-empowered customer, receives a valid IP address for the subnet to which it is connecting.
- What is DHM (Digital Height Model)?
Digital height models are made from stereo images utilizing direct and indirect image highlights. One approach to get a digital height model is to examine the distinction between the rasters of the digital surface model and the digital terrain model. For this situation, the digital height model will address the real height of trees, buildings, etc. It is utilized for broadcast communications network demonstrating, flood reenactment, 3D city creation, obstruction study, and archeological examination.
- What is DIR (Dominant Interference Ratio)?
The planning base stations in the sub-clusters are chosen depending on the proportion between the dominant interference (DI) and the remainder of the apparent interference, known as the dominant interference ratio (DIR).
- What is DLDC (Downlink Dual Carrier)?
The Downlink Dual Carrier (DLDC) assigns PDTCH resources to a portable on two distinct transporters. The downlink throughput hypothetically scales directly with the complete number of timeslots dispensed to a downlink TBF with DLDC-based transfer. Dual carrier is an element presented in HSPA+ that permits planning a client on two carriers at same time. While this element has been to a great extent contemplated, and conveyed, in the downlink and it has been demonstrated that it gives huge limit gains, its exhibition in the uplink is still to be researched.
- What is DLL (delay-locked loop)?
Delay-locked loop (DLL) is a digital circuit like a phase-locked loop (PLL), but has the principle distinction being the shortfall of an internal voltage-controlled oscillator, supplanted by a delay line. It gives high-bandwidth information transmission rates between devices. A DLL attempts to decide the period of that reference clock by changing a feedback by means of the delay in a variable delay buffer. At the point when the delayed clock signal matches the approaching clock signal, the loop is considered locked.
- What is a DLL (Data Link Layer)?
The data link layer is the second layer of the seven-layer OSI model. This layer is the protocol layer. It conveys information between nodes on a network section across the physical layer. The data link layer is concerned with local conveyance of frames between nodes on the similar level of the network. Data link layer works amongs two hosts which are directly associated in some sense. This direct association could be point to point or broadcast. Frameworks on broadcast networks are supposed to be on the same connection.
- What is DLSCH (Downlink Shared Channel)?
In LTE the Downlink Shared Channel is utilized for the conveying of user information, devoted control and client explicit higher layer data and downlink framework data. The Physical Downlink Shared Channel (PDSCH) is the physical channel that conveys the DL-SCH coded information. This model defines the various stages associated with the Downlink Shared Channel (DL-SCH) and Physical Downlink Shared Channel (PDSCH) processing and gives admittance to the information from these intermediate stages.
- What is DM RS (Demodulation Reference Signal)?
DM-RS was upheld effectively in the first release of LTE. A demodulation reference signal (DM-RS) is proposed to be utilized for channel assessment by a particular device and is then only communicated inside the resource blocks allotted for transmission to that device. The utilization of DM-RS was then restricted to the demodulation of single-layer PDSCH transmission—that is, no spatial multiplexing—corresponding to transmission mode 7.
- What is DMA (Direct Memory Access)?
Direct memory access (DMA) is an element of computer frameworks that permits certain hardware subsystems to get to principal framework memory independently of the central processing unit. DMA can likewise be utilized for “memory to memory” duplicating and transfer of information inside memory. A DMA controller requires the similar old circuits of an interface to transmission with the CPU and Input/Output devices.
- What is DMB (Digital mobile Broadcast)?
Digital multimedia broadcasting (DMB) is an advanced radio transmission innovation created in South Korea as a segment of the public IT project for transmitting multimedia like TV, radio and datacasting to cell phone devices like mobile phones, laptops and GPS route frameworks. DMB likewise has a few similarities with its former competing versatile TV standard.
- What is DME (Distance Measurement Equipment)?
Distance measuring equipment (DME) is a radio navigation method that determines the range between an airplane and a ground station. DME is comparative in fundamental level to secondary radar ranging function, with the exception of the roles of the hardware in the airplane and on the ground are reversed. DME was a post-war improvement dependent on the recognizable IFF frameworks of World War II. It has timing the propagation delay of radio signals in the frequency band between 960 and 1215 megahertz (MHz).
- What is DMM (Distributed mobility management)?
DMM arrangements focus on transparency over the IP layer, incorporating upkeep of active transport level sessions when versatile hosts or portable networks change their point of connection to the Internet. DMM arrangements are basically designated at IPv6 deployments and are not needed to assist IPv4, specifically for the situation where private IPv4 addresses and/or NATs are utilized. DMM arrangements should keep up with in reverse compatibility, If the portable does not assist the disseminated portability management protocol that should not prevent the versatile host/router acquiring essential admittance to the network.
- What is DMO (Direct mode operation)?
Direct Mode Operation (DMO) is utilized to portray the capacity of radio terminals to communicate straightforwardly with one another independent of the network. DMO is utilized by numerous traditional Private portable Radio networks to permit communications out of reach of the network.
The typical applications for DMO are local area communications outside the TMO network and range extension of the TMO network. To further develop correspondence abilities when utilizing these applications, offices are given to empower DMO clients to be attached by TMO network clients while working outside the organization just as offices to improve local area DMO RF coverage performance.
- What is DMR (Digital Mobile Radio)?
Digital mobile radio (DMR) is a limited open digital versatile radio standard. It is characterized in the European Telecommunications Standards Institute Standard TS 102 361 parts 1–4. The essential objective of the standard is to indicate a computerized framework with low intricacy, minimal expense and interoperability across brands. It is utilized in commercial products all throughout the planet. DMR was intended with three tiers. DMR tiers I and II were first published in 2005, and DMR III (Trunked version) was established in 2012.
- What is DMRS (demodulation reference signal)?
The DMRS is explicit for specific UE. It is utilized to examine the radio channel. The framework can beamform the DMRS, keep it inside a scheduled asset, and send it only when essential in DL or UL. This is a reference signal for PUSCH shows that eNodeB would not have the option to decode PUSCH when PUSCH DMRS is not correct. It is utilized by a receiver for radio channel assessment for demodulation of related physical channels. PUSCH DMRS consistently takes up the center symbol of a slot.
- DNAI (Data Network Access Identifier)
A Data Network Access Identifier (DNAI) is an administrator characterized identifier of a client plane’s admittance where applications are conveyed to at least one DN(s). A DNAI will distinguish the user plane admittance to at least one Data Networks at which explicit applications can be discovered, especially in assist of Multi Access Edge Computing.