Glossary of DTV abbreviations and expressions Term
Definition
Description
AFC
Automatic Frequency Control
AI ASCII
Amplitude Imbalance American Standard Code for Information Interchange
ASI
Asynchronous serial interface
Is a method (or device) to automatically keep a resonant circuit tuned to the frequency of an incoming radio signal. It is primarily used in radio receivers to keep the receiver tuned to the frequency of the desired station. Related to MER (see MER) Is a character‐encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text. Most modern character‐encoding schemes are based on ASCII, though they support many more characters than did ASCII. Not synchronised to another signal or clock. Start‐stop working. An ASI signal can carry one or multiple SD, HD or audio programs that are already compressed, not like an uncompressed SD‐SDI (270Mbs) or HD‐SDI (1.45Gbs). An ASI signal can be at varying transmission speeds and is completely dependent on the user's setup requirements. For example, an ATSC (US Digital Standard for Broadcasting) has a maximum bandwidth of 19.392658 Mbps. Generally, the ASI signal is the final product of video compression, either MPEG2 or MPEG4, ready for transmission to a transmitter or microwave system or other device. Sometimes it is also converted to fibre, RF or SMPTE310 for other types of transmission. There are two transmission formats commonly used by the ASI interface: the 188 byte format and the 204 byte format. The 188 byte format is the more common ASI transport stream. When optional Reed‐ Solomon error correction data is included the packet is extended by an extra 16 bytes to 204 bytes total.
ATM
Asynchronous Transfer Mode
ATSC
Advanced Television Systems Committee
AVCHD AVI
Advanced Video Coding High Definition Audio Video Interleave
AWGN
Additive White Gaussian Noise
BAT
Bouquet Association Table
BEP
Bit Error Probability
BER BGP
Bit Error Rate Border Gateway Protocol
C/N
Carrier to noise ratio (of RF or IF signal)
CAM
Conditional Access Module
CAT
Conditional Access Table
CATV CC
Community Antenna TeleVision Continuity Counter
Codec COFDM
Compressor‐Decompressor or Coder‐Decoder Coded Orthogonal Frequency Division Multiplexing
CP CPE
Content Provider Customer Premises Equipment
CPE CWDM
Common Phase Error Coarse Wave Division Multiplexing
DCM DHCP DNS
Digital Content Manager Dynamic Host Configuration Protocol Domain Name System
DOCSIS DRM
Data Over Cable Service Interface Specification Digital Rights Management
DSL DSLAM
Digital Subscriber Line Digital Subscriber Line Access Multiplexer
Is a standardized digital data transmission technology. ATM is implemented as a network protocol and was first developed in the mid 1980s. The goal was to design a single networking strategy that could transport real‐time video conference and audio as well as image files, text and email. ATM uses 53‐byte cells (5 bytes for the address header and 48 bytes for the data). These extremely small cells can be processed through an ATM switch fast enough to maintain data transfer speeds of over 600 mbps. Is a set of standards developed by the Advanced Television Systems Committee for digital television transmission. ATSC replaced much of the analogue NTSC television system in the United States on June 12, 2009 and replaced NTSC in August 31, 2011 in Canada. Is a format for the recording and playback of high definition video Is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio‐with‐ video playback. Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used. Most AVI files also use the file format extensions developed by the Matrox OpenDML group in February 1996. Is a channel model in which the only impairment to communication is a linear addition of wideband or white noise with a constant spectral density (expressed as watts per hertz of bandwidth) and a Gaussian distribution of amplitude BAT provides information regarding bouquets. As well as giving the name of the bouquet, it provides a list of services for each bouquet. Is the number of received bits that have been altered due to noise, interference and distortion, divided by the total number of transferred bits during a studied time interval. BER is a unitless performance measure, often expressed as a percentage number. Bit Error Rate. (Errors per second) Is the core routing protocol of the Internet. It maintains a table of IP networks or 'prefixes' which designate network reachability among autonomous systems Is the signal‐to‐noise ratio (SNR) of a modulated signal. The term is used to distinguish the CNR of the radio frequency passband signal from the SNR of an analogue base band message signal after demodulation, for example an audio frequency analogue message signal. If this distinction is not necessary, the term SNR is often used instead of CNR, with the same definition. Is an electronic device, usually incorporating a slot for a smart card, which equips an Integrated Digital Television or set‐top box with the appropriate hardware facility to view conditional access content that has been encrypted using a conditional access system This table is used for conditional access to the streams. This table provides association with EMM stream. When the TS is scrambled then this section contains the EMM PID. This EMM pid is encrypted using the smart card number. Cable Television Each Transport Stream (TS) packet with the same PID carries its own 4‐bit counter. The CC makes it possible to recognize missing TS packets Is a device or computer program capable of encoding and/or decoding a digital data stream or signal essentially identical to coded OFDM (COFDM) and discrete multi‐tone modulation (DMT), is a frequency‐division multiplexing (FDM) scheme utilized as a digital multi‐carrier modulation method. A large number of closely‐spaced orthogonal sub‐carriers are used to carry data. The data is divided into several parallel data streams or channels, one for each sub‐carrier. Each sub‐carrier is modulated with a conventional modulation scheme (such as quadrature amplitude modulation or phase‐shift keying) at a low symbol rate, maintaining total data rates similar to conventional single‐carrier modulation schemes in the same bandwidth. Any organisation that delivers contribution data (Audio, Video etc) Is any terminal and associated equipment located at a subscriber's premises and connected with a carrier's telecommunication channel(s) at the demarcation point ("demark"). The demark is a point established in a building or complex to separate customer equipment from telephone company equipment. Noise Combines up to 16 wavelengths onto a single fibre using a standard 20nm spacing between the wavelengths. Transponders are inexpensive compared to DWDM because wavelengths are far apart. Is an MPEG Processor, a compact 1RU platform capable of processing a high number of MPEG video streams A protocol for assigning dynamic IP addresses to devices on a network. Is a hierarchical naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participants. Most importantly, it translates domain names meaningful to humans into the numerical (binary) identifiers associated with networking equipment for the purpose of locating and addressing these devices worldwide. An often‐used analogy to explain the Domain Name System is that it serves as the "phone book" for the Internet by translating human‐friendly computer hostnames into IP addresses. Industry standard that defines how cable modems communicate over cable television line. Covers the description, identification, trading, protection, monitoring and tracking of all forms of rights usages over both tangible and intangible assets including management of rights holders. This is an access technology for implementing broadband transmission over a normal telephone connection Chassis which contains multiple DSL modems that link many DSL connections to a single high‐speed line
DTH
Direct to The Home
DTT
Digital Terrestrial Television
DVB
Digital Video Broadcasting
DVB‐C
Digital Video Broadcasting Cable
DVB‐CI
Digital Video Broadcasting – Common Interface
DVB‐CS
Digital Video Broadcasting baseline system for SMATV distribution systems(ETS 300 473) Digital Video Broadcasting ‐ Handheld
DVB‐H
This was initially meant to distinguish the transmissions directly intended for home viewers from cable television distribution services that sometimes carried on the same satellite. The term DTH predates DBS and is often used in reference to services carried by lower power satellites which required larger dishes (1.7m diameter or greater) for reception. Is the technological evolution and advance from analogue terrestrial television, which broadcasts land based (terrestrial) signals. The purpose of digital terrestrial television, similar to digital versus analogue in other platforms such as cable, satellite, telecoms, is characterised by reduced use of spectrum and more capacity than analogue, better‐quality picture, and lower operating costs for broadcast and transmission after the initial upgrade costs. A terrestrial implementation of digital television technology uses aerial broadcasts to a conventional antenna (or aerial) instead of a satellite dish or cable connection. Is a suite of internationally accepted open standards for digital television. DVB standards are maintained by the DVB Project , an international industry consortium with more than 270 members, and they are published by a Joint Technical Committee (JTC) of European Telecommunications Standards Institute (ETSI), European Committee for Electrotechnical Standardization (CENELEC) and European Broadcasting Union (EBU). The interaction of the DVB sub‐ standards is described in the DVB Cookbook . Many aspects of DVB are patented, including elements of the MPEG video coding and audio coding. Is the DVB European consortium standard for the broadcast transmission of digital television over cable. This system transmits an MPEG‐2 or MPEG‐4 family digital audio/video stream, using a QAM modulation with channel coding. Is a defined standard, to enable the addition of a conditional access module (CAM) in a DTV Receiver, to adapt it to different kinds of cryptography Where one satellite antenna system supplies many televisions; the received signal may come from a satellite or terrestrial source. Is one of three prevalent mobile TV formats. It is a technical specification for bringing broadcast services to mobile handsets. DVB‐H was formally adopted as ETSI standard EN 302 304 in November 2004. The DVB‐H specification (EN 302 304) can be downloaded from the official DVB‐H website
DVB‐MC
Digital Video Broadcasting baseline system for Multi‐point Video Distribution Systems below 10 GHz (ETS 300 749)
DVB‐MS
Digital Video Broadcasting baseline system for Multi‐point Video Distribution Systems at 10 GHz and above (ETS 300 748) Digital Video Broadcasting Satellite Digital Video Broadcasting ‐ Satellite ‐ Second Generation Is designed as a successor for the popular DVB‐S digital television broadcast standard, and was developed in 2003 and ratified by ETSI (EN 302307) in March 2005. It is based on DVB‐S and the DVB‐DSNG (Digital Satellite News Gathering) standard, used by mobile units for sending external footage back to television stations. DVB‐S2 is envisaged for broadcast services including standard and HDTV, interactive services including Internet access, and (professional) data content distribution. The development of DVB‐S2 coincided with the introduction of HDTV and H.264 (MPEG‐4 AVC) video codecs Service Information Digital data describing the delivery system, content and scheduling/timing of broadcast data streams, etc. Digital Video Broadcasting Terrestrial Is the DVB European‐based consortium standard for the broadcast transmission of digital terrestrial television that was first broadcast in the UK in 1997. This system transmits compressed digital audio, video and other data in an MPEG transport stream, using COFDM modulation. Dense Wave Division Multiplexing Combines up to 64 wavelengths onto a single fibre using a standard 100GHz or 200GHz spacing between the wavelengths, arranged in several bands. Transponders are complex and expensive because the high density wavelengths are close together and can reach longer distances than CWDM Dense Wave Division Multiplexing Refers originally to optical signals multiplexed within the 1550 nm band so as to leverage the capabilities (and cost) of erbium doped fibre amplifiers (EDFAs), which are effective for wavelengths between approximately 1525‐1565 nm (C band), or 1570‐1610 nm (L band). Entitlement Control Message Message that carries content descrambling keys and a brief description of the content (content ID, date, time, cost, etc.). ECMs are tightly bound with the associated content and may be delivered simultaneously with it. Entitlement Control Message The first type of conditional access messages of the DVB standard The exiting of a signal External Integration Interface for easy integration into 3rd A Bridgetech interface that allows their IP/ASI/RF network monitoring probes to communicate with any 3rd party NMS party OSS/NMS system Event Information Table Contains data concerning events, such as event name, start time, duration, etc. The use of different descriptors in EIT allows the transmission of different kinds of event information, like the different service types. It is also used to transmit the information relating to the all events that occur or will occur in the MPEG multiplex. EPG Entitlement Management Message Message that specifies service‐related authorization levels for the customers. N.B. EMMs are not usually directly related to content items and can be delivered together with or independently from service distribution channels.
DVB‐S DVB‐S2
DVB‐SI DVB‐T
DWDM
DWDM
ECM ECM Egress Eii™ EIT
EMM
EMM ENB
Entitlement Management Message Equivalent Noise Bandwidth
One of the conditional access messages used in the DVB system The concepts of resolution and dynamic range tend to be somewhat subjective, depending on what the user is actually trying to do. But they also tend to be highly correlated with the total leakage, which is quantifiable. It is usually expressed as an equivalent bandwidth, B. Think of it as redistributing the DTFT into a rectangular shape with height equal to the spectral maximum and width B. The more leakage, the greater the bandwidth. It is sometimes called noise equivalent bandwidth or equivalent noise bandwidth , because it is proportional to the average power that will be registered by each DFT bin when the input signal contains a random noise component (or is just random noise). A graph of the power spectrum, averaged over time, typically reveals a flat noise floor , caused by this effect. The height of the noise floor is proportional to B. So two different window functions can produce different noise floors.
END
Equivalent Noise Degradation
EPG
Electronic Program Guide
E‐QAM
Edge Quadrature amplitude modulation
ES
Errored Second
ETR
ETSI Technical Report
Is a measure of the implementation loss caused by the network or the equipment where the reference is the ideal performance. An on‐screen guide that provides details of current and future programs and helps guide the user to the program of choice. Features include: program summaries, search by subject or channel, immediate access to the selected program, reminders, and parental control functions. Accepts MPEG transport streams coming over IP‐networks as unicast or multicast data packets are converted and available at the output as RF‐signal in the selected frequency range to feed them into local CATV networks or HFC cluster Is an interval of a second during which any error whatsoever has occurred, regardless of whether that error was a single bit error, or a complete loss of communication for that entire second, is not important for the purpose of counting errored seconds. European Telecommunications Standards Institute
ETSI
European Telecommunications Standards Institute
EVM
Error Vector Magnitude
FEC
Forward Error Correction
FTTB
Fiber‐to‐the‐building or Fiber‐to‐the‐basement ‐
FTTC FTTH FTTLA
Fiber‐to‐the‐cabinet or fibre‐to‐the‐curb ‐ Fiber To The Home Fiber to the last amplifier
FTTN
Fiber‐to‐the‐node ‐
FTTP
Fiber‐to‐the premises ‐
Glop Addressing
H.264
MPEG‐4 Part 10, or as AVC
HD
High Definition Television
HE HEX
Head End Hexadecimal
HFC
Hybrid fibre‐coaxial
IAT
Inter Arrival Time
ICMP
Internet Control Message Protocol
IEEE 802.11
WLAN
IEEE 802.11n
IEEE 802.1Q
VLAN Tagging
iFrame
IGMP
Internet Group Management Protocol
IGMP Snooping
Ingress IOS
The entry of a signal Internetwork Operating System
Is an independent, non‐profit, standardization organization in the telecommunications industry (equipment makers and network operators) in Europe, with worldwide projection. ETSI has been successful in standardizing the GSM cell phone system and the TETRA professional mobile radio system. Is a measure used to quantify the performance of a digital radio transmitter or receiver. A signal sent by an ideal transmitter or received by a receiver would have all constellation points precisely at the ideal locations, however various imperfections in the implementation (such as carrier leakage, low image rejection ratio, phase noise etc.) cause the actual constellation points to deviate from the ideal locations. Informally, EVM is a measure of how far the points are from the ideal locations Is a system of error control for data transmission, whereby the sender adds redundant data to its messages, also known as an error‐correction code. This allows the receiver to detect and correct errors (within some bound) without the need to ask the sender for additional data. The advantages of forward error correction are that a back‐channel is not required and retransmission of data can often be avoided (at the cost of higher bandwidth requirements, on average). FEC is therefore applied in situations where retransmissions are relatively costly or impossible. In particular, FEC information is usually added to most mass storage devices to protect against damage to the stored data. Fiber reaches the boundary of the building, such as the basement in a multi‐dwelling unit, with the final connection to the individual living space being made via alternative means. This is very similar to FTTN, but the street cabinet is closer to the user's premises; typically within 300m. Fiber reaches the boundary of the living space, such as a box on the outside wall of a home. The network cables being able to use several amplifiers, the FTTLA aims at replacing the coaxial cable to the last amplifier (towards the subscriber) by optical fibre. It acts as a new technology aiming at re‐using the network cables existing in particular on the final part while installing of optical fibre more closely to the subscriber while using the coaxial cable of the networks cables for the "last mile" or "last meters" connected with the subscriber. Fiber is terminated in a street cabinet up to several kilometres away from the customer premises, with the final connection being copper. This term is used in several contexts: as a blanket term for both FTTH and FTTB, or where the fibre network includes both homes and small businesses. RFC 2770 proposes that the 233.0.0.0/8 address range be reserved for statically defined addresses by organizations that already have an AS number reserved. The AS number of the domain is embedded into the second and third octets of the 233.0.0.0/8 range. For example, the AS 62010 is written in hex as F23A. Separating out the two octets F2 and 3A, we get 242 and 58 in decimal. This would give us a subnet of 233.242.58.0 that would be globally reserved for AS 62010 to use. H.264/MPEG‐4 AVC is a block‐oriented motion‐compensation‐based codec standard developed by the ITU‐T Video Coding Experts Group (VCEG) together with the International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) Moving Picture Experts Group (MPEG). Refers to video having resolution substantially higher than traditional television systems (standard‐definition TV, or SDTV, or SD). HD has one or two million pixels per frame, roughly five times that of SD. Early HDTV broadcasting used analogue techniques, but today HDTV is digitally broadcast using video compression. Is a master facility for receiving television signals for processing and distribution Is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F (or alternatively a through f) to represent values ten to fifteen. For example, the hexadecimal number 2AF3 is equal, in decimal, to (2 × 163) + (10 × 162) + (15 × 161) + (3 × 160) , or 10,995 Is a telecommunications industry term for a broadband network which combines optical fibre and coaxial cable. It has been commonly employed globally by cable TV operators y p y g y y p Is the Delay Factor is the maximum difference, observed at the end of each media stream packet, between the arrival of media data and the drain of media data. Is one of the core protocols of the Internet Protocol Suite. It is chiefly used by networked computers' operating systems to send error messages—indicating, for instance, that a requested service is not available or that a host or router could not be reached. Is a set of standards carrying out wireless local area network (WLAN) computer communication in the 2.4, 3.6 and 5 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802). Is a recent amendment which improves upon the previous 802.11 standards by adding multiple‐input multiple‐output (MIMO) and many other newer features. The IEEE has approved the amendment and it was published in October 2009. Prior to the final ratification, enterprises were already migrating to 802.11n networks based on the Wi‐Fi Alliance's certification of products conforming to a 2007 draft of the 802.11n proposa Is a networking standard written by the IEEE 802.1 workgroup allowing multiple bridged networks to transparently share the same physical network link without leakage of information between networks. IEEE 802.1Q — along with its shortened form dot1q — is commonly used to refer to the encapsulation protocol used to implement this mechanism over Ethernet networks. iFrame is a constraint of the H.264 codec specified by Apple to ensure ease of consumer video editing. It provides a square‐pixel 16:9 image format of 960 horizontal by 540 vertical pixels, with progressive scanning at 30 frames per second and can be identified as the format "540p30". These parameters are one‐half the spatial resolution of 1080p in each direction, one‐quarter the total number of pixels. iFrame has 1.5 times the number of pixels in standard definition 4:3 720×480 CCIR 601 NTSC video. However, its progressive The 30 fps frame rate used for iFrame may result in increased “judder” with moving images, when compared to the nominal frame rate of 60 pictures per second typically used for professional video in North America. Scanning increases the approximate perceived resolution advantage over 480i to roughly a factor of 2. Is a communications protocol used to manage the membership of Internet Protocol multicast groups. IGMP is used by IP hosts and adjacent multicast routers to establish multicast group memberships. It is an integral part of the IP multicast specification, operating above the network layer, though it does not actually act as a transport protocol. It is analogous to ICMP for unicast connections. IGMP can be used for online streaming video and gaming, and allows more efficient use of resources when supporting these types of applications. IGMP is vulnerable to some attacks, and firewalls commonly allow the user to disable it if not needed. Is the process of listening to Internet Group Management Protocol (IGMP) network traffic. IGMP snooping, as implied by the name, is a feature that allows a layer 2 switch to listen in on the IGMP conversation between hosts and routers. By listening to these conversations the switch maintains a map of which links need which IP multicast streams. Multicasts may then be sent only to the links that need them. The entry point for data into a network or system Is the software used on the vast majority of Cisco Systems routers and current Cisco network switches. (Earlier switches ran CatOS.) IOS is a package of routing, switching, internetworking and telecommunications functions tightly integrated with a multitasking operating system.
IP
Internet Protocol
IPTV
Internet Protocol television
IQ
In‐phase/Quadrature components
IRD
Integrated Receiver Decoder
ISO ITIL
International Organization for Standardization Information Technology Infrastructure Library
ITU
International Telecommunication Union
LAT LNB
Link Available Time Low Noise Block
LO
Local Oscillator
MBGP
Multiprotocol Border Gateway Protocol
MDI
Media Delivery Index
MER
Modulation Error Ratio
MHEG‐5
Multimedia and Hypermedia Experts Group
MIB
Management Information Base
MicroETR
MIP
Mega‐frame Initialization Packet
MLR
Media Loss Rate
MMDS
Microwave Multi‐point Distribution Systems (or Multi‐ channel Multi‐point Distribution Systems)
MPEG
Moving Picture Experts Group
MPLS MPTS MRD MSDP
MultiProtocol Label Switching Multi Program Transport Stream Modular Receiver Decoder Multicast Source Discovery Protocol
MTTF
Mean Time To Failure
MTTR
Mean Time To Repair
IP is the primary protocol in the Internet Layer of the Internet Protocol Suite and has the task of delivering distinguished protocol datagrams (packets) from the source host to the destination host solely based on their addresses. For this purpose the Internet Protocol defines addressing methods and structures for datagram encapsulation. The first major version of addressing structure, now referred to as Internet Protocol Version 4 (IPv4) is still the dominant protocol of the Internet, although the successor, Internet Protocol Version 6 (IPv6) is being deployed actively worldwide. Is a system through which internet television services are delivered using the architecture and networking methods of the Internet Protocol Suite over a packet‐switched network infrastructure, e.g., the Internet and broadband Internet access networks, instead of being delivered through traditional radio frequency broadcast, satellite signal, and cable television (CATV) formats. Any sinusoidal waveform with arbitrary phase can be considered to be composed of the sum of in‐phase and quadrature components, that is, two sinusoids with phases of 0° and 90° Is an electronic device used to pick‐up a radio‐frequency signal combined with the necessary hardware to convert digital information transmitted back to baseband. A worldwide federation of national standards bodies from some 100 countries, one from each country Is a set of concepts and practices for Information Technology Services Management (ITSM), Information Technology (IT) development and IT operations. Founded in 1865 in Paris and is now the specialized agency of the United Nations which is responsible for information and communication technologies, and is based in Geneva, Switzerland. Is the proportion of time a system is in a functioning condition. Is the (receiving, or downlink) antenna of what is commonly called the parabolic satellite dish commonly used for satellite TV reception. It is functionally equivalent to the dipole antenna used for most other TV reception purposes, although it is actually waveguide based. Whereas the dipole antenna is unable to adapt itself to various polarization planes without being rotated, the LNB can be switched electronically between horizontal and vertical polarization reception. The LNB is usually fixed on or in the satellite dish, for the reasons outlined below. The corresponding component in the uplink transmit link is called a Block upconverter (BUC). Is an electronic device used to generate a signal normally for the purpose of converting a signal of interest to a different frequency using a mixer. This process of frequency conversion, also referred to as heterodyning, produces the sum and difference frequencies of the frequency of the local oscillator and frequency of the input signal of interest. These are the beat frequencies. Normally the beat frequency is associated with the lower sideband, the difference between the two. Gives a method for providers to distinguish which route prefixes they will use for performing multicast RPF checks. The RPF check is the fundamental mechanism that routers use to determine the paths that multicast forwarding trees will follow and successfully deliver multicast content from sources to receivers. The MDI provides a relative indicator of needed buffer depths at the consumer node due to packet jitter as well as an indication of lost packets. The MDI consists of two components: the Delay Factor (DF) and the Media Loss Rate (MLR). Is a measure used to quantify the performance of a digital radio transmitter or receiver in a communications system using digital modulation (such as QAM). A signal sent by an ideal transmitter or received by a receiver would have all constellation points precisely at the ideal locations, however various imperfections in the implementation (such as noise, low image rejection ratio, phase noise, carrier suppression, distortion, etc.) or signal path cause the actual constellation points to deviate from the ideal locations. Is a cost‐effective, licence‐free, efficient, public standard interactive TV middleware that is used to both send and receive interactive TV signals. It allows a wide range of TV‐centric iTV services to be deployed. It is used by Freeview and Freesat in the UK, Freeview in New Zealand, TVB in Hong Kong and has been specified in Ireland, Australia and South Africa. Is a virtual database used for managing the entities in a communications network. Most often associated with the SNMP protocol One of bridgeTech's display technologies that presents the measurements for many of transport streams in one easy to comprehend GUI. The operator can easily click on the stream with errors and drill down to find the cause of the problem. MIP insertion occurs once per megaframe (once per second) and indicates when the first packet in a mega‐frame (Synchronization Time Stamp, STS) begins transmitting. The time reference is an external 1 pulse per second signal, easily obtained from a GPS receiver. The Media Loss Rate is the count of lost or out‐of‐order flow packets over a selected time interval, where the flow packets are packets carrying streaming application information. Now more correctly known as Broadband Radio Service (BRS) is a wireless telecommunications technology, operating at microwave frequencies at 2.1 GHz and from 2.5 GHz to 2.7 GHz. Its used for general‐purpose broadband networking or, more commonly, as an alternative method of cable television programming reception Is a working group of experts that was formed by ISO and IEC to set standards for audio and video compression and transmission. Network for virtual private networks, LANs, leased lines, and high speed services A transport stream that offers multiple program services Is an electronic device used to pick‐up a radio‐frequency signal and convert digital information transmitted in it In the PIM Sparse mode model, multicast sources and receivers must register with their local Rendezvous Point (RP). Actually, the closest router to the sources or receivers registers with the RP but the point is that the RP knows about all the sources and receivers for any particular group. RPs in other domains have no way of knowing about sources located in other domains. MSDP is an elegant way to solve this problem. MSDP is a mechanism that connects PIM‐SM domains and allows RPs to share information about active sources. When RPs in remote domains know about active sources they can pass on that information to their local receivers and multicast data can be forwarded between the domains. A nice feature of MSDP is that it allows each domain to maintain an independent RP which does not rely on other domains, but it does enable RPs to forward traffic between domains. Is the predicted elapsed time between inherent failures of a system during operation. MTBF can be calculated as the arithmetic mean (average) time between failures of a system. The MTBF is typically part of a model that assumes the failed system is immediately repaired (zero elapsed time), as a part of a renewal process. This is in contrast to the mean time to failure (MTTF), which measures average time between failure with the modelling assumption that the failed system is not repaired Is a basic measure of the maintainability of repairable items. It represents the average time required to repair a failed component or device. Expressed mathematically, it is the total corrective maintenance time divided by the total number of corrective maintenance actions during a given period of time. It generally does not include lead time for parts not readily available, or other Administrative or Logistic Downtime (ALDT
MUX
Multiplexer
MVDS NIT
Multi‐point Video Distribution Systems Network Information Table
NPVR
Network Personal Video Recorder
NTP
Network Time Protocol
NTSC
National Television System Committee
Null Packets
NVOD NW ID OEM
Near Video On Demand Network Identification Original Equipment Manufacturer
OFDM
Orthogonal Frequency Division Multiplex
PAL
Phase Alternate Line
PAR
Pixel Aspect Ratio
PAT PCR
Program Association Table Program Clock Reference
PES
Packetized Elementary Stream
PGM
Pragmatic General Multicast
PID PIM
Packet ID Protocol‐Independent Multicast l d d l
PIM‐DM
PIM Dense Mode
PIM‐SM
PIM Sparse Mode
PLL
Phase Locked Loop
PMT
Program Map Table
POTS
Plain Old Telephone Service
Is a device that combines several input information signals into one output signal, which carries several communication channels, by means of some multiplex technique MVDS is a part of broader MWS (Multimedia Wireless System) standards This table provides information about the multiplexes and transport streams on a given network, Information about the current network uses table_id of 0x40, that about other networks uses table_id of 0x41 , It is segmented into network information sections and Also this table contains the private stream information too. For example, Teletext, Subtitle Previously broadcast material can be viewed without the user having to make a request to the head‐end or download content locally. Is a protocol for synchronizing the clocks of computer systems over packet‐switched, variable‐latency data networks. NTP uses UDP on port 123 as its transport layer. It is designed particularly to resist the effects of variable latency by using a jitter buffer. NTP also refers to a reference software implementation that is distributed by the NTP Public Services Project. Is the analogue television system used in most of North America, South America, Burma, South Korea, Taiwan, Japan, Philippines, and some Pacific island nations and territories (see map). NTSC is also the name of the U.S. standardization body that developed the broadcast standard. The first NTSC standard was developed in 1941 and had no provision for colour TV. Constant bitrate requirements on the transport stream. In order to ensure that the stream maintains a constant bitrate, a Multiplexer may need to insert some additional packets. The PID 0x1FFF (8191) is reserved for this purpose. The payload of null packets may not contain any data at all, and the receiver is expected to ignore its contents. PPV with multiple showings of the same movie at staggered times, so there are more chances to view a movie Derived from the NIT (see NIT) Designation for companies that manufacture equipment that is then marketed and sold off to other companies under their own names An OFDM signal consists of a number of closely spaced modulated carriers. Although the sidebands from each carrier overlap, they can still be received without mutual interference because they are orthogonal to each another. This is achieved by having the carrier spacing equal to the reciprocal of the symbol period. Is an analogue television encoding system used in broadcast television systems in large parts of the world. Other common analogue television systems are SECAM and NTSC Use of pixel aspect ratio mostly involves pictures that need to maintain compatibility with older standards such as standard‐definition television and some other exceptional cases. Most other imaging systems, including those which comply with SMPTE standards and practices, are based on square pixels. Lists all programs available in the transport stream To enable a decoder to present synchronized content, such as audio tracks matching the associated video, at least once each 100 ms a Program Clock Reference , or PCR is transmitted in the adaptation field of an MPEG‐2 transport stream packet Is a specification in the MPEG‐2 Part 1 (Systems) (ISO/IEC 13818‐1) that defines carrying of elementary streams in packets within MPEG program stream and MPEG transport stream. The elementary stream is packetized by encapsulating sequential data bytes from the elementary stream inside PES packet headers. Pragmatic General Multicast (PGM) is a reliable multicast transport protocol for applications that require ordered, duplicate‐free, multicast data delivery from multiple sources to multiple receivers. PGM guarantees that a receiver in a multicast group either receives all data packets from transmissions and retransmissions, or can detect unrecoverable data packet loss. Each table or elementary stream in an MPEG2 transport stream is identified by a 13‐bit packet ID (PID) Is a family of multicast routing protocols for Internet Protocol (IP) networks that provide one‐to‐many and many‐to‐ f l f l l f l( ) k h d d many distribution of data over a LAN, WAN or the Internet. It is termed protocol‐independent because PIM does not include its own topology discovery mechanism, but instead uses routing information supplied by other traditional routing protocols such as the Border Gateway Protocol (BGP). PIM Dense Mode (PIM‐DM) uses a push model to flood multicast traffic to every corner of the network. This is a brute‐ force method for delivering data to the receivers, but in certain applications, this might be an efficient mechanism if there are active receivers on every subnet in the network. PIM‐DM initially floods multicast traffic throughout the network. Routers that do not have any downstream neighbours prune back the unwanted traffic. This process repeats every 3 minutes. The flood and prune mechanism is how the routers accumulate their state information—by receiving the data stream. These data streams contain the source and group information so that downstream routers can build up their multicast forwarding tables. PIM‐DM can support only source trees—(S,G) entries. It cannot be used to build a shared distribution tree. PIM Sparse Mode (PIM‐SM) uses a pull model to deliver multicast traffic. Only networks that have active receivers that have explicitly requested the data will be forwarded the traffic. PIM‐SM is defined in RFC 2362. PIM‐SM uses a shared tree to distribute the information about active sources. Depending on the configuration options, the traffic can remain on the shared tree or switch over to an optimized source distribution tree. The latter is the default behaviour for PIM‐ SM on Cisco routers. The traffic starts to flow down the shared tree, and then routers along the path determine whether there is a better path to the source. If a better, more direct path exists, the designated router (the router closest to the receiver) will send a join message toward the source and then reroute the traffic along this path. PIM‐ SM has the concept of an RP, since it uses shared trees—at least initially. The RP must be administratively configured in the network. Sources register with the RP, and then data is forwarded down the shared tree to the receivers. If the shared tree is not an optimal path between the source and the receiver, the routers dynamically create a source tree and stop traffic from flowing down the shared tree. This is the default behaviour in IOS. Network administrators can Is a control system that generates a signal that has a fixed relation to the phase of a "reference" signal. A phase‐locked loop circuit responds to both the frequency and the phase of the input signals, automatically raising or lowering the frequency of a controlled oscillator until it is matched to the reference in both frequency and phase. A phase‐locked loop is an example of a control system using negative feedback Contains information about programs. For each program, there is one PMT. While the MPEG‐2 standard permits more than one PMT section to be transmitted on a single PID, most MPEG‐2 systems such as ATSC and SCTE require each PMT to be transmitted on a separate PID that is not used for any other packets. The PMTs provide information on each program present in the transport stream, including the program_number, and list the elementary streams that comprise the described MPEG‐2 program. There are also locations for optional descriptors that describe the entire MPEG‐2 program, as well as an optional descriptor for each elementary stream. Each elementary stream is labelled with a stream_type value Basic voice service available in most residences
PSI
Program Specific Information
Is metadata about a program (channel) and part of a MPEG transport stream. PSI is carried in the form of a table structure. The table structure can span multiple transport stream packets. Adaptation field also occurs in TS packets carrying PSI data. The PSI data will never be scrambled so that the decoder at the receiving end can easily identify the properties of the stream.
PSI PTS
MPEG‐2 Program Specific Information (as defined in ISO/IEC 13818‐1 [1]) Presentation Time Stamps
There are 4 PSI tables: Program Association (PAT), Program Map (PMT), Conditional Access (CAT), and Network Information (NIT). The MPEG‐2 specification does not specify the format of the CAT and NIT. Is a metadata field in an MPEG transport stream or MPEG program stream that is used to achieve synchronization of programs' separate elementary streams (for example Video, Audio, Subtitles) when presented to the viewer. The PTS is given in units related to a program's overall clock reference, either Program Clock Reference (PCR) or System Clock Reference (SCR), which is also transmitted in the transport stream or program stream.
PVR QAM
Personal Video Recorder Quadrature amplitude modulation
QE
Quadrature Error
QEF QEV QPSK
Quasi Error Free Quadrature Error Vector Quadrature Phase Shift Keying
RF
Radio Frequency
RFC
Request For Comments
RGW
Residential Gateway
RMS
Root Mean Square
RPF
Reverse Path Forwarding
RS
Reed‐Solomon
RS232
Recommended Standard 232
RST
Running Status Table (see ETS 300 468)
RTE RTP RTSP
Residual Target Error Real Time Transport Protocol Real Time Streaming Protocol
RUDP
Reliable User Datagram Protocol
R‐UDP SD
Microsoft Version of RUDP Standard Definition Television
SDH (1)
Synchronous Digital Hierarchy
Is both an analogue and a digital modulation scheme. It conveys two analogue message signals, or two digital bit streams, by changing (modulating ) the amplitudes of two carrier waves, using the amplitude‐shift keying (ASK) digital modulation scheme or amplitude modulation (AM) analogue modulation scheme. These two waves, usually sinusoids, are out of phase with each other by 90° and are thus called quadrature carriers or quadrature components — hence the name of the scheme. The modulated waves are summed, and the resulting waveform is a combination of both phase‐shift keying (PSK) and amplitude‐shift keying (ASK), or in the analogue case of phase modulation (PM) and amplitude modulation. In the digital QAM case, a finite number of at least two phases, and at least two amplitudes are used. PSK modulators are often designed using the QAM principle, but are not considered as QAM since the amplitude of the modulated carrier signal is constant. Also referred to as quadrature skew, describes a complex signal impairment such that the I and Q components are not perfectly orthogonal. Generally refers to the notion that there is less than one uncorrected error per hour. A measure of how far the received constellation points to deviate from their ideal locations Sometimes known as quaternary or quadriphase PSK, 4‐PSK, or 4‐QAM, QPSK uses four points on the constellation diagram, equispaced around a circle. With four phases, QPSK can encode two bits per symbol, shown in the diagram with Gray coding to minimize the BER — twice the rate of BPSK. Analysis shows that this may be used either to double the data rate compared to a BPSK system while maintaining the bandwidth of the signal or to maintain the data‐rate of BPSK but halve the bandwidth needed. Radio frequency is a small section of the electromagnetic spectrum with a wavelength of 100 km to 1 mm, which corresponds to frequency band of 3 kHz to 300 GHz, respectively. RF can refer to electromagnetic oscillations in either electrical circuits or radiation through air and space. In computer network engineering, a Request for Comments (RFC) is a memorandum published by the Internet Engineering Task Force (IETF) describing methods, behaviours, research, or innovations applicable to the working of the Internet and Internet‐connected systems Is a home networking device, used as a gateway to connect devices in the home to the Internet or other WAN. It is an umbrella term, used to cover multi‐function networking computer appliances used in homes, which may combine a DSL modem or cable modem, a network switch, providing LAN switching, a consumer‐grade router, and a wireless access point. In the past, such functions were provided by separate devices, but by technological convergence, they have often merged into a single device. Is a statistical measure of the magnitude of a varying quantity. It is especially useful when variates are positive and negative, e.g., sinusoids. RMS is used in various fields, including electrical engineering; one of the more prominent uses of RMS is in the field of signal amplifiers. Reverse path forwarding (RPF) is a fundamental concept in multicast routing that enables routers to correctly forward multicast traffic down the distribution tree. RPF makes use of the existing unicast routing table to determine the upstream and downstream neighbours. A router forwards a multicast packet only if it is received on the upstream interface. This RPF check helps to guarantee that the distribution tree will be loop‐free. Cyclic error‐correcting codes invented by Irving S. Reed and Gustave Solomon. They described a systematic way of building codes that could detect and correct multiple random symbol errors. By adding t check symbols to the data, an RS code can detect any combination of up to t erroneous symbols, and correct up to ہt /2ۂ symbols. As an erasure code, it can correct up to t known erasures, or it can detect and correct combinations of errors and erasures. Furthermore, RS codes are suitable as multiple‐burst bit‐error correcting codes, since a sequence of b +1 consecutive bit errors can affect at most two symbols of size b . The choice of t is up to the designer of the code, and may be selected within wide limits. Is a standard for serial binary single‐ended data and control signals connecting between a DTE (Data Terminal Equipment) and a DCE (Data Circuit‐terminating Equipment). It is commonly used in computer serial ports. A similar ITU‐T standard is V.24. Mechanism for instantly updating the event information when the current program changes. RST is transmitted on PID 19 with table id 113. This protocol defines a standardized packet format for delivering video and audio over the internet. Real Time Streaming Protocol. A protocol used in streaming media systems. It enables the client to remotely control streaming media is a transport layer protocol designed at Bell Labs for the Plan 9 operating system. It aims to provide a solution where UDP is too primitive because guaranteed‐order packet delivery is desirable, but TCP adds too much complexity/overhead. It extends UDP by adding the following additional features: 1.Acknowledgment of received packets 2.Windowing and congestion control 3.Retransmission of lost packets 4.Overbuffering (Faster than real‐time streaming) Is a television system that has a resolution that meets standards but not considered either enhanced‐definition television (EDTV) or high‐definition television (HDTV). The term is usually used in reference to digital television, in particular when broadcasting at the same (or similar) resolution as analogue systems. In the USA, SDTV refers to digital television broadcast in 4:3 aspect ratio, the same aspect ratio as NTSC signals. When a television set is labelled "SDTV", this means that the set includes an ATSC tuner, but scans its picture in the same 480i pattern used in NTSC. European standard for transmission in synchronous optical networks. Defines a family of rates and formats, interfaces, transport options and maintenance capabilities. Transfer Rate: 45Mbps (minimum).
SDH (2)
Synchronous Digital Hierarchy (see SONET)
SDI
Serial digital interface
SDT
Service Description Table
SECAM
Sequential Colour with Memory
SEP SFN
Symbol Error Probability Single Frequency Network
SID SIP
Service Identification Second frame Initialization Packet
SNMP
Simple Network Management Protocol
SNR SONET
Signal to Noise Ratio Synchronous Optical Networking (see SDH)
Spectral Inversion SPTS SSM
Single Program Transport Stream Source Specific Multicast
STB STS Symbol Rate y
Set Top Box Synchronization Time Stamp
TCP
Transmission Control Protocol
TDT TOT
Time and Date Table (mandatory) Time Offset Table (optional)
TS
Transport Stream
UDP
User Datagram Protocol
UI
Unit Interval
Unicast
USB
Universal Serial Bus
UTC
Universal Time Coordinated
VBC
Video Bridge Controller
Standardized multiplexing protocols that transfer multiple digital bit streams over optical fibre using lasers or light‐ emitting diodes (LEDs). Lower rates can also be transferred via an electrical interface. The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting larger amounts of telephone calls and data traffic over the same fibre wire without synchronization problems. SONET generic criteria are detailed in Telcordia Technologies Generic Requirements document GR‐253‐CORE. Generic criteria applicable to SONET and other transmission systems (e.g., asynchronous fibre optic systems or digital radio systems) are found in Telcordia GR‐499‐ CORE. Refers to a family of video interfaces standardized by SMPTE. For example, ITU‐R BT.656 and SMPTE 259M define digital video interfaces used for broadcast‐grade video. A related standard, known as high‐definition serial digital interface (HD‐SDI), is standardized in SMPTE 292M; this provides a nominal data rate of 1.485 Gbit/s Is one of the DVB Service Information tables. The Service Description table describes services which are part on an MPEG transport stream. It contains data describing the services in the system, such as the names of services, the service provider, etc. It lists the names and other parameters associated with each service in a multiplex. Is an analogue colour television system first used in France. A team led by Henri de France working at Compagnie Française de Télévision (later bought by Thomson) invented SECAM. It is, historically, the first European colour television standard. There is no simple expression for the symbol‐error probability Is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel SIP insertion occurs once per second and is synchronized with the 1PPS signal from a GPS receiver. The SIP contains the transmission parameters for the modulator and the SFN maximum delay Is a UDP‐based network protocol. It is used mostly in network management systems to monitor network‐attached devices for conditions that warrant administrative attention. SNMP is a component of the Internet Protocol Suite as defined by the Internet Engineering Task Force (IETF). It consists of a set of standards for network management, including an application layer protocol, a database schema, and a set of data objects A measure used in science and engineering to quantify how much a signal has been corrupted by noise Standardized multiplexing protocols that transfer multiple digital bit streams over optical fibre using lasers or light‐ emitting diodes (LEDs). Lower rates can also be transferred via an electrical interface. The method was developed to replace the Plesiochronous Digital Hierarchy (PDH) system for transporting larger amounts of telephone calls and data traffic over the same fibre wire without synchronization problems. SONET generic criteria are detailed in Telcordia Technologies Generic Requirements document GR‐253‐CORE. Generic criteria applicable to SONET and other transmission systems (e.g., asynchronous fibre optic systems or digital radio systems) are found in Telcordia GR‐499‐ CORE. Most of us are familiar with the process of flipping the spectrum (spectral inversion) of a real signal by multiplying that n signal's time samples by (‐1) . In that process the centre of spectral rotation is f s /4, where f s is the signal's sample rate in Hz. In this blog we discuss a different kind of spectral flipping process. A transport stream that offers just one program service Is a method of delivering multicast packets in which the only packets that are delivered to a receiver are those originating from a specific source address requested by the receiver. By so limiting the source, SSM reduces demands on the network and improves security. Source‐specific multicast is best understood in contrast to any‐source multicast (ASM). In the ASM service model a receiver expresses interest in traffic to a multicast address. Is uses as a way of maintaining a tight timing relationship another stream Is the number of symbol changes (signalling events) made to the transmission medium per second using a digitally y g ( g g ) p g g y modulated signal or a line code. The Symbol rate is measured in baud (Bd) or symbols/second. In the case of a line code, the symbol rate is the pulse rate in pulses/second. Each symbol can represent or convey one or several bit of data. The symbol rate is related to but should not be confused with gross bitrate expressed in bit/s. Is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite (the other being Internet Protocol, or IP), so the entire suite is commonly referred to as TCP/IP . Whereas IP handles lower‐ level transmissions from computer to computer as a message makes its way across the Internet, TCP operates at a higher level, concerned only with the two end systems, for example a Web browser and a Web server. In particular, TCP provides reliable, ordered delivery of a stream of bytes from a program on one computer to another program on another computer. Besides the Web, other common applications of TCP include e‐mail and file transfer. Among its other management tasks, TCP controls segment size, flow control, the rate at which data is exchanged, and network traffic congestion. Provides UTC (Universal Time) coded as MJD (Modified Julian Date). The PID value is 0x0014. This table provides information regarding the local time offset from the UTC time. It is used to define the local time. The PID value is the same as the TDT Is a communications protocol for audio, video, and data. It is a type of digital container format encapsulating packetized elementary streams and other data. TS is specified in MPEG‐2 Part 1, Systems (ISO/IEC standard 13818‐1). It is also known as ITU‐T Rec. H.222.0. Its design goal is to allow multiplexing of digital video and audio and to synchronize the output. Transport stream offers features for error correction for transportation over unreliable media, and is used in broadcast applications such as DVB and ATSC. It is contrasted with MPEG program stream, designed for more reliable media such as DVDs. A connectionless protocol that, like TCP, runs on top of IP networks. Unlike TCP/IP, UDP/IP provides no error recovery services. Is the minimum time interval between condition changes of a data transmission signal, also known as the symbol duration time. The term unicast is formed in analogy to the term broadcast which means transmitting the same data to all possible destinations. Another multi‐destination distribution method, multicasting, sends data only to interested destinations by using special address assignments. Is a specification to establish communication between devices and a host controller (usually personal computers), developed and invented by Ajay Bhatt while working for Intel. USB is intended to replace many varieties of serial and parallel ports. USB can connect computer peripherals such as mice, keyboards, digital cameras, printers, personal media players, flash drives, and external hard drives. Coordinated Universal Time (UTC) is a time standard based on International Atomic Time (TAI) with leap seconds added at irregular intervals to compensate for the Earth's slowing rotation Is the aggregation server for all underlying Bridge Technologies analysis probes
VLAN
Virtual Local Area Network
Is a group of hosts with a common set of requirements that communicate as if they were attached to the same broadcast domain, regardless of their physical location. A VLAN has the same attributes as a physical LAN, but it allows for end stations to be grouped together even if they are not located on the same network switch. Network reconfiguration can be done through software instead of physically relocating devices.