- 行业: Telecommunications
- Number of terms: 29235
- Number of blossaries: 0
- Company Profile:
ATIS is the leading technical planning and standards development organization committed to the rapid development of global, market-driven standards for the information, entertainment and communications industry.
1. In frequency-division multiplexing, the frequency band occupied by the aggregate of the signals in the line interconnecting the multiplexing and radio or line equipment. 2. In frequency division multiplexed carrier systems, at the input to any stage of frequency translation, the frequency band occupied. Note: For example, the output of a group multiplexer consists of a band of frequencies from 60 kHz to 108 kHz. This is the group-level baseband that results from combining 12 voice-frequency input channels, having a bandwidth of 4 kHz each, including guard bands. In turn, 5 groups are multiplexed into a super group having a baseband of 312 kHz to 552 kHz. This baseband, however, does not represent a group-level baseband. Ten super groups are in turn multiplexed into one master group, the output of which is a baseband that may be used to modulate a microwave-frequency carrier.
Industry:Telecommunications
1. In facsimile, the number of pixels per unit distance in the direction of scanning or recording. 2. In digital telegraphy, the number of pixels in the horizontal direction. 3. In raster-scanned television, the number of picture elements in a scan line. 4. In a computer monitor, the number of pixels per unit distance in the horizontal direction. Note: This value is inversely proportional to the dot pitch of the monitor.
Industry:Telecommunications
1. In facsimile systems using amplitude modulation, recording in which the maximum received power corresponds to the maximum density of the record medium. 2. In a facsimile system using frequency modulation, recording in which the lowest received frequency corresponds to the maximum density of the record medium.
Industry:Telecommunications
1. In facsimile or television, the ratio of the width to the height of a scanning field or image. Note: For example, the classical NTSC television standard specifies an aspect ratio of 4:3, and the new high-definition television standard specifies 16:9. 2. The ratio of the width to the height of any video or scanned image display.
Industry:Telecommunications
1. In facsimile or display systems, such as television, a nonuniformity in the white area of the image, i.e.,, document or picture, caused by the presence of noise in the received signal. 2. A signal or signal level that is supposed to represent a white area on the object, but has a noise content sufficient to cause the creation of noticeable black spots on the display surface or record medium.
Industry:Telecommunications
1. In facsimile or display systems, such as television, a nonuniformity in the black area of the image, i.e., document or picture, caused by the presence of noise in the received signal. 2. A signal or signal level that is supposed to represent a black area on the object, but has a noise content sufficient to cause the creation of noticeable white spots on the display surface or record medium.
Industry:Telecommunications
1. In e-mail, a specified portion of a message (e.g., the header, the body. ) 2. In cryptography, a predefined meaning or data representation within a message.
Industry:Telecommunications
1. In e-mail, a periodic mailing of a collection of messages compiled from a mailing list or interest group. 2. A command issued to a list server or to a list processor requesting that postings be delivered to a subscriber in summary form.
Industry:Telecommunications
1. In data transmission, the sequence of contiguous bits delimited by, and including, beginning and ending flag sequences. Note 1: A frame usually consists of a specified number of bits between flag sequences and usually includes an address field, a control field, and a frame check sequence. Note 2: Frames usually consist of a representation of the original data to be transmitted, together with other bits which may be used for error detection or control. Additional bits may be used for routing, synchronization, or overhead information not directly associated with the original data. 2. In the multiplex structure of pulse-code modulation (PCM) systems, a set of consecutive time slots in which the position of each digit can be identified by reference to a frame-alignment signal. Note: The frame-alignment signal does not necessarily occur, in whole or in part, in each frame. 3. In a time-division multiplexing (TDM) system, a repetitive group of signals resulting from a single sampling of all channels, including any required system information, such as additional synchronizing signals. Note: "In-frame" is the condition that exists when there is a channel-to-channel and bit-to-bit correspondence, exclusive of transmission errors, between all inputs of a time-division multiplexer and the output of its associated demultiplexer. 4. In ISDN, a block of variable length, labeled at the Data Link Layer of the Open Systems Interconnection--Reference Model. 5. In video display, the set of all picture elements that represent one complete image. Note: In NTSC and other television standards used throughout the world, a frame consists of two interlaced fields, each of which has half the number of scanning lines, and consequently, half the number of pixels, of one frame. 6. In video display, one complete scanned image from a series of video images. Note: A video frame is usually composed of two interlaced fields. 7. In computer screen displays of HTML documents, a portion (usually rectangular) of the screen where one usually finds the same types of fields/information displayed, in the same manner as one usually finds the same or similar information displayed in the same segment of different copies of a printed form. 8. An HTML feature that allows multiple Web pages to be viewed simultaneously (by means of scrolling or re-sizing) through a browser window.
Industry:Telecommunications
1. In electronic marketing, to send data to another computer without a direct request from (via) that computer. 2. In networking, to send data from a server to a client in compliance with a previous request from (via) the client, as soon as the data are available.
Industry:Telecommunications
