- 産業: Telecommunications
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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.
In data transmission, an operation in which manual, semiautomatic, or automatic shifts in the data modulation rate are accomplished by gating or slewing the clock modulation rate. Note: For example, bit-by-bit asynchronous operation may be at 50 b/s one moment and at 1200 b/s the next moment.
Industry:Telecommunications
In data transmission, all frames that may be transmitted by a secondary station.
Industry:Telecommunications
In data transmission, a secondary channel in which the direction of transmission is constrained to be opposite to that of the primary, i.e., the forward (user-information) channel. Note: The direction of transmission in the backward channel is restricted by the control interchange circuit that controls the direction of transmission in the primary channel. 2. In a data circuit, the channel that passes data in a direction opposite to that of its associated forward channel. Note 1: The backward channel is usually used for transmission of supervisory, acknowledgement, or error-control signals. The direction of flow of these signals is opposite to that in which user information is being transferred. Note 2: The backward-channel bandwidth is usually less than that of the primary channel, i.e., the forward (user information) channel.
Industry:Telecommunications
In data transmission, a response that does not contain sequence numbers in the control field.
Industry:Telecommunications
In data transmission, a functional unit that permits a common path to handle more data sources than there are channels currently available within the path. Note: A concentrator usually provides communication capability between many low-speed, usually asynchronous channels and one or more high-speed, usually synchronous channels. Usually different speeds, codes, and protocols can be accommodated on the low-speed side. The low-speed channels usually operate in contention and require buffering. 2. A device that connects a number of circuits, which are not all used at once, to a smaller group of circuits for economy.
Industry:Telecommunications
In data transmission, a field assigned to contain user information. Note: The contents of the information field are not interpreted at the link level.
Industry:Telecommunications
In data transmission, a frame, containing a command, transmitted by a primary station.
Industry:Telecommunications
In data transmission, a device that accepts a data stream from one line and places a sequence of signals, one or more at a time, on several lines, thus performing a spatial multiplexing of the original stream. Note: Examples of a distributor are (a) a mechanical unit with input to a rotor and output through many contacts wiped by the rotor and (b) a set of combinational logic circuits, such as a series of AND gates, that are sequentially enabled by a set of pulses and that are all connected to a common bus carrying the input signals.
Industry:Telecommunications
In data transmission or processing, an indicator, such as a signal, symbol, character, or digit, used for identification. Note: A flag may be a byte, word, mark, group mark, or letter that signals the occurrence of some condition or event, such as the end of a word, block, or message. Synonym field tag.
Industry:Telecommunications
In data communications systems, control of the rate at which data are transmitted from a terminal so that the data can be received by another terminal. Note 1: Transmit flow control may occur between data terminal equipment (DTE) and a switching center, via data circuit-terminating equipment (DCE,) or between two DTEs. The transmission rate may be controlled because of network or DTE requirements. Note 2: Transmit flow control can occur independently in the two directions of data transfer, thus permitting the transfer rates in one direction to be different from the transfer rates in the other direction.
Industry:Telecommunications