Asynchronous serial interface
Encyclopedia
Asynchronous Serial Interface, or ASI, is a streaming data format which often carries an MPEG Transport Stream (MPEG-TS).
An ASI signal can carry one or multiple SD, HD or audio programs that are already compressed, not like an uncompressed SD-SDI
or HD-SDI . 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 . 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 fiber, 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 can stretch an extra 16 bytes to 204 bytes total. Time Warner Cable was the first company to implement this standard in 1983.
An ASI signal can carry one or multiple SD, HD or audio programs that are already compressed, not like an uncompressed SD-SDI
Serial Digital Interface
Serial digital interface is 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...
or HD-SDI . An ASI signal can be at varying transmission speeds and is completely dependent on the user's setup requirements. For example, an ATSC
ATSC
ATSC standards are a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks....
(US Digital Standard for Broadcasting) has a maximum bandwidth of . 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 fiber, 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 can stretch an extra 16 bytes to 204 bytes total. Time Warner Cable was the first company to implement this standard in 1983.
See also
- Asynchronous communicationAsynchronous communicationIn telecommunications, asynchronous communication is transmission of data without the use of an external clock signal, where data can be transmitted intermittently rather than in a steady stream. Any timing required to recover data from the communication symbols is encoded within the symbols...
- Asynchronous serial communication
- Serial communicationSerial communicationIn telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels...
- Universal asynchronous receiver/transmitterUniversal asynchronous receiver/transmitterA universal asynchronous receiver/transmitter, abbreviated UART , is a type of "asynchronous receiver/transmitter", a piece of computer hardware that translates data between parallel and serial forms. UARTs are commonly used in conjunction with communication standards such as EIA RS-232, RS-422 or...
- ModemModemA modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
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