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Asynchronous serial interface

The asynchronous serial interface (ASI), also known as DVB-ASI, is a unidirectional point-to-point digital interface for transporting one or more MPEG-2 transport streams (MPEG-TS) between professional broadcast equipment, using 75-ohm coaxial cable or optical fiber.^[1] Defined in the DVB specification A007 (March 1996) and detailed in EN 50083-9, it operates at a fixed bit rate of 270 Mbit/s, allowing bursty transmission of 188-byte (or optionally 204-byte with DVB_SPI header) packets separated by idle characters to handle variable data rates up to approximately 213 Mbit/s payload.^[2]^[3] This interface employs parallel clocking internally (27 MHz clock with 10-bit symbols) but serial transmission over BNC connectors for coax, enabling simple cabling for distances up to 300 meters on coax or longer on fiber, without requiring clock synchronization between devices beyond the fixed rate.^[4] ASI supports both single and multiple program transport streams, with stuffing to maintain the constant rate, and is widely used in digital video headends for interconnecting encoders, multiplexers, and modulators in DVB systems.^[1]

Overview

Definition and Purpose

The Asynchronous Serial Interface (ASI), also known as DVB-ASI, is a unidirectional point-to-point digital interface designed for transmitting MPEG Transport Streams (MPEG-TS) between professional broadcast equipment.^[5] It operates over 75-ohm coaxial cable or optical fiber, providing a streamlined method for delivering multiplexed streams of compressed video, audio, and data in environments such as cable television headends and satellite distribution systems.^[5] ASI encapsulates standard MPEG-TS packets, either the mandatory 188-byte format or the optional 204-byte variant with additional Reed-Solomon bytes, ensuring compatibility with the MPEG-2 transport stream structure defined in ISO/IEC 13818-1.^[5] The primary purpose of ASI is to enable reliable, high-speed interconnection of signal processing devices in professional broadcasting workflows, supporting standards such as DVB for digital video delivery and ATSC for advanced television systems, both of which rely on MPEG-TS for multiplexing programs.^[4] By facilitating the transport of these streams without requiring precise timing alignment, ASI simplifies integration in headend and distribution setups, accommodating both single-program and multi-program transport streams for efficient content handling.^[5] Key benefits of ASI include its inherent simplicity, as the asynchronous design eliminates the need for clock synchronization between transmitter and receiver, allowing flexible handling of variable or bursty data flows.^[4] This makes it particularly cost-effective for short-distance links within facilities, such as interfacility connections or internal routing, where it leverages existing coaxial infrastructure without additional synchronization hardware.^[6] Furthermore, ASI's compatibility extends to modern compressed streams, including MPEG-4 formats like H.264, within the MPEG-TS framework, supporting ongoing evolution in broadcast video and audio delivery.^[6]

Historical Development

The Asynchronous Serial Interface (ASI) emerged in the late 1990s as part of the Digital Video Broadcasting (DVB) Project's efforts to standardize the transport of MPEG-2 Transport Streams (MPEG-TS) across professional broadcast equipment, addressing the need for a reliable, unidirectional interface in digital television workflows.^[7] The DVB Project, formed in 1993, initially focused on transmission standards for satellite, cable, and terrestrial broadcasting, but by the late 1990s, it extended to interface specifications to ensure interoperability among devices handling compressed video streams.^[4] A key milestone occurred in January 2001 with the publication of ETSI Technical Report TR 101 891 V1.1.1, which provided guidelines for implementing and using the DVB-ASI to convey MPEG-2 transport streams between professional equipment.^[4] This was complemented by the CENELEC standard EN 50083-9, finalized in December 2002, which formally defined the ASI as a serial, encoded transmission system for DVB/MPEG-2 data signals over coaxial cable, specifying parameters for burst-mode and continuous-mode operations to support rates up to 270 Mbps.^[5] These documents established ASI as a core interface for professional video environments, building on the MPEG-TS framework to facilitate seamless data transfer in headends and distribution systems. ASI's evolution included its integration into North American broadcasting via the Advanced Television Systems Committee (ATSC) standards, where it supported MPEG-TS distribution in equipment chains despite the ATSC's distinct modulation schemes like 8-VSB. It persisted through the global transition to digital TV in the 2000s and 2010s, offering a robust alternative to emerging IP-based transports by maintaining compatibility with legacy coaxial infrastructure. As of 2025, ASI remains relevant in many broadcast facilities for its simplicity and low latency, though no major standard updates have occurred since 2002, with industry focus shifting toward ATSC 3.0 compatibility, which emphasizes IP-centric delivery and reduces reliance on traditional serial interfaces like ASI.^[8]

Standards

DVB-ASI Core Specification

The DVB Asynchronous Serial Interface (ASI) is specified in the CENELEC standard EN 50083-9 (2002), with implementation guidelines provided in the ETSI Technical Report TR 101 891 V1.1.1, published in February 2001.^[5]^[4] EN 50083-9 defines ASI as a unidirectional transmission link designed to transfer MPEG-2 transport streams (TS) between professional digital video equipment, such as encoders, multiplexers, and modulators, ensuring reliable data conveyance in broadcast environments. The interface uses 8b/10b encoding at a fixed line clock rate of 270 Mbit/s, providing an effective payload capacity of up to approximately 214 Mbit/s.^[5] Core requirements specified in the standards emphasize unidirectional transmission of MPEG-TS packets, supporting both burst and continuous modes to accommodate varying data rates and timing needs.^[5]^[4] In burst mode, packets are transmitted consecutively at the full line rate of 270 Mbit/s, while continuous mode allows for steady flow with potential variable delays managed by receiver buffers to handle aperiodic arrivals.^[5] The standard defines precise packet alignment using synchronization characters such as K28.5 and includes provisions for stuffing to maintain alignment and fill gaps, preventing data corruption during transmission.^[5]^[4] Packet handling follows strict protocols to preserve data integrity, mandating the use of standard 188-byte TS packets as the baseline format, with an optional extension to 204-byte packets that incorporate forward error correction for enhanced reliability.^[5]^[4] Stuffing is achieved using specific idle characters, such as K28.5, to pad packets without altering the original content.^[4] The interface is designed for transparent transport of the TS, preserving the original packet structure from source to destination.^[5] These guidelines promote interoperability across DVB equipment by specifying minimum buffer sizes and timing tolerances, allowing seamless integration of encoders, multiplexers, and modulators in professional broadcast chains without proprietary adaptations.^[4] For instance, recommended buffer capacities help mitigate jitter and ensure consistent packet delivery in multi-device setups. The original standards, however, provide incomplete coverage on certain aspects, such as detailed specifications for optical fiber implementations or guidance on transitioning to IP-based systems, which have been addressed through subsequent industry practices and extensions.^[4] The Asynchronous Serial Interface (ASI) finds integration in ATSC standards, where it serves as a transport mechanism for MPEG-2 Transport Streams (MPEG-TS) in ATSC 1.0 systems, enabling efficient distribution of digital television signals in headends and broadcast facilities.^[9]^[10] For ATSC 3.0, known as NextGen TV, compatibility is maintained through MPEG-TS encapsulation during service conversion and redistribution processes, as outlined in the ATSC A/370 standard, which was updated in July 2025 to address transitions from ATSC 3.0's IP-based protocols back to legacy formats like ATSC 1.0.^[11] This encapsulation leverages the MPEG-TS structure to bridge the IP-centric ATSC 3.0 with traditional transport interfaces such as ASI.^[12] Beyond core DVB specifications, the CENELEC EN 50083-9 standard, approved in 2002, defines cabling and interface requirements for community antenna television (CATV) and satellite master antenna television (SMATV) systems, incorporating ASI as a key physical interface for interconnecting headend equipment in cabled distribution networks.^[5] This standard ensures reliable signal handling in professional environments, specifying parameters for asynchronous serial transmission over coaxial or fiber media to support television and interactive services.^[13] Evolving aspects of ASI standards reflect broader transitions in broadcasting, particularly the U.S. Federal Communications Commission's (FCC) October 2025 actions promoting a voluntary, market-driven shift to ATSC 3.0, which encourage the use of ASI for redistributing legacy ATSC 1.0 content during the phased rollout.^[14] No new standards specifically dedicated to ASI have emerged, as the interface remains tied to foundational DVB guidelines from the late 1990s and early 2000s; however, DVB systems incorporate guidelines for ASI-to-IP conversion, often aligning with protocols like SMPTE ST 2022-6 for transporting MPEG-TS over IP networks to facilitate hybrid broadcast-IP workflows.^[15] These conversions enable seamless integration of ASI-based equipment into modern IP infrastructures without requiring full overhauls.^[16] Variants of DVB-related standards include extensions to the DVB Common Interface (DVB-CI), which enhance security through CI Plus specifications, providing end-to-end encryption and content protection mechanisms that complement ASI's role in transporting protected MPEG-TS streams in headends.^[17] Hardware implementations, such as Lattice Semiconductor's DVB-ASI IP cores, continue to support these interfaces in FPGA designs, with ongoing availability underscoring ASI's persistence despite its legacy status in evolving ecosystems.^[18] A notable gap in ASI standards is their predating of 4K and 8K video formats, with the original DVB-ASI specification limited to a maximum bit rate of approximately 213 Mbps, necessitating multiple ASI links or higher-capacity alternatives for ultra-high-definition content delivery.^[19] Modern applications rely on backward compatibility, where MPEG-TS encapsulation allows ASI to carry compressed 4K/8K streams using codecs like HEVC, though without formal updates to the physical layer to natively handle increased bandwidth demands.^[20]

Technical Specifications

Physical Interface Characteristics

The Asynchronous Serial Interface (ASI) employs a physical layer designed for reliable transmission of MPEG transport streams in professional broadcasting environments, utilizing either coaxial cable or optical fiber as the primary media. The interface operates over 75-ohm unbalanced coaxial cable, which provides a cost-effective solution for short to medium distances within equipment racks or studios. This coaxial medium ensures low signal attenuation and resistance to electromagnetic interference through its characteristic impedance and shielding.^[5] Coaxial implementations typically use RG-59 or RG-6 cables, both of which offer low loss suitable for ASI signals; RG-59 is commonly specified for runs up to 100 meters, while RG-6 supports similar performance with enhanced flexibility for installations. Connections are made via standard BNC connectors, which facilitate secure, quick mating and are polarity-sensitive to maintain signal integrity. The cables incorporate braided shielding to minimize crosstalk and external noise, aligning with the 75-ohm impedance requirement for unbalanced transmission. ASI supports unidirectional communication, necessitating separate cables for return paths in bidirectional setups.^[5]^[21] For extended distances, optical fiber variants extend ASI reach significantly, with single-mode fiber enabling transmission up to 10 km in studio and distribution links, reducing latency and eliminating electrical interference. Multimode fiber is also viable for shorter optical runs, though single-mode predominates for its superior bandwidth and distance capabilities. Optical connectors include SC or LC types, with SC being the standard recommendation for compatibility and low insertion loss. As of 2025, fiber-based ASI has become prevalent in professional setups for its robustness in long-haul applications.^[5]^[22] Daisy-chaining is supported in coaxial configurations, allowing up to four devices to be interconnected via BNC loop-through ports without additional splitters, optimizing cabling in rack-mounted systems. This feature enhances deployment flexibility while preserving the unidirectional nature of the interface.^[23]^[24]

Data Encoding and Transmission

In the Asynchronous Serial Interface (ASI) for Digital Video Broadcasting (DVB), data encoding employs 8B/10B block coding, which maps each 8-bit data byte to a 10-bit code word to maintain DC balance and facilitate clock recovery at the receiver.^[5] This encoding ensures a bounded run length of no more than five consecutive zeros or ones, providing sufficient bit transitions for reliable synchronization without a dedicated clock line, while the running disparity mechanism helps detect transmission errors.^[5] The asynchronous nature of ASI relies on burst timing and embedded synchronization patterns rather than a shared clock signal, allowing flexible data flow over the fixed line rate of 270 Mbit/s.^[4] ASI supports two primary transmission modes: burst mode and continuous mode, each designed to handle MPEG transport stream (TS) packets differently while adhering to the 8B/10B encoding. In burst mode, individual packets are transmitted at the full line rate, achieving peak rates up to 270 Mbps for a single packet, followed by idle periods filled with delimiter bytes to allow receiver processing.^[5] Continuous mode, in contrast, delivers a steady stream of data at an effective rate of approximately 200 Mbps, with packets sent contiguously and minimal gaps, suitable for constant-bit-rate applications.^[4] Packet synchronization in both modes is achieved using special delimiter bytes, specifically at least two K28.5 comma characters (encoded as 8B/10B control symbols) inserted between packets to enable byte alignment and prevent bit slip at the receiver.^[5] Framing in ASI encapsulates standard MPEG-TS packets, which are 188 bytes long and begin with a fixed sync byte of 0x47 (hexadecimal 47h) to demarcate the start of each transport packet.^[5] An optional extended format uses 204-byte packets, where the additional 16 bytes incorporate Reed-Solomon forward error correction (FEC) for enhanced robustness in noisy environments, though the core 188-byte structure remains mandatory for compatibility.^[5] These packets are serialized after 8B/10B encoding, with the sync byte preserved to allow higher-layer demultiplexing. Clocking in ASI is inherently asynchronous, with no common clock distributed between transmitter and receiver; instead, the receiver employs a phase-locked loop (PLL) to recover the bit clock from the data stream's transitions guaranteed by the 8B/10B encoding.^[5] This approach supports variable packet rates and aperiodic transmission, as the fixed 270 Mbit/s line rate accommodates bursts without requiring precise timing alignment, though receivers must buffer data to handle rate variations.^[4] Error handling at the ASI level primarily leverages the 8B/10B encoding's inherent checks, including detection of invalid code words or running disparity violations, which act as a basic parity mechanism to flag bit errors with high probability.^[5] For greater reliability, the interface relies on transport stream-level FEC, such as the optional Reed-Solomon coding in 204-byte packets, to correct burst errors common in serial links, achieving a target bit error rate below 10^{-13}.^[5]

Performance Parameters

The Asynchronous Serial Interface (ASI) operates at a fixed nominal line rate of 270 Mbit/s, with a tolerance of ±100 ppm, aligned with the STS-1 rate in SONET/SDH systems.^[5] Due to 8B/10B encoding for DC balance and clock recovery, the effective payload capacity is reduced to approximately 216 Mbit/s, with practical rates often around 200 Mbit/s after accounting for additional protocol overhead such as stuffing bytes.^[25] This bandwidth supports multiplexing of multiple compressed video streams, for example, up to 20 high-definition (HD) programs at typical bit rates of 10-15 Mbit/s each or around 100 standard-definition (SD) programs at 2-3 Mbit/s per stream.^[26] For coaxial connections using 75 Ω cable, the transmitter outputs a signal level of 800 mV peak-to-peak ±10%, while receivers accommodate input ranges from 200 mV to 880 mV peak-to-peak to ensure reliable detection.^[5] Optical implementations, typically over multimode fiber with a 62.5 μm core at 1300 nm wavelength using LED transceivers, specify average launched power from -20 dBm to -14 dBm at the transmitter and minimum received power of -26 dBm, though practical systems often operate in the -10 dBm to -3 dBm range for improved margin.^[5] Transmission distances are limited to 100 m maximum over standard RG-59 coaxial cable to maintain signal integrity, though up to 220 m is possible with lower-loss RG-216/U cable.^[5] Optical links extend this to 300 m over multimode fiber or up to 10 km over single-mode fiber, depending on transceiver power budget and attenuation.^[27] Jitter specifications ensure timing stability, with deterministic jitter limited to less than 0.1 UI (10%) at the coaxial transmitter and up to 0.19 UI (19%) at the receiver; random jitter is capped at 0.09 UI (9%) for both.^[5] In burst mode, ASI permits transmission of complete transport packets (188 or 204 bytes) in continuous bursts without interspersing idle bytes, facilitating efficient handling of variable-rate MPEG streams while maintaining synchronization via K28.5 characters.^[25] As of 2025, these performance parameters remain unchanged from the core DVB specifications established in the early 2000s.^[5] However, the growing prevalence of IP gateways for video transport has diminished ASI's role in some headend and distribution setups, even as ATSC 3.0 deployments continue to employ ASI for interim 270 Mbit/s streams in hybrid broadcast workflows.^[28]

Applications

Broadcasting and Distribution

The Asynchronous Serial Interface (ASI) serves as a fundamental component in traditional broadcast workflows, primarily facilitating studio-to-transmitter links for systems such as DVB-T, DVB-S, DVB-C, and ATSC. This uni-directional interface transports MPEG-2 transport streams from production studios to remote transmission sites, ensuring the reliable delivery of compressed digital video, audio, and data over coaxial cables.^[4] By standardizing the physical and electrical characteristics, ASI enables seamless connectivity between encoders, multiplexers, and modulators in professional environments.^[6] A key strength of ASI in broadcasting lies in its ability to multiplex multiple standard-definition (SD) and high-definition (HD) channels into a single transport stream, optimizing bandwidth for efficient content distribution. For instance, broadcasters can combine several video programs, along with associated audio and ancillary data, into one ASI stream for transmission, reducing the need for parallel links and simplifying infrastructure.^[6] In headend operations, ASI supports encoding and modulation processes before satellite uplinks, accommodating MPEG-2 and MPEG-4 video formats at transport stream rates of up to 19.39 Mbps in ATSC systems or up to 216 Mbps in DVB configurations.^[29]^[30]^[5] This capability is essential for delivering multiplexed content over terrestrial, satellite, and cable networks without compromising signal integrity. Practical applications of ASI are evident in television stations, where it is employed for local program insertion, allowing operators to overlay regional content onto national feeds before transmission.^[31] Similarly, cable headends utilize ASI to aggregate and distribute local programming to subscribers, integrating feeds from various sources into a unified stream for modulation and delivery.^[32] These uses highlight ASI's operational efficiency in legacy broadcast chains, operating at a 270 Mbps line rate to handle bursty transport streams with minimal overhead.^[6] ASI's advantages in broadcasting include its inherently low latency, which is vital for live events such as sports or news, enabling near-real-time transmission without significant buffering delays.^[4] Furthermore, its compatibility with existing equipment facilitates easy integration into established workflows, allowing broadcasters to maintain and upgrade systems cost-effectively while supporting both SD and HD content.^[31]

Integration with Modern Systems

Asynchronous Serial Interface (ASI) continues to play a transitional role in modern broadcasting systems through IP convergence, where ASI-to-IP converters facilitate the integration of legacy ASI streams into IP-based workflows. Devices such as Thor Broadcast's gateways enable bidirectional conversion between ASI and IP transport streams, supporting standards like SMPTE ST 2022 for encapsulating compressed video over IP networks.^[16]^[33] This allows ASI equipment to interface with SMPTE ST 2110 environments, which are prevalent in professional video production, thereby extending ASI's utility in cloud-based content distribution and remote production setups.^[34] In the context of ATSC 3.0, also known as NextGen TV, ASI supports the redistribution of streams by converting RF signals to ASI outputs for further processing or legacy integration.^[35] The FCC's October 2025 rules promote voluntary transitions to ATSC 3.0, including datacasting applications, by permitting flexible deployment without mandatory ATSC 1.0 simulcasts, which indirectly sustains hybrid ASI usage in transitional infrastructure.^[14] Modern encoders and decoders, such as the ADV-4200EC 4K HEVC unit, incorporate ASI inputs alongside IP for handling high-resolution HEVC streams, ensuring compatibility in evolving broadcast chains.^[36] Similarly, decoders like the VITEC MGW Ace support DVB-ASI alongside IP for 4K workflows.^[37] Wireless extensions for ATSC 3.0 datacasting, exemplified by EdgeBeam Wireless launched in 2025, leverage IP-based transmission for nationwide data delivery, though ASI remains relevant in supporting studio-to-transmitter links during hybrid implementations. Despite these integrations, ASI faces obsolescence in new designs, with FPGA IP cores like Intel's ASI MegaCore discontinued as of product obsolescence notice PDN1306, reflecting the broader industry shift to Ethernet and IP protocols.^[38] ASI persists primarily in legacy and hybrid setups to bridge existing equipment during migrations, as commercial modems increasingly drop ASI support in favor of IP. By 2025, ATSC 3.0 pilots have seen increased adoption of IP-to-ASI bridging in gateways, such as Vislink's IP Link platform, to maintain compatibility with legacy ASI interfaces during the standard's rollout.^[28] This addresses gaps in earlier documentation by enabling seamless integration of IP-centric ATSC 3.0 streams into ASI-dependent workflows, supporting ongoing voluntary transitions.^[39]

Terminology

Core Concepts

The Asynchronous Serial Interface (ASI), specifically in the context of Digital Video Broadcasting (DVB-ASI), relies on the MPEG-2 Transport Stream (MPEG-TS) as its primary container format. MPEG-TS serves to multiplex elementary streams of video, audio, and data into fixed-length packets, typically 188 bytes each, enabling efficient transmission of compressed audiovisual content over the interface.^[5] This structure allows ASI to handle multiple programs or services within a single stream, distinguishing it from simpler serial protocols by supporting robust synchronization and error handling for broadcast applications.^[4] DVB-ASI operates in two distinct transmission modes: burst and continuous. In burst mode, transport stream packets are sent in contiguous groups at a data rate of 8 Mbit/s, followed by idle periods, which requires receivers to employ buffering to manage the intermittent flow.^[5] Conversely, continuous mode delivers bytes steadily with embedded synchronization, maintaining a more uniform throughput closer to the interface's maximum capacity of 270 Mbit/s and simplifying receiver design by reducing buffer demands.^[4] These modes accommodate varying equipment capabilities while ensuring compatibility across professional video systems. At the physical layer, DVB-ASI employs 8B/10B encoding to convert 8-bit data bytes into 10-bit symbols, guaranteeing DC balance and sufficient signal transitions for reliable clock recovery without a separate clock line.^[5] This encoding also facilitates error detection through disparity checks and includes special control characters, such as K28.5 for packet delimiters and stuffing, enhancing transmission integrity over coaxial or fiber links.^[4] The interface is inherently unidirectional, supporting one-way data flow from transmitter to receiver without provisions for bidirectional communication or acknowledgments.^[5] This design simplifies cabling and hardware for point-to-point connections in broadcast environments, contrasting with bidirectional serial standards that include handshaking.^[4] Commonly referred to as TS-ASI to emphasize its role in transporting MPEG-TS packets, DVB-ASI is distinct from general asynchronous serial communication protocols like RS-232, which lack the specialized encoding and high-speed framing tailored for digital video streams.^[5] This alias highlights its specificity to transport stream handling rather than arbitrary data transfer.

Common Variants and Aliases

The Asynchronous Serial Interface (ASI), often denoted as DVB-ASI in standards documentation, serves as a primary alias within the Digital Video Broadcasting (DVB) framework for transporting MPEG-2 transport streams in professional broadcast environments.^[5] In industry parlance, particularly in Europe, "ASI" typically implies this DVB-specific interface unless otherwise specified, while in the United States, it aligns with similar transport needs under the Advanced Television Systems Committee (ATSC) standards, which also rely on MPEG transport streams.^[4] However, the term can occasionally overlap with general asynchronous serial communication protocols like UART in non-broadcast contexts, leading to potential confusion; broadcast ASI is distinctly tailored for high-speed, unidirectional MPEG stream delivery rather than low-speed data exchange in computing applications.^[4] Standard ASI implementations utilize coaxial cabling (ASI-C) over 75 Ω BNC connectors at a fixed 270 Mbit/s rate, providing reliable short-range connections in headends and studios.^[5] An extended variant, optical ASI (ASI-O), employs multimode fiber with SC connectors and LED emitters, enabling transmission distances of several kilometers while maintaining compatibility with the core protocol.^[5] A less common variant involves 204-byte packets, which optionally append 16 Reed-Solomon forward error correction (FEC) bytes to the mandatory 188-byte MPEG transport stream packets; this FEC-enhanced mode, introduced for improved error resilience, has seen limited adoption since the early 2000s due to advancements in compression and network reliability.^[5] ASI must be distinguished from the Serial Digital Interface (SDI), a SMPTE-standardized synchronous protocol for uncompressed video signals with embedded clocking, whereas ASI asynchronously encapsulates compressed MPEG streams at the same 270 Mbit/s line rate as SD-SDI but without parallel clock synchronization.^[4] Similarly, it differs from DVB's Synchronous Parallel Interface (SPI) and Synchronous Serial Interface (SSI), which require clock synchronization for parallel or serial data transfer, in contrast to ASI's asynchronous, burst-tolerant design.^[5] By 2025, ASI is increasingly regarded as a legacy interface in broadcast workflows, as the industry shifts toward IP-based distribution protocols like those in DVB-NIP and ATSC 3.0, prioritizing scalable, bidirectional networking over dedicated serial links.^[40]^[41]

References

[1]
Asynchronous Serial Communication: The Basics - ITP
Asynchronous serial communication involves sending digital pulses at an agreed rate, without a common clock, where devices keep time independently.Missing: definition | Show results with:definition
[2]
What is a serial interface?
Feb 1, 2009 · A serial interface is a communication interface between two digital systems that transmits data as a series of voltage pulses down a wire.
[3]
[PDF] Introduction to Serial Communication
Serial communication describes main elements, using DTE/DCE devices. RS-232 is a standard for low-speed serial data between computers and devices.
[4]
[PDF] EN 50083-9 - CENELEC - DVB
The Asynchronous Serial Interface (ASI) is a serial link operating at a fixed line clock rate. A detailed specification of ASI is provided in normative annex B.
[5]
[PDF] TR 101 891 - V1.1.1 - Digital Video Broadcasting (DVB) - ETSI
The ASI is a uni-directional transmission link to transfer data between professional digital video equipment. Figure 1 presents an abstract model of an ASI ...
[6]
Asynchronous Interfaces For Video Servers - TVTechnology.com
Nov 12, 2003 · DVB-ASI is designed to transport MPEG-2 video streams, primarily for television applications over coaxial cable, at up to 270 Mbps. The DVB-ASI ...
[7]
History - DVB
The DVB Project began the first phase of its work in 1993. The initial task was to develop a complete suite of digital satellite, cable, and terrestrial ...
[8]
[PDF] A/300, "ATSC 3.0 System Standard"
In June 2019, ATSC established a process (revised in December 2022) for updating the current version of the full suite of ATSC 3.0 documentation (i.e. ...
[9]
ASI in Broadcast Transport Streams: The Backbone of Digital TV ...
May 6, 2025 · The purpose of ASI is to transmit the MPEG Transport Streams, which serve as the standard for video and audio encoding and transmission. This ...
[10]
https://www.dtvinnovations.com/news-article_2024041100
[11]
[PDF] Conversion of ATSC 3.0 Services for Redistribution
This document describes methods for converting ATSC 3.0 services for Redistribution to legacy ... Conversion of ATSC 3.0 Services for Redistribution. 17 July 2025.
[12]
A/370, “Conversion of ATSC 3.0 Services for Redistribution”
This document provides recommended practices for the conversion of ATSC 3.0 services for redistribution into ATSC 1.0 and other legacy services.
[13]
https://standards.iteh.ai/catalog/standards/clc/4ab7de90-25a8-4143-89ff-f7d6bfc3ba3e/en-50083-9-2002
[14]
[PDF] October 7, 2025 FCC FACT SHEET∗ Authorizing Permissive Use of ...
Oct 7, 2025 · Background: Next Gen TV (which uses the “ATSC 3.0” or “3.0” standard) is the future of broadcast television. ATSC 3.0 promises to revitalize ...
[15]
Specifications - DVB
DVB and ETSI publication types · Deprecated specifications. Select ... DVB-ASI (Asynchronous Serial Interface) - Guidelines. Latest Version. TR 101 891 V1.1.1.
[16]
Best ASI to IP Converters - Thor Broadcast
Features · RF / IPTV / ASI INPUT - All Audio-Video Outputs incl. · Tuner available as OFF AIR ATSC, QAM CABLE, ISDBT, DVBT, DVBC, DMBT - Any standard · 10/100 ...
[17]
DVB Extensions to the CI Plus Specification
May 17, 2019 · The DVB Common Interface specifications were extended by the CI Plus specification, developed by CI Plus LLP, which provides common methods (i. ...Missing: ASI | Show results with:ASI
[18]
(DVB-ASI) IP Core - Lattice Semiconductor
DVB via Asynchronous Serial Interface (DVB-ASI) is one of the primary mechanisms to transport MPEG-2 based streams over cable media.
[19]
Development of Millimeter-wave Link for 8K Super Hi-Vision ... - NHK
However, given that the upper limit of the DVB-ASI bit rate is 213 Mbps, it is assumed that 4K/8K video encoder will divide a high-rate TS streams into two DVB ...
[20]
[PDF] Comparing ATSC 3.0 with DVB-T2
ATSC 3.0 uses an IP-based transport layer, while DVB-T2 relies on the MPEG-2 Transport Stream. DVB has also defined an encapsulation scheme for using IP on. DVB ...
[21]
[PDF] QWEST Communications International, Inc. Technical Publication
Digital Video Broadcasting-Asynchronous Serial Interface (DVB-ASI) is a standard 270. Mb/s transport of single or multiple MPEG2 transport streams as defined in ...Missing: ATSC | Show results with:ATSC
[22]
8 Channel DVB ASI Over Fiber
In stock Free deliveryThis device is an 8 channel DVB-ASI or SD-SDI transmitter and receiver for sending digital video signals over fiber optic cable for distances up to 120KmMissing: daisy chaining
[23]
GS2965 | 3G-SDI Dual-input Reclocker - Semtech
A serial host interface provides the ability to configure and monitor multiple GS2965 devices in a daisy-chain configuration. ... Supports DVB-ASI at 270Mb/s ...
[24]
[PDF] 7707VB-8-ASI-OC3 8 Channel ASI + Ethernet SONET / SDH Fiber ...
ASI OUT 1-8: Eight independent BNC output connectors compatible with DVB-ASI for a combined bandwidth of 135Mb/s. OPTICAL INPUT: SC/PC, SC/PC with cover ...
[25]
[PDF] DTA-140 DVB/ASI Input+Output Adapter for PCI Bus - DekTec
The DTA-140 is a DVB/ASI input/output adapter for PCI bus, with 214 Mbps input/output, 8MB buffers, and 0-214 Mbit/s bit rate.Missing: delimiter | Show results with:delimiter
[26]
DVB ASI Digital Video Broadcasting Asynchronous Serial Interface
Nov 13, 2017 · ASI stands for Asynchronous Serial Interface. ASI is Transport Stream mechanism or protocol which used in headends and satellite broadcast etc.
[27]
[PDF] HD-1500 Series - MultiDyne
DESCRIPTION: The HD-1500 is an economic solution designed for transmission of SDI and HD-SDI TV signals on single mode fiber optic.Missing: levels | Show results with:levels
[28]
[PDF] NEXT GENERATION TELEVISION (ATSC 3.0) STATION ...
Existing STL links that handle SMPTE 310 or a 20 Mbps ASI stream will not work for ATSC. 3.0. ATSC A/324 describes a Broadcast Gateway that produces a SMPTE ...
[29]
[PDF] ATSC Digital Television Standard (A/53) Revision E, with ...
Dec 27, 2005 · The terrestrial broadcast mode (known as 8 VSB) delivers an MPEG-2 Transport Stream. (MPEG-2-TS) of up to 19.39 Mbps in a 6 MHz channel. Two ...
[30]
[PDF] Guide to the Use of the ATSC Digital Television Standard, including ...
This is necessary, since the MPEG-2 equipment creating the Transport Stream must maintain a constant bit rate output. Note that null packets may be added ...
[31]
https://www.thebroadcastbridge.com/content/entry/21485/monitoring-compliance-in-broadcast-feeding-the-transmitter
[32]
ASI to SDI best converters - Thor Broadcast
... optical fiber. This kind of signal processing is quite common in the ... DVB - ASI · Fiber Jumpers, Cables, Attenuators, · Optic Splitters Couplers CWDM ...Missing: specification | Show results with:specification
[33]
Video: SMPTE ST 2022 - Moving Serial Interfaces (ASI & SDI) to IP
Dec 14, 2017 · A video on the often overlooked parts of SMPTE 2022 useful for carrying compressed as well as uncompressed video.Missing: converter Thor
[34]
SMPTE ST 2110 - Society of Motion Picture & Television Engineers
The SMPTE ST 2110 standards suites specifies the carriage, synchronization, and description of separate elementary essence streams over IP.Missing: ASI converter Thor
[35]
ATSC 1.0/3.0 RF Demodulator/Gateway - Sencore
The AG 2700 is a versatile and dense solution for receiving ATSC 1.0 and 3.0 RF signals and turning them around to ASI and IP outputs useful for retransmission.
[36]
4K-HEVC IP & ASI ENCODER - advsat
It integrates encoding in H.265/HEVC and H.264/AVC and multiplexing functions in one standard rack 1U case. It also support four HD-SDI and two HDMI ( ...
[37]
MGW Ace Decoder - Professional Portable HEVC & H.264 ... - VITEC
Rating 4.8 (47) The decoder provides 4:2:2 10-bit HEVC and H.264 decoding from IP or DVB-ASI as well as genlock support. Ready for 4K with its 12G-SDI and HDMI outputs, the ...
[38]
[PDF] Asynchronous Serial Interface (ASI) MegaCore Function User Guide
The ASI MegaCore function works with 270 megabits per second (Mbps) DVB-. ASI, as defined by the DVB-ASI specification EN 50083-9 from CENELEC / December. 2002 ...
[39]
Making the (Smooth) Transition to ATSC 3.0 with IP Link - Vislink
Nov 2, 2022 · This all-new IP-centric radio platform provides Ethernet connectivity for ATSC 3.0 while maintaining legacy ASI interfaces that broadcasters ...
[40]
ATSC 3.0 Transition Solutions for Fiber and IP Networks - Artel
Artel's InfinityLink ATSC 3.0 Transition Solutions enable next-generation, over-the-air broadcast and content delivery for the new IP-based ATSC 3.0 standard ...
[41]
[PDF] DVB Scene – Issue 65 – March 2025
Mar 18, 2025 · Our industry's shift to the. 'streaming tech stack' is also a shift to more flexible but more fragmented ecosystems and for DVB, striving for ...
[42]
What Regulatory Shifts Mean for Broadcasters' IP-First Future
Jun 17, 2025 · Forward-thinking broadcasters now see IP-based distribution and new delivery standards as urgent business imperatives.