Increased adoption of professional Audio-Video over Ethernet systems opens up a world of possibilities for the development of much richer multimedia applications that will provide users with unsurpassed advantages at low costs.
By Francisco Villarreal
Audio Video Bridging (AVB) technology based on the IEEE 802.1Q standard is revolutionizing audio and video transfers in a wide variety of industrial ecosystems, such as auditoriums, recording studios, television stations, conference rooms and any place that uses networks to transmit any audiovisual data over a LAN.
This is a solution that allows you to maintain and design AV systems with basic standards technology already applied to switched networks and devices such as cameras, laptops, speakers, projectors and other devices.
Previously, the audio and video connections of the equipment were analog or single-way point-to-point, and one-way such as S/PDIF for audio, or the SDI serial digital interface for video, which were managed through a large number of cables, which implied complexity in their handling.
Attempts to overcome these problems included new technologies such as IEEE 1394 (FireWire) or MIDI interfaces, as well as the adaptation of standard technologies in the network of data switches such as digitized audio and encapsulated in Ethernet or Voice over IP packets.
Undoubtedly, this change has brought more benefits and with it a better panorama is glimpsed. At this point the requirements then were to provide multiple synchronization, as well as having the ability to reserve resources on the network in order to deliver Audio and Video information in real time, with good fidelity and free of errors.
By 2004, the AVB initiated a working group on Ethernet technologies, so that in 2005 it would become sponsored by the IEEE 802.1 project, which had as its mission to make the technology scalable with low-cost applications in professional audio and video environments, resulting in this new concept.
Generally speaking, Audio Video Bridging (AVB) is the set of technical standards developed by the Institute of Electronic and Electrical Engineers (IEEE), in particular by the Audio Video Bridging Working Group of the IEEE 802.1 Standards Committee. These statutes provide specifications that enable synchronized low-latency streaming services over IEEE 802 networks, which are listed below:
IEEE 802.1AS: Synchronization and timing for time-sensitive applications.
IEEE 802.1Qat: A stream backup protocol.
IEEE 802.1Qav: Streaming for time-sensitive streams.
IEEE 802.1BA: Audio Video Bridging Systems.
IEEE 802.1Qat and 802.1Qav are enhancements to the IEEE 802.1Q base document, which points to the operation of local area virtual networks with bridging functions, which are performed by ethernet switches.
Benefits of the AVB-based system include: simplified cabling, maintaining fidelity of audio video transmission with real-time synchronization, integrated quality of service, and low latency delivered by open standards for multi-vendor interoperation.
Simultaneously, the network infrastructure itself balances and manages the network for optimal hierarchy in the transmission of data. That is, the possibility of using the same conventional data infrastructure making a differentiation of the services for AV among other services of the transport network.
Additionally, AVB technology offers an open standards-based path that leverages Ethernet to reduce costs within the use of key applications, as well as providing high-speed interfaces, better manageability, and high availability. Currently Ethernet has the technological maturity for the faithful transmission of digitized Audio and Video signals.
The interoperability of the AVB will benefit hundreds of different types of headquarters, highlighting the operation centers that execute, produce and edit audiovisual content. Undoubtedly, this technology guarantees that audio and video technicians can deploy and use the system satisfactorily, in addition to benefiting from cost optimization, simplification of functionalities and improvements that this technology could have.
The pure transmission of AV signals (digital), is benefited with the already proven technological development achieved with transmissions over long distances and safely, offered by Ethernet technology.
It is important to mention that AVB technology provides superior flexibility in integrating various AV systems into one.
AVB, revolutionizing the film and TV industry
The sector most benefited from AVB solutions is dedicated to the transmission, broadcast and dissemination of audiovisual content for the film and television industry. Through the processes of data transfers with the help of AVB, television signals can be transmitted with High Definition (HD) quality with 1920 X 1080p resolution, 4K Ultra High Definition (4K UHD) with 3840 × 2160p resolution and 8K Ultra High Definition (8K UHD), 7680 × 4320p resolution.
All these formats are already being used in the world, some massively in the transmission of daily television signals as it happens with the High Definition; 4K UHD is used in the new era of cinematography and 8K UHD is being piloted by Japanese news network NHK.
As I pointed out above, the most used and common among people is the HD format that is still to be standardized in Latin America (LATAM) in a total way as Digital Terrestrial Television (DTT). Many or almost all LATAM television stations already have transmissions and repeaters with high definition signals and formats, however, viewers need equipment that supports the reception of this signal, an issue that can only occur through a television with a digital screen and receiver. This drawback has caused the standardization of ultra-high quality audiovisual formats to be delayed throughout the Latin region.
Despite this, in the next 5 years DTT will be a reality for all of Latin America, a consequence that makes special and adequate tools necessary for sending high-performance AVB data. To this we must add the cost of storing content in these high-quality formats, since simply 1 minute of video and audio in 4K UHDTV occupies about 3 Gigabytes of storage and needs switches with data transfer rates greater than 24 Gbps.
That means that a live broadcast of some event – as NHK did at the London 2012 Olympic Games – would need switches with speeds of 40 to 100 Gbps. Today, very few manufacturers could meet this need because finding a data switch with high densities of ports of such speeds and that also integrate the functions of the standards already described, could only be among a few firms in the market.
For now this service can only be found in Japan but it is estimated that in less than 10 years these technologies will allow everyone to watch television content with a quality similar to that perceived by the human eye.
*Francisco Villarreal, is Director of Regional Engineering at Extreme Networks.
