Paving The Way For AVB...

The emergence of the Audio/Video Bridging (AVB) standard - a combination of new and augmented IEEE standards - brings media facilities a new opportunity to improve the way in which audio and video are transmitted. By John Terrey, Vice President of Sales, Wohler.

Supporting bandwidth allocation and priority rules based on timing, AVB enables the delivery of time-synchronised, low-latency audio and video over Ethernet networks with perfect quality of service (QoS) and full compatibility with ‘legacy’ Ethernet networks. In short, the AVB standard makes it possible to leverage the unmatched data-networking capabilities of Ethernet in assuring reliable real-time audio/video networking.
For network designers and administrators, AVB simplifies end-to-end digital networks and makes them much easier to manage. In addition to reducing interoperability issues, and in turn improving the selection, pricing, and support options open to engineers designing a system, AVB enables better sharing, monitoring, and management of network resources throughout a facility. Ongoing standards work will assure that AVB remains a future-proof approach.
The first step that facility engineers need to take in preparing for AVB adoption is to ensure that the IP network has been designed and implemented properly and that network switches and routers are AVB-compatible. With this backbone in place, media facilities can begin working with the increasing number of AVB-enabled products now coming to market.
To allow media facilities to take advantage of the AVB standard in the monitoring realm, whether now or in the future, Wohler has developed a new AVB Monitoring Option card for the company’s flagship AMP2 Series modular audio/video monitoring solution. The Wohler AMP2-E16V offers a complete suite of tools for analysing and managing audio quality, level, and loudness; metadata; Dolby D, E, and DD+ decoding; and more. The 2-RU workstation provides 16 channels of simultaneous mixed-format audio metering and management and allows users to customise its two large high-resolution LCD screens, which auto-detect 3G/HD/SD-SDI video, to display application-specific audio/video data. With this Wohler system, users also can mix, sum and route program audio live, without the need for a separate audio console.
The open architecture and ease of use that have made the AMP2-E16V a popular choice for demanding applications also allow for a seamless upgrade of the system to support AVB. Users can simply download the appropriate software update from Wohler and insert the AVB Monitoring Option card into the monitoring unit, and they’ve made their unit AVB-compliant.
Two factors in the development of monitoring solutions are making this type of upgrade an easy choice for broadcasters.
The first is that some monitoring units already deployed in the field may be upgraded easily to support AVB; no new external systems are necessary. The modular design of units such as the AMP2-16V enables users to add AVB support when and as needed. The second key factor is the way in which such audio/video monitors incorporate AVB inputs. When users have the ability to add AVB inputs without losing any of their other inputs, they retain the full power and flexibility of their monitoring systems.
The Wohler AMP2-E16V AVB implementation employs a 100 BaseT Ethernet port and familiar RJ-45 connection. Each AVB Monitoring Option card decodes two AVB streams of eight channels each (IEC 61883-6 format), and these two streams must be locked to the same media clock. Just like any other module for the AMP2-E16V, the AVB card occupies a single card slot.
AVB channels can be mixed, level-adjusted and monitored just like - and along with - AES, SDI, analog and other input types (even loudness monitoring can be applied to AVB channels). If users need to increase AVB channel count, they can install as many as five AVB cards in the monitoring unit.
The AMP2-E16V performs automatic sample rate conversion on inputs to the unit’s internal sample clock. AVB channels can be output via AES and analog outputs or re-embedded within an SDI stream.
Going forward, those customers that employ the AVB card will be able to update its firmware just as they would the firmware for any other I/O module.
Given the significant benefits promised by AVB such as a simpler network infrastructure, lower implementation costs, unified management and the ability to deliver current and next-generation video and audio applications with high QoS, it’s no wonder it has been steadily gaining support from broadcast manufacturers.
By making AVB support available within the widely used AMP2-E16V audio/video monitor, Wohler is reducing the cost and complexity of adopting this important standard.

The article is available in the online edition of RFV here.
(IT/MH)