Audio Video Bridging (AVB) for Immersive Audio

AVB 101

The Audio Video Bridging (AVB) defines a group of network protocols for the distribution of time synchronized and low latency Audio & Video streams over IEEE802 networks. AVB technology lays the ground work for un-paralleled guaranteed media streaming over Ethernet networks. The overall concept of AVB is actually simple and is based from the combination of three IEEE protocols providing:

  • Timing and synchronization
  • Bandwidth allocation through the Stream Reservation Protocol (SRP)
  • Traffic shaping to insure that low priority Ethernet traffic does not interfere with AVB traffic

 AVB template diagram

 

Engineered from the ground up for media streaming applications, AVB has a definitive edge over legacy Ethernet technology in the sense that it allows bandwidth allocation and priority rules based on timing. Unlike similar Audio Over IP (AOIP) technologies, AVB will dynamically assign and defend bandwidth allocation for AVB streaming thanks to the concept of Stream Reservation Protocol (SRP). A strong advantage over legacy audio streaming protocols that have no way of controlling bandwidth usage and prioritization on the network.

AVB in immersiveDSP platforms

Networked audio plays a key role in immersiveDSP plaforms. We leverage tight clock synchronization and flexible network to grow and scale your network.

Here is a demo system using a Mac OSx running immergo server along with few NDAC8 to build a large audio soundscape.

 

 

AVB Terminology

Audio Video Bridging (AVB): General descriptive for a group of protocols providing audio/ video streaming, timing,synchronization, Quality of service (QoS) , control and discovery.

AVB Endpoint: AVB powered device, capable of transmitting and/ or receiving audio streams using P1722/ P1733 transport protocols.

Talker: AVB endpoint transmitting audio to the network. (Source)

Listener: AVB endpoint receiving audio from the network. (Destination)

Talker/Listener: AVB endpoint that is both transmitting and receiving. AVBStreamer are by default Talker/ Listener modules.

Precision Time Protocol (PTP): Allows devices on the network to get a notion of global time in the effort to synchronize with each other. PTP component in each AVBStreamer can act as a Grand Master (providing clock) or as a slave (receiving clock). Once a grand master negotiates and is selected as a sync source, all units will synchronize to him.

Streams: General term describing packetization of one or multiple audio/ video channels over the network. Stream can be unicast or multicast.

Stream ID: Unique 64-bit stream identifier used by AVB transport protocols to identify streams.