While in the past there have been a variety of different data transport technologies that cars have relied upon (most notably the combination of CAN and LIN, with others like FlexRay and MOST also being utilised), there is growing impetus for in-vehicle network infrastructure to be consolidated.
The move to an all-encompassing networking technology will mean that outdated domain-based architectures can be replaced by more operationally effective zonal ones.
Through the advent of Automotive Ethernet, car manufacturers are now to rely on a unified networking platform, which is capable of supporting the markedly higher data rates that next generation automotive functions are going to mandate. One of the key aspects that needs to be addressed, as the uptake of Ethernet-based networking starts to become more commonplace in modern automobile models, is how to deal with latency. Take the vehicle’s audio systems - these have moved on from the days when there was just a rudimentary radio accompanied by two speakers. Now there are individual sound zones assigned to each vehicle occupant. Rather than a central amplifier powering all the speakers, there is a separate amplifier associated with each of them, with digitised audio packets being transported to these.
It is via audio video bridging (AVB) that latency determinism has been brought to Automotive Ethernet infrastructure. This allows the quality of service (QoS) provided by in-vehicle audio systems to be maintained. Incorporation of AVB into Ethernet-based automotive networks will ensure that the highest levels of user experience are maintained. Through mechanisms like time synchronisation and stream reservation, it is possible for the multimedia nodes on the network to all be kept running on the same time base. The audio streams emanating from them will thus be synced up with one another.
Aimed predominantly at infotainment audio deployments, the TC9562 supports the AVB protocols (namely IEEE 802.1AS and IEEE 802.1Qav) and even TSN. Through use of this advanced interfacing and its implemented audio hardware, such as an integrated audio-PLL with Media-Clock recovery system, the multimedia nodes in the car’s network can all work together for an Ethernet-based audio system.
A whitepaper on the implementation of AVB for superior in-vehicle audio has been produced by Toshiba. You can download itbelow: