In fact, the problems encountered by the automotive industry, the audio and video industry as early as more than 10 years ago. In that era, a millisecond synchronization time, has made many industrial engineers very happy, but in the professional audio and video field in order to maintain the phase of multiple speakers and video screen,
In 2012, Tesla delivered the world's first luxury electric sports car Model S to American customers. Its control system uses a communication method that is a bus system invented 26 years earlier than Model S - CAN bus, which is used to connect various ECU control units on the car. At the time, the Model S was still using radar technology, and Musk wasn't yet obsessed with cameras and visual solutions. But at the time, some audio and video experts were getting crazy about cables, so they formed a working group at the IEEE to develop a technology to reduce the number of audio and video cables.
In fact, the problems encountered by the automotive industry, the audio and video industry as early as more than 10 years ago. In that era, a millisecond synchronization time, has made many industrial engineers very happy, but in the professional audio and video field in order to maintain the phase of multiple speakers and video screen, while preventing audio and video packet delay caused by the fault needs to achieve microsecond synchronization accuracy, so the IEEE working group found the importance of low delay in network communication. They changed the name of the working group from AVB (Audio Video Bridging) to TSN, which stands for Time Sensitive Networking, which is a very fancy name. Since then, TSN technology has been as time-sensitive as its name, and its functions have become more and more rich, gradually including three aspects of content:
1. Time synchronization
All devices involved in real-time communication need to have a common understanding of time.
2. Scheduling and traffic shaping
All devices involved in real-time communication follow the same rules when processing and forwarding communication packets.
3. Select maintenance and fault tolerance for the communication path
All the devices involved in real-time communication abide by the same rules for the selection of the communication path bandwidth and the retention of the time slot, and can use multiple synchronous paths to achieve fault tolerance.
In fact, Ethernet has long been able to solve the problem of communication rate, and now 2.5G network ports are fast becoming the standard of many PCS. However, Ethernet adopts the technology of carrier monitoring multiplexing, which simply means that there can be many parties speaking at the same time on the network, but the listener must listen according to the priority of the speaker, which results in the high priority will be heard first, and the low priority will be heard after the meeting. This is the non-real-time Ethernet communication, that is, the time delay. This is anathema to many industrial firms, especially those that control them. Around 2003 have magic to change Ethernet technology to meet the real-time requirements, but these protocols are basically patches, many of these patches affect the 1.2 layer, and involve special hardware resulting in hardware incompatibility. TSN's job is to define the second layer of the OSI model, the data link layer, so that the physical layer can be standardized, so that the same hardware can be used in the future to serve different industrial bus protocols. At this time, there will be the following situation that the dedicated fieldbus interface will disappear, and then be unified to the network port with TSN function, as for what communication method to achieve, it can be determined by the software, and even with the help of OPC UA, a cross-platform, cross-operating system unified hardware and software communication architecture can be achieved. Back to the EtherLoop used in CyberTruck, let's boldly assume that it also uses TSN technology to achieve the interconnection between different devices and different service protocols, so that the possibility of dedicated hardware interfaces can be greatly reduced, so as to achieve Musk's "first principles" practice at the vehicle network level.
