What is BroadR-Reach and how is it used?
BroadR-Reach is an ethernet physical layer standard that allows for more cost-effective applications in automobile computing, extending the range of twisted-pair connections without significant sacrifices to speed and connectivity.
One of the most prominent uses of BroadR-Reach is in advanced driver-assistance systems (ADAS). ADAS tasks are broken down into active or passive applications. Passive ADAS tasks simply provide a warning or alert to drivers. These applications include backup cameras or lane departure warnings. Active ADAS applications can take corrective action based on the warning, such as performing emergency braking or returning a vehicle to its lane.
BroadR-Reach maxes out at 100 Mb/s, making it best suited for passive ADAS. Active ADAS applications require lossless video (for, say, identifying and reacting to roadbound obstacles). The technology is also used for infotainment and in touchscreen displays, either for on-board operating systems or video screens.
Much of the cost savings is in the cabling, with BroadR-Reach offering the advantages of thinner, lighter-weight, twisted-pair cables, making it notably more cost-effective than Media Oriented Systems Transport (MOST) or low-voltage differential signaling (LVDS).
How Does BroadR-Reach Compare with CAN FD?
Ethernet is very efficient when used to transfer data from a camera to a central computer on a dedicated communication line. However, when it comes to real-time system control, Ethernet demands additional complex rules to compete with CAN FD.
Every CAN FD frame can have a maximum latency time before it is sent, while Ethernet doesn’t provide this function, requiring additional protocols (such as TDMA, Toke-bus, or Toke-ring) on top of Ethernet to provide predictable latency. This, unfortunately, can lead to problems during configuration, at start-up, and in recovering after failure.