BroadR-Reach

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The broadr-reach technology is Ethernet - physical layer standard for connectivity applications the automotive sector. BroadR-Reach technology enables multiple vehicle on-board systems to access information simultaneously via unshielded single twisted pair cables. According to Broadcom Corporation , which invented the BroadR-Reach standard, automobile manufacturers that integrate the BroadR-Reach Ethernet standard benefit from reduced connection costs and a lower weight of cabling, among other things.

BroadR-Reach networks

The use of BroadR-Reach technology in the automotive sector enables the migration of several closed applications to a single, open and scalable Ethernet network in the vehicle. This allows electronic systems and devices to be integrated into the vehicle, for example safety systems (360-degree all-round parking aid, reversing cameras, collision avoidance systems), comfort and infotainment solutions. The BroadR-Reach-Ethernet-Physical-Layer standard, suitable for the automotive sector, can be combined with switch technology according to IEEE 802.3, whereby 100 Mbit / s can be achieved via unshielded single-twisted-pair cables. This replaces the wiring of all components in the vehicle with twisted pair cables.

Physical layer / bit transmission layer

With the BroadR-Reach automotive Ethernet standard, there is a simultaneous transmission and reception operation, i.e. H. Full duplex , via an unshielded twisted pair cable instead of half duplex operation with 100BASE-TX , where one pair is necessary for sending and one pair for receiving with the same data rate. For a better decorrelation of the signal, the digital signal processor (DSP) uses a highly optimized scrambler compared to the scrambler used in 100BASE-TX. This provides a signaling scheme that is needed for automotive applications. The BroadR-Reach automotive Ethernet standard uses a signaling scheme with a higher spectral efficiency than the signaling scheme used for 100BASE-TX. This limits the signal bandwidth of automotive Ethernet to 33.3 MHz, about half the bandwidth of 100BASE-TX. A lower signal bandwidth improves return loss, reduces crosstalk and ensures that the BroadR-Reach automotive Ethernet standard meets the strict EMC requirements in the automotive sector.

Strict standards and internal specifications of the automobile manufacturers (driven by the "Open Alliance") require the use of a low-pass filter made of discrete components with low tolerances (1%). Components with tight tolerances reduce impedance deviations between the differential lines. Semiconductor manufacturers such as STMicroelectronics have presented an integrated solution that combines both low-pass filters and ESD protection on a single silicon chip. An integrated solution of the discrete components on a silicon chip enables perfect coordination of all R, C and L values, as they are subject to the same manufacturing process. This solution reduces the design complexity of this interface and simplifies the “BroadR-Reach” penetration of the automotive market.

standardization

The OPEN Alliance SIG is a Special Interest Group (SIG) formed by BMW , Broadcom , Freescale , Harman , Hyundai and NXP to establish BroadR-Reach as the open standard and the widespread use of automotive Ethernet as the connectivity standard for automotive network applications. Since it was founded at the end of 2011, 160 companies (as of December 18, 2013) have become members of the group.

Licensing

The BroadR-Reach automotive Ethernet standard was released in December 2011, following the formation of the OPEN Alliance Special Interest Group . A license for the specification of BroadR-Reach is available to all interested OPEN Alliance SIG members under RAND terms via a license from Broadcom Corporation .

Web links

Individual evidence

  1. ↑ EMIF02-02OABRY - IPAD automotive-grade integrated protected low-pass filter for BroadR-Reach interfaces