D2B/SMARTwireX

• Market Dynamics
• Networking Benefits
• Technology Overview
• Cost Benefits

D2B/SMARTwireX Technology Overview

FUNDAMENTALS

Automotive infotainment networks typically transmit data of three types:

• Source Data, such as streaming digital audio data from a CD Changer
  - This is typically handled by the dedicated hardware in the device
• Asynchronous Data, such as real-time telematics or navigation information
  - This can be quite a lot of data and is typically handled by a micro-controller
• Control Data, which is the data used to control the devices on the network
  - This is typically low-bandwidth information, handled by a micro-controller

D2B is an isochronous TDM network system, connected in a ring topology, which is able to transmit all three types of data in any combination, simultaneously over low cost Polymer Optical Fibers (POF) or Unshielded Twisted Pair (UTP) Copper Cables.

D2B also describes a networking protocol for automotive multimedia data communication that enables robust interconnection and interoperability between in-car multimedia devices such as Radio Head Units, CD Changers, Navigation, Telephones, TV and others.

SMARTwireX defines an electrical physical layer (PHY) supporting D2B networks running up to 25Mbps over standard low-cost UTP cabling, with full automotive EMC compatibility.

C&CE carried out a significant amount of EMC evaluations in conjunction with OEMs in Europe and Japan. Results have been excellent with D2B/SMARTwireX meeting, and very often exceeding, OEM emission and susceptibility requirements.

Components of a network ‘node’

Our Conan family of Media Access Controllers (Network Transceivers) handle some parts of the D2B Protocol automatically (e.g. network timing, framing, arbitration, synchronization and channel encoding/decoding), and the remaining Network Management Protocols are typically implemented in software within each device.

Media Access Controllers can be connected to the network medium via C&CE’s D2B/SMARTwireX Physical Layer Controller (PLC8002) in the case of Unshielded Twisted Pair (UTP) media or via a Fibre Optic Transceiver (FOT) in the case of optical media.

NETWORK MANAGEMENT PROTOCOLS

Network Management Protocols are designed to ensure that network operation during start up, initialisation, normal operation or alarm recovery and shut down is carried out in a deterministic manner.  

The key NMP functions are:

• Start-up/Shut-down
• Message Scheduling
• Bandwidth Allocation
• Slave Initialisation
• Address Initialisation
• Source Data Allocation & Routing
• Alarm Condition & Fault
• Monitoring
• Retry Mechanisms
• Normal Operation

C&C Electronics supply a gold-standard production-proven Network Management Protocol implementation for master or slave devices that will save you time and money. more…

APPLICATION PROTOCOLS

D2B APIs are designed to give network users access to device functionality. They describe the behavior models of the devices on the network and provide the means for meaningful communications by combining commands reporting and data messages into a flexible interoperability concept.

APIs include a range of Mandatory Control Protocols (the basis of plug and play interoperability), Optional Control Protocols, Data Message Handling, Diagnosis and Proprietary Data Messages.

C&CE manages the maintenance and evolution of the D2B/SMARTwireX protocols, including core protocols and application protocols. Our objectives are to:

• Develop and/or adapt protocols to suit the needs of carmakers and their suppliers
• Maintain overall consistency and compatibility at all levels
• Offer standardised software implementations of protocol stack and APIs
• Support Standardisation
• Keep protocols up-to-date

Electronic version of the Core Protocols and Application Protocols are available for download free of charge, upon request. more…

FURTHER INFORMATION

More detailed technical information can be found in our Downloads section.

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