OSI Layers in Automotive Networks

Home , Data communication, Link layer, Logical link control, MOST Bus, Transport layer

2013-03-20

IEEE 802.1 Plenary Meeting - Orlando

Aboubacar Diarra, Robert Bosch GmbH

1 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Outline

 OSI Reference Model

 Simplified generic Architecture for Automotive Serial Busses

 Basic Automotive E/E Architecture

 Automotive Bus Systems in the OSI Model

 Ethernet Impact on Automotive Bus Layering

2 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks OSI Reference Model ECU 1 ECU 2 Data Application A Application B

Application Protocol 7 Application 7 Application

6 Presentation 3 relevant Layers for 6 Presentation

5 Session Automotive Control Data 5 Session Communication with Area 4 Transport Busses: Layers 1, 2 and 7 4 Transport

3 Network 3 Network Communication Protocol 2 Data Link 2 Data Link Bit Transmission Protocol 1 Physical 1 Physical

Transmission Medium

3 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Simplified generic Architecture for Automotive Serial Busses

Bus Node Bus Node Application Application Layer 7

Communication Communication

Communication Communication Controller Communication Protocol Controller Layer 1, 2

Transceiver Physical Layer Definition Transceiver Layer 1

BUS

4 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Basic Automotive E/E Architecture

Diagnosis Layer 4 * over CAN Central Gateway

CAN FlexRay

MOST LIN High speed CAN

Layer 1, 2, 4* Layer 1, 2, 4* Layer 1, 2, 4* Layer 1 to 7

* Layer 4 is used in this case for Diagnosis Services

5 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Automotive Bus Systems in the OSI Model: Example of the CAN Bus

. Logical Link Control (LLC) Acceptance Filtering 7 Application Overload Notification Recovery Management 6 Presentation . Medium Access control(MAC) Data Encapsulation/Decapsulation 5 Session Frame Coding Error Detection/Signaling/Handling 4 Transport . Physical Signaling (PLS) 3 Network Bit Encoding/Decoding Bit Time Synchronization 2 Data Link . Physical Medium attachment(PMA) Driver/Receiver Characteristics .Media Dependant Interface(MDI) 1 Physical Connectors

6 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Automotive Bus Systems in the OSI Model: Example of the FlexRay Bus

7 Application . Logical Link Control (LLC) 6 Presentation Protocol Operation Control . Medium Access control(MAC) 5 Session Message Framing Communication Cycle 4 Transport . Physical Signaling (PLS) 3 Network Bit Encoding/Decoding Bit Time Synchronization 2 Data Link . Physical Medium attachment(PMA) Driver/Receiver Characteristics .Media Dependant Interface(MDI) 1 Physical Connectors

7 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Automotive Bus Systems in the OSI Model: Example of the MOST Bus

7 Application Application Programming Interface 6 Presentation Netservices Layer 2 5 Session

4 Transport Netservices Layer 1 3 Network 2 Data Link MOST Transceiver 1 Physical Electrical PHY, FOT’s Connectors and Plastic Fiber

8 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Ethernet Impact on Automotive Bus Layering: Example of On-Board Communication * Remark: Central Layer 3 and 4 can be Gateway solicited for Car2X Communication Applications.

Switch CAN FlexRay

LIN High speed CAN Ethernet Layer 2 * Excepted On-Board Diagnosis (OBD) which needs a Layer 4 support

9 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Ethernet Impact on Automotive Bus Layering: Example of Off-Board Communication Layer 3 / 4 Diagnosis over IP (DoIP) Central Gateway

Switch

CAN FlexRay

LIN High speed CAN Ethernet Layer 3 / 4 Layer 4

10 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Conclusion(1)

 In reference to the OSI Data Communication Model, the Serial Interface of CAN, FlexRay and LIN Busses typically needs 3 OSI Layers for On- Board Communication excepted OBD: the Physical Layer, the Data Link Layer and the Application Layer

 The MOST Bus covers all the 7 OSI Layers for On-Board Communication

 The Transport Layer is used for Off-Board Communication like Diagnosis and also for OBD on these typical Automotive Area Networks.

 The Layers 3 and 4 can be used for Vehicle On-Board Communication in Car2X Communication Applications

11 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks Conclusion(2)

 Therefore, for a Control Data Communication that occurs in an In- vehicle closed Network, the need of the Layer 2 is justified.

 On top of that, Layer 3 Routing Processes require more infrastructure (eg. IP stack implementation, software implementation, memory need . . .) and costs investments than Layer 2 solutions from an Automotive Perspective

 For In-vehicle Control Applications which require a very low Latency, a Layer 2 solution is more pragmatic than a Layer 3 solution

 However, Diagnosis over IP, Car2X and In-Car Wireless Communication Applications need Layer 3 Routing Support

12 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando OSI Layers in Automotive Networks

Thank You for your Attention

13 2013-03-20 - IEEE 802.1 Plenary Meeting - Orlando