1. OVERVIEW OF AUTOMOTIVE
NETWORK PROTOCOLS

2. INTRODUCTION
 An In-Vehicle network integrates many automobile
Electronic Control Units(ECUs) with each other by
standard automobile communication protocols like LIN,
CAN, Flexray, MOST, etc.
 The Society of Automotive Engineers(SAE) has classified
the automotive applications into classes A,B and C with
increasing order of criticality on real-time and
dependability constraints.

3. Automotive Networks Overview
The CAN protocol has been developed by Bosch and
nowadays utilized by almost every car manufacturer. It
supports data rates of up to 1MBit/sec.

4. CAN
 Event based communication protocol
 Low speed CAN have speed up to 10kbps to 125kbps,
dedicated for supporting data exchange between ECU’s
 High speed CAN have speed up to 125kbps to 1 Mbps, used in
powertrain
 The future of CAN is CAN FD
 CAN FD is a CAN with Flexible data rate developed in 2011
 Now CAN transfer data faster than 1 Mbps with 64 Byte long
payload

5. Automotive Networks Overview
The LIN protocol has been developed for less demanding
applications in terms of communication speed and latency

6. LIN
 Low cost Class A network protocol
 Is a Master-Slave protocol
 Lin master can manage up to 16 slaves on one bus
 Application: Body and comfort, like door module,
steering wheel module, etc.
 LIN standard allows vehicle manufacturers to add
functionality and extended comfort with minimum
development cost.

7. Automotive Networks Overview
In contrary the MOST protocol satisfies the high data rates
needed for multimedia application

8. MOST
 Is a Class D point to point protocol
 Optical media used for transmission
 A MOST network, may include up to 64 MOST devices.
 Due to its plug and play functionality it is not very difficult to
either add or remove a MOST device
 used for connecting multiple devices in the car including car
navigation, digital radios, displays, cellular phones, and DVDs.

9. Automotive Networks Overview
Finally, FlexRay has been especially developed for
safety related applications in automotive industry

10. FlexRay
 Developed to support X-by wire
 It has 2 communication channel
 Combination of time triggered (i.e. for Static window) and
event triggered(i.e. for Dynamic window)
 Used in chassis, driver assistant, safety control, etc.

11. Future is Automotive Ethernet
 High speed in-vehicle network
 Is client –server based protocol, i.e. it needs a server to
serve all ECU’s in network
 Events are client centric
 In near future it can replace MOST as well as CAN as
well!!