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.
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.
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!!