1. October 26, 2016
MOST
Abhishek Mishra
Tata Consultancy Services

2. October 26, 2016
What is MOST
MOST History
MOST Devices
MOST Communication
Versions of Most
Agenda

3. October 26, 2016
What is MOST
• MOST (Media Oriented Systems Transport) is a
high-speed multimedia network technology optimized
by the automotive industry. It can be used for
applications inside or outside the car. The serial
MOST uses a ring topology and synchronous data
communication to transport audio, video, voice and
data signals.
• • A network can consist of up to 64 devices
• • Sample rates of 44.1 or 48 kHz

4. October 26, 2016
MOST device
A MOST device consists of three parts
1. Physical interface
2• Network Services
•- A Network Interface Controller (NIC) handles these
•services.
•Modern NICs have a built in processor and are
•called INICs, Intelligent NICs
3• Function Blocks (FBlocks)
•- These take care of the services that the device can
•supply
•A MOST device is not connected to a bus in the
•common sense. It has an inport and an outport and
•passes the information from the inport to the outport

5. October 26, 2016
MOST device

6. October 26, 2016
MOST device

7. October 26, 2016
FBlocks
• FBlocks can have functions with two different targets
• • The application
• . The MOST system (network)
• FBlocks can be of three types
• • Controllers - Controls one or more FBlocks
• Slaves - FBlocks that are controlled by other FBlocks
• HMIs – Human Machine Interface
• - Used for the interaction between the user
• and the device

8. October 26, 2016
MOST Versions
MOST25
•Optical network with a bit rate of just under 25 Mbits/s
•• Sampling rate 44.1 or 48 kHz
•• Each frame consists of 512 Bits
•• A block consists of 16 frames
•• A frame can hold 60 Bytes of data
•• 24 – 60 Bytes of the data can be synchronous data
•• The rest of the 60 Bytes holds asynchronous data
•• On top of that the Control Channel can hold
•2 Bytes of data
•• The total amount of Control Channel data (32 Bytes)
•is spread out over 16 frames (one block)

9. October 26, 2016
MOST Versions
• MOST50
• Optical or electrical network with a bit rate of just
• under 50 Mbits/s
• • Each frame consists of 1024 Bits
• • The frame can hold 117 Bytes of data
• • The border between synchronous and
• asynchronous data can change dynamically
• • Sampling rate 44.1 or 48 kHz
• • The Control Channel can hold 4 Bytes of data
• • The total amount of Control Channel data (64 Bytes)
• is spread out over 16 frames (one block)

10. October 26, 2016
MOST Versions
• MOST150
• MOST150 was introduced in October 2007 and
provides a physical layer to implement Ethernet in
automobiles.
• MOST150’s advanced functions and enhanced
bandwidth will enable a multiplex network
infrastructure capable of transmitting all forms of
infotainment data, including video, throughout an
automobile.

11. October 26, 2016
Why MOST
1.high data rate transmission
2.lighter and more flexible compared to shielded electric
data lines
3.does not cause any interference radiation
4.insensitive to electromagnetic interference irradiation
CAN (Controller Area Network), LIN (Local Interconnect
Network) and other automotive standards are not suitable
because they are too slow to carry video.

12. October 26, 2016
Further reading
• The MOST Specification can be downloaded from
• www.mostcooperation.com
• There you will also be able to download a more
• readable book on MOST

13. October 26, 2016
Thank You
By :Abhishek Mishra