Data Communication And Network Routing With Controller Area Networking (CAN Bus)

Students who successfully complete this module will be able to:

1.Demonstrate a broad understanding of the knowledge base of this module, and its terminology and discourse (with specific reference to transmission media, data encoding, transmission modes, error detection and correction, flow control, multiplexing, switching techniques, and routing);

2.Identify and evaluate the principles and concepts underlying theoretical frameworks highlighted in this module, and demonstrate an ability to identify their strengths and weaknesses, especially in relation to the evolving networking scene (covering network topologies, protocols, layering, standardisation, LANs, WANs & MANs, internetworking, management, and multicast);

3.Collect and evaluate information from a variety of authoritative sources to inform a choice of solutions to standard data communication and network problems highlighted in this module, including online open source and subscription-only literature;

4.Evaluate the reliability of data and information provided in this module, using pre-defined techniques and/or criteria, especially in relation to free resources.

You are required to research one of above technologies and produce a report covering the issues related to the underlying networking technology. You should use online open-source materials, together with the subscription-only resources available to you via the University’s electronic library. Select and explain one of the listed technologies, explaining the fundamental method by which it operates, exploring the underlying networking principles. Explore and investigate the strengths, weaknesses and potential risks.

Assignment Preparation Guidelines  

1.All components of the assignment report must be word processed (hand written text or hand drawn diagrams are not acceptable), font size must be within the range of 12 point to 14 point including the headings, body text and any texts within diagrams.

2.Standard and commonly used fonts such as Times New Roman, Arial or Calibri should be used.

3.Your document must be aligned left or justified with line spacing of 1.5.

4.All figures, graphs and tables must be numbered and labelled.

5.Material from external sources (both free and subscription-only) must be properly refereed and cited within the text using the Harvard referencing system.

6.All components of the assignment (text, diagrams. Code etc.) must be submitted in one word file.  

This report aims to discuss the topic data communication and network routing. The selected technology for this document is the Controller Area networking (CAN Bus). A brief discussion of the fundamental working method of CAN bus is provided in this report. The advantages and the weaknesses and the potential risks of CAN bus is briefly discussed in this report. Lastly, this report concludes with an appropriate conclusion for this report.

A CAN bus or Controller Area Network is a strong standard of vehicle bus that is designed for allowing the devices and microcontrollers in communicating with each other in several applications without any host computer (Davis et al. 2013). The CAN bus is a protocol that is protocol based and it was designed fundamentally for multiplex electrical wiring in the automobiles for saving copper and now it is used it several fields.

A CAN bus or Controller Area Network bus is a system of communication that is made for the intercommunication among vehicles. This bus allows the communication among microcontrollers and several kinds of devices among one another in real time and without any host computer. A CAN bus do not need any schemes of addressing as the network nodes use distinct identifiers (Kelkar and Kamal 2014). This delivers the information to the nodes about the urgency and the priority of the message that is transmitted. The architecture of CAN bus consists of these following layers:

• Data link layer: the linking of the actual data to the protocol in the terms of receiving, sending and data validation is done in this layer.
• Physical layer: The actual hardware is included in this section.
• Application layer: This layer interacts with the operating system or the CAN devices application

A standard frame of CAN consists of these following bits:

Start of Frae me or SOF: This is the origin point of the message.

RTR: It stands for Remote Transmission Request. This node is activated when some information is required from a node.

Identifier: The priority of the messages are decided in this. The priority of the lower binary value is the highest (Zhang et al. 2017).

DLC: It stands for Data Length Code. The data length is defined by this.

IDE: Single Identification Extension. The more dominant this is, it is perceived that the identifier of CAN with no extension is being sent.

Data: Transmission of upto 64 bits can be done

R0: This is the reserve bit

ACK: this means Acknowledge. When the correct message is transmitted, this is dominant.

CRC: This stands for Cyclic Redundancy Check. The checksum is contained in this.

A CAN bus utilises two dedicated wires to communicate among one another. The respective wires are CAN low and CAN high. The controller of CAN is linked with all the components of the network using two wires (Cena et al. 2013). Each node of the network has a distinct identifier. All the ECUs on the bus are efficiently in parallel connection and this is the reason why all the data is visible to all the nodes. The response of any node is received when it detects its respective identifier. The individual nodes can be detached from the network without disturbing other nodes (Shah et al. 2013). When a CAN bus is Idle, both the lines carry 2.5V. When the transmission of data bits is done, the CAN low line descends up to 1.25V and the CAN high line increases up to 3.75V, and therefore it generates a differential of 2.5V among the lines, and each CAN line is connected to another, and not the vehicle ground.  As the communication depends on the differential voltage among the two lines, the CAN bus is found to be NOT sensitive to the electrical fields, inductive spikes or any other noise. This is the reason why CAN bus is preferred on mobile equipment for communications that are networked. CAN bus can be used for providing power to the CAN. Or any power supply for the modules of the CAN bus can be structured distinctly (Mubeen, Mäki-Turja and Sjödin 2015). The wiring of the power supply can be totally distinct or the integration into the same bus can be done in the same cable as the lines of CAN bus and lead to a single 4-wire cable. The nature of the communications of CAN bus permits all the modules to receive and transmit the data on bus. Data can be transmitted by any module, which is received by all the other modules. It is essential to allocate the bandwidth of CAN bus to the systems that are critical to safety (Shin 2014). The nodes are usually assigned to one of a number of levels of priority.

Strengths of CAN Bus

The following are the strengths of CAN bus:

• It is utilised for reducing the issue of wiring in several automobiles application.
• The CAN bus permits the data rate upto 1Mbps.  CAN FD or flexible data rate wersion allows more than 2Mbps speed. CAN FD support huge bandwidth which is approximately eight times greater than the basic CAN bus.
• 8 bytes are supported by the Standard CAN protocols, while the CAN FD protocol backs 64 bytes in the part of data field.
• Overall time and cost is reduced due to the simple and lower wiring and the utilisation of flash programming (Groza and Murvay 2013).
• It can work in adverse electrical environments
• Lost messages can be retransmitted automatically using CAN bus

The disadvantages of CAN bus can be the following:

• The maximum length that is supported by the CAN bus is 40 meters
• Even though the maximum nodes number is not determined in the network, it can support a maximum 64 nodes due to the electrical loading
• It requires additional expenditure for the development of software and the maintenance
• Undesirable interactions among the nodes can be found in this network
• As the network needs to be contained in a topology, the stubs are limited increasingly (Chan et al. 2014)
• The removal of nodes requires the utilisation of termination resistors of value of 120 Ohm at the suitable places on the CAN bus
• For reducing the issues of integrity of signal like the reflections, CAN bus needs to be properly terminated at both ends with the resistors.

Several researches were conducted and it was observed that the CAN buses are not produced for withstanding attacks with malicious intent, instead these buses are created for reliability (Hu et al. 2013). Due to the shared nature of broadcasting, the risks in the CAN buses increases. With the alteration of the messages of the CAN, the control of the car can be gained by the attacker. Researchers demonstrated this vulnerability by controlling the steering wheel of Jeep by spoofing the assist of parking (Xie et al. 2013). The CAN is of significantly fragile in nature and it can be easily overridden by any attacker. The messages of speedometer that are sent by other ECUs can be easily detected and the attacker and they can assert a bus state that is dominant, which makes all the other receivers reject the messages that are sent to them as invalid. Even the brake control can be compromised when the car is travelling at a high speed. The Read Memory By Address is one more service of diagnosis that can be misused by the attackers for reading the arbitrary pieces of the address space of ECU. The sensitive values such as the keys of authentication can be leaked easily with the use of this service. A risk that is associated with the CAN bus is that the CAN does not possess any intrinsic security tool. They are susceptible to the attacks from any surface of physical attacks like OBD-II port and the surfaces of wireless attack such as the GPS, Bluetooth, GSM module, Wi-Fi. In a CAN, the broadcasting of each message is done over a bus and the nodes decide whether to accept the message or discard it (Mubeen, Mäki-Turja and Sjödin 2014). It creates the availability of every message on every ECU on the bus.

Conclusion

Therefore, it can be concluded that the Controller Area Network is used in the automobiles for enhancing the capability of the vehicles. A CAN bus or Controller Area Network is a strong standard of vehicle bus that is designed for allowing the devices and microcontrollers in communicating with each other in several applications without any host computer. A CAN bus or Controller Area Network bus is a system of communication that is made for the intercommunication among vehicles. This bus allows the communication among microcontrollers and several kinds of devices among one another in real time and without any host computer. Due to the shared nature of broadcasting, the risks in the CAN buses increases. With the alteration of the messages of the CAN, the control of the car can be gained by the attacker. Researchers demonstrated this vulnerability by controlling the steering wheel of Jeep by spoofing the assist of parking. The CAN is of significantly fragile in nature and it can be easily overridden by any attacker.

References

Cena, G., Bertolotti, I.C., Hu, T. and Valenzano, A., 2013. Fixed-length payload encoding for low-jitter controller area network communication. IEEE Transactions on Industrial Informatics, 9(4), pp.2155-2164.

Chan, M.C., Chen, C., Huang, J.X., Kuo, T., Yen, L.H. and Tseng, C.C., 2014, April. OpenNet: A simulator for software-defined wireless local area network. In Wireless Communications and Networking Conference (WCNC), 2014 IEEE (pp. 3332-3336). IEEE.

Davis, R.I., Kollmann, S., Pollex, V. and Slomka, F., 2013. Schedulability analysis for Controller Area Network (CAN) with FIFO queues priority queues and gateways. Real-Time Systems, 49(1), pp.73-116.

Groza, B. and Murvay, S., 2013. Efficient protocols for secure broadcast in controller area networks. IEEE Transactions on Industrial Informatics, 9(4), pp.2034-2042.

Hu, C., Zhang, N., Li, H., Cheng, X. and Liao, X., 2013. Body area network security: a fuzzy attribute-based signcryption scheme. IEEE journal on selected areas in communications, 31(9), pp.37-46.

Kelkar, S. and Kamal, R., 2014. Adaptive fault diagnosis algorithm for controller area network. IEEE Transactions on Industrial Electronics, 61(10), pp.5527-5537.

Mubeen, S., Mäki-Turja, J. and Sjödin, M., 2014. MPS-CAN analyzer: Integrated implementation of response-time analyses for Controller Area Network. Journal of Systems architecture, 60(10), pp.828-841.

Mubeen, S., Mäki-Turja, J. and Sjödin, M., 2015. Integrating mixed transmission and practical limitations with the worst-case response-time analysis for Controller Area Network. Journal of Systems and Software, 99, pp.66-84.

Shah, M.N., Husain, A.R., Punekkat, S. and Dobrin, R.S., 2013. A new error handling algorithm for controller area network in networked control system. Computers in Industry, 64(8), pp.984-997.

Shin, C., 2014, February. A framework for fragmenting/reconstituting data frame in Controller Area Network (CAN). In Advanced Communication Technology (ICACT), 2014 16th International Conference on (pp. 1261-1264). IEEE.

Xie, Y., Zeng, G., Chen, Y., Kurachi, R., Takada, H. and Li, R., 2013. Worst case response time analysis for messages in controller area network with gateway. IEICE TRANSACTIONS on Information and Systems, 96(7), pp.1467-1477.

Zhang, Y., Chen, M., Guizani, N., Wu, D. and Leung, V.C., 2017. SOVCAN: Safety-oriented vehicular controller area network. IEEE Communications Magazine, 55(8), pp.94-99.