Improved protocol the key to better communication between embedded real-time systems

Dec 05, 2014 | Research/Cooperation

The purpose of IDT doctoral student Mohammad Ashjaei’s research is to improve the communication between several embedded systems, and also to ensure that the messages between them are sent at the right time. This creates more secure and resource-effective systems. On 18 November he defended his Licentiate thesis at MDH in Västerås.


An embedded system is constructed to perform a specific function. In many contexts several systems are connected to one another, and talk to one another by means of a communications system, a protocol as it is known.

- In an aeroplane for example there are hundreds of embedded systems linked to one another via a communications system. We can mention GPS, navigation systems, maintenance systems, autopilot systems and thousands of sensors which send information to the master computer, says Mohammad Ashjaei.

The time aspect is often of great importance. Messages sent over the network must be received at their respective destinations within a certain time, called the deadline.

- Embedded systems which work in groups and have specific time demands which have to be met so that correct functionality can be achieved we call distributed embedded real-time systems. Depending on which type of functionality is in question, a missed deadline, that is to say that a message is delivered too late, can lead to catastrophic consequences, says Mohammad Ashjaei.

Improvement of the protocol

In his Licentiate thesis he has focused on a particular protocol called FTT-SE. The protocol is based on Ethernet technology and gives a time guarantee for delivery of messages. It was originally developed for relatively simple networks, and the objective of the thesis has been to improve it so that it can handle several embedded systems simultaneously, without losing the original functions.

- The main goal of this thesis is to suggest solutions to adapt the FFT-SE protocol for distributed embedded real-time systems consisting of several switches. There are lots of protocols that have been developed to be used for such systems, but FTT-SE has a lot of advantages. A few examples are the handling of both regular and sporadic communication, online adaption and resource effectiveness. Therefore the protocol will be of great use in industry, for example the car industry.

Mohammad Ashjaei is of the opinion that improvements of embedded systems will of benefit to everybody in society in the long term, even though it’s perhaps nothing we think about.

- We must aim to optimise safety in embedded systems, and work towards reducing our energy and resource consumption. An improvement of these communications systems will lead to safer and also more cost- and resource-effective systems, he says.

Outstanding research in embedded systems

Mohammad Ashjaei began his studies at MDH’s Master’s programme in Intelligent Embedded Systems, and after graduating from there in 2012 he was admitted as a doctoral student at the University.

- I chose MDH for my doctoral studies since the University has a very large research environment, particularly in embedded systems. The research into real-time solutions exerts a great influence on the national as well as the international research community, with hundreds of publications per year at large conferences and in journals. A lot of professors are working in the subject and it’s a great opportunity for us doctoral students to be able to work together with them. I am very happy that my supervisor believed in me and that I was employed as a doctoral student.