Since the 1990s, she has been interested in how to build and develop reliable software systems – particularly important in aeroplanes, but also of great importance for most other computer systems.
Communication without power networkOne thing her research group have studied is how society and its citizens would be able to communicate if both the power and telecommunications networks were down, as during the major Swedish storms Per and Gudrun. In 2009, Professor Nadjm-Tehrani’s research team produced a solution that functions well, using a data protocol that made it possible to communicate with the aid of networked mobile telephones.
“In 2011, the United States National Security Council reported that, in conjunction with Google and researchers at George Mason University, they had begun to look at this area in the wake of fresh terrorist attacks,” she explained.
Resource efficiencyShe is currently conducting research in several different areas that have resource efficiency as a common factor - regardless of whether that resource is computing capacity, memory, bandwidth or power.
A Saab-related project, where a PhD student is now working flat out, concerns investigating the extent to which standard commercial computers can be used in aeroplanes. Because while the computer manufacturers have gone almost entirely over to making computers with multi-core processors, where computing happens in parallel, aeroplanes still have processors with just a single core.
Simin Nadjm-Tehrani“But the issue is how long and at what prices computers with single core processors will continue to be manufactured. We must quite simply address this problem and study how reliable software in systems with multiple cores can become. In the case of mechanical construction, there are certain limits in the form of the laws of physics and mechanics. But there are no such limits in software, the world of possibilities is too big to know what it contains,” she says.
In an aeroplane there are also a large number of different systems, each in their own housing where both software and hardware are tested thoroughly as is the communication between them.
Integrated modular avionics“A new concept has arisen – integrated modular avionics. The aim is to bring together a number of systems into the same housing to reduce weight and space. But the critical functions must not be affected by the less critical ones. We haven’t solved that one yet.”
She has also researched into optimising the bandwidth resource. When unmanned craft cover large areas while gathering information – for example in the event of a forest fire – they need to communicate with each other, sending maps and images wirelessly. The contact will be interrupted now and again, when they move a little too far apart. A protocol has been developed that manages interruptions without the transfer of information being seriously affected.
Energy is the third resource she is looking at. We are seeing mobile telephones being equipped with new apps at a fast rate. Battery technology has not had the chance to keep up.
“The people developing apps don’t often think about the energy consumption of the software. Also, the transfer of information depends on both which provider is chosen and how the base station works. Telephone manufacturers cannot optimise for a particular app, and the apps are not optimised for the different models of telephone. I have a PhD student researching how we can record and compare power consumption of different apps,” says Professor Nadjm-Tehrani.
Spotify has become so interested that they are now looking for a student from Linköping University to do a graduation project to help implant tools in their development environment.
“We must constantly be thinking about what will happen as we go forward. What I am working on at the moment did not exist as a concept five or ten years ago. And development is going ever faster. We are in the middle of digital evolution, and we don’t know what it will bring,” she says.
How, for example, will security operate in the smart electricity network? Could someone take over control of the mobile or the fixed smart units, someone with malicious intent, and what would happen then?
“Few want to pay for security. But it is important that we decide what level we want to be on; this applies to connected homes just as much as to the power network or the risk of terror attacks. If we take a risk, we have to know what level of security we are talking about and what we have paid for.
Åke Svensson awardShe is receiving the Åke Svensson scholarship for her research breakthroughs on the development of reliable computer systems for security-critical applications, and for her work on accessibility to communications systems in the event of crises that threaten the public security. In the justification of the choice of recipient, her work with reliable software for multi-processor units was also mentioned, as was her work on networked unmanned vehicles.
The scholarship, which amounts to SEK 50,000 was instigated by Saab at Åke Svensson’s retirement ceremony. For a period of five years, it will be awarded in the name of Åke Svensson. The scholarship will reward a researcher at the Faculty of Science and Engineering at Linköping University in the field of public security, aviation and defence, and is to be used to help previous findings have a greater reach and impact. In particular researchers who have successfully disseminated their findings outside the research world are to be encouraged. Previous scholarship recipients are Professor Fredrik Gustafsson, Department of Electrical Engineering; Professor Peter Krus, Department of Management and Engineering; and Professor Patrick Doherty, Department of Computer and Information Science.
Monica Westman Svenselius 2014-12-10