Developing survival instincts in computing systems

Complex information and communication systems have been studied for a long time. Many approaches and methodologies exist to date. Amongst the properties of interest in those studies the prominent place is occupied by the property of systems to stay alive and functional in spite of harsh environmental conditions that may surround them. Typically such conditions are assumed to generate higher rates of errors such as those that are caused by radiation. They are considered mostly in the scope of information processing, and to a lesser extent in the domain of resource availability, for example, the availability of energy. While the system may remain fully functional under the nominal conditions of energy supply, its behaviour may be highly unpredictable when the energy flow to the system is impaired for one or another reason. Design of systems with varying power modes is a rapidly emerging area of research, and it comes from many different directions; for example, intelligent autonomous systems, systems with energy harvesting, green computing etc. Much of this research is about systems that are still sufficiently complex that even their most energy-frugal mode of action still requires a certain stable level of energy flow. What about systems that have to 'live on the poverty line', the conditions in which power levels drop to zero and systems that have to self-recover upon the arrival of the 'first glimpse of sunlight'? In this presentation we shall be looking at the first glimpses of, perhaps, still naive, approaches to building computing systems whose power sources can be defined in a wide band of modes. Such systems will effectively need survival instincts as part of their intrinsic characteristic. An important element of this new design discipline is a close proximity of the design methods required for power conditioning and those necessary for computational blocks as the latter form the load for the power chain. This proximity and associated holisticity drives for codesign, which involves new methods for modelling, simulation, synthesis and hardware and software implementation. This talk will address a number of paradigms for such designs, such as energy-modulated computing, power-proportional, power-adaptive and elastic system design, and present examples of problems formulated and solutions obtained in the context of research on the new generation of systems with energy-harvesting. Amongst those examples are a power-proportional FFT unit, a static RAM that can operate under varying power levels, reference free voltage sensor, power electronics with capacitor banks. One of the most critical aspects of any system design is its communication fabric. Its survival in power-deficient modes, in whatever form or shape, is essential for keeping even the most basic functions alive in the system. The talk will invite the audience to speculate on what sort of heuristics and principles of design of the interconnect fabric can be developed to support its activity in some basic forms.