Keynote Presentation Pervasive Computing: Towards Self-Aware Systems Volker Christian Johannes Kepler Universität Linz, Austria [email protected] 1. INTRODUCTION The last decade of the past century has changed the world more than any decade before. This change was mostly enforced by technological advances in information and communication technologies. Observably, information and communication technology has found its place in our everyday life. Most of us are equipped with at least a cellphone and more and more often by some kind of Personal Digital Assistant (PDA). In the same way as the potential and the power of those devices has grown up and their size has been reduced, they have become cheaper and cheaper. The consequence of that fact is that the number of those devices has enormously grown since 1990. They could be found in many different objects of everyday life. And in the near future, it will be completely normal for us to be surrounded by a huge number of new evolving smart gadgets, assisting us in day-to-day processes [Bohn et al. 2003]. The level of apparentness of such support will differ for different applications and different types of devices. Some will be completely hidden from the user and some others would be located more prominently in the environment. However, the kind of interaction with those visionary devices and systems would be unfamiliar for us from the present point of view. In contrast to the way of traditional interaction based on keyboard, mouse, and display, we will use human native interaction mechanisms like gestures, voice, or even more elaborated, facial expressions [Wellner et al. 1993]. Thus, no direct interaction with technology would happen – the devices observe and collect information about humans during natural situations and affectations and intelligent software is responsible for drawing conclusions out of it. These conclusions lead to reactions which, via various different actuators, are affecting the real physical world again. This “information-loop” - sensing, analyzing, and reacting - would generate highly complex scenarios completely new in computer science. On the other hand, rendered possible due to advances in network and sensor technology, a complete new feature, namely awareness, is just evolving. Devices independently sense and collect information about their environment using various different technologies like Global Positioning System (GPS), Radio Frequency Identification tags (RFID) systems, magnetic and optical tracking systems, biometric and biological sensors, but contribute with that information to the knowledge of a collaborative system. This collaborative system is formed by those devices itself interconnected by modern network technologies like e.g. Global System for Mobile Communication (GSM), Universal Mobile Telecommunication System (UMTS), Wireless LAN (WLAN), Bluetooth, Infrared, and other radio based technologies. Such huge connected systems of many individual devices additionally equipped with an adequate software system would form a meta-system showing a self-aware behavior in analogy with biological meta-systems like ant-hills or fish swarms for example. The study of the structure, the construction, and the modeling of the behavior and the characteristics of such interconnected sensor-equipped systems is the domain of Pervasive Computing, expecting to introduce a new quality into human computer interaction and a grant of unobtrusive support of humans during their everyday life. 2. MOORE'S LAW AND ITS IMPACT ON PERVASIVE COMPUTING Pervasive Computing would not be possible without the availability of very small but yet powerful systems. This has been fertilized by the process of constant miniaturization of hardware along with an increase in performance. 1965, Gordon Moore has observed that the number of transistors to be able to be integrated error-free on a square inch of silicon-tie almost doubles every 12 month [Moore 1965]. This legality known as “Moore's law”, flatters somewhat to 18 month per duplication in the years after 1965. However, since 1970 this rate is more or less constant. Along with the reduction of the structure size on silicon, also the speed of the chips is continuously growing. Due to already perceivable further technologies like chips based on quantum mechanic principles, it is supposed that Moore's law would be valid for the next 20 years. Based on that period of time and the doubling rate one could calculate, that the performance of devices would increase by a factor of 16384. This enormous increase will make it possible to build much smaller but much more powerful devices in the future. Beside the almost established integration of computer hardware into consumer electronics, vehicles, home appliances, etc. we will find some kind of computer hardware in almost every object in the future – clothes, foot, walls, doors, and possibly implantations even in the human body itself [Schmidt & Laerhoven 2001]. 3. THE SOFTWARE CHALLENGE As clear as the future could be seen for hardware at least for the next view years, as diffuse it is for the software. It is a known fact that software didn't evolve as fast as hardware. But especially in this new situation of an highly visible number of devices embedded into physical objects forming a smart environment, the situation for software is an even bigger challenge. The well established client/server network architecture is presumably not the ideal solution in this new situation. Scalability and maintainability appear to be one of the main problems which immediately emerge. Many different projects have evolved to investigate and to cope with that new situation and different nomenclatures describing more or less the same quality of approaches could be found in literature. Pervasive Computing, Ubiquitous Computing, Ambient Computing, Calm Computing, Sentient Computing, Autonomous Computing, Hidden Computing, Invisible Computing, and Disappearing Computing – all of them have the same guiding idea: “The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it”, formulated by Mark Weiser from the Xerox PARC group [Weiser 1991]. And all of them break with the old client/server based computing and propose new architectures based on spontaneous adhoc peer to peer technologies. Even the big number of projects and project titles reflects the big effort put into those new software systems. Today, the term “Pervasive Computing” has become most widely accepted describing in short the guideline of the just evolving paradigm: Reduced to functionality, device independent, intelligent information technology which is not identifiable as technology but providing background assistance which acts proactively and largely autonomously. 4. COMPUTATIONAL PERCEPTION AND CONTEXT The interaction with smart environments where everything is connected to everything is of fundamental importance. It is obvious that the established interaction technologies like keyboard, mouse, and display are not appropriate for pervasive computing systems. These interfaces are replaced by a potpourri of diverse sensors and modern technologies like RFID tags, GPS, temperature sensors, cameras, microphones, acceleration and rotation sensors, to note only some of them. It is a fundamental must for such systems, which are based on those new interfaces some kind of computational perceptional is integrated into them. Autonomous cognition, localization, perception, and prediction of future situations would be essential and necessary abilities of software components for pervasive systems. The goal is to develop a pervasive computing environment which could collect information about its associated physical environment by use of all those different sensors and which could generate a representation of the direct and indirect context out of that sensory informations, interpret this context representation and act back into the real world controlled by an automatically generated context prediction [Ferscha 2003]. “Context” as a term in software engineering has been introduced and defined by different groups. A.K. Dey, for example, defines context as “any kind of information necessary to characterize the situation of an entity. An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves” [Dey 2000]. It is not specified in more detail what an entity is – in fact, an entity is a placeholder for an arbitrary physical object, e.g. Mahadma Ghandi, a rubber, a rose, etc. Other projects have done a categorization on top of the entities. In the Cooltown Project the categories “People”, “Place”, and “Thing” are introduced and postulated to be sufficient for most applications [Kindberg et al. 2000]. The term “context-aware” in general describes the ability of a system to recognize and appoint objects and persons along with their intentions. Furthermore, the Xerox Parc Group defines the term “context-aware computing” as “the ability of a mobile user's application to discover and react to changes in the context in which they are situated” [Schilit 1995]. To advance towards the aim of developing context-sensing and interpreting applications, the process of perception has to be formalized and structured in a general way to be easily and flexible applicable during software development. This formalization is the domain of the field of “Computational Perception”. Combined with the field of “Pervasive Computing”, one gets context-aware and context-based applications able to integrate themselves into and cooperate with the natural human environment. As far as the context-information collecting sensors permit the digital representation of context at a particular moment is at the same time a digital snapshot of the physical world automatically. This snapshot combined with context-information interpretation and context prediction could be viewed as the virtual representation of a psychological cognitive process. 5. EVERYWHERE AND NATURAL INTERFACES The consequent incorporation of all human senses, not just audio and visual perception, and the rigorous replacement of traditional interfaces like keyboard, mouse, and display, is the central challenge of the field of “Everywhere and Natural Interfaces”. Even adding speech-processing and speech-recognition to an application doesn't cover all the possible human computer interaction. Gesture, emotion, facial expression, habits, grasping, etc. are all potential interfaces to embedded systems and enable intuitive alternative interfaces to smart, cooperative applications. The challenge is to make those new interfaces situational, intelligent, and autonomous to make the ambient digital environment easily and intuitively accessible to humans, everytime and everywhere. 6. Context Aware Frameworks and Applications By formalizing the whole process of context-processing, six different layers could be identified and specified [Beer 2003]. 1. 2. 3. 4. 5. 6. Context Sensing Context Aggregation Context Representation Context Interpretation Context Prediction Context Controlled Acting A variety of software frameworks have been developed supporting this layer structure to help developing context-aware applications [Schilit 1995][Kindberg et al. 2000][Dey 2001]. The first layer, Context Sensing, is responsible for collecting as much information as possible about the context Sensor Sensor Sensor Sensor Sensor Sensor Context Aggregation Context Representation Context Interpretation Context Prediction Actuator Actuator Actuator Actuator Actuator Actuator Typical Architecture of a Context-Aware Application of the physical environment, to transform this information into a consistent collective data format, and to forward this data to the next layer. During Context Aggregation, all data coming from the Context Sensing layer are collected and combined in a way, that the Context Representation could generate a unified abstraction of the real world. The Context Interpreter together with the Context Prediction takes this abstraction and performs some application specific transformations to provide control values to perform Context Controlled Acting. The challenge in developing context-applications following this architecture is the modeling of the interpretation of the context representation in terms of the semantics of the application. While earlier approaches have modeled context by some sort of key values, new approaches are using meta-data, object orientation models, or logic orientated systems where context are facts in rule based compositions. No satisfying general solution has been found so far for the provision of proactivity for context-aware applications. Applications following a state-based context model approach need some sort of prediction component to adjust the application, to meet some potential future context configurations. Here the triggered action is not just controlled by a previous context representation but it also takes into account the not yet achieved but conceivable future state. Applications equipped with interpretation and prediction systems would have the ability to anticipate the future and to accomplish actions aimed at an anticipated future context configuration. Proactivity would enable context-aware systems to rate the consequences of its activity in the physical world. By treating this rating as the input for a tuning process of the application and the prediction module itself, one would end with a process comparable to learning of creatures, for which some level of self-awareness is a necessary precondition. 7. The Future Beside the open questions already mentioned above, there are many more not yet solved challenges not discussed so far. Some of them are of technical nature while others are of more political and juridical character. ● Everywhere Access: Guaranteeing time, location, and device independent access to relevant information on the bases of wireless personal, local, and global communication technologies. ● Security: Due to the enormous increase of the number of independent but connected devices and the heterogeneity of software and operating systems, security will be of even higher priority than today. A virus-attack would have a dramatical impact on a connected system of small devices where, due to the enormous number of such devices and the lack of direct interfaces like keyboards and displays, nobody is able to react fast enough to take some counteractive measures. The whole system has to be equipped with some sort of immune system able to react autonomously to adversary attacks. ● Privacy: Some new techniques have to be developed to preserve the data-highness of individuals. Iris-scanner, fingerprint-scanner, and even more sophisticated technologies are promising to guarantee absolute safety that personal data could only be accessed by authorized persons. Also basic juridical and political conditions have to be developed to guarantee order and safeness in this evolving new environment. We have already gone a long way towards the realization of the idea of embedded interconnected devices forming a smart self-aware environment. But many problems are left open. Further work has to be done until we really live in a world where such systems would be reliable and treated as normal as the traditional television set today, assisting us in everyday processes. With the support of Moore's law, we could expect to converge to this vision soon. 8. Literature [Bohn et al. 2003] Bohn, J.; Coroama, V.; Langheinrich, M.; Mattern, F.; Rohs, M.: Allgegenwart und Verschwinden des Computers – Leben in einer Welt smarter Alltagsdinge. In: Ralf Grötker (Hrsg.): Privat! 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