Context management for ubiquitous applications Denis Conan, Chantal - PDF document

Context management for ubiquitous applications Denis Conan, Chantal Taconet, Sophie Chabridon Ubimob 2010 Institut Télécom; Télécom SudParis; CNRS UMR SAMOVAR; équipe ACMES; projet MARGE juin 2010

Context management for ubiquitous applications Contents Context management for ubiquitous applications Denis Conan, Chantal Taconet, Sophie Chabridon, , Institut Télécom; Télécom Sud- Paris; CNRS UMR SAMOVAR; équipe ACMES; projet MARGE, Ubimob 2010 juin 2010 1 Acknowledgements 3 Introduction 4 Outline 4 1 Context-awareness and context managment 5 1.1 Some definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 Context management requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3 Functionalities and architecture of a context manager . . . . . . . . . . . . . . . . . . . . . . . 6 2 COSMOS context manager concepts 8 2.1 What the client application accesses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 What the context node designer builds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.3 What the context source provider builds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.4 How the context designer composes context nodes . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.5 Context node parameterisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.6 Performance evaluation of COSMOS-ME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.6.1 Hardware and software platforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.6.2 Time for observing and notifying a context node . . . . . . . . . . . . . . . . . . . . . . 12 2.6.3 Time for instantiating a context node . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.6.4 Maximum number of context nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.7 General information on the COSMOS project . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 Design of context-aware applications with CA3M 15 3.1 CA3M: Meta Model and Middleware for Context Awareness . . . . . . . . . . . . . . . . . . . . 16 3.2 CA application design process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.3 CA3M runtime architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.4 Context awareness meta-model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.5 From observable model to runtime bridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4 Quality of context information 19 4.1 Definition and motivations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.2 Quality criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.3 QoC-aware context operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.4 Architecture of QoC-aware context operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 5 E-commerce flash-sale demonstrator 21 5.1 Flash sale cosmos node . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 5.2 Siafu simulator of the shopping center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 5.3 Flash sale notifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 6 Complementarity of ontology-based and process-oriented context management 24 6.1 Two abstraction levels for classifying situations . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.2 Hybrid architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 6.3 Comparison of OCM and PCM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7 Concluding remarks 27 Related work/Process-oriented context management . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Related work / Distribution of context data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 References 29 Télécom SudParis — Denis Conan, Chantal Taconet, Sophie Chabridon — juin 2010 — Ubimob 2010 2

Context management for ubiquitous applications ✬ ✩ Acknowledgements � Institut Télécom, Télécom SudParis; CNRS UMR SAMOVAR � Sébastien Leriche, Amel Bouzeghoub # 2 � Zied Abid, Léon Lim, Mohammed El-Amine Matougui � Cong Kinh Nguyen, Cao Cuong Ngo � INRIA ADAM, LIFL: Romain Rouvoy, Lionel Seinturier � INRIA MASCOTTE: Judicaël Ribault ✫ ✪ Télécom SudParis — Denis Conan, Chantal Taconet, Sophie Chabridon — juin 2010 — Ubimob 2010 3

Context management for ubiquitous applications ✬ ✩ Introduction � Results of the cappucino project # 3 � Mobile commerce domain � Context management on mobile and (relatively) constrained devices ✫ ✪ ✬ ✩ Outline 1 Context-awareness and context managment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 2 COSMOS context manager concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3 Design of context-aware applications with CA3M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 # 4 4 Quality of context information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 5 E-commerce flash-sale demonstrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 6 Complementarity of ontology-based and process-oriented context management . . . . 40 7 Concluding remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 ✫ ✪ Télécom SudParis — Denis Conan, Chantal Taconet, Sophie Chabridon — juin 2010 — Ubimob 2010 4

Context management for ubiquitous applications 1 Context-awareness and context managment ✬ ✩ 1 Context-awareness and context managment � Need for adaptation to environment changes � Control loop of autonomic computing [Kephart and Chess, 2003] Analysis Planning Adaptation policy # 5 Knowledge base Observation Execution Platform Causal link Execution environnement � Context management = 1st class concern ✫ ✪ � Identify/detect situations requiring adaptations/reactions ✬ ✩ 1.1 Some definitions � Context = Any information that can be used to characterise the situation of an entity [Dey et al., 2001] � Entity = An element representing a physical or logical phenomenon (person, concept, etc.) to which “observables” can be associated [Denning et al., 2005] � E.g. , person, room # 6 � Observable = An abstraction which defines something to watch over (observe) [Taconet et al., 2009] � E.g. , location, luminescence � An Observable is associated to an entity � Observation = The state of an observable at a given time [Taconet et al., 2009] � E.g. , (48°52 ′ N,2°19 ′ E), 50 lux ✫ ✪ Télécom SudParis — Denis Conan, Chantal Taconet, Sophie Chabridon — juin 2010 — Ubimob 2010 5

Context management for ubiquitous applications 1 Context-awareness and context managment ✬ ✩ � Situation change = relevant state change in the set of observables [Taconet et al., 2009] � Situations inject meaning into the application and are more stable, and easier to define and maintain than basic contextual cues [Ye et al., 2009] � E.g. , enter a place, ((lumin. < 100lux) = indoor) � A situation change may trigger adaptations # 7 ✫ ✪ ✬ ✩ 1.2 Context management requirements From [Bouzeghoub et al., 2010] (similar list in [MUSIC, 2007]) � Observation/Notification: context data both observed by and notified to applications � Handling constantly evolving context � Situation detection latency: recommendations shall be presented to end-users with appropriate delays according to end-users’ perception � For scalability and efficiency purpose: distributed context management, # 8 ==> CM on constrained device � Observation preparation: when permitted by the freshness requirement, context data requiring resource intensive processing shall be prepared in order to be consumed rapidly later on � Handling unforeseen situation: dynamic context data and application-specific knowledge unforeseeable at design time � Expression of situations: Application designers shall have a means to express ✫ ✪ relevant situations to be detected by the system Télécom SudParis — Denis Conan, Chantal Taconet, Sophie Chabridon — juin 2010 — Ubimob 2010 6

Context management for ubiquitous applications 1 Context-awareness and context managment ✬ ✩ 1.3 Functionalities and architecture of a context manager � Functionalities � Situation detection = “clients” negotiate observation contracts � Interpretation = different context processors � Collection = different context sources Versus # 9 Hierarchies of Design pattern "Layer" processing nodes Adaptation situation detection Situation detection Context interpretation Context interpretation Context collection Context collection System ressources User profiles Sensors Remote data ✫ ✪ Télécom SudParis — Denis Conan, Chantal Taconet, Sophie Chabridon — juin 2010 — Ubimob 2010 7