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Mobile Computing and Wireless Communication. Pisa 26 November 2002 Roberto Baldoni University of Roma “La Sapienza”. Motivation. Towards Pervasive Computing within mostly invisible mobile computing infrastructure Convergence of enabling technologies Mobile devices
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Mobile Computing and Wireless Communication Pisa 26 November 2002 Roberto Baldoni University of Roma “La Sapienza”
Motivation • Towards Pervasive Computing within mostly invisible mobile computing infrastructure • Convergence of enabling technologies • Mobile devices • PDA, Notebooks, sensors, …… till smart dust • Cellular Communication (already pervasive) • Wireless Networking • Cheap, high bandwidth with limited range
Communication Internetworking Middleware Security Availability -Awareness Adaptability ……………… Emerging research aspects Large body of research Technology Available Activity Domains • One-hop mobile networks • Ad-hoc (or multi-hop) mobile Networks • Sensor networks
Common Characteristics • Dynamic environment • Location is a key notion • Self-Organization • Hot topic in industry (IBM, ATT, Microsoft) • Results from MANETs research can be applied to autonomous systems and generally to reduce administration costs • Interaction between mobile and fixed infrastructure
What is really missing? Glue existing results in an unique framework Development of a coherent set of theories and rigorous methos passes through ....... • Defining a “system model” for mobile computing capturing • Networks • Ad-hoc, one-hop etc. • Mobility • Mobility patterns, mobility behaviour (voluntary vs involuntary disconnections) • Awarness • Power-awareness, Location-Awareness • Failure model
Research Themes: Communication Efficient communication is stil an open issue e.g. • smart dust protocols in sensors networks , • time Bounded Medium Access Control in ad-hoc, • handover in single hop Is layering the right stack protocol architecture? • TCP needs to look into the data-link/routing • Caching has to look at routing table to do a good object placement and routing has to know where cached copies are to do a good routing • Smart token-based algorithms can be done by using network layer information • A bundled approach
Research Themes: Internetworking • Ensuring Caching of fresh routes in manet • Selecting next hop in sensor netwoks • K-clustering
Research Themes: Middleware Services • Necessary for enabling application • Not defined and available yet • Which services should be available in most mobile middleware systems? • Data agregation, distributed hash-tables, persistent messaging, garbage collection, spacial data management • Completelty decentralized vs core-based solutions vs hybrid solutions
V- Research themes: -Awareness • Location-awareness • How to describe, store, rate and use location information • Common formats/interfaces? • Energy-awareness • Common interfaces? • Context-awareness • As a generalization of previous bullets • Infrastructure awareness • Execution environement awarness
V - Research themes: Security • Current data link technologies do not provide enough protection • Security features are not built-in in any routing protocol • Energy efficient key management • Authentication
V- Research Themes: Availability • Group communication would not work well in Mobile Setting desptite many work on adaptability • Lack of –awareness (power, location, context) • Network Partition is a matter of life • Group membership determined by proximity constraints • Caching • Placing proxies in an optimal location • Collaborative caching • Adaptability vs dependability
Other Research Themes • Programming and application models • Location based programming • Consistency models • Is eventual consistency the right answer? • Do we need to support lots of models at the same time? • Mobility patterns coordination • To maximize connectivity • Overlay Networks vs Mobile Networks • Formal specification for getting rigorous design
Applications • Identify relevant applications • Ambient intelligence • Rescue • Augmented reality • Social issues • Health care .........
Conclusions • Enabling platform is forthcoming!! • Lots of open difficult problems (Horizontal and Vertical) • Both practical and theoretical