Computing and Communication in the Presence of Mobility

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Computing and Communicationin the Presence of
Mobility

• Gruia-Catalin Roman
• 19 November 2004
• Mobile Computing Laboratory
• Department of Computer Science and Engineering

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Project Team

• Faculty
• Gruia-Catalin Roman
• Doctoral Students
• Chien-Liang Fok
• Radu Handorean
• Jamie Payton
• Rohan Sen
• Octav Chipara (NSF - ITR)
• Gregory Hackmann (WU)

• Doctoral graduates
• Christine Julien (UT Austin2004)
• Qingfeng Huang (PARC2003)

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Project Visibility

• Paper publication statistics (since 2002)
• published 24
• in press 9
• under review 14
• Keynote talks invited papers
• ASM 2003
• FASE 2004
• SELMAS 2004
• PRISE 2004
• Professional leadership
• ICSE 2005General Chair
• ACM TOSEMAssociate Editor

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Research Themes

• MURI Project Themes
• Interoperability
• Context-awareness
• Formal models
• Middleware

• WUSTL Distinct Perspective
• Rapid development of dependable applications in
  the presence of mobility

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CONTESSA Technologies
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Problem Formulation

• Building software for a brave new world
• mobility of environmental entities
• physical mobility of hosts
• logical mobility of code
• open environment operation
• spatiotemporal constraints
• expectation gap
• highly individualized
• resource sensitive
• task-centered

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Solution Path

• Clean conceptual models
• context awareness
• spatiotemporal dimension

• Formalization and analysis
• understanding fundamentals
• supporting analysis
• Middleware encapsulation
• interoperable
• adaptive

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Foundations for Mobile Computing

• Formal Models
• Mobile Unity
• coordination middleware semantics
• coordination schemas
• Context Unity
• Algorithms
• network abstraction
• disconnected message delivery
• Protocols
• mobicast
• spatiotemporal communication

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Middleware for Mobility

• Egocentric Context-Aware Computing (EgoSpaces)
• asymmetric coordination constructs
• transparent context maintenance
• simplification of application development
• Service Provision in Ad Hoc Networks (Lime
  Limone)
• automated code management
• knowledge-driven interactions
• follow-me sessions
• Mobile Agents in Sensor Networks (Agilla)
• flexible in-network reprogramming
• autonomous processing
• intelligent emergent behavior

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Middleware for MobilityEgocentric Context-Aware
Computing

• EgoSpaces agent-tailored multiple views
• declaratively specified views
• transparent context maintenance

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Foundations for Mobile Computing Network
Abstraction

• Context maintenance protocol
• agent-controlled scope
• distributed
• adaptive

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Middleware for Mobility Service Provision in Ad
Hoc Networks

• Limone coordination engine
• consistent distributed service registries
• flexible code distribution
• adaptive, secure and continuous service

application
application
service provision
service provision
secure tuples secure tuple spaces
secure tuples secure tuple spaces
Limone
security table
Limone
security table
remote interactions
interceptor
interceptor
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Foundations for Mobile Computing Service
Provision Dynamics
Server Migration
Pull Server
Use Service
Push Server
Transfer state
Task Finished
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Middleware for Mobility Spatiotemporal
Communication

• Mobicast a novel multicast paradigm
• energy efficient protocol
• novel analysis of network geometry

clear the road!
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Foundations for Mobile Computing Reliable
Mobicast Delivery
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Middleware for Mobility Mobile Agents in Sensor
Networks

• Agilla agile agent middleware
• sensor networks as a shared computing resource

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1
3
4
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Agilla System Architecture
Node (2,1)
Node (1,1)
Agents
Agents
migrate
remote access
Tuplespace
Tuplespace
Agilla Middleware
Agilla Middleware
TinyOS
TinyOS
MICA2 Mote
MICA2 Mote
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Agilla Agent Architecture
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Agilla Programming Style
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Agilla Location-Based Addressing
(3,3)
(3,1)
(3,2)
(2,2)
clone(3,3)
clone(3,1)
Fire Detection Agent
(1,3)
(1,1)
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Agilla Engineering Challenges

• Unreliable, low-bandwidth communication
• divide agent into small (lt 41 bytes) packets
• use acknowledgements, timeouts, and retransmits
• perform hop-by-hop migration

clone(4,1)
(1,1)
(2,1)
(3,1)
(4,1)
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Agilla Performance Evaluation
Local Operations
Remote Operations
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Agilla Technical Contributions

• New paradigm for programming sensor networks
• flexible coordination
• fluid, adaptive, and open software structure
• reduced development time
• reasonable performance
• Technology transfer implications
• demonstrated feasibility
• defined a research agenda
• initiated discussions with Ford, Monsanto,
  Boeing, Emerson

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Collaborative Project Dimensions

• Multi-faceted systems collaboration with UCI
• Agent Systems for Sensor Networks
• development of several applications
• deployment on a 90-mote sensor network in the
  Mobilab
• Mobile Interoperating Systems
• adaptable applications for grid and ad hoc
  networks
• intelligent evolution between modes
• deployed on 2 Dell Axims and 1 Sharp Zaurus
• Crosscutting concerns with UIUC
• Semantics of coordination
• Energy efficient protocols
• Secure communication
• Probabilistic analysis

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Grand Challenge Problems

• Escaping the towering inferno
• opportunistic code and data exploitation
• Crossing the rapids
• sensor augmented navigation
• Working on a wrist watch
• opportunistically formed distributed applications
• Conducting stealth operations
• software fluidity supporting cooperative behavior

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Ongoing and Future Research

• Context-awareness
• Predictable software development processes for
  applications over dynamic ad hoc networks
• Service provision
• Long-lived and adaptable applications serving
  resource-poor mobile devices in resource-rich
  environments
• Agent-based applications
• Analyzable, predictable, secure, adaptive, and
  survivable exploitation of sensor networks

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Conclusions

• Distinct perspective on mobility
• formal models, algorithms, protocols
• middleware implementations for ad hoc networks
• evaluation through applications
• Collaborative efforts
• design of agile and adaptive systems
• fusion of ideas from different operational
  environments
• demonstration and evaluation through
  implementation