UbiVal
Fundamental Approaches to
Validation of Ubiquitous Computing
Applications and Infrastructures
Prof David S. Rosenblum, UCL
and collaborators from
Imperial College London
Oxford University
University College London
University of Birmingham
EPSRC WINES Workshop
23 April 2007
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Project Rationale
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Very many demonstration projects in
ubiquitous computing
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Example applications and support technologies
But very little work on engineering
foundations for ubiquitous computing
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Many unique engineering challenges
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Mobility
Context-awareness
Adaptive
Leading to significant challenges for validation
EPSRC WINES Workshop
23 April 2007
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Research Objectives
1. Develop a comprehensive suite of
validation techniques for mobile, adaptive,
context-aware ubiquitous systems
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Model checking
Testing
Simulation
… and useful combinations of these
EPSRC WINES Workshop
23 April 2007
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Research Objectives
2. Develop the necessary additional scientific
and engineering foundations to support the
validation techniques
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Probabilistic representations
Realistic mobility models
Transparent instrumentation techniques
EPSRC WINES Workshop
23 April 2007
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Research Objectives
3. Evaluate the validation techniques on
significant case studies
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Cityware (from WINES 1)
Case studies from industrial partners
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BT
HP
QinetiQ
Other WINES projects
EPSRC WINES Workshop
23 April 2007
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Work Plan and Consortium
Rosenblum
WP1
Elbaum, Sama
Planning, Integration
and Consistency
& Rodrigues
Mascolo
Moustakas
Kwiatkowska
Ghica
WP2
Probabilistic
Norman & Khokhar Model
Checking
WP7
Evaluation Studies
WP3
WP4
Testing
Simulation
Ryan
Smyth
Dulay
Mostarda
Lupu
Mostarda
WP5
Instrumentation and
Trace Generation
EPSRC WINES Workshop
23 April 2007
WP6
Security Properties
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Current Work
Testing
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Context-Aware Program Points (CAPPs)
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Test Suite Enhancement
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Run test cases to discover concurrency faults
 Explore interleavings of context handler invocations
ContextNotifier
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Model of how context changes affect program flow
Framework for specifying context change rules
TestingEmulator
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Highly flexible and controllable device emulator
EPSRC WINES Workshop
23 April 2007
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Current Work
Simulation
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Social Mobility Model
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A mobility model based on social network theory that
can be plugged into a simulator to move nodes
realistically
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Model validated with real connectivity traces
Connectivity Trace Generator
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Given: A set of traces collected in a deployment
Generate: A set of synthetic traces
with contact, inter-contact time and degree
distribution
similar to those of the original traces,
for an arbitrary number of nodes
EPSRC WINES Workshop
23 April 2007
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Current Work
Probabilistic Model Checking
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IEEE 802.15.4/ZigBee Case Study (ISoLA 2006)
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Analyse the Contention Resolution Protocol CSMA-CA
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Wireless devices cannot listen during own transmissions
Solution: randomised, exponential backoff
Model Is Generic, Parametric, Reusable
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Recent (2003/2005) wireless network standard
Short range, low complexity, low data rates, low power
Includes beacon synchronisation and timing parameters
Generation of individual models on-demand
Enabling/disabling of features such as acknowledgement,
backoff limit, retransmission limit
Analysis of Energy-Performance Tradeoff
EPSRC WINES Workshop
23 April 2007
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Current Work
Security
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Flawed Systems Pose a Risk to Business and Society
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Verification Frameworks Fail to Identify Attacks
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Example: Bluesnarfing allows an attacker to access
private data and even make phone calls
Weaknesses of Direct Anonymous Attestation (DAA)
protocol demonstrated in recent paper at ESAS 2007
Changing Landscape: Emerging security
requirements/threats cannot be verified
Current work aims to develop suitable techniques
for the verification of protocols
EPSRC WINES Workshop
23 April 2007
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Overall Project Outcome
An interoperable suite of tools
embodying sound methods for valdating ubiquitous systems
applied to significant case studies
and disseminated to academia and industry
EPSRC WINES Workshop
23 April 2007
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Thank You
http://www.ubival.org/
EPSRC WINES Workshop
23 April 2007
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