College of Computer Science

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College of Computer Science

• Karl Lieberherr

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Northeastern University

• Downtown Boston Between Symphony Hall and Museum
  of Fine Arts.
• About 14000 students.
• College of Computer Science and College of
  Engineering, etc.
• Focus on Practice-Oriented Education COOP program

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Projects

• Focus on two Projects
• Karl Lieberherr Demeter and Aspect-Oriented
  Programming
• Java tools
• XML tools
• Guevara Noubir Wireless Networks (MANET)
• Both have connections to Switzerland.
• There are several more we can draw upon.

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Benefits for ABB CH

• Technology transfer
• Software design know-how
• Wireless technology
• PhD students working for ABB CH
• in house (about 2 months)
• in Boston (20 hours per week)
• Access to faculty and graduate students

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Possible Collaborations

• Minimum
• yearly presentation for ABB Software developers
  about trends and techniques in software
  development
• Next level
• send an ABB employee on Sabbatical at NEU in
  Boston. Goal learn about AOSD technology build
  prototype.

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Possible Collaborations

• Next level Support one or more PhD students.

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Some of my Background

• Dr. sc. math ETH 1977
• Princeton, GTE, Northeastern (since 1985)
• Demeter Project Early AOSD project
• IBM, Mettler-Toledo, Xerox PARC, Citibank,
• DARPA project PCES (Doug Schmidt PM)
• Several presentations at Brown Boveri Research
  Center (Dr. Speiser)

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AOSDAspect-Oriented Software Development

• The job of a SOC technology is to turn a tangled
  and scattered implementation of a concern into a
  well-modularized implementation of a concern.

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AOSDAspect-Oriented Software Development

• The job of an AOP (Aspect-Oriented Programming)
  technology, a special case of SOC, is to turn a
  tangled and scattered implementation of a
  crosscutting concern into a well-modularized
  implementation of a concern.

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Aspect-Oriented Programming (AOP)

• Turn tangled and scattered implementations of a
  crosscutting concern into a well-modularized
  implementation of a concern.
• Tools AspectJ, DJ, DemeterJ.
• Design and implementation techniques.

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Features of AOP languages

• AOP languages have the following main elements
• a join point model (JPM) wrt base PL
• a specification language for expressing sets of
  join points (JPS)
• a means of specifying behavior involving join
  points (BJP)
• encapsulated units combining JPS and BJP (CSB)
• method of attachment of units to base program (AU)

JPS and BJP are sometimes overlapping. JPS might
already define an initial behavior plus a set of
join points in that behavior.
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Comparing

• AspectJ
• DemeterJ
• DJ
• ATC
• AspectC
• Aspectual Collaborations
• D (COOL, RIDL)
• BETA
• RG
• ABB Aspects

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Applications of AOP

• Network-aware applications
• Resource management
• Fault tolerance
• Adaptive programming

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AOP

• Join point model
• Express sets of join points
• Express code to be executed at join points

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Cross-cutting of components and aspects
better program
ordinary program
structure-shy functionality
Components
structure
Aspect 1
synchronization
Aspect 2
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From Crista Lopes PhD thesis (NU/Xerox PARC)
Instead of writing this
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What's the problem? TANGLING
OOAD
Collab-1
C1
C4
C2
C3
C5
Collab-4
Collab-2
Collab-3
C1
C4
C2
C3
Implementation
C5
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Reconciliation of Both WorldsAspectual
Collaborations
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• Prof. Guevara Noubir, noubir_at_ccs.neu.edu
• Background
• 1996 PhD from ETH-Lausanne
• 1997-2000 senior research scientist at CSEM
  (Neuchâtel)
• Participated in main 3G-UMTS European Projects
  (FRAMES, RAINBOW, SLATS) and other projects on
  wireless networks (European Space Agency IPSAT,
  MAD Hiperlan 2, etc.)
• Main Research Area Quality of Service for
  Wireless Systems
• Optimal resource management
• Reliability, fault-tolerance
• Security

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Current Research

• Development of adaptive schemes for optimal
  resource management in wireless systems with
  applications in multi-hop wireless ad-hoc
  networks and cellular wireless communication
  systems
• Underlying technology IEEE802.11, Bluetooth
  (scatternets), home built low-power wireless
  interfaces

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Constraints in Wireless Multi-Hop Ad Hoc
Networks (MANET)

• Limited radio spectrum
• Broadcast Medium (resulting in collisions and
  interference)
• Limited power available at the nodes (i.e.,
  energy, computation)
• Limited storage memory
• Connection QoS requirements (e.g., delay, packet
  loss)
• Unreliable network connectivity (depends on the
  channel)
• Dynamic topology (i.e., mobility of nodes gt
  variable density)
• Need to provide a full coverage
• Need to enforce fairness

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Parameters Available to System Designer in MANET

• Use of various coding/modulation schemes
• Use of packets fragmentation
• Use of various transmission power level
• Use of a single hop or multiple hops
• Use of multiple RF interfaces (multiple IF
  characteristics)
• Clustering and backbone formation
• Planning of the fixed nodes location
• Packets scheduling schemes
• Application adaptivity

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Approach Adaptivity and Cooperation

• Classical networking stacks have only minimum
  interaction between adjacent layers
• Multi-hop wireless ad hoc networks require more
  cooperation between layers because
• Channel variation and network topology changes
  affect the application
• Routing versus single hop communication
  considerably affects the medium access control
  (MAC) performance and physical layer interference
• Collisions versus channel fading affects both the
  physical layer and the MAC
• Battery power has implications on all layers

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ABB versus AOSD view of aspects

• Compare ABB view of aspects with views of AOSD
  community.
• I am on the steering committee for the new series
  of conferences on AOSD.

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ABB Aspects

• page 4 Each aspect is modeled separately. AOSD
  Each aspect needs its own class graph and
  behavior expressed for classes in class graph.
• page 5, figure 4 need to customize an aspect.
  page 19 Many aspects provide some degree of
  configurability AOSD adapters.

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ABB Aspects

• page 4 an aspect object is a container of
  references to implementations of different
  aspects. AOSD an object may play multiple roles.
• page 5 An aspect is implemented by an aspect
  system which stores, manages and presents its
  information in an optimal way. AOSD different
  implementations s/d

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Comparison

• ABB aspect
• aspect adds data members or methods to an object

• AOSD aspect
• aspect adds data members or methods to an object
• enhances existing methods of an object

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What is Aspect-Oriented Software Development

• Covers analysis, design and implementation of
  software
• Maintains separation of crosscutting concerns
  down to implementation level.
• Turn tangled and scattered implementations of a
  crosscutting concern into a well-modularized
  implementation of a concern.

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Object exists in many structures

• ABB from page 6 Depending on what aspect we
  look at, the same entity fits naturally in
  several different structures.
• AOSD Object plays several roles
• each role playing places object in structure of
  corresponding collaboration

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Object exists in many structures

• ABB Example (from page 7)
• functional structure
• location structure
• batch structure
• AOSD Object plays several roles
• each role playing places object in structure of
  corresponding collaboration

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Perspectives/Views/Aspects

• Aspect a well modularized cross-cutting concern
• Perspective/view a special kind of aspect that
  adds members to a group of objects
• page 4 each object can be described from several
  different perspectives

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Attach aspects dynamically

• page 8 when an instance of an object type is
  created, it inherits the aspects that are
  defined in the object type. You can add aspects
  to a specific instance.
• AOSD composite aspects dynamically add aspects
  to an object.

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How ABB aspects fit inan open object model

• Join point model
• dynamic objects
• Express sets of join points
• enumerate objects
• Express code to be added at join points
• members

open objects
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ABB implementation

• Aspect Framework (Afw)