Lime Team

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Lime Team

• Adam Bazinet
• Hau San Si Tou

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What is LIME?

• LIME stands for Linda In a Mobile Environment
• Linda a shared memory computing model developed
  in the mid 1980s
• A Java-based middleware system for developing
  applications in mobile ad hoc networks
• Provides a coordination layer to deal with both
  physical and logical mobility

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Physical vs. Logical Mobility

• Physical mobility concerns the movement of mobile
  hosts
• Hosts roam across the physical space and modify
  the topology of the network
• Logical mobility concerns the movement of mobile
  agents
• Processes are able to migrate from one host to
  another while preserving their code and state

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The LIME Environment

• Coordination is achieved through a tuple space
  globally shared among components
• tuple space is a multiset of tuples that can be
  accessed concurrently by several processes
• Components do not need to co-exist in time for
  them to communicate
• Components can reside anywhere in the distributed
  system
• Components can access the tuple space by
  inserting, reading, or withdrawing tuples
  containing information

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LIME Distribution

• Composed of 4 packages
• lime contains the core functions of Lime
• lime.util contains the Launcher class, used for
  starting the runtime
• lime.util.console contains a graphical console
  for interacting with a LimeTupleSpace
• lime.mobileagent.mucode provides Lime-enabled
  mobile agents

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Important Concepts

• Lime Agents
• The only active entities in LIME
• The only components that carry a concrete tuple
  space with them.
• Programmatically represented by Java threads
• Transiently Shared Tuple Spaces
• An extension of the standard Linda tuple space

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More Concepts

• Tuple Location
• The tuples in the tuple spaces are physically
  stored across the multiple hosts in the system
• Each tuple is an ordered sequence of typed data
• Engagement/Disengagement of Hosts
• Engagement the process of a host coming into
  range
• Disengagement the departure of a host
• Both processes are atomic
• Reacting to Changes in Context
• Reaction defined by a method to be executed
  when a tuple matching a specific pattern is found
  in the tuple space

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Tuple Space

• Interface Tuple Space (ITS)
• Permanently and exclusively attached to the unit
  itself
• Contains tuples the mobile unit is willing to
  make availabe to other units, and that are
  concretely co-located with the unit itself
• The only content accessible to the unit when it
  is alone
• Host-Level Tuple Space
• The transiently shared ITSs belonging to multiple
  agents co-located on a host

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Tuple Space

• Federated Tuple Space
• Connection of Host-Level Tuple Spaces
• Formed when components are within range
• i.e. mobile agents are on the same host or
  communication is available between mobile hosts
  which contain agents

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Tuple Space Figure
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Applications- a. k. a. Games ?

• Roaming Jigsaw

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RedRover
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Project Objectives

• Understand the software packages that are
  available
• Work to implement a lightweight version of Lime
  that works with the m2m protocol- Anhinga Spaces
• Develop and demonstrate some applications using
  our Lime bundle

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The Source

• http//lime.sourceforge.net