Artificial immune system-based mobile node movement

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Artificial immune system-based mobile node
movement

• Adriana Ogasawara Joshua Mahaz
• EEL6788, Spring 2008

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Goal

• Use YAES to implement a mobility pattern based on
  an artificial immune system (AIS)
• Create a sensor network that contains a group of
  mobile nodes
• Nodes move towards areas of interesting phenomena
• Nodes must load balance themselves

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What is AIS?

• Algorithmic process based on the vertebrate
  immune system
• Based on how the immune system is self-protecting
  and adaptable
• Immune system can distinguish between self (other
  white blood cells) and non-self (antigens)
• Can learn to recognize and respond to new
  microbes and retain a memory of these microbes to
  facilitate future immune responses
• This is how vaccinations work

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Development Environment

• IDE Eclipse SDK 3.31
• Java 1.6 JUnit 4 (as required by YAES)
• OS Windows Vista Business Edition
• Version Control Tortoise SVN
• Created a local repository on our home network
• All milestone accomplishments were committed to
  the repository
• Repository was backed up once a week

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AIS Sink

• Main purpose is to gather information
• Sink is stationary and located in the middle of
  the area we are interested in monitoring
• Sink receives messages when mobile sensor nodes
  pass within transmission range

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AIS Intruders

• In this project, intruders are analogous to
  pathogens that invade the body
• AIS Intruders use the ActuatorNode
  ActuatorAgent classes built into YAES
• Intruders are dumb are not capable of
  creating diversions
• Intruders move randomly using the
  random_waypoint actuator movement also
  integrated into YAES
• Randomly placed within the sensor network world
  using arrangeRandomlyInARectangle() within
  ArrangementHelper.java
• Intruders have the freedom to wander throughout
  the entire defined sensor network world

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AIS Mobile Sensor Nodes

• Created a mobile sensor node class that inherits
  from SensorNode.java in YAES
• The mobile sensor nodes are comparable to the
  B-cells and T-cells in a biological immune system
  that destroy invading pathogens in the body
• The AISMobileSensorNodeAgent class is responsible
  for
• Message passing between sensor nodes the sink
• Random movement of mobile sensor nodes
• Identification of intruders

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Mobile Sensor Node Placement

• Randomly placed within the sensor network world
  using arrangeRandomlyInARectangle() within
  ArrangementHelper.java
• Mobile sensor nodes can only move and perceive
  objects within a defined portion of the sensor
  network world

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Sensor Network World

• Intruders move freely throughout
• Mobile sensor nodes are restricted to the center
  portion

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Mobile Sensor Node Movement

• Agent calls moveRandomly()
• The method generates a random int using the
  random number generator
• This number corresponds to one of the eight
  cardinal or intercardinal directions (N, S, E, W,
  NE, NW, SE, SW)
• The mobile sensor node then moves in this
  direction for 100 steps until a new direction is
  chosen
• If a mobile sensor node reaches the edges of the
  boundary, it declares itself stuck and
  moveRandomly() changes the direction of the node
  to the opposite of which it was moving before it
  became stuck
• Gives the appearance that the node bounces off
  the wall

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Mobile Sensor Node Movement

• If a mobile sensor node senses an intruder and
  does not see another mobile sensor node following
  it, moveRandomly() stops and the method
  followTheLeader() is called once the perception
  is processed
• The location of the intruder is passed with the
  perception
• Once an intruder is perceived, the mobile sensor
  node accelerates until it catches up to the
  intruder
• followTheLeader() measure the distance between
  the node and the intruder for each call of the
  agent and divides this by a speed factor which is
  added to its normal step to apply a slight
  increase in speed

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Mobile Sensor Node Movement

• Once the mobile sensor node reaches the intruder,
  it places a lock on the intruder to help with
  load balancing so no other mobile sensor nodes
  begin following it
• From here on out, the mobile sensor node will
  continuously follow the intruder around the world
  as long as it does not leave the defined area of
  interest

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Mobile Sensor Node Load Balancing

• Ideally, once a mobile sensor node has locked
  onto an intruder, it should try to help free
  mobile nodes to find the other unlocked intruders
  within the area
• Even after a mobile sensor node locks onto an
  intruder, it still continues to process
  observations about other unlocked intruders
  within their range
• Information about the intruders location and a
  time of sighting are passed to other mobile
  sensor nodes within range
• If an unlocked mobile sensor node receives the
  message, it will examine how long ago the
  intruder sighting occurred
• If the sighting was recent, it then moves to the
  location received in the message

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Mobile Sensor Node Load Balancing

• If a mobile sensor node which is already paired
  to an intruder receives more recent intruder
  location information, it will replace its own
  with the newly received data
• From then on it will broadcast the received data
  until it receives newer information or spots a
  lone intruder itself
• Only the most recent sighting will propagate
  through the network

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Timer Marks

• An intruder entering the inner square triggers
  the start mark
• The moment a lock is obtained on an intruder
  another mark is saved
• The timer ends when the lock on the intruder
  terminates (when an intruder leaves the area)

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Timer Marks

• Tstart Time intruder enters the designated
  area
• Tend Time intruder leaves the designated
  area
• TLstart Time a mobile sensor node obtains a
  lock on an intruder
• TLend Time a mobile sensor node loses its lock
  on an intruder

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Formulas

• (TLend TLstart) / (Tend Tstart)percentage_cov
  ered
• Sumpercentage_covered/intrusions
  average_coverage
• TLstart Tstart time_to_obtain_lock
• Sumtime_to_obtain_lock/successful_locks
  average_obtain_time

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Testing

• Performed 10 runs with 5, 10, and 20
  intruder/mobile node pairs respectively
• Each run the Timer Marks were recorded and
  processed with our defined formulas

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Metrics
  Avg Amt of Time Intruder is Locked Onto () Avg. Time for Mobile Node to Lock Onto Intruder (ms)
5 intruder/MSN pairs 58.24 356.99
10 intruder/MSN pairs 67.52 292.25
20 intruder/MSN pairs 75.32 208.96
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Metrics 5 intruder/mobile node pairs
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Metrics 10 intruder/mobile node pairs
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Metrics 20 intruder/mobile node pairs
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Conclusion

• The project can be applied to the development and
  testing of search and spy algorithms
• Already includes necessary infrastructure
  results calculations
• The developer can concentrate on creating new and
  better ways to maintain coverage of a designated
  area

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Conclusion

• Algorithm works best with higher numbers of
  intruder and mobile sensor nodes
• Increases the likelihood that a mobile sensor
  node will sense an intruder within the area of
  interest
• Also improves how well the message passing
  portion of our algorithm works
• More intruders present results in more recent
  accurate sightings of intruders that are passed
  onto to the other nodes

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Future Work

• Create a more sophisticated random movement
  algorithm
• Create intelligent intruders or intruders capable
  of creating a diversion
• Allow mobile sensor nodes to recognize the
  likelihood of diversions and in turn command free
  mobile sensor nodes to cover vulnerable areas.

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Demo