Review of Geocasting Protocols for a Mobile Ad Hoc Network

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Review of Geocasting Protocols for a Mobile Ad
Hoc Network

• Xia Jiang, Tracy Camp
• Dept. of Math. And Computer Science
• Colorado School of Mines
• Golden,Colorado,80401
• U.S.A

Xia Jiang / Tracy Camp
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Review of Geocasting Protocols for a Mobile Ad
Hoc Network

• What is mobile ad hoc network?
• What is geocasting protocol?
• Review of five Geocasting protocols.

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Mobile Ad Hoc Network

• MANET -- Mobile Ad Hoc Network
• A set of mobile hosts capable of communication
  with each other without the assistance of base
  stations.
• Why Mobile?

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Geocasting Protocol

• Geocast Region A specified geographical area
• A variant of the conventional multicasting
  problem
• Deliver Packets to a group of nodes in Geocast
  Region.

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Geocasting Protocol (cont.)

• The location information of all the nodes will be
  known by GPS
• Whenever one node in Geocast region receives
  message from outside, it will flood it to all its
  neighbors.
• Data-Transmission Oriented vs.Routing- Creation
  Oriented

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Data -- Transmission OrientedGeocasting Protocol

• Location Based Multicast (LBM)
• An improvement of LBM - Geocasting protocol based
  on Voronoi diagram.
• GeoGRID

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Routing -- Creation Oriented Geocasting Protocol

• GeoTORA
• Geocast Communication via a Mesh

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Location Based Multicast (LBM) Scheme I

• Definition of Forwarding Zone (FZ).
• If a node in FZ receives packets, it will
  forward the packet to its neighbors.
• If a node OUTSIDE of the FZ, it will discard the
  packet.

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Example of LBM Scheme I
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Location Based Multicast (LBM) Scheme II

• No explicit Forwarding Zone.
• Whether a packet should be forwarded just based
  on the relative distance of the nodes.
• For some parameter d, compare whether the current
  node is at least d closer to the center of the
  Geocast region than the last hop neighbor.

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Example of LBM Scheme II
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Performance Evaluation of LBM

• High accuracy (ratio of the of multicast group
  members which actually receive the multicast
  packets and the of group members which were
  supposed to receive the packets)
• Lower overhead ( of multicast packets) compared
  to multicast flooding

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Geocasting Protocol based on Voronoi Diagram

• Definition of Voronoi Diagram
• Carve up the whole plane into several Voronoi
  regions based on the source and its neighbor
• Only neighbor nodes which is in the same Voronoi
  region as the Geocast Region will be selected to
  receive the message from Source.

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Example of Geocasting Protocol based on Voronoi
Diagram
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Performance Evaluation

• No any simulation of this algorithm
• Expect to reduce the flooding rates and hop
  counts of LBM
• High overhead to define Voronoi Diagram for each
  step

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GeoGRID

• Partition the geographic area of the MANET into
  2D logical grids, each grid is a square of size d
  x d.
• Definition of Forwarding region
• Only Gateway in every grid with Forwarding region
  will decide whether forward this packet or not.

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GeoGRID Flooding based
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GeoGRID Ticket Based and Gateway Election

• The philosophy is that each ticket is responsible
  for carrying one copy of the geocast packet to
  geocast region
• Gateway Election

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Performance Evaluation

• Based on the simulation, GeoGRID has advantage
  over LBM when the MANET is crowded.
• Higher accuracy and lower delivery cost than LBM.

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GeoTORA

• Unicast routing protocol TORA (Temporally
  Ordered Routing Algorithm)
• GeoTORA, source node essentially performs an
  anycast to any geocast group member via TORA.

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TORA and GeoTORA
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Performance Evaluation

• High accuracy of GeoTORA, but not as high as pure
  flooding or LBM
• Overhead is small
• GeoPROTOCOL, use other unicast routing protocols
  (DSR, AODV) to replace TORA

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Mesh-based Geocast Routing Protocol

• Create redundant routes via control packets
• Flood JOIN-DEMAND packet
• Unicast JOIN-TABLE packet

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Example of Mesh-based Geocast Routing Protocol
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Observation

• High accuracy and low overhead than GeoTORA
• Reducing the area of the forwarding zone reduces
  control overhead, network-wide data load,
  end-to-end delay
• Increasing average node
• speed results in decreased
• network reliability

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Conclusion

• Introduction of MANET and Geocasting protocol
• Data-Transmission Oriented Geocasting protocols
• Routing- Creation Oriented Geocasting protocols

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Reference

• J. Boleng, Meshed-based geocast routing protocols
  in an ad hoc network.
• Y. Ko, GeoTORA a protocols for geocasting in
  mobile ad hoc network.
• Y.Ko, Geocasting in mobile ad hoc networks
  Location-based Multicast algorithms.
• W. H. Liao, Geogrid A geocasting protocol for
  mobile ad hoc networks based on grid.
• I. Stojmenovic. Voronoi diagram and convex hull
  based geocasting and routing in wireless networks.

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Acknowledgement
Research Group Toilers.mines.edu This work is
supported in part by NSF Grants ANI-9996156 AND
ANI-0073699
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Thank you

• Questions?
• Comments?

Xia Jiang / Tracy Camp