Probabilistic Broadcasting Based on Coverage Area and Neighbor Confirmation in Mobile Ad Hoc Network

1
Probabilistic Broadcasting Based onCoverage Area
and Neighbor Confirmationin Mobile Ad Hoc
Networks

• Jae-soo Kim
• Qi Zhang and Dharma P. Agrawal
• IEEE Communications Society Globecom 2004
  Workshops
• 
  by ??

2
Outline

• Introduction
• Related Work
• Dynamic Probabilistic Broadcasting with Coverage
  Area and Neighbor Confirmation
• Performance Evaluation

3
Outline

• Introduction
• Related Work
• Dynamic Probabilistic Broadcasting with Coverage
  Area and Neighbor Confirmation
• Performance Evaluation

4
Introduction

• MANET (Mobile Ad hoc Network) is a special type
  of wireless mobile network in which mobile hosts
  can communicate without any aid of established
  infrastructure.
• Broadcastings can be applied to many areas, such
  as paging a particular host, sending an alarm
  signal, and finding a route to a particular host,
  etc.
• The simplest broadcasting is flooding but cause
  broadcast storm problem.

5
Outline

• Introduction
• Related Work
• Probabilistic lt Improve this approach
• Counter-based
• Distance-based
• Location-based
• Cluster-based
• Dynamic Probabilistic Broadcasting with Coverage
  Area and Neighbor Confirmation
• Performance Evaluation

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Related Work

• Ni et al. 4 classified broadcasting schemes
  into five classes
• Probabilistic
• Counter-based
• Distance-based
• Location-based
• Cluster-based
• 4 Y. C. Tseng, S. Y. Ni, Y. S. Chen, and J. P.
  Sheu, The broadcast storm problem in a mobile ad
  hoc network, Wireless Networks, vol. 8, no. 2/3,
  pp. 153167, Mar.-May 2002.

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Related Work- Probabilistic

• On receiving a broadcast message for the first
  time, a host will rebroadcast it with probability
  P ,every host all have the same P.
• When P 1, this scheme is equivalent to
  Flooding.
• If the network is sparse , the P is good to set
  high.
• If the network is dense , the P is good to
  set low.

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Related Work- Counter-based

• Previous work
• When a node receives more times the same
  broadcast packet , the expected additional
  coverage will be smaller.
• A node determines whether it rebroadcast a packet
  or not by counting how many identical packets it
  receives during a random delay.
• The Additional Coverage is small when the number
  of recipient broadcasting packets exceeds a
  threshold value.
• k 1 , AD 0.41pr2 k 4
  , AD 0.05 pr2

B
C
A
D
Additional Coverage
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Related Work- Distance-based

• Using the relative distance between a mobile node
  and previous sender to make the decision whether
  it rebroadcast a packet or not
• When sender and receiver are just on the edge of
  each other, the dr, that will get the largest
  Additional Coverage
• When sender and receiver are just on the same
  place, the d0 , that will get the smallest
  Additional Coverage0.

d
r
Additional Coverage
NO Additional Coverage
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Related Work- Location-based

• If we can get the locations of those broadcasting
  hosts, it cab estimate the additional coverage
  more correctly.
• This approach may be supported by positioning
  devices such as GPS (Global Positioning System)
  receivers.
• Suppose a host has received the same broadcast
  message from k hosts located at
  (xl,yl),(x2,y2),... , (xk,yk). We can calculate
  the additional area that can be covered if the
  host rebroadcasts the message.

(x 3,y3)
(x l, yl )
(x 2,y2)
Additional Coverage
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Related Work- Cluster-based

• MANET is divided into clusters, which is a set of
  mobile hosts.
• There are one cluster head and several gateways
  in a cluster.
• Cluster head is representative of a cluster and
  its rebroadcast can cover all hosts in that
  cluster.
• Only gateways can communicate with other clusters
  and have responsibilities to propagate the
  broadcast message.

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Outline

• Introduction
• Related Work
• Dynamic Probabilistic Broadcasting with Coverage
  Area and Neighbor Confirmation
• Shadowing Effect
• Dynamic Probabilistic Rebroadcast with Coverage
  Area
• Dynamic Probabilistic Rebroadcast with Coverage
  Area
• and Neighbor Confirmation
• Performance Evaluation

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Shadowing Effect

• In a general probabilistic approach, the
  rebroadcast probabilities of all hosts are fixed
  as same value.
• A MANET may be sparse or dense, the rebroadcast
  probabilities value might be set too small or too
  large.
• The rebroadcast probabilities need to be adjusted
  by the circumstances of the node.

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Dynamic Probabilistic Broadcasting with Coverage
Area and Neighbor Confirmation Cluster-based

Shadowing Effect

• Allow each node to choose different probability
  according to its distance from the sender.
• The distance from a node to the sender can be
  calculated from the signal strength or GPS
  (Global Positioning System).

with low retransmission probability
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Outline

• Introduction
• Related Work
• Dynamic Probabilistic Broadcasting with Coverage
  Area and Neighbor Confirmation
• Shadowing Effect
• Dynamic Probabilistic Rebroadcast with Coverage
  Area
• Dynamic Probabilistic Rebroadcast with Coverage
  Area
• and Neighbor Confirmation
• Performance Evaluation

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Dynamic Probabilistic Broadcasting with Coverage
Area and Neighbor Confirmation with Coverage
Area

• If a node is a farer node, the node assumes that
  it has larger coverage area, and if a node is
  closer node, the node has smaller coverage area.
• Using its coverage area to determine its
  rebroadcast probability

d
d
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Dynamic Probabilistic Broadcasting with Coverage
Area and Neighbor Confirmation with Coverage
Area

• Equation that defines the relationship between
  the coverage area and rebroadcast probability .

The coverage ratio µ
the rebroadcast probability (p)
a is a sensitivity parameter to control the
rebroadcast probability.
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Outline

• Introduction
• Related Work
• Dynamic Probabilistic Broadcasting with Coverage
  Area and Neighbor Confirmation
• Shadowing Effect
• Dynamic Probabilistic Rebroadcast with Coverage
  Area
• Dynamic Probabilistic Rebroadcast with Coverage
  Area
• and Neighbor Confirmation
• Performance Evaluation

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Dynamic Probabilistic Broadcasting with Coverage
Area and Neighbor Confirmation Neighbor
Confirmation

• The probabilistic approached presented above may
  cancel a non-redundant packets retransmission.
• To prevent from early die-out of rebroadcast,
  neighbor confirmation scheme is applied.

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Dynamic Probabilistic Broadcasting with Coverage
Area and Neighbor Confirmation Neighbor
Confirmation

• It is executed by the nodes which do not
  rebroadcast the packet according to dynamic
  probability with coverage area.
• After a given amount of time t, a node checks if
  all the neighbors have received the broadcast
  packet.

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Performance Evaluation

• Comparing with a simple flooding algorithm
• Using network simulator Glomosim
• Using three kinds of measures rebroadcast
  number, reachability, and collision, to evaluate
  the performance of this
• approach.

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Performance Evaluation - Rebroadcast Number

• In flooding, a mobile node rebroadcasts all
  routing request packets that are received for the
  first time. There are N-1 possible rebroadcast.

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Performance Evaluation - Reachability

• Flooding approach guarantees that all nodes can
  receive the broadcast packets if no packet is
  dropped.
• High reachability is the result of neighbor
  confirmation.

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Performance Evaluation - Collision

• Collision is measured as the number of collision
  packet that mobile nodes send.
• Flooding scheme causes enormous collisions.

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Performance Evaluation - Delay

• The start times are recorded when source node
  send broadcast packets as well as the end times
  are recorded when the broadcast packet reaches
  the last node.
• Need to execute Neighbor Confirmation and Dynamic
  Probabilistic Rebroadcast with Coverage Area

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Performance Evaluation - Throughout

• Throughput as the amount of broadcast data (bits)
  transmitted during a second in the MANET.

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Conclusion

• This scheme combines probabilistic approach with
  the area-based approach.
• A mobile host can dynamically adjust the value of
  the rebroadcast probability according to its
  additional coverage in its neighborhood.
• Our scheme combines neighbor confirmation concept
  to prevent early die-out of rebroadcast.
• This is one of self-pruning approach .