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Using Manhattan Mobility Model for the Counter-Base Broadcasting protocol in
MANETs
Sara Omar al-Humoud
END’s Talk
Outline
• Introduction
• Cbase
• Mobility Models
• RWP
• MMM
• Results
• Future Direction
Research Outline
Routing
Broadcasting
Wireless MANET
Flooding
Probabilistic Deterministic
ACBase1
Introduction
Related
work
Contribution ACBase2
Counter Base Broadcast
• When receiving a message: – counter c is set to keep track of number of duplicate
messages received. – Random Assessment Delay (RAD) timer is set.
– When the RAD timer expires the counter is tested against a fixed threshold value C, broadcast is inhibited
if c > C.
Scheme
Get the Broadcast IDGet degree n of node X
c = 1
n < avg
C = c1Tmax = Tmax1
C = c2Tmax = Tmax2
Set RAD [0..Tmax]
While (RAD)
same packet heard
c = c + 1
End while
C < c
drop packetTrans packet
Get the Broadcast IDc = 1
Set RAD [0..Tmax]
While (RAD)
same packet heard
c = c + 1
End while
C < c
drop packetTrans packet
Get the Broadcast ID
same packet heard
drop packetTrans packet
Adjusted Counter-based1
Comparison
Flow charts
between
Counter-based Flooding
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Adjusted Counter-Based Broadcast
• Adjusted Counter-Based Broadcast– Based on the original counter-based scheme
– Add the ability to decide the counter and the RAD according to neighbourhood density
– Neighbourhood density is divided according to the Average number of neighbours into:
• Density1: Sparse
• Density2: Dense
ACBase1 Scheme
Avg
Sparse DenseNeighbourhoodDensity
Outline
• Introduction
• Cbase
• Mobility Models
• RWP
• MMM
• Results
• Future Direction
Mobility Models
• Traces
• Synthetic Model
– Entity
– Group
MobiLib Dartmouth
Random Way Point Mobility Model
How it works:– at every instant, a node
randomly chooses a destination and moves towards it with a velocity chosen randomly from [0, Vmax], where Vmax is the maximum allowable velocity for every mobile node.
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RWP
25 nodes
Manhattan Mobility Model
How it works:– A node is allowed to move along
the grid of horizontal and vertical streets on the map.
– At an intersection the node can turn left, right or go straight.
– P of same street = 0.5 – P of turning left = 0.25– P of turning right = 0.25
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MMM
25 nodes (3x3 street)
MANHATTANHOR_STREET_NUM 3VER_STREET_NUM 3LANE_NUM 12
Outline
• Introduction
• Cbase
• Mobility Models
• RWP
• MMM
• Results
• Future Direction
Prameters
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Simulation parameters
Simulation parameter Value
Simulator ns-2 version (2.33)
Network Area 1000 x 1000 meter
Transmission range 250 meter
Data Packet Size 256 bytes
Node Max. IFQ Length 50
Simulation Time 900 sec
Pause Times 0 sec
Number of Trials 30
MAC layer protocol IEEE 802.11
Mobility model Random waypoint model, Manhattan Mobility Model
Channel Bandwidth 2Mb/sec
Confidence Interval 95%
Packet Rate 2 packets per sec
Node SpeedMax = 30 km_per_hour
Min = 5 km_per_hour
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Performance metrics
• Saved Rebroadcast (SRB)
(r − t)/r
• r = number of hosts receiving the broadcast message
• t = number of hosts that actually transmitted the message.
• Reachability
r/e
• r = number of hosts receiving the broadcast packet
• e = number of mobile hosts that are reachable, directly or indirectly, from the source host .
• Average latency
– the interval from the time the broadcast was initiated to the time the last host finished its rebroadcasting.
Results
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SRB
Results
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Reachability
Results
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Average Latency
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Future Directions
• MMM
– Limiting the number of nodes (cars) in a lane
– Building a bigger map (Glasgow cc)
• Scripting a mobility map generator
• Develop the ACBase2 that calculates the threshold
value according to a function of the number of
neighbours
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Questions
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Introduction
• Discovering neighbours
• Collecting global information
• Addressing
• Helping in multicasting and Unicast
– Route discovery, route reply
– in on-demand routing protocols like DSR, AODV to broadcast
control messages.
• Conventionally broadcast is done through flooding
Broadcasting Applications
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Introduction
• Flooding may lead to– Redundancy
x Consume limited bandwidth
– Contentionx Increase in delay
– Collisionx High packet loss rate
– Broadcast storm problem!
Broadcasting Applications
0
10
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6 7 8 9 10
Nu
mb
er
of M
es
sa
ge
s
Number of Nodes
f(n) = n2 – 2n + 1
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Related work
• Probability-based– Rebroadcast with probability P
• Counter-based– Rebroadcast if the node received less
than Cth copies of the msg
• Location-based– Rebroadcast if the area within the
node’s range that is yet to be covered by the broadcast > Ath
• Distance-based– Rebroadcast if the node did not receive
the msg from another node at a distance less than Dth
Probabilistic Broadcasting Methods
Receiver rebroadcast
decision
Simple Implementation RD based on instantaneous information from broadcast msgs
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Related work
• Reliable Broadcast
• Self-pruning
• Scalable broadcasting
• Dominant Pruning
• Cluster-based
Deterministic Broadcasting Methods
Sender rebroadcast
decision
Elaborate Implementation Rebroadcast decision based on neighbourhood study
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Related work
1. Counter-based broadcast
– Adaptive Counter-based broadcast [Tseng2003]
– Adjusted Counter-Based [Aminu2007]
2. Color-based broadcast [Haddad 2006]
3. Distance-aware counter-based broadcast
[Chen 2005]
Counter-Based related Broadcasting Methods
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Questions
• Is there a realistic mobility model?– Obstacle Mobility Model Project 2005
• Ns2, GlomoSim• the Mobility Management and Networking (MOMENT) Lab,
the Networking and Multimedia Systems Lab (NMSL)
and the Geometric Computing Lab (GCL).
University of Califorrnia at Santa Barbara
– RealMobGen 2008• Ns2
• Dartmouth's and University of Southern California's• C. Walsh, A. Doci, and T. Camp, A Call to Arms: It’s Time for REAL
Mobility Models, ACM's Mobile Computing and Communications Review, to appear 2008
Towards a better simulation
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Questions
• Is there a visualisation tool to view network topology? – iNSpect
Towards a better simulation
iNSpect
NS-2Mobility files Trace files
OpenGL animation
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Questions
• How to validate and compare scenarios?– SCORES tool (SCenariO characteRizEr for Simulation)
Towards a better simulation
SCORES
Num nodesNode coverage
Simulation area
Transmission range
Nw diameter
Neighbor count
Foot print
…
Mobility file topology change rate
Delivery ratio, end-to-end delay, throughput, overheadMetamodels
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Questions