Introduction
Related work
Proposed protocol
Cluster formation
No. of nodes N
i
in the cluster C
i
| Weights W1, W2, W3 | Degree difference | Mobility M in m/s | Remaining battery power in J | Node value NV | Selected node as cluster head |
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3 (N1, N2, N3) | (0.09, 0.38, 0.53) | 7,5,2 | 2,4,6 | 200,150,150 | 106,78, 77 | N1 |
5 (N4, N5, N6,N7, N8) | (0.27,0.31, 0.42) | 2,6,4, 8,5 | 3,1,3,1,7 | 174,190,188, 200,182 | 73,81,79, 86,76 | N7 |
6 (N9, N10, N11, N12, N13, N14) | (0.33,0.24, 0.43) | 3,4,9, 8,7,2 | 2,3,1,5,4,2 | 130,156,195,169,179,120 | 56,68,87, 74,78,52 | N11 |
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The degree difference Δi: It is defined as the difference between the cluster's size 'N' and the actual number of neighbors. It allows estimating the remaining number of nodes that each node can still handle.
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The mobility of the node M.
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The remaining battery power of the node is Pa.
Message | Description |
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HELLO | Contains broadcaster's ID, location information, node status, neighbour table, cluster adjacency table and sender's node value |
INFO | Contains node value |
CH_INFO | Contains cluster head ID and cluster neighbour table |
CH_ACK | The new node's HELLO message is acknowledged by cluster head (CH) |
JOIN | A new node joins as member in the cluster after cluster head (CH) is activated by sending JOIN message |
CH_NEWNODE | The new node's JOIN is acknowledged by cluster head. |
CH_NACK | The new node's HELLO is rejected by cluster head |
CH_RELIEVE | Notifies the members about its intention to resign as cluster head |
CH_RACK | Present cluster head relieves finally after broadcasting new cluster head ID |
Cluster maintenance
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Reduction in the node value of the CH
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Mobility of a node
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Mobility of CH
Reduction in the Node Value of the Cluster Head
Mobility of a node
Mobility of Cluster Head
Route discovery
Intra cluster routing
Algorithm 1 as shown in Figure 3 is used for intra cluster routing in one hop cluster
Algorithm 2 as shown in Figure 4 is used for intra cluster routing in multihop m (= 2)cluster
Inter cluster routing
Algorithm 3 as shown in Figure 5 is used for inter cluster routing between adjacent clusters
Algorithm 4 as shown in Figure 6 is used for inter cluster routing between clusters which are m clusters away
Route recovery
Simulation results
Simulation parameters
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Performed using NS-2 network simulator [30] with MANET extensions.
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IEEE 802.11 is used as the MAC layer protocol.
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The radio model simulates with a nominal bit rate of 2 Mbps.
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Nominal transmission range is 125 m.
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The radio propagation model is the two-ray ground model.
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First 100 nodes are deployed for one experiment and then 100 nodes are used for another experiment in a field of 1000 m × 1000 m.
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The traffic pattern is CBR (constant bit rate) with a network traffic load of 4 packet/s and the packet length are 512 bytes.
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The mobility model used is the Random Waypoint Model
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The pause time of the node reflects the degree of the node mobility. The small pause time means intense node mobility and large pause time means slow node mobility. The pause time is maintained as 5 s.
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The simulation time is 900 s.
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The first set of simulations are performed by varying the speed from 2 to 10 m/s with an increment of 2 m/s keeping number of nodes constant to 40.
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The second set of simulations are performed by creating 20, 40, 60, 80, 100 nodes, keeping speed constant to 5 m/s.
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The value of weights W1, W2 W3, for simulation are (0.09, 0.38, 0.53), (0.27, 0.31, 0.42) and (0.33, 0.24, 0.43), respectively.