CHAPTER 7 COMPARISON OF DIFFERENT ROUTING SCHEMES

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1 80 CHAPTER 7 COMPARISON OF DIFFERENT ROUTING SCHEMES 7.1 PERFORMANCE METRICS In the preceding chapters data delivery rate, buffer space, node density and message delay, average hop count, average buffer time have been considered for evaluating the performance. Data delivery rate is defined as the ratio of number of successfully delivered messages to the total number messages generated. The average end-to-end delay is defined as the average delay time between the time a message is generated at the source and the time the message is received at the destination. Average hop count is defined as average number of hop counts between the source node and the destination node. Overhead ratio can be calculated using the formula: (Number of packets relayed Number of packets delivered)/number of packets delivered. These metrics reflect how efficiently the data are delivered. In epidemic routing, multiple copies may be delivered to the destination. So the delay is computed based on the time the first copy is delivered. 7.2 SIMULATION SETUP The simulation period for each scenario is 20,000 seconds and the simulated mobility network area is 5400 m 5500 m rectangle. Similarly, the network area is divided into three disconnected clusters. Nodes can move anywhere in the cluster. This section analyses the results of simulations, by comparing the performance of the proposed protocols with epidemic routing

2 81 protocol. Next, the performance is analyzed with varying node density, buffer space, mobility speed, transmission range, transmit speed and the number of messages. 7.3 COMPARISON OF DIFFERENT PROPOSED ROUTING PROTOCOLS WITH EPIDEMIC ROUTING PROTOCOL Table 7.1 depicts a comparison of different routing schemes with varying parameter values. In the following pages, Figures 7.1 to 7.5 there is a comparison of performance of epidemic routing protocol and different proposed techniques with different node densities with 10, 25, 50, 75, 100, 125, 150, 200, 250 and 300 hosts. In all the cases, the buffer size of the nodes is set as 50 MB and Ferry is 250 MB, transmission range is 50 m, mobility speed is ~1meter/second, transmit speed of 250 kbps and infinite message TTL. Figure 7.1 Number of nodes vs Delivery probability

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5 84 Figure 7.2 Number of nodes vs Overhead ratio Figure 7.3 Number of nodes vs Average latency Figure 7.4 Number of nodes vs Average buffer time

6 85 Figure 7.5 Number of nodes vs Average hop-count Figures 7.6 to 7.10 make a comparison of different routing protocols with different node mobilities of 0.1 to 0.5 m, 0.5 to 1 m, 1 to 2 m, 2 to 3 m, 4 to 5 m, 10 to 15 m, 20 to 25 m and 30 to 40 m. In all these cases, buffer size of the nodes is set as 50 MB and Ferry is 250 MB, transmission range is 50 m, total number of nodes 75 nodes (25 nodes per cluster), transmit speed of 250 kbps and infinite message TTL. Speed (m/s) Figure 7.6 Mobility speed vs Delivery probability

7 86 Speed (m/s) Figure 7.7 Mobility speed vs Overhead ratio Speed (m/s) Figure 7.8 Mobility speed vs Average latency Speed (m/s) Figure 7.9 Mobility speed vs Average buffer Time

8 87 Speed (m/s) Figure 7.10 Mobility speed vs Average hop-count Figures 7.11 to 7.15 represent a comparison with varying transmission ranges of 10 m, 25 m, 50 m, 75 m, 100 m, 200 m and 300 m. In all the cases, the buffer size of the nodes is set as 50MB and Ferry is 250 MB, node mobility is ~1 meter/second, total number of nodes 75 nodes (25 nodes per cluster), transmit speed of 250 kbps and infinite message TTL. Figure 7.11 Transmission range vs Delivery probability

9 88 Figure 7.12 Transmission range vs Overhead ratio Figure 7.13 Transmission range vs Average latency Figure 7.14 Transmission range vs Average buffer time

10 89 Figure 7.15 Transmission range vs Average hop-count Figures 7.16 to 7.20 show a comparison with varying number of messages with 50, 100, 250, 500, 1000, 1500 and 2000 messages. In all these cases, the buffer size of the nodes is set as 50 MB and Ferry is 250 MB, node mobility is ~1 meter/second, total number of nodes 75 nodes (25 nodes per cluster), transmit speed of 250 kbps, transmission range is 50 meters and infinite message TTL. Figure 7.16 Number of messages vs Delivery probability

11 90 Figure 7.17 Number of messages vs Overhead ratio Figure 7.18 Number of messages vs Average latency Figure 7.19 Number of messages vs Average buffer time

12 91 Figure 7.20 Number of messages vs Average hop-count From Figure 7.21 to 7.25, comparison is done with varying buffer space of the nodes with ten different buffer spaces: 10 MB, 20 MB, 30 MB, 40 MB, 50 MB, 60 MB, 70 MB, 80 MB, 90 MB, 100 MB. In all the cases, the buffer size of the Ferry is 250 MB, node mobility is ~1 meter/second, total number of nodes 75 nodes (25 nodes per cluster), transmission range is 50 meters, transmit speed of 250 kbps and infinite message TTL. Figure 7.21 Buffer size vs Delivery probability

13 92 Figure 7.22 Buffer size vs Overhead ratio Figure 7.23 Buffer size vs Average latency Figure 7.24 Buffer size vs Average buffer time

14 93 Figure 7.25 Buffer size vs Average hop-count Figures 7.26 to 7.30 exhibit a comparison with varying transmit speeds of the nodes with six different transmit speed of 50, 100, 150, 200, 250, 300 KBps. In these cases, the buffer size of the node is 50 MB and Ferry is 250 MB, node mobility is ~1 meter/second, total number of nodes 75 nodes (25 nodes per cluster), transmission range is 50 meters and infinite message TTL. Figure 7.26 Transmit speed vs Delivery probability

15 94 Figure 7.27 Transmit speed vs Overhead ratio Figure 7.28 Transmit speed vs Average latency Figure 7.29 Transmit speed vs Average buffer time

16 95 Figure 7.30 Transmit speed vs Average hop-count Figures 7.31 to 7.35 represent a comparison with varying buffer space of the global ferry with ten different buffer spaces: 10 MB, 20 MB, 30 MB, 40 MB, 50 MB, 60 MB, 70 MB, 80 MB, 90 MB, 100 MB. In all these cases, the buffer size of the regular node is 50 MB, node mobility is ~1 meter/second, total number of nodes 75 nodes (25 nodes per cluster), transmission range 50 meters, transmit speed of 250 kbps and infinite message TTL. Figure 7.31 Buffer size (Global Ferry) vs Delivery probability

17 96 Figure 7.32 Buffer size (Global Ferry) vs Overhead ratio Figure 7.33 Buffer size (Global Ferry) vs Average latency Figure 7.34 Buffer size (Global Ferry) vs Average buffer time

18 97 Figure 7.35 Buffer size (Global Ferry) vs Average hop-count Figures 7.36 to 7.40 involve a comparison with varying buffer space of the local ferry with ten different buffer spaces: 10 MB, 20 MB, 30 MB, 40 MB, 50 MB, 60 MB, 70 MB, 80 MB, 90 MB, 100 MB. In all these cases, the buffer size of the regular node is 50 MB, node mobility is ~1 meter/second, total number of nodes 75 nodes (25 nodes per cluster), transmission range 50 meters, transmit speed of 250 kbps and infinite message TTL. Figure 7.36 Buffer size (Local Ferry) vs Delivery probability

19 98 Figure 7.37 Buffer size (Local Ferry) vs Overhead ratio Figure 7.38 Buffer size (Local Ferry) vs Average latency Figure 7.39 Buffer size (Local Ferry) vs Average buffer time

20 99 Figure 7.40 Buffer size (Local Ferry) vs Average hop-count Figures 7.41 to 7.45 denote a comparison with varying buffer space of the gateway node with ten different buffer spaces: 10 MB, 20 MB, 30 MB, 40 MB, 50 MB, 60 MB, 70 MB, 80 MB, 90 MB, 100 MB. In all these cases, the buffer size of the regular node is 50 MB, node mobility is ~1 meter/second, total number of nodes 75 nodes (25 nodes per cluster), transmission range 50 meters, transmit speed of 250 kbps and infinite message TTL. Figure 7.41 Buffer size (Gateway) vs Delivery probability

21 100 Figure 7.42 Buffer size (Gateway) vs Overhead ratio Figure 7.43 Buffer size (Gateway) vs Average latency Figure 7.44 Buffer size (Gateway) vs Average buffer time

22 101 Figure 7.45 Buffer size (Gateway) vs Average hop-count 7.4 CONCLUSION The simulation results show that CMF and SMFGW produce good delivery ratio only when connectivity exists between nodes within the cluster. If partition occur between nodes in the cluster, then, routing schemes with multiple ferries like MMF, MMFGWFR and MMFGWDR produce a higher delivery ratio than other techniques.