Conclusion and Future work
Energy consumption is the main task to be considered when dealing the wireless sensor networks, where the general energy consumption is more due to the operations of the sensor nodes. In general the sensor nodes across the wireless sensor networks operated with the battery power and this power is limited and thus the energy consumption should be optimized at the possible levels to improve the battery life and also the performance of the overall network. The sensor nodes across the wireless sensor networks are mobile in nature and they consume the energy due to many reasons like data forwarding, data processing and data storing and all these operations should be optimized against the energy consumption.
In general the overall consumption of energy by the wireless sensor networks depends on MAC protocol configuration as the main medium access patterns consumes more energy when compared to the other operations and the energy optimization should be at this level and there are many proposal towards the MAC energy consumption and most of them are successful with respect to energy consumption. Taking this aspect in to consideration in this project a new sensor MAC protocol is proposed and the energy consumption patterns of the S-MAC configuration are studied across the simulation process. OPNET modeler is used as the required simulation tool as it provides the feasibility to create the wireless networks and for this simulation MANET is considered as the required model to simulate the wireless sensor networks.
Two scenarios are considered in this process, where the first scenario holds 15 mobile nodes and a single wireless LAN server for the communication to happen and the MAC configuration is set to default values and these values are changed and optimized in the second scenario and the simulation is run against the FTP application to generate the TCP traffic. The simulation is run for 5 minutes and the corresponding results are analyzed in this process and based on the results following section gives the required analysis and performance of S-MAC against energy efficiency.
The overall energy consumption towards the upload of the file across the sensor nodes is optimized in terms of the download response time and thus a lot of energy is saved with the S-MAC routing protocol and even the download response time is constant for the S-MAC when compared to ordinary MAC configuration and thus it can be concluded that S-MAC is better configuration to optimize the performance of the energy efficiency and if the packet loss is less across the traffic received from the network the overall energy can be optimized and this is proved to be true with the case of S-MAC.
The overall traffic sent and traffic received for the S-MAC configuration protocol is constant for the complete simulation time and this indicates that the overall packet loss is almost negligible using this energy efficient protocol and again it is proved to energy saving measure and it can be observed the upload wait time is less with the S-MAC as the response time is more and this indicates that the overall time consumed is less with the S-MAC and this directly implies that energy consumption with this protocol is less when compared to the ordinary MAC configuration.
When this case is considered with MAC protocol it is observed that the upload response time is low and this indicates that the time taken to upload the files across the network is more and thus more energy of the sensor nodes is consumed in this context and again it can be concluded that the overall the energy consumption can be optimized with the proposed S-MAC protocol across the wireless sensor networks.
The actual data drop with the MAC configuration is not shown in the graph and this indicates that there is no perfect traffic generated with this default configuration and thus there is lot of packet loss with this implementation and thus the energy optimization can be optimized using the S-MAC protocol. From this analysis as well it indicates that S-MAC is always the best option to optimize the energy consumption and if the delay is more, the nodes across the wireless sensor networks are idle for some time and thus if the nodes are in idle or sleep mode the overall energy consumption is reduced a lot.
But when the scenario with the normal MAC protocol is observed the delay is less and this indicates that the sensor nodes are active in nature all the time and thus the overall delay is reduced and also the energy consumption is more when the nodes are active in nature. Thus the average wireless LAN delay plays an important role in estimating the overall energy consumption and from this analysis it is clear that S-MAC reduces the energy consumption in this context where it sets most of the sensor nodes to sleep or idle mode.
As the FTP application is used as the required application and even the medium load is incurred and thus the overall load on the network is more due to the sleep mode of the sensor nodes. From this analysis it is clear that with the implementation of the S-MAC protocol the overall energy can be optimized at a large extend and again from this metric as well it is proved that modification to the normal MAC protocol to improve the overall energy optimization. The overall energy consumption by the normal MAC configuration is more when compared to the proposed S-MAC and thus again from this indication it can be concluded that S-MAC is more efficient that the MAC in terms of Medium access delay and thus this value is directly proportional to the energy consumption.
Even from this comparison it can be observed that the MAC delay is constant with the S-MAC when compared to the normal MAC protocol and if the throughput is less at end of the simulation it means that the overall performance of the network is improved in terms of energy consumption at the end of the communication across the network. Initially the energy consumption is not affected with the proposed S-MAC configuration and later at the end of the simulation it has improved a lot in terms of energy efficiency and thus this scenario indicates that at the end of the communication all the nodes implements the S-MAC configuration and tries to conserve low energy and thus the overall energy efficiency is improved a lot as the nodes being to sleep when their task is completed.
From the above analysis it is clear the performance of S-MAC is better when compared to the normal MAC configuration and apart from this analysis there is some scope to improve the research and simulation in few aspects and is as given below
- S-MAC is proposed by changing the default values of MAC configuration and in future more mathematical evaluation can be done in this context
- Few more scenarios can be improved to understand the exact energy consumption patterns of the wireless sensor networks
- Even the number of mobile nodes can be increased and the simulation time can be run for 2 hours in future to get the exact energy consumption results.