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International Journal of Computer & Organization Trends – Volume 9 Number 1 – Jun 2014

Energy Study in the WSN S-MAC Protocol using OMNETPP M.Thangaraj*, S.Anuratha**, A.Suryakala*** Department of Computer Science, Madurai Kamaraj University, Madurai, India Abstract— As Wireless Sensor Network (WSN) uses battery for energy source which are limited, the challenge is to keep the network alive and keep the network sustainability. One of the main aspects of WSN communication is the transmission protocol. Even WSN uses multiple protocols, SMAC is the widely used protocol because it addresses the energy efficiency by the state changes, and virtual clusters are also formed to autosynchronize on sleep schedule. This paper is going to focus on how to study the energy efficiency at the S-MAC protocol level without affecting the transmission protocol relevant to QOS parameters like throughput, strict wireless bandwidth, and channel utilization. Signal interference and varied load and peak loads. The platform selected should support and enhance the energy study at different level of transmission in the MAC protocol. OMNETPP simulator along with its other frameworks has been considering as the platform for studying the energy efficiency at MAC level.

Keywords— WSN, ENERGY, OMNETPP, MAC, S-MAC, PROTOCOL, MEDIUM, ACCESS

I. INTRODUCTION The main consideration for the design of the any MAC protocol is the duty cycling. In a simple method, the nodes take the duty cycles periodically to change its state from sleep to wake. For improving the energy consumption, the nodes must select the sleep time adaptively. We need dynamic algorithms to adjust the duty cycles for the low energy latency.

The other aspects of MAC design are collision, overhead, overhearing, and idle listening [1]. The collision is when two nodes try to communicate at the same time and because of that the data get corrupted and need retransmission. Overhead are the extra processing and transmission overhead involved in the control packets (preamble packets) which are not actually data but the instructions about how to use the data.

Overhearing is a node receives the packet which is not meant for it and meant for other nodes. The idle listening is the case where the receiver and sender waits and listens to the channel expecting the arrival of the bandwidth. If these are challenges at the data message passing level, there are further more challenges in case of transmissions like multi-hop communication, data management, geographical routing challenges, and resource limited system utilization. The next case is the communication patterns like local gossip broadcast is by the base station node to all the other nodes to alarm or indicate information. In the convergence cast, the nodes get the data from the neighbouring node and pass on the information to a specific node. Prolonging network lifetime [2] for these nodes is a vital issue. SMAC design consideration all these design issues to optimize the energy at the data packet

ISSN: 2249-2593

message passing level, transmission level and the communication pattern level [1].OMNETPP is the simulation platform with its frameworks MIXIM, INETMANET, INET, and CASTALIA helps us to study the energy usage at different level of communication and energy consumption at each and every operation [3]. With this study on the decided platform any one can identify the further scope for the energy optimization by analysing the energy leakages and wastages.

II. ARCHITECTURE AND DESIGN OF MAC PROTOCOL IN OMNETPP There are two aspects in case of a protocol implementation in a simulation medium. First is to configure and decide a particular protocol in the NED (Network Description) while setting up the WSN profile. The second is the mechanism in which it operates during the run time so that any researcher can have a look at the design perspective and energy study.

Herewith the sample of NED files for the OMNeT MAC description.

Fig. 1 Configuring the MAC details in the WSN node definition

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International Journal of Computer & Organization Trends – Volume 9 Number 1 – Jun 2014 Herewith the architecture and working mechanism of MAC protocol Sender MAC Receiver

MAC BIT RATE, TX POWER, ANTENNA, CHANNEL, SDU, PHYSICAL Physical LAYER Layer

Collision Over hearing Over head Path loss Fading Energy Utilization

Signal, SDU, RSSI

III.MESSAGE PASSING OF MAC ON OMNETPP Message passing could be in multiple schemes like duplex and half duplex based on whether sending and receiving possibility at the same time [1]. The transceivers convert the bit stream into radio waves; the circuitry for transmitting includes modulation, demodulation, amplifiers, filters, mixers.

The power efficiency in transmission can be measured as follows.

Power efficiency=Radiated power / Overall power.

3.1 Idle Listening-Collision Avoidance in SMAC

Physical Layer

Signal

Signal

The voltage range is the range of voltage supply in which the transceiver should operate. The collision in SMAC is avoided by the internal synchronization, the nodes 1, 2, 3....n are said to agree on the time. To achieve this we need a reliable source of real time / UTC timer. Here the question is how often the synchronization protocol runs and a resynchronization is needed at every 50 seconds [4].

Sim. Kernel Event scheduling, Sending and receiving

Parallel Simulation Sub System Synchronization, partitioning, communication

Fig. 3 SMAC Internal Synchronization mechanism between nodes in a crowded WSN

Communication Library , sockets

Fig. 2 MAC architecture and working mechanism in OMNETPP

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Further to internal synchronization, SMAC uses the message passing technique where the long messages are converted into smaller fragments and converted into bursts.

OMNETPP supports the internal synchronization and internal time, DMESG ACK packet configuration.

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International Journal of Computer & Organization Trends – Volume 9 Number 1 – Jun 2014 1) Cooperative Handshaking 2) Partner Selection 3) Forwarding Decision 4) Combining Decision

Fig. 4 MAC Radio signal state during run time in a WSN communication using OMNETPP

3.2 Approach to Overhear on SMAC The nearby node goes to sleep when receivers RTS, CTS, ACK messages. Even it reduces the node to node fairness and increases latency; it saves energy [5]. OMNETPP supports messages schedules and time schedules to set and visualize during run time.

For a cooperative protocol, correctly received packets at the Decider will be passed to the MAC layer. However, for incorrectly received packets, Decider would need to take a decision based on its role defined during handshake. At destination, decider can buffer incorrectly received packets for later combining [7].

At partner, Decider can either discard erroneous packets or request retransmission from source, or buffer the packet if it expects to receive redundancy from any other node. The destination node is responsible for combining packets received from source and partner. Traditionally, only the correctly received packets are passed on to the MAC layer.

This is to avoid unnecessary or scheduling of erroneous packets.

Fig. 5 OMNETPP analysis files with the chart sheet on the packet arrival for a time frame

IV. TRANSMISSION CONTROL IN MAC USING OMNETPP In the cooperative communication scheme the nodes nearby also overhears the data which is usually gets discarded in the traditional network. The destinations receive the packet both from the transmitter node and its partner by exploring the spatial integrity and assemble the packet with original accuracy [6]. This is called Virtual Multiple Input and Multiple Output (VMIMO). It necessitates the cooperative diversity protocol.

4.1 Multihop Transmission OMNeT++/MiXiM. Cooperative diversity protocols usually address one or more of the following challenges for enabling cooperation.

ISSN: 2249-2593

Fig. 6 OMNETPP MIXIM MAC transmission with power details

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International Journal of Computer & Organization Trends – Volume 9 Number 1 – Jun 2014 4.2 Data Management in MAC using OMNETPP MIXIM Energy efficient data management at different levels of the architecture of WSN, data aggregation, data sampling, routing and MAC is the prime focus in most of the researches. They are worried about how efficient the data is to be handled. The data modules and algorithms support of MAC in OMNETPP are energy efficient. Some of the application needs a subset of the data and some need the whole data for decision.

Distributed query management with advanced data management technique is needed for the MAC [8]. The vector, scalar and snapshot data in XML format are maintained along with the routing table, blackboards in OMNET for the intermediate data management which can be plotted as chart.

Data Funnelling: Data transferred to edge nodes which in turn communicate to the internal nodes.

Dynamic Code Scattering: Data stored in a network and only the indication of storage is passed to the network rather data.

Geographical Scoping: The nodes publish their interest on a specific type of data and when that type of data is broadcast, they read them. Push diffusion arises when many receivers and few senders are there.

Data Centric Routing: Rather one shot queries, the node advertise the name of the data needed to the neighbours, if the receiver of an advertisement can compare it with tits local knowledge, if data is unknown the it request the data to its neighbours.

All these operations are to energy efficient. OMNETPP MIXIM framework MAC protocol implementation supports all these activities and aspects in the support of WSN simulation.

Fig. 7 Collision multiplicity in a WSN communication for a time interval

Fig. 9 Battery with MAC protocol in a WSN communication with OMNETPP

V. COMMUNICATION PATTERN & CHANNEL UTILIZATION TECHNIQUES

The communication pattern doesn’t only deal with how the data packets are moved but also on how the channel is utilized [9].

Fig. 8 Hybrid (wired, wireless) Network in OMNET with data management details

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Random Access: Same as the traditional methods, no restriction on accessing the channel, nodes compute all the time to access the medium, and this adds flexibility to these protocols.

Slotted Access: Here every node wakes up only during the beginning of every slot and listens to the channel.

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International Journal of Computer & Organization Trends – Volume 9 Number 1 – Jun 2014 Frame Based Access: Here every node is given the time slot to utilize and listen periodically to the channel.

Hybrid: Combination of any of these channel utilization techniques based on the need.

OMNETPP has the NED object of channel manager which is configured with the necessary details.

Broadcast: Broadcast patterns used by a base station (Sink node) to transmit some information to all the sensor nodes to execute queries processing to send the data – control packets to all the nodes. Broadcast are the nodes within the communication range of the transmitting node.

Local Gossip: In Local Gossip, a sensor node sends a message to its neighbour nodes within a range. After the sensors detect an event, they need to send what they perceive to the information center.

VI. CONCLUSIONS Even there are basic features and additional options to work with the different MAC protocol, adding security and changing algorithm needs the programming effort than the porting effort. Real hardware integration and embedded coding is not very straight forward. The output formats are very limited applications become very simple.

REFERENCES [1]

[2]

[3] [4] [5] [6]

Converge Cast: In this communication pattern, a group of nodes communicate to a specific node which could be sink node, data cluster head, data fusion center or it could be base node. In multicast, the cluster head communicate to the neighbours.

OMNETPP MIXIM framework supports all communication patterns with the simple commands.

these

[7] [8]

[9]

Simarpreet Kaur1,* and Leena Mahajan2,”Power Saving MAC Protocols for WSNs and Optimization of S-MAC Protocol”, 1 BBSBEC, Fatehgarh Sahib, Punjab 2 IGCE, Abhipur, Punjab Tijs van Dam, Koen Langendoen, “An Adaptive Energy-Efficient MAC Protocol for Wireless Sensor Networks”, Faculty of Information Technology and Systems, Delft University of Technology, The Netherlands. www.omnetpp.org/doc/omnetpp/Manual.pdf www.omnetpp.org/doc/omnetpp/UserGuide.pdf Ilker Demirkol, Cem Ersoy, and Fatih Alagöz,” MAC Protocols for Wireless Sensor Networks: a Survey” Bhavana Narain, Anuradha Sharma, Sanjay Kumar and Vinod Patle, International Journal of Computer Science & Engineering Survey (IJCSES) Vol.2, No.3, August 2011 Sarika Khatarkar , Indian Journal of Computer Science and Engineering (IJCSE), 304-309 Abdul Maalik, Mamoona Naz and M. J. Qureshi, International Journal of Computer Science and Telecommunications [Volume 4, Issue 8, August 201 S. Chatterjea, L.F.W. van Hoesel, P.J.M. Havinga, Intelligent Sensors, Sensor Networks and Information Processing Conference, 2004.

Proceedings of the 2004, (381 – 388)

Fig. 10 Multicast Networks with the OMNETPP

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