AIRCC PUBLISHING CORPORATION
DESIGN AND IMPLEMENTATION OF NEW ROUTINGSTRATEGY FOR ENHANCED ENERGY
EFFICIENT IN WSN
Mehdi Bouallegue1,2, Hager Benfradj3, Kosai Raoof1 and Bouallegue Ridha3
1 Laboratory of Acoustics at University of Maine, LAUM UMR CNRS n 6613, France
2 System of communication SysCom, ENIT, Tunisia
3Innovation of communication and cooperative mobiles, InnoV’COM Lab, University of
Energy consumption is a key element in the Wireless Sensor Networks (WSNs) design. Indeed, sensor nodes are really constrained by energy supply. Hence, how to improve the network lifetime is a crucial and challenging task. Several techniques are available at different levels of the OSI model to maximize the WSN lifetime and especially at the network layer which uses routing strategies to maintain the routes in the network and guarantee reliable communication. In this paper we intend to propose a new protocol called Combined Energy and Distance Metrics Dynamic Routing Protocol (CEDM-DR). Our new approach considers not only the distance between wireless sensors but also the energy of node acting as a router in order to find the optimal path and achieve a dynamic and adaptive routing. The performance metrics exploited for the evaluation of our protocol are average energy consumed, network lifetime and packets lost. By comparing our proposed routing strategy to protocol widely used in WSN namely Ad hoc On demand Distance Vector(AODV), simulation results show that CEDM-DR strategy might effectively balance the sensor power consumption and permits accordingly to enhance the network lifetime. As well, this new protocol yields a noticeable energy saving compared to its counterpart
Energy saving, Routing protocol, lifetime, WSN, power consumption, Sensor node, NS2.
In the last few years, wireless sensor networks have increasingly attracted considerable attention among researchers in the field of Telecommunications. They are considered as one of the most active areas of technology development due to their unique characteristics, low cost, easydeployment and flexibility . WSN help human to perform many tasks such as habitat monitoring, industry application, collaborative and distributed computing, military, agriculture, emergency operations and health care application  . Although wireless sensor network is employed in various fields, it has many constraints such as limited storage capacities, limited communication abilities and especially limited energy resources due to the finite battery-power available . In this type of networks, each wireless sensor is able of acting as a router along with being a source node ordestination node. Hence, when sensor cannot achieve correctly its task, the performance of WSN can be greatly impeded and eventually the basic availability of the network such as routingapproach can be affected.
On the other hand, reload or replace sensor nodes battery after their exhaustion is very difficult especially in unreachable areas such as desert or battlefield . So a careful energy resource management is needed to increase the lifetime of wireless sensor networks. Substantial researches have been carried out to analyze and overcome the constraints of WSNs.
Hence, several routing protocols have been designed and implemented to improve the performance of these types of networks.
Indeed, routing protocols play an important role in WSNs. They permits to determine the optimal path to a destination, ensures successful connectivity and guarantee reliable communication. But the problem in existing energy aware communication protocols is that they try to find an optimal path and then repeatedly use this best route for every communication, which conducts to rapid energy diminution of the wireless sensors on the selected path. Substantial researches have been=carried out to analyze and overcome the constraints of WSNs. Hence, several routing protocols have been designed and implemented to enhance the performance of these types of networks. Authors in  proposed a new protocol called MAODV derived from AODV mechanism. Their idea was to take into account the bit error rate as the metric to be reduced for route selection. The simulation results showed that MAODV improves the packet delivery ratio at the cost of a delay increase.
In addition, in  authors considered the transmit power control as a metric to improve the performance of AODV routing technique. The same authors proposed in  a new strategy to set a timeout for a path in order to remove the stale paths after a certain timeout period and minimize the number of control packets. Hence, this approach permits to reduce the power consumption of the network. A small change in the traditional AODV protocol which integrates local routing of intermediate sensors in order to improve energy consumption of the network isproposed in  and called E-AODV approach.
Among these works, most of them just integrated one cost metric (as energy or BER or transmit power, etc.) to optimize the energy consumption of the wireless network.
In this paper, we propose a new routing strategy which considers not only the distance between wireless sensors but also the energy of node acting as a router in order to find the best path and achieve a dynamic and adaptive routing to increase network lifetime as long as possible.
Performance analysis of both reactive and proactive routing protocols namely DSR, AODV, DSDV was studied in our earlier work  on the basis of various performance metrics and under various traffic scenarios. Through extensive simulations, we deduced that AODV and DSR yielded better performance than the DSDV even when the network has a large number of sensor nodes. The results also disclose that AODV routing technique becomes more effective in
providing better performance when the studied metrics are simulated. So we concluded that AODV technique can be considered as the most energy efficient protocol.
In this regard, we suggest a new energy efficient communication protocol for wireless sensor networks based on the AODV platform. The main goal of our approach is to enhance the network lifetime as well as discover the optimal path from the source sensor to the destination based on combination of two most important metrics to evaluate the optimal path namely: distance relative to the sink and energy available in each sensor node acting as router. Our new algorithm extendsand optimizes the routing AODV approach.
This work is arranged into five sections. Section II covers a brief overview of routing strategy. Section III describes the considered performance metrics. Section IV provides a detail description of the design and implementation of our proposed routing approach. In section V we compare the performance of CEDM-DR protocol with its counterpart routing technique. Finallythe conclusion of the work and future directions are provided in the last section.
2. OVERVIEW OF WSN ROUTING PROTOCOL
In wireless communication we can distinguish two categories. The first needs to have direct access to the base station (BS) for the transmission of communications. While the second has the opportunity to access to the BS via the intermediate nodes using a communication hop by hop . The most important problem for an ad-hoc network is the delivery of data packets between the mobile nodes. Since the node topology changes frequently this makes routing veryproblematic.
Low bandwidth, limited battery capacity, and proneness to errors add to the complexity of the design of an efficient routing protocol. A routing technique in WSN presents many challenges compared to data routing in wired networks.
Indeed, the choice of the route is done by routing algorithms. Different routing methods are proposed for wireless sensor networks. These protocols are classified according to many parameters and to the strategies of discovering and maintaining routes.
Protocols can be classified  as reactive, proactive and hybrid, depending on their operation and type of requests. Proactive protocols control peer connectivity to ensure the availability of any path between the active nodes. In order to maintain a common network topology, sensor nodes announce their routing state tables of the entire network.
On the other hand, reactive protocols establish paths only on request. Meanwhile, the sensors are inactive in terms of routing behavior. Nodes transmit each routing request to their peers untiln comes to a sink node and the last answer on the reverse communication path.
2.1. DSDV Routing protocol
Destination Sequenced Distance Vector (DSDV)  is a hop-to-hop distance vector routing protocol. It is characterized by each host maintaining a table consisting of the next-hop neighbor and the distance to the destination in terms of number of hops.
In order to obtain the optimal path, the protocol DSDV guarantees loop free routes to each destination node, this is based on an average settling delay, which is a delay before advertising a route. All the hosts periodically broadcast their tables to their neighboring nodes in order to maintain an updated view of the network.
2.2. DSR Routing Protocol
The DSR protocol is a reactive protocol that aims to limit the bandwidth consumed by packet routing in wireless ad-hoc wireless networks. Dynamic source routing protocol  is based on the concept of a routing algorithm from the source node to discover routes.
This means that every node needs only forward the packet to its next hop specified in the header and need not check its routing table as in a table-driven algorithm. Determining source routes requires accumulating the address of each device between the source and destination during the route discovery.
2.3. AODV Routing Protocol
The ad-hoc on demand distance vector is an on demand algorithm, meaning that it builds routes between nodes only as desired by source nodes. It maintains these routes as long as they are needed by the sources. AODV   uses sequence numbers to ensure the freshness of routes. This routing protocol builds routes using a route request on a route reply query cycle.
AODV uses a reactive approach for finding routes and a proactive approach for identifying the most recent path. This protocol uses the same route discovery process to DSR protocol for finding fresh routes.
3. PERFORMANCE METRICS
The technical performance of our proposed routing algorithm is evaluated based on various performance metrics .
3.1 Average energy consumption
The energetic consumption is the average of the total energy consumption of the entire network to transmit data packets from a source to destination. We obtain the energy consumption by calculating the ratio of the sum of the total energy consumed by each node to the total number of nodes . So a protocol that uses less energy during the simulation is considered more effective .
Network lifetime is the time span from the deployment to the instant when the WSN is considered non-functional. It can be, for example, the instant when a percentage of sensors die and consequently the loss of coverage occurs  .
3.3 Packet Lost
It represents the total number of data packets dropped during the simulation. The loss of a packetmay be due to a collision during transmission process.
4. CEDM-DR PROTOCOL DESIGN AND IMPLEMENTATION
4.1 WSN Energy Consumption Model
In this work, the energy consumed by both the transmitter and the receiver blocks was evaluated for calculating the total energy consumption in the network. We perform the transmitter and receiver hardware model as introduced in  .
The total energy consumed by a wireless sensor S is the consumed energy by its communication block (transmitter / receiver), sensing block and processing block .
We consider that transceiver circuit of a wireless node operates according to three modes. Indeed, when there is information to send the sensor node operates in the communication mode so all these circuits are active.
But, if there is no data to communicate the sensor circuits switch to standby mode. During this mode, wireless node is in a state of listening and sensing. This strategy contributes to reduce energy consumption that’s why the power consumption in this mode is small enough to be neglected.
In this study we assume that the energy consumed by the sensing and the processing block is neglected because it is quite negligible with respect to the energy consumed by the communication block  .
4.2 CEDM-DR Algorithm
In this section, we describe the algorithm of our new routing protocol which is based on combination of two major metrics: distance and energy.
– Step 1: Each network node(s) transmits hello messages to discover neighboring nodes to one hop.
– Step 2: Verification that the sink and the source node own neighboring nodes. ( If true go to Step3 else Stop )
– Step 3: All network nodes discover neighboring nodes through the Step 1.
– Step 4: All network nodes evaluate the distance between each neighbor and the sink. This
distance is expressed as follows:
– Step 5 : The weight is calculated using two parameters which are the remaining energy in the node receiver and the distance between the receiver node and the sink.
– Step 6 : When one of the sensor nodes needs to transmit data it will choose the node with the highest weight among these neighbors.
The setting parameters considered in our simulations are summarized in Table II.
To simulate different routing protocols we choose network simulator 2 (Ns2) since it is open source free software in which different specifications in the environment can simply modified and changed. Figure 2 presents an example of wireless sensor network under NS2.
Performance of the routing protocols AODV and the new protocol CEDM-DR are evaluated based on different performance metrics, average energy consumption, the lifetime of the network and total dropped data packets.
The average energy consumed by the sensor nodes as a function of the number of nodes is illustrated in Figure 3. We note that for all variations of the number of node the new routing protocol implemented still consumes less than the traditional AODV protocol using CEDM-DR, we observe between 0% and 66% energy savings when compared with AODV.
Figure 4 depicts the number of nodes living on a total of 200 nodes with respect to the number of transmissions during the simulation. These curves show that the new protocol CEDM-DR improves the entire network’s lifetime. This is mainly due to the dynamic priority-weight adopted.
The total number of packet lost as a function of the number of sensor nodes is drawn in Figure 5. From this plot, we confirm that our new approach allows to obtain lower number of packet lost than its counterpart. The CEDM-DR protocol reduces between 0% and 50% of packet lost.
In this paper, the performance of a new routing protocol using two important cost metrics has been evaluated through extensive simulations verifying that our proposed algorithm is effective in saving energy and leads the system to overall enhancements. Indeed, implementation and experimentation of Combined Energy and Distance Metrics Dynamic Routing Protocol (CEDM-DR) using network simulator reveals that our new approach is better than AODV in energy consumption, Packet Lost and especially in Lifetime. To sum up, the above results illustrate that the CEDM-DR strategy works well when compared with AODV. Hence, our future plan is to evaluate security issues in this new routing approach CEDM-DR.
This work was supported in part by Laboratory of Acoustics at University of Maine, LAUM UMR CNRS n_6613 in France and Laboratory of System of communication Sys’Com, ENIT in Tunisia.
 Lee, S.hyun. & Kim Mi Na, (2008) “This is my paper”, ABC Transactions on ECE, Vol. 10, No. 5, pp120-122. Anna, H. Wireless sensor network design , (Wiley), 2003.
 I.F. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, A survey on sensor networks, IEEE Communications Magazine, pp. 102-114, Aug. 2002.
 Mehdi Bouallegue, Kosai Raoof, Maha Ben Zid, Ridha Bouallegue, Impact of Variable Transmission Power on Routing Protocols in Wireless Sensor Networks, 10th International Conference on Wireless Communications, Networking and Mobile Computing (Wicom14),Beijing, China September 2014. International Journal of Computer Networks & Communications (IJCNC) Vol.7, No.4, July 2015 136
 W. B. Heinzelman, Application-specific protocol architectures for wireless networks, Ph.D. dissertation, Massachusetts Institute of Technology, May 2000.
 Heinzelman W B, Chandrakasan, A.P., An application-specific protocol architecture for wireless microsensor networks, Wireless Communications IEEE Transaction, vol 1, 2002.
 Y. Chen and Q. Zhao, On the lifetime of wireless sensor networks, Communications Letters, IEEE, vol. 9, no. 11, pp. 976978, 2005.
 Awatef Benfradj Guiloufi, Nejeh Nasri, Abdennaceur Kachouri, Energy- Efficient Clustering Algorithms for Fixed and Mobile Wireless Sensor Networks, in The International Wireless Communications and Mobile Computing Conference, IWCMC´14 Cyprus, 2014.
 Gianluigi Ferrari, Simone A. Malvassori, Marco Bragalini, Ozan K. Tonguz, Physical Layer- Constrained Routing in Ad-hoc Wireless Networks: A Modfied AODV Protocol with Power Control, IWWAN, 2005.
 Tamilarasi M., Palanivelu T.G., Integrated Energy-Aware Mechanism for MANETs using On demand Routing, World Academy of Science, Engineering and Technology,2008.
 Tamilarasi M. and Palanivelu T.G., Adaptive link timeout with energy aware mechanism for on demand routing in MANETs, Ubiquitous Computing and Communication Journal, 2010.
 Charu Gupta, Pankaj Sharma, Implementation of Energy Aware Routing Protocol for Mobile Ad Hoc Networks, International Journal of Advanced Research in Computer Science and Software Engineering, Volume 3, Issue 11, November 2013.
 Chetan, B.M, Deshpande P.P., Gireesh Hegde, B. and Srinivas, Analysis of DSDV and AODV for Disaster Management System in Coal Mines, Wireless Communications, Networking and Mobile Computing (WiCOM), 23-25 Sept. 2011.
 A. Almutairi and T. Hendawy, Performance Comparison of Dynamic Source Routing in Ad-Hoc Networks, IEEE GCC Conference ,Dubai,19 – 22 Feb. ,2011.
 Bhardwaj, M and Chandrakasan, A.P ,Bounding the Lifetime of Sensor Networks Via Optimal Role Assignments,in Proceedings of the 21st IEEE INFOCOM.Vol 13.No.4, January 2011.
 I. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, Wireless sensor networks: a survey, Computer Networks, vol. 38, pp. 393 422, 2002.
 Proakis, J. G. Digital communications, New York: McGraw Hill, 1995.
 Rappaport, T. S., Wireless communications: principles and practice, New York: Prentice Hall, 1996.
 Gopinath Balakrishnan , Mei Yang , Yingtao Jiang, and Yoohwan Kim, Performance Analysis of Error Control Codes for Wireless Sensor Networks, Fourth International Conference on Information Technology, ITNG’07, 2007.
 Tran Cong Hung and Nguyen Hong Quan, A proposal for improve the lifetime of wireless sensor network, International Journal of Computer Networks & Communications (IJCNC), Vol.6, No.5, September 2014.
 J. N. Al-karaki and A. E. Kamal, Routing techniques in wireless sensor networks: A survey, IEEE Wireless Communications, vol. 11, pp. 628, 2004.
 Zhongwei zhang and Hong Zhou, Empirical examination of mobile Ad-hoc routing protocols on wireless sensor networks, International Journal of Computer Networks & Communications (IJCNC),Vol.1, No.1, November 2010.
Mehdi Bouallegue received the B.S. degree in 2008 from Higher Institute of Computerand Communication Techniques, Tunisia and M.S. degree in 2010 from National Engineering School of Tunis. Currently he is a Ph.D. student at the School of Engineering of Tunis. He is a researcher associate with Laboratory of Acoustics at University of Maine, LAUM UMR CNRS n° 6613, France, and Laboratory System of communication SysCom, ENIT, Tunisia.He is Assistant in National school of Engineering of Carthage (ENI Carthage), Tunisia. His research interests are mainly in the field of telecommunications, wireless sensor networks, optimization of routing protocols, Network simulation
Kosai Raoof obtained his M.Sc. and Ph.D. from Grenoble University 1990 and 1993 respectively; in 1998 he obtained the Habilitation à Diriger Des Recherches Degree (HDR). He was invited to join Laboratoire des Images et Signaux (LIS) in 1999, to participate in the founding of telecommunication research group. His research interest was first focalized on advanced MIMO systems and joint CDMA synchronization; he studied and introduced polarized diversity in MIMO systems. In 2007 he joined GIPSA-LAB to continue his research on Smart Sensor Networks and cooperative MIMO antenna systems. He is a referee for many international journals and conferences in the field of telecommunications and signal processing. He is currently a full professor at the ENSIM Engineering College, University of Maine, Le Mans.
Ridha Bouallegue received the Ph.D. degrees in electronic engineering from the NationalEngineering School
of Tunis. In Mars 2003, he received the Hd.R degrees in multiuser detection in wireless communications. From September 1990 He was a graduate Professor in the higher school of communications of Tunis (SUP’COM), he has taught courses in communications and electronics. From 2005 to 2008, he was the Director of the National engineering school of Sousse. In 2006, he was a member of the national committee of science technology. Since 2005, he was thelaboratory research in telecommunication Director’s at SUP’COM. From 2005, he served as a member of the scientific committee of validation of thesis and Hd.R in the higher engineeringschool of Tunis