Energy efficient routing in wireless sensor networks


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Energy efficient routing in wireless sensor networks

  1. 1. Energy Efficient Routing in Wireless Sensor Networks Gunti Spandan1, C R Manjunath2, Nagaraj GS3 1,2 Dept of CSE, SET, Jain University, 3RVCE, VTU , , nagarajgs2000@yahoo.comAbstract:Wireless Sensor Networks present a great Energy-efficient multicast routing protocol is ofpotential in monitoring systems. Routing problem is one of paramount importance for many new applications beingthe most important issues in a wireless sensor network developed for the resource scarce WSN.(WSN).Any routing protocol designed for wireless sensornetworks is should take into consideration, the challenging II - MULTICAST AD HOC ON-DEMANDfactors like fault tolerance, energy efficiency, scalability, DISTANCE V ECTOR(MAODV)latency, power consumption and network topology. The MAODV like DSR has the same on demandstringent requirement of energy budget has been an routing characteristics, but uses an entirely differentemerging issue in the design specification for a wireless approach for maintaining routing table information. Assensors network (WSN). In this paper we present a study MAODV belongs to the family of on demand routingon demand &cluster multicast routing protocols with protocol, so it follows the conventional scheme ofenergy-efficiency perspective. maintaining routing table i.e. only one entry will be made for each destination. The entry made contains twoKeywords: multicast, routing, wireless sensor informations, first one is it will update its destination withnetworks, energy efficient. the next hope and then the next hope will update itsI - Introduction sequence number which shows that how recently this node Wireless sensor network(WSN) is a multi-hop has updated.wireless networks consists of a large of small-size, low-cost MAODV also updates the upstream link if anyand low-power sensor nodes which are capable of sensing, link associated against this entry goes down. MAODV alsocomputation and communication. WSN take advantage of uses the same broadcasting mechanism as used by the DSRdeployment rapidly and strong survivability without fixed for discovery within the network but it is different fromnetwork support,but also with features of dynamic topology AODV as it only receives route reply from those nodesstructure and energy resources are limited and so on.The which belongs to a family of multicast group.application of WSN technology is a revolution of perceivedand collection of information andused for variousapplications such as habitat monitoring,automation, and agriculture [1]. Routing in WSNs is very challenging due to theinherent characteristics that distinguish these networksfrom other wireless networks like mobile ad hoc networksor cellular networks.Sensor nodes are tightly constrained interms of energy, processing, and storage capacitiestheyrequire careful resource management. Multicast is thecommunication paradigm of one-to-many or many-to-many, based on defined groups and constitutedby members, whose interest is to receive/sharethe same information for a specificapplication.Multicast routing is to find a multicast tree Figure 1 MAODV Joining Process- Image reproducedwhich is rooted from the source and spans all destination The group leader broadcast a HELLO message to all thenodes.The whole routing process includes two phases. The nodes and they update their request table upon this groupfirst phase is to seek a minimal energy path from the sink to HELLO message. If a new node is interested to be a part ofthe access point based on the idea of dynamic join this group, initially it will generate a route requestprogramming. The second phase is to search for a broadcast packet (RREQ). The node unicast this request if it alreadytree between the access point and the destination nodes in knows the group leader address otherwise it will bethe multicast region [2]. broadcasted. The group leader or any other node of the Energy Efficient Routing method is proposed for requested group having a grater sequence number than thata static wireless sensors network, which consists of a large of the RREQ packet is allowed to respond. As the messagenumber of energy-constrained sensors and a few hubs as is broadcasted the members of the group or the groupthe cluster heads of sensors. Since each battery-powered leader will receive several RREQ packets but it willsensor only has limited energy resource and the battery consider only one having the highest sequence number andrecharge or replacement is impractical, a network with least hope count. After selecting the request packet, itenergy-aware design becomes important to achieve the unicast a route reply packet to the desired node. Thisdesired lifetime performance. replying packet consists of the sequence number which is
  2. 2. recently updated and the distance of the node from the heads. After selecting the cluster head (CH) it receives thegroup leader. The requesting node at its end also attribute from the user. The CH broadcasts the attribute,receivesnumerous replies from different nodes and group hard threshold (HT), soft threshold (ST), schedule andleader but selects only one having the shortest distance count time (CT) parameters to the cluster members. Theamong all RREP packets and most recently received. After sensor nodes sense continuously. If the sensed value isselecting the most suitable route it generates a multicast above the HT it is stored in the internal variable (SV) andactivation packet (MCAT) to its neighbor node to enable transmitted to the CH through the TDMA schedulethe desired route.Figure2 shows the node joining process of assigned for it. All the clusters formed here may not haveMAODY. uniform number of sensor nodes. The cluster formed with maximum number of nodes requires more time to aggregateIII - THRESHOLDSENSITIVEENERGY the captured data from nodes and transmit to BS than theEFFICIENT SENSOR NETWOR K ( TEEN) cluster with minimum number of nodes. Threshold sensitive Energy Efficient sensor Suppose in any cluster, adjacent nodes have theNetwork (TEEN)[5] belongs to on-demand routing similar sensed data to transmit then those nodes are formedprotocols category and mostly used for time crucial as a pair. Only one node from the pair will respond to theapplications. In TEEN, nodes have two levels of cluster query while the another node goes to sleep mode. The nodeheads and also they follow hierarchical clustering design. which responds to the query is considered as active nodeAfter nodes have selected their cluster head, user needs to and the other node which goes to sleep mode is consideredmanually enter the attribute values, which will be as sleep node. This protocol supports one time query,broadcasted by cluster head in form of two parameters soft historical query and persistent query. The BS needs tothreshold and hard threshold. respond to nodes query only after receiving the data from The sensor nodes will start transmitting data all the CHs.when minimum threshold value is greater than hard As the cluster head of cluster with maximumthreshold. Another variable called sensed value is used for members require more time to communicate with BS atransmitted data. Teen saves data continuously. The soft modified TDMA schedule is assigned as per which BSthreshold also saves energy by reducing the transmission, needs to wait until data from CH of cluster with morewhen there no or little change in the attribute value. Cluster members reaches it. Apart from responding to time criticalhead will definitely consume more energy than a normal events, the nodes were also forced to transmit data to CH atnode because it needs to do extra processing. periodic intervals as CT even though the sensed data does not exceed the threshold value. Where CT is the maximum time period between two successive reports sent by a node. Due to this periodic transmission, frequent updates of the nodes sensed value are transmitted to its CH. In this protocol the energy consumption can be reduced by properly selecting the CT and threshold values. CDMA schedule is used to avoid collisions during cluster heads communicating with BS. The attributes can be changed during the every cluster head change time. The main drawback ofthis protocol is the additional complexity required to implement the threshold functions and CT. Figure 2 Operational Flow of TEENThe biggest disadvantage of this protocol is that when hardthreshold value is higher than sensed value there will be notransmission to clustered head from node, so the clusterhead will have no information updation even if the node isno more in network. This problem can easily be addressedby fixing soft threshold to as minimum value as possibleeven though it would increase energy consumption butnodes sensibility will also be increased. This protocol usesTime Division Multiple Access (TDMA) as a scheduler tosend data between nodes and their cluster heads.Figure 2shows operational flow diagram of TEEN protocol.IV - Adaptive Periodic Threshold-sensitive EnergyEfficient sensor network protocol (APTEEN) APTEEN, is a hybrid protocol proposed in [5] for V - SPEED Protocolboth periodic data collection and time critical events. Inthis, cluster is formed with 1st level and 2nd level cluster
  3. 3. SPEED maintains a desired delivery speed across congestion. Figure 4 shows the protocol structure ofsensornetworks by both diverting traffic at the SPEED protocol.networkinglayer and locally regulating packets sent to theMAC layer. VI - REAL-TIME POWER-AWARE ROUTINGIt consists of the following components: An API, A IN SENSOR NETWORKS (RPAR)neighbor beacon exchange scheme, A delay estimation RPAR is a real time protocol proposed in which achievesscheme, the Stateless Non-deterministic Geographic application-specified communication delays at low energyForwardingalgorithm (SNGF), A Neighborhood Feedback cost by dynamically adapting transmission power andLoop (NFL), Backpressure Rerouting, Last mile processing routing decisions based on packet deadlines. The primaryAs shown in Figure 4,.SNGF is the routing module design objective of RPAR is to increase the number ofresponsible for choosing the next hop candidate that can packets which meets their deadlines. Anothersupport the desired delivery speed. NFL and Backpressure distinguishing feature of RPAR is that it handles realisticRerouting are two modules to reduce or divert traffic when properties of WSN such as lossy links, limited memory,congestion occurs, so that SNGF has available candidates and bandwidth. RPAR has four components:to choose from. The last mile process is provided to support A. Dynamic velocity assignment policythe three communication semantics mentioned before. It uses the velocity assignment policy to map a packet’sDelay estimation is the mechanism by which a node deadline to a required velocity.determineswhether or not congestion has occurred. And B. Delay estimatorbeacon exchange provides geographic location of the This evaluates the one-hop delay of each forwarding choiceneighbors so that SNGF can do geographic based routing. in the neighbor table, i.e. the time a node takes to deliver a packet to neighbor N at power level p. C. Forwarding policy Based on the velocity requirement and the information provided by the delay estimator, It forwards the packet using the most energy efficient forwarding choice in its neighborhood table that meets the required velocity. D. Neighborhood manager This manager attempts to find a new forwarding choice that meets the required velocity through power adaptation and neighbor discovery, when the forwarding policy cannot find a forwarding choice that meets the required velocity in the neighbor table. RPAR trades-off between the communication delay and throughput. It trades capacity and Figure 4 SPEED Protocol- Image reproduced energy for improving latency by increasing transmission power and when there are loose deadlines, the transmission power is adjusted accordingly. The delay bounds for eachSPEED facilitates real-time communication because it packet is provided by the applicationprovides desired transfer rate over the network. It providesdifferent types of communication services i.e. VII - MULTIPATH AND MULTIPLE-SPunicast,multicast and any cast. Stateless Non-deterministic EED(MMSPEED)Geographic Forwarding (SNGF) identifies next hop MMSPEED is an extension of SPEEDwhenever source node transmit the data. protocol[4]. The aim of MMSPEED is to make routing decisions locally on the nodes and also to facilitateSPEED only stores the information of very next node, so it differentiated QOS in timeless and reliable domain. Torequires less memory. Neighboring beacon is used for make decisions locally without maintaining end-to-endinformation interchange between nodes. To identify routes, it uses geographic routing method. It assumes thattrafficchanges in the network two types of on demand main identifier for destination is its geographic locationbeacons are used i.e. delay estimation and back pressure rather than node ID. Periodic location update packets arebeacon. used to instantly update the location information with SPEED uses Backpressure rerouting mechanism neighbors, so that every node is aware of its very nextfor congestion controlhandling in the network. Packets are neighbor within its range. Each node makes pre-packetgiven an alternative route to destination and normally no decisions depending on the geographic location of thepackets are dropped in Backpressure rerouting mechanism. neighbor.Only when there is no alternative route to destination and The geographic localized routing mechanism hasnetwork become very congested than the packets are many advantages over traditional routing approach:dropped. It will consume less energy if there is no i) This approach is suitable for larger networkscongestion in the network and also it will save energy by (scalability).selecting shortest path to the destination but if there is ii) Minimum delay suitable for time-critical applications.congestion in the network, the energy consumption will be iii) Dynamic adoption to network topology changes.slightly higher. SPEED is a hybrid protocol because it To achieve higher performance, MMSPEEDcombines the functionality of MAC and network layer to needs MAC layerto support following function:minimize the delay and to provide better response to
  4. 4. i) To assign priority for accessing shared-medium energyconsumption, but repeatedly re-clusteringdependingupon the speed layer. will still consume more energy.ii) Reliable packet delivery (2) different clusters, the cluster head nodeiii) Average delay measurement and cluster head nodes from non-different, theiv) Measurement of loss to individual neighbors communication process increases the energy consumption of cluster head. (3)The cluster head node need to communicate with the sink node to complete the data fusion work, energy consumption increased. VIII - Conclusion: Providing an energy-efficient multicast routing protocol is of paramount importance for many new applications being developed for the resource scarce in WSNThis paper presents an overview of different energy efficientmulticast routing protocols for wireless sensor networks. Generally,all of them needs low processing and memory forrouting that means lower energy requirements. Figure 5 MMSPEED Protocol- ImageTo achieve above MAC layer goals another protocol is References [1].D.Baghyalakshmi, Jemimah Ebenezer, S.A.V.profromposed in. MMSPEED establishes redundant path to Satyamurty,”LOW LATENCY AND ENERGYeach destination and also provides multi-speed EFFICIENTROUTING PROTOCOLS FOR WIRELESSSENSORtransmission. Fordifferent speeds different QOS levels can NETWORKS” ICWCSC, set to improve performance. MMSPEED and SPEED [2].Abid Ali Minhas, Fazl-e-Hadi, Danish Sattar, KashifMustaqare different in way that MMSPEED offers different level and S. Ali Rizvi” Energy Efficient Multicast Routing Protocols forof QOS according to network and traffic requirements. Wireless Sensor Networks” IEEE 2011.Figure 5 shows the protocol structure of MMSPEED [3]. Ricardo Silva #1, Jorge S´a Silva #2.”Why Should Multicastprotocol be used in WSNs” IEEE ISWCS 2008 [4]. W. B. Jaballah and N. Tabbane, "Multi path multi speed contention window adapter," IJCSNS International Journal ofVIII - LEACH Protocol Computer Science and Network Security" vol. 9, no. 2, 2009. In the LEACH protocol, random, adaptive, [5]. A. Manjeshwar and D. P. Agarwal, "Teen: A routing protocolself-organizing cluster formation method. Figure for enhanced efficiency in wireless sensor networks," Proceedings 15th International Parallel and Distributed Processing. IPDPS, 20016depicts a wireless sensor network protocol based on 6.PAN Xue-feng, LI La-yuan,”Design of an Energy BalancedLEACH is divided into five clusters, each cluster has a Based Routing Protocol for WSN”IEEE circle represents the first cluster node , the rest of the 7.Taehee Kim, Hosung Park, Min-Sook Jin, BatzorigSambuu, andwhite circle indicates a non cluster head node. Each cluster Sang-Ha Kim “Energy-balancing Multicast Routing Protocolforhas a cluster head node, protocol randomly selecting cluster Wireless Sensor Networks” IEEE 2008.head node cycle, the energy of the entire network loadequally distributed to each sensor node can achieve lowerenergy consumption, the purpose of improving networklifetime Figure 6 LEACH protocol cluster structureFrom the above analysis shows that LEACHprotocol has the following deficiencies: (1) the use of cluster head nodes in randomrotation method which can reduce the