Design and implementation of variable range energy aware dynamic source routing protocol

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  • 1. INTERNATIONAL January- February (2013), © IAEME ISSN 0976-6367(Print), ISSN 0976 – International Journal of ComputerJOURNAL OF COMPUTER ENGINEERING 6375(Online) Volume 4, Issue 1, Engineering and Technology (IJCET), & TECHNOLOGY (IJCET)ISSN 0976 – 6367(Print)ISSN 0976 – 6375(Online)Volume 4, Issue 1, January- February (2013), pp. 105-123 IJCET© IAEME: Impact Factor (2012): 3.9580 (Calculated by GISI) © DESIGN AND IMPLEMENTATION OF VARIABLE RANGE ENERGY AWARE DYNAMIC SOURCE ROUTING PROTOCOL FOR MOBILE AD HOC NETWORKS Shiva Prakash Department of Computer Science & Engineering, Madan Mohan Malaviya Engineering College, Gorakhpur, INDIA J. P. Saini Madan Mohan Malaviya Engineering College, Gorakhpur, INDIA S.C. Gupta Sandip Vijay Department of ECE Department of ECE Dehradun Institute of Technology, Dehradun Institute of Technology, Dehradun, INDIA Dehradun, INDIA ABSTRACT Nodes in decentralized infrastructure-less wireless networks have limited battery power. Thus energy is the one of the most challenging issue, majority of the research work in energy efficient routing is based on the constant transmission power model, where nodes are transmitting the data with its constant power which minimizes number of forwarding nodes. Conversely, it results in interferences and decreases network lifetime. In this paper, we have designed variable range energy aware dynamic source routing in which the route selection based on energy, stability and load aware. We select two routes main and alternate; due to this we are able to reduced requirement of number of route discoveries. In this approach nodes are transmitting message with variant transmission power approach means that transmission power dynamically tuned as per nodes distances. Network performance is tested using NS-2 and their simulation results shows that a significant improvement in performance of modified DSR was achieved. Keywords: Ad Hoc Network, Routing, Power Aware Routing, Stability, Traffic Load, Variable Range Transmission Power. 105
  • 2. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 – 6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEI. INTRODUCTION Major research efforts have been focusing such as unreliable wireless links, limited energy, security, and dynamic network topology. Energy efficient routing is one the important issues in MANETs. Thus design an energy efficient routing approaches to save the energy consumption of the network because all the nodes are battery powered. Failure of one node may affect the entire network for the reason that nodes involved not only in data communication but also in forwarding data on behalf of other. If a node runs out of energy the probability of network partitioning will be increased. Thus routing in mobile ad hoc network should be in such a way that it consider to use the remaining battery power in an efficient way with stability and traffic load to increase the life time of the ad hoc network. To bring about the goal in receipt of longer lifetime for a network, we must minimizing nodes energy consumption not only during active communication but also when nodes are in inactive state. There are two approaches to minimize the active communication energy [1] as transmission power control and load balancing approaches and to minimize energy during inactive approach as sleep/power-down mode. The majority of energy efficient/energy aware routing protocols for ad hoc network try to reduce energy consumption. These protocols try either to route data through the path which minimize the end-to-end transmission energy for packets [2]. The aim of energy-aware routing protocols is to reduce energy consumption in transmission of packets between source and destination. In recent years most of the research work in this field is based on the constant transmission power model, so, nodes transmitting the data with constant power which improves network performance by reducing the number of forwarding nodes. Conversely, it results in interference and decreases network lifetime. Only very few works in which they used variant power model but route selection is not based on stability, energy and load factors in unified way. In this paper, we have designed variable range energy aware dynamic source routing in which the route selection is based on stability, energy and load factors in unified way, so we are able to select the route which is more stable, energy efficient. We minimize route reply by sending RREP to only two RREQs which have maximum path selection factor values due to this we are able to reduced number of route reply. In this approach, nodes are transmitting message with variant transmission power control approach so the transmission power dynamically tuned as per nodes distances i.e. hop-by-hop power control. Calculation of required power to transmit packet to next hop in the path has done at each node with help of GPS. In this paper first of all We describes the analytical models of stability, energy, variant power model and traffic load after that we presents algorithms for the modified route discovery process and route maintenance process. This protocol reduces the total energy expenditure in the network and thus maximizes the life time of the network. Our simulation studies show that the proposed modified protocols are more efficient than the existing one. The rest of the paper is organized as in section 2 presents literature review we review the conventional DSR protocol and other relented works, section 3 presents different models used in our proposed approach. Section 4 presents design and implementation of VREA- DSR in NS-2; simulation results and analysis is presented in section 5, finally we provide conclusion in section 6. 106
  • 3. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 – 6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEII. RELATED WORKS Since routing is a most important and significant energy-consuming activity in ad hoc networks, more research attention has been committed for designing energy-efficient routing protocols. In this paper we describe the various research efforts done in the area of power- aware routing protocols. This routing protocol based on global information was proposed on [3], such as data generation rate or power level information of all nodes (node costs), may not be convenient because each node is provided with only the local information like distance between nodes and other. The authors assumed that the power needed for transmission and reception is a α linear function of d where d is distance between the two adjacent nodes and α constraint that depends on the physical environment. The optimal route selection, node evaluates and compares the power expenditure of each path candidate. Power utilization of the direct α transmission, p(d), can be calculated if the distance is known, i.e., p(d)=a d + c, where a and c are constants, d is the distance between two nodes and α is 2. The authors make used of GPS to get location information to transmit packets with the minimum necessary transmit energy. The key requirement of this technique is that relative positions of nodes are known to all nodes in the MANET. However, this information may not be readily available. Variable Range DSR [1][3] the use of variable range transmission for packet transmission, it improved the drawback of general range transmission in terms of energy used. Author has used DSR for our experimentation. Energy efficient design of the protocol can be generated using the variable transmission range. The modifications in the MAC layer are done, as it is major part of controlling the different parameters of network behavior. Author has analyzed the impact of variable-range transmission power control on the energy savings of wireless multi-hop networks. A power control technique affects the physical layer performance. The choose of the high transmission range reduces the number of forwarding nodes needed to reach the destination, but creates large interference. Due to this we can reduces the transmission range demands more number of forwarding nodes but energy utilization is less. The assessment of different parameters for the network is done for both the protocols. Range is an important necessity for any RF application. This modified protocol show the improvement in number of active nodes, network lifetime is due to variable range transmitter power adjustment done at every node before transferring the data. This makes effective utilization of different nodes in the network. In this modification not considers the path selection on the basis of the energy aware and other factors. The DSR protocol [4][5] belongs to the class of reactive protocols and allows nodes to dynamically discover a route across multiple network hops to any destination. Dynamic source routing means that each packet in its header carries the complete ordered list of nodes through which the packet needed to pass. DSR uses no periodic routing messages, due to this we are reducing network bandwidth and delay overhead, conserving battery power and avoiding large routing updates throughout the ad-hoc network. Instead DSR relies on support from the MAC layer (the MAC layer should inform the routing protocol about link failures). The DSR protocol [6] is designed primarily for mobile ad hoc networks of up to about two hundred nodes and is designed to work well even with very high rates of mobility, when number of nodes is increasing its performance detonated very fast. It has two main phases as route discovery and route maintenance, which work collectively to allow nodes to determine and maintain routes to random destinations in the ad hoc network. Route reply would only be generated when the message has reached the projected destination node. To return the route reply, the target node must have a route to the source node. If the desired route is in the destination nodes route cache, the path would be used otherwise, the node will reverse the 107
  • 4. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEpath based on the path record in the route reply message header (this requires that all links aresymmetric). In case of communication error, the route maintenance phase is initiated wherebythe route error packets are generated at a node. The erroneous hop will be removed from thenodes route cache; all routes containing the hop are condensed at that point. Again, the routediscovery phase is initiated to establish the most feasible route. The major difference betweenthis and the other on-demand routing protocols is that it is beacon-less and hence does notneed periodic hello packet (beacon) transmissions, which are used by a node to inform itsneighbors of its existence. The fundamental approach of this protocol, during the routecreation stage is to establish a route by flooding route request packets in the network. Thedestination node, on in receipt of a route request packet, responds by convey a route replypacket back to the source, which carries the route traversed by the route request packetreceived. Dynamic Source Routing (DSR) [4][6] protocol is a milestone in this development but ithas various shortcomings like • The route cache used without their validity checks which degrade the performance if invalid cache tried to use. • This protocol performs well in static and low-mobility environments, as well as when number of nodes not more than two hundred; the performance decreases quickly with increasing mobility. • DSR is not energy efficient as mobile nodes have limited power supply and energy efficient protocols are essential for routing in MANETs so proper modification of DSR is required. • DSR does not consider the energy efficiency in route discovery. When multiple routes then DSR select the route on basis of minimum hop count which could result poor route selection. • It used constant transmission power for transmission of packets, nodes transmits information with constant power which increases interference of the signals. In [7][8] geographic routing algorithms are a promising candidate for large-scalewireless ad hoc networks. It takes advantage of the location information of the nodes are thevery valuable for wireless networks. In geographic routing protocols every node is aware ofits own position in the network; via mechanisms like GPS or distributed localization schemes.This can save a lot of protocol overhead and consequently, energy of the nodes. The mostsignificant difference between MANETs and traditional networks is the energy constraint.However, the majority of geographic routing algorithms take the shortest local path, depletingthe energy of nodes on that path easily. Thus, Energy efficient geographic routing techniquesplay a significant role in saving the energy consumption of the network. Link stability based routing [1][9] where nodes should keep an up-to-date informationabout link status. In prediction-based link availability estimation algorithm is used to developa metric for path selection in terms of path reliability, which is improving the networkperformance. The dynamic nature of MANETs leads difficulty in maintaining the precise linkstate information. Main causes of path breakage, due to node’s mobility and or powerdepletion of the mobile hosts. The mobility factor and energy factor to calculate the linkstability metric as Link Stability Degree (LSD) is defined as LSD = Mobility factor / Energy factorIt means that the degree of the stability of the link depends on the value of LSD. Higher thevalue of LSD, higher is the stability of the link and greater is the duration of its existence. Weight Based DSR (WBDSR) [10] is enrichment to the existing DSR protocol.Node’s weight is computed on the basis of stability and battery backup. Battery backup is themain constraint to improve energy efficiency in DSR protocol. WBDSR improves the 108
  • 5. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEstability of nodes because on receiving RREQ all nodes calculates their node weight andadded to their battery life and stability in header of RREQ and before further broadcastingand at every intermediate node this process is repeated. When RREQ reached to destinationnode it waits for a small predefined time t for additional route requests. After that destinationnode computes minimum of node weight among all nodes all received route requests thensend RREP to maximum route weight of the path. As insertion of own weight value by allnode to route request packet, the packet size increases fast which causes overhead to eachintermediate node and if the route has several intermediate nodes then overhead becomessevere. Minimum total power routing (MTPR): Various power aware routing proposals forMANETs are investigated in [11]. MTPR is one of the routing proposals belong to thiscategory tries to minimize the total transmission power consumption of nodes participating inan acquired route. The main goal of this routing protocol is to minimize the totaltransmission power for route R. But in route selection process it does not consider the energylevel of the mobile node battery source during energy efficient route computation. Thisapproach may select the route that includes one or more mobile node with smallest amountenergy level Minimum Battery Cost Routing (MBCR) protocol [12] used battery power always byusing a cost function which is inversely comparative to residual battery power. The route isdefined on the basis of sum of costs of nodes that are the major components. The routeselection is based on the minimum total cost. MCBR protocol can expand the networklifetime due to selection of route whose nodes have high enduring battery power. The maindrawback of MCBR is that it may select a rather short path containing mostly nodes withhigh enduring battery capacity but also a few nodes with lower remaining battery capacity.The cost of this routing solution may be lower than that of a path with a large number ofnodes all having medium level of remaining battery capacity. Although, the previous routingsolution is in general less desirable from the network extended existence point of view sincesuch a path will become disconnected as soon as the extremely first node on that path dies. Minimum Energy Routing (MER) [13] protocol includes the power levels that shouldbe used by all intermediate nodes. Processing of these levels done during initial phase whenall receiving intermediate node calculates the required power from the knowledge of transmitpower and received power. MER protocol has eight options, few in firmware and others areimplemented in software. Min-Max Battery Cost Routing (MMBCR) protocol [11] considers the residualbattery power capacity of nodes as the metric in order to make longer the lifetime of nodes.Let ci(t) be the battery capacity of host ni at time t. We can define fi(t) as a battery costfunction of host ni. The smaller amount capacity it has, the more reluctant it is to forwardpackets; the proposed value is: fi(t) = 1/ci(t). It selects the route with the minimum path costamong possible routes. Because this metric takes into account the remaining energy level ofindividual nodes instead of the total energy, the energy of all nodes can be regularly used.The limitation of this algorithm is that since there is no guarantee that paths with theminimum hop-count or with the minimum total power are selected. The minimization of energy consumption of mobile nodes try to adjust thetransmission power of wireless nodes [14][15]. Finding the energy efficient (min-power)route [16] and to finding the least cost path in the weighted graph and power aware localizedrouting [3] protocols of this category. The main concept, to balance the energy consumptionby avoiding low energy nodes when selecting a route. The minimum energy routing schemeis not only to provide energy efficient routes [2][17] but also to formulate the given routeenergy efficient by adjusting the transmission power just enough to reach to the next hopnode. The smallest common power (COMPOW) protocol [11] shows a straightforward 109
  • 6. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 – 6375(Online) Volume 4, Issue 1, January- February (2013), © IAEME solution to maintain bi-directionality between whichever pair of communicating nodes in a MANET. Other articles tend to efficiently manage a sleep state for the nodes: various solutions range from pure MAC-layer solutions (power management of 802.11) few more solutions with combining MAC and routing techniques [8]. There are many other proposals based an energy efficient routing protocol which are capable of routing data over the network and of saving the battery power of mobile nodes [12][18]. And also some proposals aim to add energy-aware functionalities to existing DSR protocols [19]20]. Energy aware protocols of ad hoc networks nodes are defined as data delivered in one hop to the total energy expended in multi-hop. Overall minimizing energy consumption is an significant challenge in multi-hop ad hoc networking. The related study [21][22] shows that energy efficient/energy aware routing all these protocols have improvement over existing protocols in energy point of view. Our motivation to consider as one of the important design objectives to minimize network breakage means that extend the life of network. A. Problem Identification Lot of research has been conducted in current years to build up different approaches to convey energy efficient routing in MANETs. Many improvements to existing DSR have been discussed, and observed that these approaches make them energy efficient but they have limitations also. Few limitations are as follows: • In DSR protocol, the RREP send through all the available route large number of unnecessary route replies leading to waste of energy. This protocol has not considered energy efficiency in their path selection and routing of the packets. • If there is any error due to depletion of node leads to link broken then nodes inform to source, now source send remaining packets by route available in their route cache, but this route may not be valid more, then route discovery initiated hence consume more energy and increase the packet delay time. • The protocol weight based DSR used battery power and stability of node to compute node weight each node insert its node weight in route request packet which results packet size keeps increasing very fast, if route have many intermediate nodes then overhead becomes ruthless. • Many more energy based modifications of DSR routing protocols have taken energy based different metrics, but to the best of my knowledge there is know any work which considered stability, energy efficiency and traffic load as well as variant transmission power model. All these routing protocols are assuming that all of the nodes in MANETs are battery powered. Energy efficient routing approaches play a major role in saving the energy consumption of the network. This motivated us for the search of new innovative approaches. Thus, we have proposed a new energy aware dynamic source routing protocol, which used variant transmission power model instead of fixed-transmit power as used in DSR and path selection is based on stability, energy and traffic load. In next section, first we have discuss stability model, energy consumption model, variant transmission power control and traffic load model after this we describe working of our proposed protocol.III. PROPOSED WORK As we discussed in related work that maximum work done to minimize the flooding in route discovery, or energy base route discovery, or in route maintenance or other metric but to the best of my knowledge there is no any work which considered stability factor, energy factor and traffic load factor all these three factor at a time as well as variant 110
  • 7. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEtransmission power model for transmitting packet. Our proposed energy aware design ofDSR protocol has modified route discovery, route maintenance and packet transmissionstrategies in energy efficient way. This protocol used variable transmission power model totransmit packet. The modifications in the MAC layer are also done, as it is main part of controlling thevarious parameters of network activities. In this work, nodes are transmitting message withvariant transmission power control approach so the transmission power dynamically tuned asper nodes distances i.e. hop-by-hop power control. Range is a significant requirement for anyRF application. Long range is achieved through larger receiver understanding. The bestreceiver understanding is desirable as it lowers the power requirement allowing recognitionof weaker signals and can increase the transmission range. Calculation of required power totransmit packet to next hop in the path has done at each node with help of GPS. This protocolreduces the total energy expenditure in the network and thus maximizes the life time of thenetwork. Simulation studies show that the proposed modified protocols are more efficientthan the existing one A. Network Model We model an ad hoc network by a directed graph G = (N, E). N is the set of mobile ∈ ∈devices and |N | = n. For i, j N, (i, j) E means that i is in the communication range of j(but not necessarily vice versa). We assume that the network G is unknown, meaning that thenodes do not have any knowledge about the nodes that can receive their messages, nor thenumber of nodes from which they can receive messages by themselves. This assumption ishelpful since in a lot of applications the graph G is not fixed because the mobile agents canmove around (which will results in a changing communication structure). We analyze energycost function to the network layer and center of attention on routing algorithms. We discusshow the error rate related with a link affects the overall probability of reliable delivery, andconsequently the energy allied with the reliable transmission of a single packet. For anyparticular link (i, j) between a transmitting node i and a receiving node j, let Pi, j denote thetransmission power.B. Stability Model Link stability is always very augmenting problem of the mobile ad-hoc network. Thestability of a link [16] is given by its probability to persist for a certain time span, which isnot necessarily linked with its probability to reach a very high age. Stable path selection isvery fundamental criteria when we are talking about routing. The stability of the constitutinglinks, because the break of any link will lead to the break of the whole path. Thus, linkstability is anticipated to be obtained before the determination of path stability. If relative position of node with its neighborhood doesn’t changes frequently then this is saidto be stable. Stability factor of node k is defined as follows.Stability S fk = ((total numberof neighbor s node) t −t1 − (number of absent nodes) t ) (1) (total numberof neighbor s node) t −t1 where Sfk is the stability factor of node k, t is the current time and (t – t1) is the time before t.C. Energy Model Energy aware communication in MANETs is needed to improve lifetime of thenetwork. Thus, we calculate the energy factor in view of residual energy of the node k atparticular instance [23]. The main steps of energy consumption during packet transmissionare as follows a) transmit, b) receive, c) idle, and d) sleep. The major sources of energywastage in MAC as collision, message overhearing, cost of control packet and idle listening. 111
  • 8. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMENodes battery level affects the transmission range consequently we have to consider nodescurrently available energy to choose the optimal route. Energy factor of the node k iscalculated as the remaining energy of node k at instance is divided by total initial energy ofnode k and remaining energy of node k considered as total initial energy of node k minusenergy consumed by node k. The energy consumption of node k is addition of energyconsumed when node k is in idle mode, energy consumed when node k is in active mode,energy consumed when node k is in sleep mode and energy consumed when node k is intransient mode. The values of power consumption measurements in a wireless ad hocnetwork interface are selected IEEE 802.11 interfaces (2.4GHz). The energy dissipated intransmitting (Etransmit) or receiving (Ereceived) in one packet can be calculated as follows: Etransmit = Ptransmit × TD Erecieved = Preceived × TDwhere TD denote the transmission duration of the packet.On the basis of energy and stability of node, we calculate factor of energy with stability, andthen we calculated minimum energy stability factor (ESf ) of the path. ESfk= Efk + Sfk (2) ESfsdi = Min {ESf1, ESf2, ESf3, ESf5,----, ESfNsdi} where ESfsdi : Minimum value of the energy factor and stability factor of ith path Nsdi : Set of node on ith path from source s to destination d ESf1, ESf2, ESf3,ESf5,-----, ESfNsdi : nodes energy factor of ith pathD. Variant Transmission Power Model Designing a variable-range transmission power control algorithm is more appropriateto the needs of these promising wireless ad hoc networks to determine the appropriate packettransmission energy at each node in a path through which communication packet can betransmitted in more energy efficient. Changing from existing a common-range transmissionpower design to a variable-range transmission power design is difficult in straight forwardtransition, and in numerous cases requires a considerable re-design of the operation of thesystem in order to increase enhanced power-conserving performance over existing systems.We have used variable-range transmission power control to improve the overall performanceof wireless ad hoc networks. We considered that the coordinates are known by GPS at eachnode and correspondingly known distances between nodes and then calculate desired powerto transmit packet. At every node in a path calculated transmission power for transition ofpackets and stored in their cache if any change occurs correspondingly updated their cache.We assumed that all packets are of a fixed size, Ei, j energy involved in a packet transmissionover link (i, j) is simply a fixed multiple of Pi, j. There are two factors: attenuation due to themedium, and interference with ambient noise at the receiver which affected to any signaltransmitted. The attenuation is relative to Dα, where D is the distance between the receiver jand the transmitter i. The bit error rate associated with a particular link is essentially afunction of the ratio of the received signal power to the ambient noise. In the constant-powermodel, Pi, j is independent of the characteristics of the link (i, j) and is a constant. In this case,a receiver situated further away from a transmitter will suffer greater signal attenuation(proportional to Dα) and will, accordingly, be subject to a larger bit-error rate. In the variable-power model, a transmitter node adjusts Pi, j to ensure that the strength of the (attenuated)signal received by the receiver is independent of D and is above a certain threshold level Th.The minimum transmission power associated with a link of distance D in the variable-powermodel is Pm = Th × γ ×Dα, where γ is a constant and α is the coefficient of channel attenuation(2≤ α ≤ 6). Since Th is usually a technology-specific constant and considered α =4, we cansee that the minimum transmission energy over such a link (i, j) varies as Em(D) Dα . ∝ 112
  • 9. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEE. Traffic Load Model The traffic load balance [23][24] also play major role in enhancing the network life.As node in the high traffic load path will die off faster in comparison with nodes in the paththat have lower traffic load. So traffic load aware routing provides not only a smaller end -to-end delay, but also improve energy efficiency by efficient energy distribution of routing. Thenetwork interface queue, a packet being transmitted could be queued in a variety of ways.For example, outgoing packets from the network protocol stack might be queued at the linklayer, before transmission by the network interface. The network interface might alsoprovide a retransmission mechanism for packets, such as occurs in IEEE 802.11; the DSRprotocol, as part of Route Maintenance, requires limited buffering of packets alreadytransmitted for which the reach ability of the next-hop destination has not yet beendetermined. The Network Interface Queue of a node implementing DSR is an output queue ofpackets from the network protocol stack waiting to be transmitted by the network interface;this queue is used to hold packets while the network interface is in the process of transmittinganother packet. The default queue size is 50 packets.Traffic load factor is defined as follows: Lfk = Qpk/ Qtk (3) Qpk = Qtk - Qrk (4) whereQrk : Remaining network interface queue size of node k at instanceQtk : Initially full interface queue size of node kQpk : At instance number of data packets in interface queue of node kLfk : Traffic load factor of node kNow, traffic load factor of the ith route is calculated as follows: ∑ L fk k∈N sdi L fsdi = (5) N sdi + 1 whereNsdi : Set of node on ith path from source s to destination dNsdi + 1 : Number of nodes in ith path Percentage of network interface queue that is occupied capacity of the node at theinstance as in section 3.4. The default maximum size of network interface queue is 50. Lfsdiindicated the traffic load of ith path from source s to destination d that is occupied capacity ofnetwork interface queue. The higher value of the Lfsdi indicates that route has maximumtraffic means congested route, such paths should avoided to choose because it leads to higherpacket loss and longer delay. We will choose the path which has lower Lfsdi value. Theintegrated model is the combination of all three the energy factor, traffic load factor andStability factor. So, these factors use to calculate path selection factor is as follows: ES fsdi Pfsdi = (6) L fsdiThe route will be selected with highest Pfsdi value for the data transmission.F. Energy Aware Route Discovery Process Route discovery process is desired when a source node S wishing to send a packet toa destination node D, then source node see their route cache if route found, send validationmessage and stat timer, if ACK received in before timer expire then node can send the packetwith this path, otherwise source node start route discovery process, required to discover theenergy efficient path. Using VREA-DSR obtains an energy, load and stability aware path 113
  • 10. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEfrom source route to destination. The process of energy aware route discovery is entirely ondemand. Energy aware route discovery procedure used a route request (RREQ) and routereply (RREP) messages, to find a route from source to destination. When several sourcenodes originates a new packet addressed to some destination node, the source node places inthe header of the packet a source route giving the sequence of hops along with the stable,energy efficient and load balanced route at which the packet is transmitted for each hop.Using GPS model to know the coordinates of each other’s nodes thus node calculate distancebetween nodes and corresponding desired transmit power as in section 3.4 so that receivercan receive it.Algorithm 1: Route Discovery Process in VREA-DSRStep 1: Source node have packet to send, check route cacheIf (route to D is found) {prepare route validation message send to path mentioned in route cache and start timerIf (ACK arrived before timer expires) { Send data packet by this path }}Else{Prepare RREQ message, initialize SEf = (Sf = Maximum value (i.e. 1) + Ef = Maximum value(i.e. 1)) = 2; Lf = 0 and transmission power and append these value to RREQ headerthen broadcast to their neighbor. }Step 2: If (power of node < α && Neighbor ≠ Destination){Discard RREQ packet}Else if (power of node ≤ || ≥ α && Neighbor = Destination){ If ( it is first root request ) {calculate Pf1 and store into RREQ table and node waits for ∆ t time formore RREQ;}Else if ( it is next RREQ && time < ∆ t time){ calculate Pf2 Pf3, Pf4,...,Pfn and also stored in RREQ table;}Else if (more than two RREQ && time = ∆ t time){See RREQ table and compare RREQ’s Pf’s value; destination sendRREP packet with these two RREQ paths which have highest and nexthighest Pf values (means main path and alternate path)} Else if (less than or equal to two RREQ && time ≤ ∆ t time) { 114
  • 11. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEME Destination send RREP packet with these two RREQ paths (means main path and alternate path) } else { No update; } }Step3: Else (power of node ≥ α && Neighbor ≠ Destination){ Neighbor’s node extract values RREQ header and calculate ESf = (Sf + Ef ) and Lf calculate average value of Lf with nodes values of Lf, calculate transmission power; If (node’s ESf < header’s ESf ) { Replace hedader’s ESf = node’s ESf ; add values of ESf, Lf , and transmission power in header’s field of, ESf , Lf; and power and broadcast RREQ to their neighbor.} Else { No change in header’s value of ESf and replace header’s Lf with calculated average value of Lf and broadcast RREQ to their neighbor.}} Where Pf1 : Path factor of first RREQ message at particular instance Pf2 : Path factor of second RREQ message at particular instancePfn : Path factor of nth RREQ message at particular instanceAlgorithm 2: Route Maintenance Process in EA-DSRStep 1: Source node sends data to destination node with the main path;if (any node in route have ERR message){Node send back RERR message to source node;}Step2: When source node received RERR message, check the alternate route in route cache;if (alternate route found in route cache){Send route validation message by alternate path mentioned in the route cache and start timer;if ( ACK received before timer expires){Source send remaining data packet by this alternate path;}else{ Source initiate new route discovery;}} Modification of existing DSR header, we adds three more field in reserved field of basicDSR header. We describe the packet structures for VREA-DSR and discuss the changes ineach packet option below. 115
  • 12. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 – 6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEIV. DESIGN AND IMPLEMENTATION OF VREA-DSR In this section first we design packet structure as route request packet, route reply packet, acknowledgement packet etc. and then provide ns-2 implementation details. A. Design of Packet Structure for VREA-DSR Route Request (RREQ) Packet: The receiving node of RREQ must compute the stability factor Sfk with energy factor Efk, and traffic load factor Lfk of node k for this hop node according to stated three equations (1), (2) and (5). Table I shows the RREQ packet format in VREA-DSR, by which efficient route will be selected; the path selection factor. Table I: Route Request Packet Format in VREA-DSR IP DSR DSR Request ESf Lf DSR Header Fixed Route Address. Source Header Request [Src,1,......., Power to Header N,dest] Pwr1… to PwrN Route Reply Packet: The reply paths based on energy, stability and traffic load in unified way included path and alternate path in the new route reply packet format. As discussed in section 3.5 and 3.6, the RREPs are forwarded to the next hop defined on the source route addresses [Src, 1…N, dest]. The source route for RREP is the reverse of source route of the RREQ. Hence, the destination node reverses the source route of RREQ with maximum value of path factor and also route reply to next maximum valued of path factor as alternate path to source route of RREP. The table II shows the format of RREP packet that includes the energy aware information for implementation of VREA-DSR. Table II: Route Reply Packet format in VREA-DSR Data Packet Format: IP DSR DSR DSR DSR DSR Header Fixed Route source Reply Source Header Reply Route Addresses Power Header Header [Src,1..N, Dest] Pwr1… to… PwrN The power Pt value required that the packet is actually transmitted on the link. The power Pt value considered to on the basis of distance of the link, a node chooses to change the transmit power dynamically for hop i. Table III shows the data packet format for VREA-DSR includes the DSR fields besides the special fields of VREA-DSR. Table III: Data Packet Format in VREA-DSR IP DSR DSR DSR DSR DSR Data Header Fixed Route Source Reply Source Header Header Route Addr. Power Addr. [Src,1.. Pwr1…to [Src,1 N, Dest] PwrN …N, Dest] ACK Packet Format: The Acknowledgement option in a DSR Options header is encoded as in order to allow nodes that have lost flow state to determine the previous hop, the address of the preceding hop can optionally be stored in the Acknowledgement Request as given in table IV. This extension used when a Source Route option is present, MAY be used when flow state routing is used without a Source Route option, and SHOULD be used before Route Maintenance determines that the next-hop destination is unreachable. 116
  • 13. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEME Table IV: ACK Packet Format in VREA-DSR IP DSR DSR Header Fixed Header Route HeaderRoute Error packet: These packets are generated at a node when the link-layer reports abroken link at some stage in a data-packet transmission. When a node is unable to validatereach ability of a next-hop node. It should send a Route Error to the source node of thepacket. When a node receives a packet containing a Route Error option, then that node mustremove from its route cache all the intermediate node repeat the same process, when RERRmessage reach to source node check their route cache, is route to destination found, sourcesend route validation message to destination, and if received ACK of route validationmessage received in time. Source sends remaining packets to destination with this path.Otherwise, source initiates a new route discovery process to find new route to communicateremaining packets. The route error packet format as given in table V. Table V: Route Error Packet format in VREA-DSR IP DSR DSR Unreachable DSR DSR Header Fixed Route Node Source Source Header Error Address Route Route Header Header Addresses [Src,1…N, dest]B. Implementation of VREA-DSR in NS-2 This section presents the precise implementation of VREA-DSR intended for the proposedsolutions. Our proposed solutions are anticipated to make longer the lifetime of the network andnodes. In this section we discussed the main function which required for implementing our proposedprotocol. The DSR, MAC, COMMON and QUEUE folders of NS-2.34 have been modified toimplement VREA-DSR. Most of the works have been done on modification of existing DSR programfiles. The required changes made to existing DSR are to implement VREA-DSR in NS-2. Details ofthe implementations of existing DSR protocol in NS-2 can be found in the documentation [17][25]. Inthis section we present the changes made on existing DSR protocol for implementation of VREA-DSR. Many C++ program files of existing DSR are modified in order to implement the desiredfeatures of VREA-DSR in the NS-2 simulator. In addition to the DSR program files folder, furthersupportive files folders are also modified like MAC, COMMON and QEUEU. Here are the modifiedprograms files of DSR protocol are as follows: We have implemented required modification in and dsragent.h and define other DSRrouting protocol in NS-2. The is prepared in to functions. The functions are designedbased on their objective on routing activity. These implementations starts by incorporating thecomputation of the ESf, Lf, and Pf (equations 2, 5 and 6) in handleCost(SRPacket &p) function HandlePacketReceipt and handleRouteRequest functions are modified to implementenergy aware route reque and route reply (in section 3.6) respectively. Existing ignoreRouteRequestpfunction of DSR discards the copy of RREQ. In VREA-DSR, the function is modified to receivemultiple copies of RREQs. HandleRouteRequest function to decide to route reply on the basis of pathselection factor Pf route reply to RREQs in which Pf values maximum and next maximum, but replyto maximum value of Pf RREQ with both main and alternate routes. replyFromRouteCache isreplaced by VREAreplyFromCache in this process we added to test its validity before we can use pathlies in their route cache. This function uncast the route request to the destination rather than reply theroute from cache to initiator of the request. VREADSR route reply send to only first two route requestnot to all route request to minimize huge route reply to destination. Delay forwarding is handled bythe timer driven function. File dsragent.c is included this function with function name of rreq_purge.The route is maintained during data communication, the destination node of the data must reply to thesource node. The DSR source route format is modified to handle power, stability aware and loadbalanced information of VREA-DSR (section 3.4). In addition to the above source files, other sourcefiles are also modified. 117
  • 14. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEB.1 Changes made to other common folders to implement VREA-DSR This COMMON folder includes a number of source files. packet-stamp.h is one of the mostimportant source file in COMMON folder. It defines the information which is embossed with thepacket. The sender node must trample vital information for VREA-DSR on the packet. Thisinformation includes its node’s stability, residual batteryenergy, and traffic load i.e. is queue length.The receiver node has to extract this information from the packet for further processes. The packet.hfile defined the packet structure. The packet structure contains headers and data energy, and trafficload i.e. is queue length. The receiver node has to extract this information from the packet for furtherprocesses. The packet.h file defined the packet structure. The packet structure contains headers anddata. The struct hdr_cmn is one of the general headers on the packet structure and this header isaccessed by every layers. structure. The packet structure contains headers and data. The structhdr_cmn is one of the general headers on the packet structure and this header is accessed by everylayers. Therefore, this is used to swap over information between the layers. In VREA-DSR protocol,the remaining battery energy of receiver node is used for link cost computation on the network layer.The physical layer should send the remaining energy of the node to the network layer using hdr_cmn.These are many more mains modifications made to implement VREA-DSR in NS-2 simulator.V. SIMULATION RESULTS AND ANALYSIS An energy model is presented, based on 802.11, which considers different radio states; theperformance of network protocols [17][25] is agreed using network simulators ns-2. This approach iscomputing more correct the energy consumption for Ad-Hoc network protocols. The advantages ofthis particular energy models (802.11 DCF (Distributed Coordination Function) and SMAC) are theconsideration of all the possible radio states and that the simulator can calculate the energyautomatically irrespective of the stack the protocol at particular layer designer is working. In thispaper we use Network Simulator 2 version 2.34 [17][26] to perform comparison between VREA-DSR and DSR protocols. NS2 is one of most popular network simulator tools worldwide. The NS2was installed under Fedora 10.0 as a simulation platform. The simulation scene was for 1000 × 800m2 rectangular region with movement speed 1 m/s to 5 m/s. The simulation parameters are defined asgive in table VI transmission range is assumed to be 250m, the number of CBR source nodes varies 3-16 according to size of networks and nodes are selected randomly as CBR sources and the packet sizeis fixed at 512 bytes. In order to have performance result, we used 10 to 100 nodes on the simulation.We run several simulations and distinguish the results to two protocols, DSR and SELA-DSR, toverify the superiority of the VREA-DSR protocol. Table V1: Simulation Environment Parameters MAC layer type IEEE80.11 Reception queue length 50 Radio propagation model TwoRayGround Transmission power (txPower) 1.4W Reception power (rxPower) 1.0W Idle power 0.53W Sleep power 0.13W Initial energy 1000Jules Transmission range 250 mtr. Packet size 512 bytes Channel Capacity 2Mbps Frequency 2.4 Ghz Transmitted signal power 0.2818 W Packet generation rate 2 packets/second, 4p/s Area - Environment Size 1000m x 800m Number of nodes 10 - 100 Simulation time 600 seconds 118
  • 15. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEExperimental result as shown in Figure 1. that energy consumption of each protocol on variation ofthe number of nodes in the networks. The nodes variation in the networks is 10 to 100, and number ofCBR sources varies from 3 to 20 according to size networks. As considered each node initial energy isset to 1000J. The average energy consumption increases in each protocol when number of nodesincreases although VREA-DSR consumes less energy than SELA-DSR and DSR due variable rangetransmission control. Figure 1: Energy Consumption verses number of nodes in the network Figure 2: Packet delivery ratio verses number of CBR connections The packet delivery ratio (PDR) is the number of packets received by the destination to the numberof packets transmitted by the source is shown in Figure 2. PDR reduces when increases the CBRconnections. It is considering 100 nodes scenario and observed that the VREA-DSR maintains a betterpacket delivery ratio than the existing DSR and stability energy and traffic load aware DSR (SELA-DSR). Figure 3: Energy consumption per packet versus maximum speed of the node 119
  • 16. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEIn Figure 3 the simulation results are shows that VREA-DSR protocol performs the best interms of energy consumption per packet. As expected DSR performs the worst in terms ofenergy consumption. As its path could not select on the basis of mobility or minimum energyconsumption. This is confirmed by the simulation results that as speed of node increases thenenergy consumption per packet also increases in all protocols but in VREA-DSR performbetter than other two protocols.In Figure 4, node alive count shows improvement for variable range energy aware dynamicsource routing (VREA-DSR) over SELA-DSR and DSR for duration of simulation. As thetransmitted power is dynamically adjusted according to distance in our VREA-DSR protocol,it will successfully use available node energy increasing the Number of nodes alive. Figure 4: Number of node alive verses simulation time in seconds Figure 5: Network lifetime versus number of CBR connectionsThe metric network lifetime used to analyze the network partitions, 100 nodes are consideredfor this scenario. Figure 5 shows the network lifetime decreases when we increase thenumber of CBR connection. The network lifetime of basic DSR protocol is very less ascompared to two other energy aware protocols. The Network lifetime of VREA-DSR is betterthan SELA-DSR and DSR due to the following main reasons. First, VREA-DSR implementsthe variable range transmission power control which saves energy consumption. Second,VREA-DSR selects the routes in which nodes have more energy and stability than otherpaths. The minimum transmit power route reduces the over all energy consumption of thenetwork and minimize interference also. 120
  • 17. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 – 6375(Online) Volume 4, Issue 1, January- February (2013), © IAEMEVI. CONCLUSION It is significant to design energy efficient routing protocols for mobile ad hoc networks. On the other hand, without a cautious design, an energy efficient routing protocol might have much worse performance than an ordinary routing protocol. It is observed that the use of variable range transmission power control overcomes the drawback of common range transmission power control in terms of energy consumption and improves network lifetime. The node alive count shows improvement for variable range energy aware dynamic source routing (VREA-DSR) over SELA-DSR and DSR due to transmitted power is dynamically adjusted according to distance in our VREA-DSR protocol; it will successfully use available node energy increasing the number of alive nodes. Also, our VREA-DSR protocols show improvement over SELA-DSR and basic DSR as in packet delivery ratio, and energy consumption.VII. REFERENCES [1] Khalid Zahedi, Abdul Samad Ismail, “Route Maintenance Approach for Link Breakage Predicttion in Mobile Ad Hoc Networks”, International Journal of Advanced Computer Science and Applications (IJACSA), Vol. 2, No. 10, 2011. [2] Radhika D. Joshi and Priti P. Rege, “Performance Evaluation and Simulation based Modeling of Energy Aware Variable Range DSR (VRDSR) Protocol”, International Journal of Computer Science and Communication Vol. 2, No. 2, pp. 565-575, July-December 2011. [3] Stojmenovic I, Lin X. “Power-Aware Localized Routing in Wireless Networks”, IEEE Trans. Parallel and Distributed Systems; 12(11):1122-1133, 2001. [4] David B. Johnson and David A. Maltz, “Dynamic Source Routing in Ad-hoc Wireless Network,” The Kluwer International Series in Engineering and Computer Science, Volume 353, 153-181, DOI: 10.1007/978-0-585-29603-6_5, 1996. [5] D. Johnson, Y. Hu and D. Maltz, “The dynamic source routing protocol for mobile ad hoc networks”, INTERNET-DRAFT, draft-ietf-manet-dsr-03.txt, RFC 4728, February 2007. [6] Sangeeta Biswal, Suneeta Mohanty and Dambarudhar Seth, “Study of DSR Routing Protocol in Mobile Adhoc Network”, International Conference on Information and Network Technology, IACSIT Press, Singapore, IPCSIT vol.4, 2011 [7] Gang Wang and Guodong Wang, “An Energy Aware Geographic Routing Protocol for Mobile Ad Hoc Networks”, Int J Software informatics, Vol. 4, No. 2, pp. 183-196, June 2010. [8] Xu, Y.; Heidemann, J. & Estrin, D. (2001). “Geography-informed Energy Conservation for Ad Hoc Routing”, Proc. ACM Mobile Computer and Networking Conference, pp.70-84, July 2001. [9] Al-Akaidi M.; Alchaita, M., “Link stability and mobility in ad hoc wireless networks”, IET Communications, 1(2):173-178, April 2007. [10] Benamar KADRI, Mohammed FEHAM and Abdallah M’HAMED, “Weight based DSR for Mobile Ad Hoc Networks,” in 3rd International Conference on Information and Communication Technologies: From Theory to Applications (ICTTA 2008), pp. 1- 6, 7-11 April 2008. 121
  • 18. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEME [11] Narayanaswamy S, Kawadia V, Sreenivas RS, Kumar PR. “Power Control in Ad Hoc Networks: Theory, Architecture, Algorithm and Implementation of the COMPOW Protocol”, Proceedings of European Wireless 2002. [12] C.K. Toh, “Maximum battery life routing to support ubiquitous mobile computing in wireless adhoc networks”, Communications Magazine, IEEE, vol. 39, pp. 138-147, 2001. [13] Doshi S, Brown TX., “Minimum Energy Routing Schemes for a Wireless Ad Hoc Network”. Proceedings of the Conference on Computer Communications (IEEE Infocom 2002), 2002. [14] Xiaoying Zhang, Thomas Kunz, Li Li and Oliver Yang, “An Energy-efficient Broadcast Protocol in MANETs,” Communications Networks and Services Research Conference, Proceedings of the 8th Annual Communication Networks and Services Research Conference, Pages: 199-206 SBN: 978-0-7695-4041-2, 2010. [15] Cardei, M. ; Wu, J. & Yang S.’ “Topology Control in Ad hoc Wireless Networks with Hitch-hiking”, IEEE SECON 2004, October 2004. [16] Banerjee S, Misra A. “Minimum Energy Paths for Reliable Communication in Multi- hop WirelessNetworks”. Proceedings of Annual Workshop on Mobile Ad Hoc Networking & Computing (MobiHOC 2002), 2002. [17] NS-2, [18] Kim D. ; Garcia-Luna-Aceves, J. J. ; Obraczka, K. ; Cano, J. C. & Manzoni, P., “ Routing Mechanisms for Mobile Ad Hoc Networks Based on the Energy Drain Rate”, IEEE Transactions on Mobile Computing, Vol. 2, No. 2, pp. 161- 173, Jan. 2003. [19] Jinhua Zhu, X. Wang, “Model and Protocol for Energy Efficient Routing over Mobile Ad Hoc Networks,” to appear in IEEE Transactions on Mobile Computing (IEEE, TMC), 2011. [20] Luo, Y. ; Wang, J. & Chen, S. (2006), “An energy-efficient DSR routing protocol based on mobility prediction”, Proc. International Symposium on a World of Wireless, Mobile and Multimedia Networks, June 2006. [21] Ashwani Kush, Sunil Taneja and Divya Sharma, “Energy Efficient Routing for MANET”, published in IEEE, International Conference on Methods and Models in Computer Science (ICM2CS-2010), pp 112-116, 2010. [22] Tanu Preet Singh, Shivani Dua, and Vikrant Das, “Energy-Efficient Routing Protocols in Mobile Ad-Hoc Networks”, published in International Journal of Advanced Research in Computer Science and Software Engineering, Volume 2, Issue 1, ISSN: 2277 128X, January 2012. [23] Shiva Prakash, J.P. Saini, S.C. Gupta and Sandip Vijay, “SELADSR: Stability Energy and Load Aware Dynamic Source Routing Protocols of Mobile Ad hoc Networks”, [24] Sumit Kumar Singh, Shiva Prakash, Kapil Kumar, “Energy Aware Dynamic MANET On- demand (EA-DYMO)”, published in International Journal of Computer Applications, ISBN: 978-887, vol. 25, No. 11, pp. 12-16, July 2011. [25] Margi, C.B. Obraczka, K., “Instrumenting Network Simulators for Evaluating Energy Consumption in Power-Aware Ad-Hoc Network Protocols,” in proceedings of The IEEE Computer Societys 12th Annual International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunications Systems,.(MASCOTS 2004), 2004. 122
  • 19. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976-6367(Print), ISSN 0976 –6375(Online) Volume 4, Issue 1, January- February (2013), © IAEME [26] Trishla Sutaria, Imad Mahgoub, Ali Humos, Ahmed Badi, “Implementation of an Energy Model for JiST/SWANS Wireless Network Simulator”, Computer Science & Engineering Department, Florida Atlantic University. 22-28, April 2007. [27] Sunita Kushwaha, Bhavna Narain, Deepti Verma and Sanjay kumar, “Effect Of Scenario Environment On The Performance Of Manets Routing Protocol: AODV”, International journal of Computer Engineering & Technology (IJCET), Volume 2, Issue 1, 2011, pp. 33 - 38, Published by IAEME. [28] S. Kanimozhi Suguna and Dr.S.Uma Maheswari, “Comparative Analysis Of Bee-Ant Colony Optimized Routing (Bacor) With Existing Routing Protocols For Scalable Mobile Ad Hoc Networks (Manets)”, International journal of Computer Engineering & Technology (IJCET), Volume 3, Issue 1, 2012, pp. 232 - 240, Published by IAEME. [29] Dr. Suresh Kumar D S and Mahesh D.S, “Idle Node Real Time Power Saving Mac Layer Oriented Radom Routing In Wsn”, International journal of Computer Engineering & Technology (IJCET), Volume 3, Issue 2, 2012, pp. 470 - 477, Published by IAEME. [30] Mrs.R.Rajasree and Dr.G.Kalivarathan, “A Review On Routing Protocols And Non Uniformity With Wireless Sensor Networks”, International journal of Computer Engineering & Technology (IJCET), Volume 3, Issue 3, 2012, pp. 348 - 354, Published by IAEME. 123