The Comparative Study Some of Reactive and Proactive Routing Protocols in The Wireless Sensor Network

The wireless sensor network (WSN) consists mostly of a large number of nodes in a large area where not all nodes are directly connected. The applications of comprise a wide variety of scenarios.The mobile nodes are free to move because this network has selfــstructured topology. Routing protocols are responsible for detecting and maintaining paths in the network, and it classified into reactive (OnـــDemand), proactive (Table driven), and hybrid. In this paper represents a performance study of some WSN routing protocols: the Dynamic Source Routing (DSR), Ad hoc On-Demand Distance Vector (AODV), and Destination-Sequenced Distance-Vector (DSDV). The comparison made according to important metrics like packet delivery ratio (PDR), total packets dropped, Average end-to-end delay (Avg EED), and normalized routing load under the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) traffic connection and with varying number of nodes, pause time; and varying speed. In this work used (NSــ2.35) that installed on (Ubuntu 14.04) operating system to implementing the scenario. Conclude that the DSR has better performance in TCP connection; while the DSDV has better performance in UDP protocol.


I. Introduction
WSNs are a specific class of networks; which is consisting of a group of tiny, relatively cheap, low power, and multifunctional units called sensor nodes.WSN is an active and important research area due to its wide range applications.WSN's has been used in areas such as environmental, industrial, social, security and military surveillance areas because it is comfortable and easy to use in the personal and professional life (Abu Taleb et.al., 2013).WSNs are able to communicate with each other through their having wireless channel.Simultaneously, every node is capable of working as a source or sink (Bijan et.al., 2014).The sensor node consists of four basic units: the power unit; sensor unit; the processing unit and the transceiver unit.The sensor can connected to each other or directly to an external base station (BS).The sensor node component shown in Figure 1.That each sensor node includes power units, position finding system, processing, transmission, and sensing.In addition, the figure 1 presents the communication structure of the WSN; a sensor node are dispersed in sensor field.The nodes relate to sensing for the manufacture of better information about the physical environment.Every sensor node builds the resolution for its work; where it has information and knowledge of communications, computing and power resources.The sensor nodes have the ability to collect and distribute data to adjacent sensors or return to an external BS.The BS may be a mobile node or fixed node that can connect the WSN to the existing communications infrastructure or to the Internet, hence that the user has access to the data reported (Jamal et.al., 2005).

II. Literature review
This paper relates to the following works: (Adel, 2012) presents the performance evaluation and comparison of AODV and DSDV protocols in WSN according to the PDR, throughput, and end to end delay in various environment using IEEE 802.11Media Access Control (MAC) layer and Transmission Control Protocol (TCP) ,User Datagram Protocol (UDP) traffic pattern in every experiments.The overall observation shows the AODV routing protocol is better performance in terms of packet delivery fraction and throughput but suffers from delay.(Paul et.al., in 2014)the authors evaluates the performance of Ad hoc On-demand Multipath Distance Vector Routing (AOMDV), AODV, DSR and DSDV by using routing matrices such as average end to end delay (Average End to End) , PDR, loss packet ratio (LPR), and with varying pause time and number of node under TCP.They Each sensor node consist of used (NS2-35) program for wireless sensor network.The obtain results that the DSR is the better protocol in compared with the others.(Gaber et.al., 2015) they presents a systematic performance study of AODV, DSR and OLSR routing protocols with mobile sensor nodes by comparing main matrices such as end-to-end delay, routing overhead, load, total packets dropped, route discovery time, and number of hops per route in the Network.The research is implemented and simulated using OPNET Modeler simulator.The simulation results shows that the AODV and DSR have similar behavior but with performance differentials resulted from the differences in protocol mechanics.In addition, AODV and DSR are suffering from high end-to-end delay in compared to the OLSR protocol.

III. Routing protocols type in WSN
Routing is a process of generating paths from the source to the destination, with the ability to use medium nodes to reach the final destination (Gaber et.al., 2015).An appropriate routing protocol is required to implement and manage various network control functions; traditional routing protocols are not suitable for WSN, This is because routing in the wireless network differs from traditional routing in fixed networks in different ways ( Popa et.al., 2007).The routing protocols could be categorized according the basis of the route process to: hybrid, reactive (on‫ــ‬demand) and proactive (table driven) (Gaber et.al.,2015).

AODV
The first example of reactive routing protocol is the Ad-hoc On-Demand Distance Vector is that use on‫ــ‬demand method to discover and create routes (Hussein, 2014), and the protocol is one of the most frequently used protocol assigned for MANET and WSN [Perkins et.al., 2003).AODV is one of a most well-known protocol and has included a great deal of importance by the researchers and a scientific community.In the near future, the protocol will appear in the list of protocols to be standardized.AODV is the combination of DSR and DSDV protocols.AODV use the hop‫ــ‬by‫ــ‬hop routing and sequence numbers from DSDV protocol, and it works on‫ــ‬demand mechanism for path detection and path maintenance from DSR protocol (Goswami et.al., 2012).AODV stores routes as long the source require them, and is considers one of the chief routing protocols that setup the shortest path (Gaber et.al., 2015).
Figure 2 appear flow chart and the phases of AODV protocol respectively.When a source node requires to send a data packet to the destination and does not have any path in the routing table; so that the source nodes broadcasts a route request packet (RREQ) to the destination node to every adjacent node; in addition each RREQ-message contains a unique ID, which allows the nodes to ignore duplicate RREQ-messages Which have been traded with before.The reverse path is created or updated by the destination node When the RREQ flooding from the source node and arrives at the destination node, also it unicasts a route reply packet (RREP) message which made increased the sequence number to the opposite path.When the RREP-message arrives at the source node along with the reverse route it creates or updates the forward route and communications started.Each node for local connectivity broadcasts a Hello packet message periodically.It broadcasts the RREP-message with time to live (TTL=1) as the Hello packet.When the node does not receive any packets from one of the neighbors within a few seconds, it's assumed to break the link to the neighbors.If there is any link failure in the network, then the node propagates a Route Error (RRER) message ( Khosrozadeh et.al., 2011).

DSR
Another example of reactive routing protocols is Dynamic Source Routing (DSR) is that works like AODV (Kumar et.al., 2010).The protocol is based on the link state algorithm that means each node is able maintain the better way to the destination node.The source node defines the complete path of the destination node from one hop to other, also used the source routing method where the paths are stored in the path cache.If any change accrue in the network topology, the network will get information by flooding.If there is any link failure in the network, then the node propagates a RRER message (Johnson et.al.,1996).

DSDV
An example of proactive routing protocol is Destination-Sequenced Distance-Vector (DSDV) protocol.The routing table is maintains by each node, which contain a list of all possible destinations corresponding the number of hops to the network.Routing table data is exchange between adjacent nodes and routing data is up-dated with a new data by each node.If the package cannot find its destination, then the packages were stored temporarily.Then the data packets are unable to receive until the delivery report appears from the destination (Bijan et.al., 2014).

IV. Simulation Tool
This work performed using Network Simulator (NS-2.35)under Linux (ubuntu14.04)operating system.NS-2.35 is an open source simulator program and the aim of a simulation is provide educational support for research in networks.NS2 is providing two languages: object-oriented variant of the tool command language (OTcl) and C ++ language.Figure 3 appears the NS2 simulator.The layered architecture of NS2 is shown in figure 4. The event scheduler is implemented and almost all the components of the network are in C ++ language and can be accessed for the tool command language (Tcl), so the lowest level of NS2 is implemented by C++, the level of Tcl script is top notch to create simulation material much easier to perform.These all things combined as so-called NS-2 software.After created the trace file, we can use scripting languages like AWK (Aho-Weinberger-Kernighan) script to calculate performance metrics.AWK script is used to calculate the average PDR, throughput, normalized routing load and average EED delay from the source node to the destination node (Genita et.al., 2015).

V. Research methods and proposed system  Performance Metrics & Network Parameters
The metrics utilized to evaluate the performance of protocols in network according to identified parameters to show the behavior of the simulated scenarios.In this research, we use the performance metrics such as: Avg EED, normalized routing load, average throughput, drop packet and PDR.
a. Drop packets: The communication occur by sending packets between the source node and a destination node inside the network; therefore, through a communications, some packets are dropped in the receiver side and these packets called drop packet.A Drop packet can occur due to congestion, delays, and link failure.The following formula represented the dropped packet (Varshney et.al., 2016): Where: S p :-packets send, R p :-packet receive.Throughput can be represented by the following formula (Varshney et.al., 2016): (3) The throughput are evaluated after run the simulation (10) times and a results are obtained as the average.e. Normalized Routing Load: is a number of routing packets for every packet of data delivered by destination (Nikam et.al.,2016).

…….. (5)
In the implementation used random mobile nodes for our simulation purpose.To measure the performance, we used Network Simulator (NS-2.35).The same scenario for each protocol DSR, AODV and DSDV was used.Table (1) shows the simulation parameter.

Table 1 Simulation Parameters.
A different scenario is implemented to study the behavior of proactive and reactive routing protocol like DSR, DSDV, and AODV and then made comparison according to routing metrics.A first scenario has 50 nodes, the second scenario has 100 nodes and the last scenario has 150 nodes; all of these are implemented under the TCP and UDP traffic connection with pause time and varying speed.Figure 5 presents the NAM for 100 nodes.Figure 6 shows the node range, the shape of the packet sent and present the shape of droped packets.The Gnuplot graph is used to graph the results of the work.Figure 7 shows the Gnuplot graph of packet drop performance of protocols under TCP and UDP traffic connection with varying number of nodes, varying speed and varying pause time.

VI. Results
Table 2, Table 3 and Table 4 presents simulation results for AODV, DSDV and DSR routing protocols with TCP and varying speed respectively.Table 5, Table 6 and Table 7 presents simulation results for AODV, DSDV, and DSR protocols with different pause time and speed (10 m/s) and with UDP traffic connection.

VII.Conclusion
The main concluding observations are the DSR has better performance in TCP traffic connection, while the DSDV has better performance in UDP protocol.

b.
Average End-to-End Delay ( Avg EED): can be define as, the overall time that data packet are required to send from the source node to the destination node.Following equation represented the EED (Salih , 2017): The received time in the destination-node.(s):The transmission time in the source-node.c.Throughput: A term of the number of packets received during the simulation time.
d. Packet Delivery Ratio (PDR): Is the ratio of a successful receipt of the packets.The successful number of R p at the destination node to the number of S p from source node, following equation represented PDR( Varshney et.al.,2016):

Figure 5
Figure 5 NAM window for 100 nodes.

Figure 6
Figure 6 NAM window a. NAM of sent packet and node range for simulation, b. shape of Drop packets of the nodes a. Drop packets vs. speed of protocols with 50 nodes and TCP traffic connection.b.NAM window for node rang and sent packets.a. NAM window present drop packets.Drop packet b.Drop packets vs. pause time of protocols with 150 nodes using UDP traffic connection.

Figure 7
Figure 7 drop packets performance for AODV, DSR and DSDV protocols.

Figure 8
Figure 8 appears the graph of a performance of the Avg EED of three protocols under the same environments.
Abu Taleb A., Alhmiedat T., Hassan O. A., and Turab N. M. , September 2013, "A Survey of Sink Mobility Models for Wireless Sensor Networks", Journal of Emerging Trends in Computing and Information Sciences, CIS Journal, Vol. 4, No. 9, pp.679_687.