=Paper= {{Paper |id=Vol-1830/Paper82 |storemode=property |title=Energy Efficient Routing in Wireless Sensor Network Using Ant Colony Optimization and Firefly Algorithm |pdfUrl=https://ceur-ws.org/Vol-1830/Paper82.pdf |volume=Vol-1830 |authors=M. Okwori,M. E. Bima,O. C. Inalegwu,M. Saidu,W. M. Audu,U. Abdullahi }} ==Energy Efficient Routing in Wireless Sensor Network Using Ant Colony Optimization and Firefly Algorithm== https://ceur-ws.org/Vol-1830/Paper82.pdf
   Energy Efficient Routing in Wireless Sensor Network Using Ant Colony Optimization and

                                                      Firefly Algorithm

                    M. Okwori, M.E. Bima, O.C. Inalegwu, M. Saidu, W.M. Audu, U. Abdullahi
                                    Federal University of Technology, Minna
      Email{michaelokwori, bimamuhammad, ogbole.inalegwu, samuslim, audum, umarabdullahi}@futminna.edu.ng



   Abstract—Energy conservation in Wireless Sensor Networks             Routing in WSN is handled differently from what is
(WSN) is a crucial venture as their miniaturize nature limits        obtainable in traditional wireless networks. This is because
their power capabilities. An effective way of energy conservation    of the limited resources available in sensors, and as such any
is the adoption of efficient routing of data from source to sink.
This work investigates the performance of two meta-heuristic         routing technique deployed in WSNs should minimize energy
algorithms, Ant Colony Optimization (ACO) and Firefly Al-            consumption and ultimately maximize network lifetime [4].
gorithm (FA) on optimal route detection in a WSN routing             Generally the many WSN efficient routing schemes can be
management system. An adapted ACO was used to search for             categorized into network structure, communication models,
optimal routes between selected source and sink nodes, after         topology based and reliable routing schemes. The network
which a developed Discrete FA ran same search. Performance
of both were tested on sensor networks deployed randomly, in         structure protocols on which this paper is based takes into
a clustered pattern and finally randomly-clustered. Evaluators       consideration how the nodes are interconnected and routes
used were energy budget of reported routes. Results show that        used to send data to destination from source. They are
FA was able detect routes with less cost than those detected by      further classed into flat protocols, hierarchical protocols and
ACO for short routes while ACO performed better with longer          location based protocols [5]. This paper investigates energy
routes. Considering the enhanced speed of performance of ACO
in comparison to FA and the local search nature of FA, it would      optimization of a location based routing protocol using meta-
be beneficial for future work to explore a hybridized FA-ACO         heuristic algorithms.
algorithm.                                                              Meta-heuristic algorithms are designed to mimic natural
   Keywords—WSN, Firefly Algorithm, Ant Colony Optimiza-             phenomena as they randomly search through a space for
tion,                                                                the optimum solution subject to preconfigured constraints. In
                                                                     this paper we use two of such algorithms, Firefly algorithm
                      I. I NTRODUCTION                               and the Ant Colony algorithm, to find the optimal path that
                                                                     minimizes the total energy expended in sending a data packet
   Wireless Sensor Networks (WSN) are a collection of small          from source to sink. First, a review of related works is
devices working together to capture/monitor a particular             presented in section II. A description of the optimization
phenomenon of interest. They find useful applications in             problem and detailed report of two methods of route opti-
home automation, disasters and environmental monitoring,             mization based on each algorithm is outlined in section III.
military operations, multiple target tracking, security surveil-     A Vehicle Routing Problem with Time Windows (VRPTW)
lance, health services and other commercial purposes [1], [2].       dataset was used to test and evaluate the performance of the
Energy management in WSN is crucial as their usefulness is           algorithms, after which comparison is made between the two
dependent on how long they are alive and replacement is              algorithms in section IV. Section V presents the conclusions
difficult as deployment area usually is not easily accessible.       of the investigation
As such a lot of techniques are employed to prolong their                               II. R ELATED W ORKS
lifespan, these include topology management schemes (can
                                                                     A. Related Work on Routing Protocol in WSN
be location-driven or connection driven), power management
(sleep/wakeup protocols and MAC protocols), data reduc-                 A wireless sensor network (WSN) consists of sensor nodes
tion schemes (data compression and in-network process-               which are distributed around a given location. These sensors
ing), energy efficient data acquisition and sending (adaptive        have limited energy capability to stay alive for a long period
sampling, hierarchical sampling and efficient routing) and           of time [4]. Although, over the years, sensors have improved
mobility based schemes (such as mobile sink and mobile               in their computational capabilities, the batteries are still
relay) [3]. This work presents an investigation of efficient         highly inefficient in comparison. Consequently, in an effort
routing in WSN.                                                      to extend the life of a sensor node, research has been pointed


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   towards reducing the energy demand of the nodes. This            same discrete algorithm was also applied by the authors to
is obviously because the core design aspects in a WSN are           solve the manufacturing cell formation problem [17].
Energy Efficiency and Reliability [6]. Energy Efficient (EE)           Firefly algorithm was used for routing optimization in
Routing has been mentioned in the literature as a means             WSN in [18]. A novel fitness function depending on residual
of extending the life of a sensor node[7]. Since energy is          energy, node degree and distance was proposed, and then
expended during transmission, the most energyefficient route        optimized. Results showed superior performance to some
during transmission will consume the least energy. This has         stated existing routing algorithms.
engendered EE routing protocol for WSNs.                               Another interesting work combined firefly algorithm with
   Basically, routing protocols for WSN are classified into flat    the gossip algorithm and applied it to WSN to investigate
protocol, hierarchical protocol and location based Protocol         time of sensor synchronization and data convergence rate
[5]. In Flat protocol routing scheme, nodes are distributed         [18]. The impact of hybrid algorithm was investigated on
uniformly; with none performing a leading role; to transmit         a live network to find out how simulation results correlate
data in a cooperative manner i.e. transmitting to the next          with live field applications. Conclusion drawn from results
neighbor. In the case of the hierarchical scheme, nodes are         obtained indicate that assumptions such as fireflies commu-
given varying roles and groups known as clusters [8]. Each          nicating at the speed of light and the low latency due to fast
cluster must have a Cluster Head (CH) which is a node that          processing speed is not applicable in a live networks where
has higher capabilities than other nodes and is used to relay       much higher latency is expected. A wide range of application
data to the sink node. Within a distribution of nodes, there        in diverse fields are presented in [14], [19].
may be many possible routes to get to a particular destination.
Mathematical models were developed in [9] to determine the          C. Review of Ant Colony Optimization Related Work
most energy efficient route to use in a WSN under resource             An Adaptive Ant Colony Optimization (ACO) algorithm
restriction. The task of determining the most energy efficient      is proposed in [20] for clustering based dynamic routing in a
route is a hard optimization problem [10]. Consequently,            WSN. This was designed to take into consideration the unpre-
many meta-heuristic techniques have been developed to find          dictable nature of a Wireless Sensor Network. Sensors nodes
the most optimal energy efficient route.                            can be deployed in either a sparse or dense nature. The ACO
   Artificial Bee Colony meta-heuristics algorithm [11] and         finds the optimal network setting in order to improve data
improved harmony search algorithm [12] were used to de-             aggregation thereby reducing data redundancy. An adaptive
termine the optimal energy efficient route in a WSN. An             routing scheme based on ACO was also developed in [10].
Improved Genetic Algorithm was developed to eliminate the           Route selection is based on the residue energy inn the nodes
possibility of choosing an invalid note for routing in a WSN        as well as the location of nodes. In this case, clusters were
[13]. Parameters used in the node selection include nodes           not used in the grouping of nodes.
position in relation to sink, neighboring nodes, remaining             Fuzzy logic was used in addition to ACO in [21] in a cross-
energy and energy requirement. Since this research work             layer WSN protocol stack to optimize routing in a WSN. To
was based on using Firefly and Ant Colony optimization              improve EE of the routing protocol, a multilayer approach
algorithms for route optimization, the literature will be based     was adopted. Nodes were grouped into clusters with cluster
on them.                                                            heads which are closest to the sink. Fuzzy logic was used
                                                                    in the cluster head selection using metrics such as residual
                                                                    energy, number of neighbors and quality of communication
B. Review of Firefly Related Work
                                                                    link for the selection. However, ACO was used for reliable
   Firefly optimization algorithm, which is presented in more       and energy efficient inter-cluster routing from cluster heads
detail in section III have been used to solve several research      to sinks.
optimizations in literature. These work include, but not               ACO was further used to determine a multi-objective
limited to a wide range of issues in the field of engineering       optimization i.e. energy efficiency and security of transmitted
design problems, image processing, identification and clus-         data [22] in a WSN. The factors used to carry out this include
tering, and software testing [14]. A review of some of its          the time delay, bandwidth and the energy consumption.
application is hereby presented.                                    Neural Network was used together with ACO to for the
   In [15], the authors modified the original firefly algorithm     purpose of routing in [23]. The neural network is used to
by discretizing it and applying several novel route operators       select the cluster head while ACO was used to determine
to solve the Vehicle Routing Problem with Time Windows              best route. An ACO was used to develop an enhanced routing
(VRPTW). Results presented showed that the developed                protocol for WSN [24] with mobility as the metric.
Evolutionary Discrete Firefly Algorithm (EDFA) is promising
compared to other versions of EDFAs. Another discrete                                     III. M ETHODOLOGY
firefly algorithm, using the sigmoidal logistic function is            This section presents details about how the Firefly al-
presented in [16], is used to find the optimal solution to per-     gorithm (FA) and Ant Colony optimization (ACO) algo-
mutation flow shop minimizing the makespan. The problem             rithms are used to optimize the selection of energy efficient
is NP-hard and formulated as a mixed integer programming.           route between two nodes. The objective function used for
Results revealed superior performance to the ant colony. This       optimization was derived from [9]. It requires finding the



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route with the least energy consumption and maintaining                B. Ant Colony Optimization Algorithm
the energy limitation of the nodes. Consequently, the next                In this section, we present the use of ant colony optimiza-
section provides details about the input parameters for the            tion (ACO) algorithm for the selection of the optimal energy
developed algorithm i.e. the objective function and defined            efficient route. The pheromone secreted along the selected
constraints. When a node wants to transmit, it searches for            path is based on the equation (5) which shows the inverse
the most optimal route to use for the transmission. Fig. 1             relationship between the deposited pheromone and the cost.
shows an overview of the link between source and sink nodes.
Subsequent sections provide details on the FA and the ACO                                                         Q
techniques adopted.                                                                     ϕ(i, j) = ϕ(i, j) +                            (5)
                                                                                                                cost(k)
                                                                         Where ϕ is the deposited pheromone, i= source node, j
                                                                       = destination node, k = selected ant and Q is a constant.
                                                                       Subsequent ants are most likely going to select the path with
                                                                       the most pheromone along its trail. This is represented in the
                     Figure 1. Schematic of WSN
                                                                       equation (6)
                                                                                                           [ϕ(i,j) ]α
                                                                                       P (i, j) =                                      (6)
A. Input Parameters                                                                                 [ϕ(i,j) ]α + [ϕ(i,k) ]α
   The model considers multi-period transmissions from                 A colony of ants (P) is generated to find possible solutions
nodes and aims at prolonging the lifetime of the WSN. It               subject to the condition of least energy consumption along
is assumed that there are n number of nodes distributed                a selected path. The decision at each node on which path to
randomly around an area with each node having a limited                select next is made using a Roulette Wheel Selection algo-
energy with an initial value of ei0. The equation for the              rithm. The pseudocode for the ACO is shown in Algorithm
optimization process is represented in equation 1 where ej             1.
is the energy at the next hop node.
                                                                       Algorithm 1 Ant Colony Optimization Algorithm
                          X       X
                      min(  ei0 −   ej )                         (1)   While termination condition is not met
                                                                         For each ant k=1 to P,
   Equation 2 is used to determine the amount of energy                         Move ant(k) until it gets to destination
consumed during transmission from source to destination                          Compute the cost of the route using the objective
node. Where cw is the energy used to wake nodes for                    function
transmission and ct is the energy expended by a node to                         Compare cost with best route
transmit to the next hop node i.e. a node directly linked.                            If lower,
This direct transmission is constrained by a a linking distance                          overwrite best route with new route,
which is a maximum distance (ld) within which nodes can                               Else
transmit. Therefore, two nodes i and j that are dij distance                             maintain best route
away from each other can only communicate directly if                                 End If
dij