An Adaptive Energy Efficient Reliable Routing Protocol for Wireless Sensor Networks
- 1. ACEEE International Journal on Network Security, Vol 1, No. 1, Jan 2010
An Adaptive Energy Efficient Reliable Routing
Protocol for Wireless Sensor Networks
Basavaraj S.Mathapati1, Dr.V.D.Mytri2 and Dr.Siddarama R. Patil3
1
APPA Institute of Engineering and Technology /Computer Science and Engineering, Gulbarga, Karnataka, India
Email: basavarajphd@gmail.com
2
GND college of Engineering, Bidar, Karnataka, India
Email: mytrivd@gmail.com
3
PDA College of Engineering/Electronics and Communication Engineering, Gulbarga, Karnataka, India
Email: pdapatil@yahoo.com
Abstract— A reliable routing protocol for wireless sensor single sensor would allow unless the correct location of
networks (WSN) should be capable of adjusting to the specified phenomenon is unknown. The multiple
constantly varying network conditions while conserving sensor nodes are needed in most of the situations to
maximum power. Existing Routing protocols provide surmount over environmental hindrances namely
reliability at the cost of high energy consumption. In this
paper, we propose to develop an Adaptive Energy Efficient
obstructions, line of sight constraints etc. Also, the
Reliable Routing Protocol (AEERRP) with the aim of environment under supervision does not possess an
keeping the energy consumption low while achieving high infrastructure for energy or communication. It is very
reliability. In our proposed protocol, the data forwarding essential that the sensor nodes have to persist on minute,
probability is adaptively adjusted based on the measured finite energy sources and communicate by means of a
loss conditions at the sink. So only for high loss rates, a node wireless communication channel.
makes use of high transmission power to arrive at the sink. Sensor networks are applied in a number of ways in
Whenever the loss rate is low, it adaptively lessens the several areas. For instance, it consist of environmental
transmission power. Since the source rebroadcasts the data, monitoring –that includes examining air, soil and water,
until the packet loss is minimized, high data reliability is
achieved. By simulation results we show that the proposed
condition based maintenance, habitat monitoring
protocol achieves high reliability while ensuring low energy (estimating the population and behavior of plant and
consumption and overhead. animal species), military surveillance, seismic detection,
inventory tracking, smart spaces and so on. In fact sensor
Index Terms—Sensor Networks, Reliability, overhead, networks have the capability of converting a better way to
Energy Consumption, Routing Protocol comprehend and assemble complex physical system [1]
because of the pervasive nature of micro-sensors.
I. INTRODUCTION
B. Routing Protocols for Sensor Networks
A. Wireless Sensor Networks Routing in sensor networks is difficult for the reason
that numerous features distinguish them from the modern
In recent years, the advancement of technologies has
communication and wireless ad-hoc networks.
resulted in the deployment of minute, low-power, cheap,
distributed devices that can be subjected to local • It is not feasible for constructing a global
processing and wireless communication in a real time [1]. addressing scheme for the deployment of pure
These nodes are referred as sensor nodes. Each sensor number of sensor nodes. Consequently, classical
node processes to a limited level. But these nodes possess IP-based protocols cannot be employed to sensor
the capability of evaluating a physical environment networks.
completely when managed by the particulars obtained • By contrasting to characteristic communication
from a number of other nodes. Hence, a sensor network networks nearly the entire applications of sensor
can be identified as a set of sensor nodes which organizes networks necessitates the sensed data flow from
to execute certain functions. In comparison the multiple regions (sources) to a specific sink.
conventional networks the sensor networks rely on dense • Multiple sensors may generate similar data
co-ordination and deployment to perform their functions. within the adjacent area of a phenomenon and
Typically, the sensor networks comprise of few sensor this leads to a main redundancy in the generated
nodes that are connected to a central processing station. data traffic. Such redundancies have to be
However, these days the spotlight is on wireless, utilized by the routing protocols to enhance
distributed sensing nodes. The distributed sensor enables energy and bandwidth exploitation.
a closer allocation as per the phenomenon whereas a
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• Sensor nodes are forcefully bounded in terms of algorithms to compute approximations to the idealized
transmission power, processing capacity, on- disjoint and braided paths. Second, they have evaluated
board energy, and storage and therefore they the relative performance of disjoint and braided
necessitate cautious resource management. multipaths.
• Node failures and packet losses are anticipated Vidhyapriya and Vanathi [12] have proposed an
to be general in several sensor networks. These energy efficient adaptive multipath routing technique
failures or losses could be for the short-term in which utilized multiple paths between source and the
nature, for instance because of the temporary sink, adaptive because they have low routing overhead.
wireless interference. That protocol was intended to provide a reliable
Accordingly, a routing protocol for such challenged transmission environment with low energy consumption,
networks could be competent of adjusting to constantly by efficiently utilizing the energy availability and the
varying network conditions while conserving maximum received signal strength of the nodes to identify multiple
power. routes to the destination.
Normally, power save protocols offers two choices to Matthew J. Miller and Indranil Gupta [13] have
the user based on the broadcast. First, the broadcast can discussed that the devices became more reliant on battery
attain a comparatively low latency, if no power save is power, it was essential to design energy efficient
employed, although at the sacrifice of large energy costs protocols. In their previous work, they have proposed
to listen for broadcasts. The second choice is to employ Probability-Based Broadcast Forwarding (PBBF) to
the power save protocol. This option conserves extra address broadcast power save by allowing users to select
energy than the first option; however it possesses high a desired tradeoff between energy consumption, latency,
latency which is not suitable to a few applications. and reliability. In their paper they have extended their
Every single data or request packet is blindly previous work. They have introduced a parameter that
rebroadcasted or forwarded by the other nodes, in the allowed a tradeoff between reliability and packet
blind flooding which augments the energy utilization and overhead to give users more options.
communication overhead. Each mobile node rebroadcasts Michele Zorzi and Ramesh R. Rao [14] have proposed
a packet on the basis of a predetermined forwarding a novel forwarding technique based on geographical
probability p, in the traditional probabilistic broadcast location of the nodes involved and random selection of
schemes. So as to create rebroadcast decisions, global the relaying node via contention among receivers. They
topological information on the network is not necessary have focused on the multihop performance of such a
in the probabilistic broadcast schemes. However, general solution, in terms of average number of hops to reach a
probabilistic methods had concentrated on pure destination as a function of the distance and of the
probabilistic state of affairs with comparatively modest average number of available neighbors.
inspection on the effects of broadcast algorithms on Dandan Liu et al. [15] have considered a distributed
particular applications namely route discovery. and efficient information dissemination and retrieval
Routing Protocols can be categorized on the basis of system for wireless sensor networks. In such a system
subsequent techniques [2]: each sensor node operates autonomously with no central
• Flooding protocols such as SPIN [4] , node of control in the network, and it can be a data source
• Gradient protocols like Directed Diffusion [5] (it produces data) as well as a data sink (it consumes
and GRAB [8] , data). They have aimed at developing energy efficient
• Clustering protocols namely LEACH [3] and protocols that disseminate information sensed at a source
HEED [10] node to any other nodes that are interested in the
• Geographic protocols namely GPSR [7], GAF information. They have proposed two protocols, one was
[6] and GEAR [9]. based on the quorum scheme and the other was based on
In this paper, we propose to develop an Adaptive the home agent scheme. Their protocols have three
Energy Efficient Reliable Routing Protocol (AEERRP) advantages: (1) Fully distributed. (2) high success rate for
with the aim of keeping the energy consumption low data retrieval; (3) capable of dealing with mobile sensors
while achieving high reliability in order to ensure high as well as static sensors.
overall network connectivity. A priority-based multi-path routing protocol (PRIMP)
was proposed by Yuzhe Liu and Winston K.G. Seah [16]
II. RELATED WORK for sensor networks to offer extended network lifetime
and robust network fault tolerance. Extensive simulations
Deepak Ganesan et al. [11] have addressed two issues. have validated that PRIMP exhibits significantly better
First, they have defined localized algorithms for the performance in energy conservation, load-balancing and
construction of alternate paths. For reasons of robustness data delivery than its comparable schemes. Moreover,
and energy-efficiency, sensor network data dissemination PRIMP addresses the slow startup issue occurred in
mechanisms used localized decisions for path setup and datacentric routing schemes.
for recovery from failure. They have proposed localized
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A reliable energy-efficient routing (REER) protocol needed. Sensor nodes endure unpredictable and recurrent
was proposed by Min Chen et al. [17] to achieve the failures because of the disturbing environment [8].
goals for dense wireless sensor networks (WSNs). Based In our proposed protocol, we estimate the density of a
on the geographical information, REER’s design region by employing the neighborhood information of
harnesses the advantage of high node density and relies nodes located in that region. The neighborhood
on the collective efforts of multiple cooperative nodes to information is obtained using a topology discovery
deliver data, without depending on any individual ones. scheme. Based on this, the current number of forwarding
They have initially selected reference nodes (RNs) nodes is kept in a forward node count (CFN), at each node.
between source and sink. Then, multiple cooperative If the packet loss ratio at the neighbor of the sink is more
nodes (CNs) are selected for each RN. The reliability was than a maximum-threshold value, CFN is incremented
attained by cooperative routing: each hop keeps multiple adaptively until the loss ratio is less than the maximum-
CNs among which any one may receive the broadcast threshold value. This guarantees the reliability of data.
data packet from the upstream hop to forward the data When the loss ratio value becomes less than the
successfully. The distance between two adjacent RNs maximum-threshold value, it specifies the successful
provides a control knob to trade off robustness, total packet delivery. In this scenario, the FNC is decremented
energy cost and end-to-end data latency. until the CFN is equal to its minimum forwarding node
Zijian Wang et al. [18] have proposed an energy count.
efficient and collision aware (EECA) node-disjoint In contrast to existing routing protocols, our protocol is
multipath routing algorithm for wireless sensor networks. neither single-path nor multi-path; rather each node
With the aid of node position information, the EECA adapts the paths based on the estimated loss conditions.
algorithm attempts to find two collision-free routes using In this protocol, only for high loss rates, a node makes
constrained and power adjusted flooding and then use of high transmission power to arrive at the sink.
transmits the data with minimum power needed through Whenever the loss rate is low, it adaptively lessens the
power control component of the protocol. transmission power. Since energy consumption is
Kavitha, C. and Viswanatha, K.V. [19] have proposed lowered, the network lifetime is maximized. Since the
an energy efficient fault-tolerant multipath routing source rebroadcasts the data, until the packet loss is
technique which utilized multiple paths between source minimized, high data reliability is achieved.
and the sink. Their protocol was intended to provide a
B. Topology Discovery Phase
reliable transmission environment with low energy
consumption, by efficiently utilizing the energy In this phase, the sink broadcasts a topology discovery
availability and the available bandwidth of the nodes to (TOPDIS) packet in the network. This packet is employed
identify multiple routes to the destination. To achieve to determine the cost of each forwarding node. A node’s
reliability and fault tolerance, their protocol selects cost is defined as the minimum power needed to reach the
reliable paths based on the average reliability rank (ARR) sink by this node. Thus, the nodes which are nearer to the
of the paths. Average reliability rank of a path was based sink have smaller cost while nodes which are far away
on each node's reliability rank (RR), which represents the from the sink have larger cost. We presume each node
probability that a node correctly delivers data to the can estimate the cost of sending data to its nearby
destination. In case the existing route encounters some neighbors on the basis of the signal-to-noise-ratio (SINR)
unexpected link or route failure, their algorithm selects of the neighbors. The packets trace the direction of
the path with the next highest ARR, from the list of lessening cost to reach the sink. When multiple paths of
selected paths. lessening cost exist, they develop a forwarding mesh.
As soon as a topology request packet is sent to all the
III. PROPOSED PROTOCOL sensor nodes by the AP, the next phase begins. After
acquiring this packet, a node first settles whether it comes
A. System Design and Protocol Overview from a neighbor or interferer. It makes use of the received
signal strength information from its interference model,
In this paper, we assume the following sensor network
to fix on the origin of the packet. If the transmitting node
model. Many minute, stationary sensor nodes are occurs to be the next hop of the receiving node, with
deployed over a field. The user acquires the sensing data minimum cost, the receiving node appends its own cost
by means of the stationary sink which communicates
information to the packet and rebroadcasts it. The
within the network. Each event is identified by multiple receiving node maintains an array to store the cost and
sensor nodes which are closer and one among them signal strength of this transmitting node. Once this phase
produces the reports as a source. Reports are forwarded
has been completed, the energy efficient forwarding
over several hops before arriving at the sink owing to the phase begins, which is discussed in the next section.
limited radio range. Nodes are competent to tune their
transmitting powers to manage how long the
transmissions may travel. These power adjustments are
able to conserve energy and lessen collisions when it is
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C. Energy Efficient Forwarding C FN =C FN +γ , until C FN ≥ C FN min
After the topology discovery phase, each node N
maintains a Neighbor Information Table (NIT), which IV. PERFORMANCE EVALUATION
contain the fields Node Id, Distance and Cost. Node Id is
the id of the neighbor node, Distance is the distance A. Simulation Setup
between that node with N and Cost is the power required We evaluate our AEERRP scheme through NS2
to send a packet from that node to the sink. simulation. We considered a random network deployed in
Let N i , i = 1,2,...n be the neighbors of N . Then N an area of 500 X 500 m. The number of nodes is varied as
sorts the NLT based on the distances of N i . (i.e.) the 25, 50, 75 and 100. Initially the nodes are placed
nodes with shortest distance with N are listed first. randomly in the specified area. The sink is assumed to be
situated 100 meters away from the above specified area.
Each node maintains a forward node count ( C FN ),
The initial energy of all the nodes assumed as 5 joules. In
which denotes the broadcast or rebroadcast probability. our simulation, the channel capacity of mobile hosts is set
Initially C FN [ Nk ] = C FN min , for all nodes to the same value: 2 Mbps. We use the distributed
Nk , k = 1,2, L C FN min is the minimum number of coordination function (DCF) of IEEE 802.11 for wireless
forwarding nodes. Without loss of generality, we can LANs as the MAC layer protocol. The simulated traffic is
assume that CBR with UDP source and sink. All experimental results
C FN min = 1 . The steps involved in the adaptive presented in this section are averages of five runs on
different randomly chosen scenarios. The following table
energy efficient forwarding phase are given below: summarizes the simulation parameters used.
1) Suppose N wants to send the collected data to
the sink, it attaches its cost to the data packet
and broadcast the packet to the nearest
neighbors.
2) When a neighbor N1 receives the packet
from N , it first checks its cost is less than that TABLE I.
of N . If it is less, it further forwards the packet. SIMULATION PARAMETERS
Otherwise it drops the packet, since N1 is not No. of Nodes 25,50,75 and 100
towards the direction of the sink. Area Size 500 X 500
3) When the packet reaches the destination D , it
Mac 802.11
measures the loss ratio (LR), which is the ratio
of number of packets dropped and total packets Simulation Time 50 sec
broadcast from the source. Traffic Source CBR
4) Then D sends this LR value as a feed back to Packet Size 512
the source N . Transmit Power 0.360 w
5) When N receives this value, it checks the value Receiving Power 0.395 w
of LR. It then modifies the value of C FN as Idle Power 0.335 w
C FN =C FN +γ , if LR > LR max . Initial Energy 5J
Where γ is the minimum increment of decrement Transmission Range 75m
count and LR max is the maximum threshold value of
B. Performance Metrics
loss rate.
6) It then rebroadcast the data packets with the We compare AEERRP with the extended PBBF [13]
incremented C FN , so that increasing the scheme. We evaluate mainly the performance according
to the following metrics.
reachability of the sink. The total power required Control overhead: The control overhead is defined as
to reach the sink is thus calculated based on the the total number of routing control packets normalized by
cost field of all the nodes in C FN . For example, the total number of received data packets.
if C FN = 4 , then the minimum required power Average end-to-end delay: The end-to-end-delay is
will be 4 * cost of each neighbor node in the averaged over all surviving data packets from the sources
NIT. to the destinations.
7) When the rebroadcast packets reach the Average Packet Delivery Ratio: It is the ratio of the
destination D , it again calculates the losses ratio number .of packets received successfully and the total
LR and sends back to N . number of packets transmitted.
8) It then reassigns the value of C FN , depending on Loss Ratio: It is the average energy consumption of
all nodes in sending, receiving and forward operations.
the value of LR. Once LR < LR max , then
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The simulation results are presented in the next scheme achieves more delivery ratio than the PBBF
section. scheme since it has both reliability features.
C. Simulation Results
Nodes Vs Overhead
Nodes Vs Delay
2000
0.002
1500
0.0015
AEERRP
AEERRP
0.001 1000
PBBF PBBF
0.0005 500
0 0
25 50 75 100 25 50 75 100
N o d es N o d es
Figure 1. Nodes Vs End-to-End Delay
Figure 4.Nodes Vs Overhead
Figure 1 shows the results of average end-to-end delay Figure 4 shows the results of routing overhead for the
for the 25, 50, 75 and 100. From the results, we can see nodes 25, 50, .100. From the results, we can see that
that AEERRP scheme outperforms the PBBF scheme by AEERRP scheme outperforms the PBBF scheme by
attaining low delay. attaining low overhead.
Nodes Vs Energy
Nodes Vs Packet Loss
0.4 1400
Energy(J)
1200
0.3
AEERRP 1000
0.2 800 AEERRP
PBBF
0.1 600 PBBF
400
0 200
25 50 75 100 0
25 50 75 100
Nodes N o d es
Figure 2. Nodes Vs Energy Figure 5. Nodes Vs Packet Loss
Next, we measure the average energy consumption of Finally, we measure the average packet loss. From
the network. From Figure 2, we can see that, our Figure5, we can see that, our AEERRP has low packet
AEERRP consumes less energy when compared with the loss when compared with the PBBF.
PBBF.
Nodes Vs Delivery Ratio
V. CONCLUSION
100
80 In order to achieve high data reliability in wireless
60
sensor networks, most of the data forwarding protocols
AEERRP
40 PBBF
uses blind flooding or probability based broadcast
forwarding, at the cost of high energy consumption. In
20
this paper, we have developed an Adaptive Energy
0
Efficient Reliable Routing Protocol (AEERRP) with the
25 50 75 100
aim of keeping the energy consumption low while
N o d es
achieving high reliability. In our proposed protocol, we
estimate the density of a region using the neighborhood
Figure 3. Nodes Vs Delivery Ratio information of nodes located in that region. The
neighborhood information is collected using a topology
Figure 3 shows the results of average packet delivery discovery scheme. The data forwarding probability is
ratio for the nodes 25, 50, .100. Clearly our AEERRP adaptively determined based on the measured loss
conditions. So only for high loss rates, a node uses high
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transmission power to reach the sink and whenever the International Journal of Computer Science, Vol.34, No.8,
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