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Formulation of Energy Consumption in Wireless Sensor Network

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					International Journal of Scientific Research Engineering &Technology (IJSRET)
Volume 1 Issue2 pp 035-039 May 2012                                    www. ijsret.org         ISSN 2278 – 0882




       Formulation of Energy Consumption in Wireless Sensor Network
                                   Anuj Kumar1, Neeraj Shukla2, Dr. Ashish Chaturvedi3
                            1,2,
                             (Department of Computer science & Engineering, MIIT, Meerut
                              Email: anuj7.kumar@gmail.com, neeraj_14000@yahoo.com
          3
           Department of Computer science & Engineering, Arni University, Indora (Kathgarh), Himachal Pradesh
                                            Email: dr_ashysh@yahoo.com




ABSTRACT
Wireless sensor networks (WSNs) depends on their                been made to minimize the energy consumption of
reliable operation for extended times without human             wireless sensor networks and lengthen their useful
intervention. Wireless and ad-hoc deployment, which             lifetime at different levels and approaches. The
is essential in some scenarios and cost- effective in           promise of a truly wireless network is to have the
others, prevents the use of a wired energy                      freedom to roam around anywhere within the range
infrastructure. Wireless Sensor Networks usually                of the network and not be bound to a single location.
battery powered, thus energy-constrained, present               Without proper power management of these roaming
energy efficiency as the main challenge. Usually in             devices, however, the energy required to keep these
WSNs the communication consumes most of the                     devices connected to the network over extended
energy. But recently wireless sensor nodes are                  periods of time quickly dissipates.
introduced that comprise also energy-consuming
                                                                The small node size puts constraints on the maximum
sensors, apart from the ‘traditional’ ones like
                                                                battery size. Batteries already dominate the node
temperature, air pressure and humidity sensors. This
                                                                volume in prototype sensor nodes. The energy
paper presents the feasible formulation to express the
                                                                density for common battery technologies varies in the
energy consumption of a wireless sensor network
                                                                range of 1200 J/cu.cm. (Alkaline) to 3780 J/cu.cm
application in terms of its energy constituents,
                                                                (Zinc-air). At such energy density, assuming a sensor
effective realization of the intended application in
                                                                node operating at 1mW (average consumption after
terms of cost, lifetime, and functionality.
                                                                power management) and assuming the full battery
                                                                capacity can be utilized, a year-long operation
Keywords-Energy Consumption, Power Constrained,
                                                                requires a battery-size of the order of 10cu.cm which
Sensors, Wireless Sensor Network.
                                                                is rather large. Thus, batteries alone cannot be
                                                                expected to reliably supply a sensor network
  I.    INTRODUCTION                                            deployment for several years.
Many differences exist between wireless networks
and tradition wired ones. The most notable difference            II.     POWER         CONSTRAINED
between these networks is the use of the wired                           WIRELESS NETWORKS
medium for communication. Energy consumption is
                                                                Wireless networks have been a hot topic for many
easily one of the most fundamental but crucial factor
                                                                years. Their potential was first realized with the
determining the success of the deployment of sensors
                                                                deployment of cellular networks for use with mobile
and wireless sensor networks (WSNs) due to many
                                                                telephones in the late 1970's. Since this time, many
severe constraints such as the size of sensors, the
                                                                other wireless wide are networks (WWANs) have
unavailability of a power source, and inaccessibility
                                                                begun to emerge, along with the introduction of
of the location and hence no further handling of
                                                                wireless Metropolitan Area Networks (WMANs),
sensor devices once they are deployed. Efforts have

                                                     IJSRET @ 2012
International Journal of Scientific Research Engineering &Technology (IJSRET)
Volume 1 Issue2 pp 035-039 May 2012                                 www. ijsret.org             ISSN 2278 – 0882



wireless Local Area Network (WLANs), and wireless            terms of data rate and power consumption. It is the
Personal Area Networks (WPANs). Table 1 shows a              one most widely used by wireless sensor networks.
number of standards that have been developed for
each of these types of networks.

             Table 1: Wireless Standards
Stand    Frequ Spee Rang Modu
                                             MIMO
ard      ency     d       e        lation
                          35
802.1    5GHz     54M meters OFD             1
1a                bps              M
                          35
802.1    2.4GH 11M meters DSSS               1
1b       z        bps
                  20-     35                                       Fig. 1: Power Consumption in IEEE 802 based
802.1    2.4GH 54M meters OFD                1                                      networks
1g       z        bps              M
                          70                                 III.       SOURCE     OF                    ENERGY
802.1    2.4/5G 300       meters OFD         4                          CONSUMPTION IN                  WIRELESS
1n       Hz       Mbp              M                                    SENSOR NETWORKS
                  s
                          10                                 In order to design a low power wireless sensor
Bluet    2.4GH 721        meters FHSS        n/a             network, first step is to analyze the power dissipation
ooth     z        Mbp                                        characteristics of wireless senor node. Each node in
                  s                                          the network is consists of four components: a sensor
                                                             which connects the network to physical world,
                  1.5M 20
                                                             computation part which is consists of microcontroller
IrDA     infrare bps      feet     n/a       n/a
                                                             or in some application microprocessor and is
         d
                                                             responsible for control of the sensors and
                                                             communication, a transceiver for communicating
USB      900M      n/a     200      n/a      n/a
                                                             between nodes and base station, and a power supply
Wirel    Hz                feet
                                                             which is usually a battery. There are wide ranges of
ess
                                                             choices for each part of the node and choosing a right
                                                             device will affect the energy consumption.
If they are to have any hope of long term usability,
the power consumed by individual nodes in each of                                Controller
these networks needs to be managed efficiently.
Although performing this power management is
important for each of these types of networks, this
paper focuses primarily on the power management
schemes used by WLANs and WPANs. The final
subsection is dedicated to the introduction of a subset
of WPANs, known as wireless sensor networks                        Sensors       Power Supply         Transceiver
(WSNs). Wireless sensor networks are specifically
designed for very low power operation and thus                     Fig. 2: Overview of sensor node hardware
deserve this degree of special attention. Fig. 1 shows                            components
how these different types of networks compare in


                                                   IJSRET @ 2012
International Journal of Scientific Research Engineering &Technology (IJSRET)
Volume 1 Issue2 pp 035-039 May 2012                                             www. ijsret.org                  ISSN 2278 – 0882



Despite the energy efficiency of specific hardware                        calculations. Each constituent is expressed in terms
platforms, Sensor network lifetime can be                                 of key parameters (or factors). These key factors are
significantly enhanced if the software of the system,                     determined based on application requirements.
including different layers and protocols are designed
in a way that lower the consumption of energy.                            The individual constituent can be a state-based
                                                                          constituent, because every unit has different energy
                                                                          level consumption in different states. It can be
IV.       FORMULATION                    OF        ENERGY                 expressed as follows:
          CONSUMPTION                                                                         Nu
The overall energy consumption of the entire systems                      Eindividual,i (Δt) =    I (eu,s , eu,w , tu,s )
is expressed in terms of relationship among                                                  u=1 sS wW                  (3)
constituents.
We suppose a continuous time between t1 and t2 for                                       eu,s >  I (eu,w)                 uU
the energy consumption measurement. Residual                                            sS      wW
energy in time t is defined by omitting consumed
energy in Δt from the initial battery power in t-Δt.                      Since most of energy minimization methodologies
Thus, the energy consumption will be determined in                        use idle and sleep states for avoid of wasting energy
Δt.                                                                       in idle states, the above constraint states that the total
    Eresidual,i (t) = Einitial,i (t– t) - Econsumed ,i (t) (1)          energy consumed for switching among states should
                                                                          be smaller than the total energy consumption of
                    E(t) = E t                                         states.
                            t                                            Energy consumption in an active state for each unit
                     t = t2 – t1                                         depends on several factors as follows:
Realistically, we anticipate a nonlinear relationship
between the overall energy consumption of the                                    e1,active (Δt) = F1( f , bproc )                 (4)
system and its constituents depending on the
application and the overall design.                                       According to Eqn.4, the energy consumption of the
The total energy consumption of node i in the interval                    processor unit in an active state depends on the
Δt based on constituent of Hierarchy Energy Driven                        number of processed bits and the frequency based on
Architecture as follows:                                                  the following equation [6][8]:

Econsumed ,i (Δt) = 1Eindividual,i (Δt) + 2 Elocal,i (Δ) +                      p  cv 2 f                                      (5)
3 Eglobal,i (Δt) + 4 Ebattery,i (Δt) + 5 Esnk,i (Δt)
                                                               (2)        This proportionality expresses that the energy
Subject to:                                                               consumption of the processor is proportional to the
1: Elocal,i > 0                                                           voltage and the frequency of the operation. Since the
2 : Eglobal,i > 0                                                         frequency and the voltage can be related. We
3 : 1Eindividual,i (Δt) + 2 Elocal,i (Δt) +3 Eglobal,i (Δt) +          consider frequency as an effective parameter in this
    5 Esnk,i (Δt) + 4 Ebattery,i (Δt)                                   unit.

The first constrain expresses condition for necessity                           e2,active (Δt) = F2 (rsense , gsense ,bsense )     (6)
to establish a collaboration connection. The second
constrain shows the necessary and sufficient                              Eqn.6 shows that the energy consumption of a sensor
condition for accessibility of the node in the network.                   unit in an active state depends on the sensor radius,
The third constrain means a node should have enough                       the data generation rate, and the number of generated
energy to do network tasks otherwise it is not active                     bits.
and should be removed from the network                                         e3,active (Δt) = F3 (bstore , e(rd),e(wt),tstore ) (7)

                                                                IJSRET @ 2012
International Journal of Scientific Research Engineering &Technology (IJSRET)
Volume 1 Issue2 pp 035-039 May 2012                                 www. ijsret.org         ISSN 2278 – 0882



Energy consumption of a memory unit in an active              their batteries so the nodes must operate without
state depends on the number of stored bits, the               battery replacement for a long time.
number of memory read and write, and the duration
of storage.                                                   REFERENCES
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number of received and transmitted bits, and the
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                                                    IJSRET @ 2012
International Journal of Scientific Research Engineering &Technology (IJSRET)
Volume 1 Issue2 pp 035-039 May 2012                             www. ijsret.org   ISSN 2278 – 0882



Networks," Journal of Communications and
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(AINA-2010), Perth, Australia, 2010.




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Description: Wireless sensor networks (WSNs) depends on their reliable operation for extended times without human intervention. Wireless and ad-hoc deployment, which is essential in some scenarios and cost- effective in others, prevents the use of a wired energy infrastructure. Wireless Sensor Networks usually battery powered, thus energy-constrained, present energy efficiency as the main challenge. Usually in WSNs the communication consumes most of the energy. But recently wireless sensor nodes are introduced that comprise also energy-consuming sensors, apart from the ‘traditional’ ones like temperature, air pressure and humidity sensors. This paper presents the feasible formulation to express the energy consumption of a wireless sensor network application in terms of its energy constituents, effective realization of the intended application in terms of cost, lifetime, and functionality.