Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
IMPLEMENTATION OF A WIRELESS SENSOR NETWORK PLATFORM FOR MONITORING TEMPERATURE IN A FOREST AREA K. Thirumala 1, V. Pandu Ranga 2 1
2
M.Tech Student, Department of ECE, CMR College of Engineering and Technology, Secunderabad Assistant Professor, Department of ECE, CMR College of Engineering and Technology, Secunderabad 1 Mail id: kurimillathirumala12@gmail.com
limiting factor to acquisition accuracy, pervasiveness
ABSTRACT The Wireless sensor networks (WSN) are well suited for continuous environmental data acquisition for
and cost. Two
technologies
were
traditionally
environment temperature representation. This paper presents the functional design and implementation of a complete WSN platform that can be used for a
considered: the radio-frequency identification (RFID) and the wireless sensor networks (WSN).
range of continuous environmental temperature monitoring in a forest area. The application requirements for low cost, high number of sensors,
While the former is well established for low-cost identification and tracking, WSNs bring forest
fast deployment, long life-time, low maintenance, and high quality of service are considered in the specification and design of the platform and of all its
applications richer capabilities for both sensing and actuation. In fact, WSN solutions already
components. Low-effort platform reuse is also considered starting from the specifications and at all design levels for a wide array of related monitoring
cover a very broad range of applications, and research and technology advances continuously
applications. expand their application field. This trend also Index Terms—Wireless Sensor Networks(WSN), Forest
applications,
long
term
environmental
monitoring applications, WSN optimized design,
increases their use in many applications for versatile low-cost data acquisition and actuation.
WSN platform, WSN protocol. However, the sheer diversity of WSN
I.INTRODUCTION
applications makes increasingly difficult to define
More than a decade ago, the parameters of an environment was coined in which computers were able to access data about objects and environment
“typical” requirements for their hardware and software. In fact, the generic WSN components
without human interaction. It was aimed to complement human-entered data that was seen as a
ISBN NO : 978 - 1502893314
often need to be adapted to specific application
International Association of Engineering and Technology for Skill Development1 91
Proceedings of International Conference on Advancements in Engineering and Technology
requirements and
environmental
conditions.
These ad hoc changes tend to adversely impact
www.iaetsd.in
physical access to the field for deployment and maintenance.
the overall solution complexity, cost, reliability, The generic WSN platforms can be and maintenance that in turn effectively curtail used with good results in a broad class of forest WSN adoption, including their use in forest monitoring
applications.
However,
many
applications. applications (e.g., those in open nature) may To address these issues, the reusable
have stringent requirements, such as very low
WSN platforms receive a growing interest.
cost, large number of nodes, long unattended
These platforms are typically optimized by
service
leveraging knowledge of the target class of
maintenance, which make these generic WSN
applications
platforms less suited.
(e.g.,
domain,
WSN
devices,
time,
ease
of
deployment,
low
phenomena of interest) to improve key WSN This paper presents the application application
parameters,
such
as
cost, requirements,
productivity,
reliability,
the
exploration
of
possible
interoperability, solutions, and the practical realization of a full-
maintenance. custom, reusable WSN platform suitable for use Among the forest application domains,
in low cost long-term environmental monitoring
the environmental/earth monitoring receives a
applications. For a consistent design, the main
growing interest as environmental technology
application requirements for low cost, fast-
becomes a key field of sustainable growth
deployment of large number of sensors, and
worldwide
reliable
Of
environmental
these,
the
monitoring
open is
nature
especially
and
long
unattended
service
are
considered at all design levels. Various trade-
challenging because of, e.g., the typically harsh
offs
between
platform
features
and
operating conditions and difficulty and cost of
specifications are identified, analyzed, and used to guide the design decisions. The development
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development2 92
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
methodology presented can be reused for
nature the maintenance can be also very difficult
platform design for other application domains, or
and costly.
evolutions of this platform.
These considerations make the open nature one of the toughest application fields for
Also,
the
platform
requirements
of large scale WSN environmental monitoring, and
flexibility and reusability for a broad range of the Internet of things applications requirements related applications was considered from the for low cost, high service availability and low start. A real-life application, representative for maintenance
further
increase
their
design
this application domain, was selected and used challenges. as reference throughout the design process. To be cost-effective, the sensor nodes Finally, the experimental results show that the often operate on very restricted energy reserves. platform
implementation
satisfies
the Premature energy depletion can severely limit
specifications. the network service and needs to be addressed
II.RELATED WORK
considering the
WSN environmental monitoring includes both indoor and outdoor applications. The later can fall in the city deployment category (e.g., for traffic, lighting, or pollution monitoring) or the open nature category (e.g., chemical hazard, earthquake and flooding detection, volcano and habitat
monitoring,
weather
forecasting,
precision agriculture). The reliability of any outdoor deployment can be challenged by extreme climatic conditions, but for the open
application requirements for
cost, deployment, maintenance, and service availability. These become even more important for monitoring applications in extreme climatic environments, such as glaciers, permafrost’s or volcanoes.
The
understanding
of
such
environments can considerably benefit from continuous
long-term
monitoring,
but
their
conditions emphasize the issues of node energy management, mechanical and communication hardening,
size,
weight,
and
deployment
procedures.
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development3 93
Proceedings of International Conference on Advancements in Engineering and Technology
Open communication
www.iaetsd.in
nature
deployments
and
configuration-free field deployment procedure
protocol
developments
and
suitable for large scale application deployments.
experiments show that WSN optimization for reliable operation is time-consuming and costly. It
hardly
satisfies
the
forest
applications
requirements for long-term, low-cost and reliable service, unless reusable hardware and software platforms
are
available,
including
flexible
Internet-enabled servers to collect and process the field data for environment applications. This paper contributions of interest for researchers
in
the
WSN
field
can
be
Fig. 1. Example of an ideal WSN deployment for in situ wildfire detection applications.
summarized as: 1) detailed specifications for a demanding WSN application for long-term
III.ENVIRONMENTAL MONITORING
environmental monitoring that can be used to
REQUIREMENTS
analyze the optimality of novel WSN solutions, 2) specifications, design considerations, and
WSN data acquisition for environmental monitoring applications is challenging, especially for open nature fields. These may require large sensor
experimental results for platform components that suit the typical application requirements of
numbers, low cost, high reliability, and long maintenance-free operation. At the same time, the nodes can be exposed to variable and extreme
low cost, high reliability, and long service time, 3) specifications and design considerations for
climatic conditions, the deployment field may be costly and difficult to reach, and the field devices weight, size, and ruggedness can matter, e.g., if they
platform distributed
reusability
for
a
event-based
wide
range
of
are transported in backpacks. Most of these requirements and conditions
environmental
can be found in the well-known application of monitoring applications, and 4) a fast and
wildfire
monitoring
using
in
situ
distributed
temperature sensors and on-board data processing. In
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development4 94
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
its simplest event-driven form, each sensor node
Since these and many related applications
performs periodic measurements of the surrounding
typically use fewer sensor nodes, they are less
air temperature and sends alerts to surveillance
demanding on the communication channels (both in-
personnel if they exceed a threshold. Fig. 1 shows a
field and with the server), and for sensor node energy
typical deployment pattern of the sensor nodes that
and cost. Consequently, the in situ wildfire detection
achieves a good field coverage. For a fast response
application can be used as reference for the design of
time, the coverage of even small areas requires a
aWSN platform
large number
making this
optimized for IoT environmental monitoring and the
application representative for cost, networking and
platform should be easily reusable for a broad class
deployment issues of the event-driven high density
of related applications. Thus, the requirements of
Internet of things application class. In the simplest
aWSN platform for IoT long-term environmental
star topology, the sensor nodes connect directly to the
monitoring can be defined as follows:
gateways, and each gateway autonomously connects
• low-cost, small sensor nodes with on-board
to the server. Ideally, the field deployment procedure
processing,
ensures that each sensor node is received by more
capabilities;
than one gateway to avoid single points of failure of
• low-cost, small gateways (sinks) with self-testing,
the network. This application can be part of all three
error recovery and remote update capabilities, and
WSN categories: event-driven (as we have seen),
supporting
time-driven (e.g., if the sensor nodes periodically
communication;
send the air temperature), and query-driven (e.g., if
• sufficient gateway hardware and software resources
the current temperature can be requested by the
to support specific application needs (e.g., local
operator). This means that the infrastructure that
transducers, and data storage and processing);
supports the operation of this application can be
• detection of field events on-board the gateway to
reused for a wide class of similar long-term
reduce network traffic and energy consumption;
environmental monitoring applications like:
•
• water level for lakes, streams, sewages;
supporting:
• gas concentration in air for cities, laboratories,
—from few sparse to a very large number of nodes;
deposits;
—low data traffic in small packets;
• soil humidity and other characteristics;
• fast and reliable field node deployment procedure;
• inclination for static structures (e.g., bridges, dams);
• remote configuration and update of field nodes;
• position changes for, e.g., land slides;
• high availability of service of field nodes and
• lighting conditions either as part of a combined
servers, reliable data communication and storage at
sensing or
all levels;
standalone, e.g., to detect intrusions in dark places;
• extensible server architecture for easy adaptation to
• infrared radiation for heat (fire) or animal
different IoT application requirements;
of
sensor
nodes,
field
self-testing,
several
and
types
communication
error
of
protocol
recovery
long-range
efficiently
detection.
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development5 95
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
• multiple-access channels to server data for both
for the platform nodes, reducing the deployment cost
human
and errors.
operators
and
automated
processing;
programmable multichannel alerts; • automatic detection and report of WSN platform
IV.WSN NODE DESIGN
faults (e.g., faulty sensor nodes) within hours, up to a day; 3–10 years of maintenance-free service.
In this section will be presented the use of the specifications defined in Section III to derive the specifications of the WSN platform nodes, design space exploration, analysis of the possible solutions, and most important design decisions.
Fig. 2. Tiered structure of the WSN platform The
gateways
process,
store,
and
A. NODE SECTION DESIGN:
periodically send the field data to the application server using long-range communication channels. The application server provides long-term data storage, and interfaces for data access and process by end users (either human or other applications). The platform should be flexible to allow the
Since forest applications may require large numbers of sensor nodes, their specifications are very important for application performance, e.g., the in situ
distributed wildfire detection selected as
reference for the reusable WSN platform design.
removal of any of its tiers to satisfy specific application needs. For instance, the transducers may me installed on the gateways for stream water level monitoring since the measurement points may be spaced too far apart for the sensor node short-range communications. In the case of seismic reflection geological surveys, for example, the sensor nodes may be required to connect directly to an on-site processing server, bypassing the gateways. And when the gateways can communicate directly with the end user, e.g., by an audible alarm, an application server may not be needed.
the sensor node cost reduction. Also, for low application cost the sensor nodes should have a long, maintenance-free service time and support a simple and reliable deployment procedure. Their physical size and weight is also important, especially if they are transported in backpacks for deployment. Node energy
source
can
influence
several
of
its
characteristics. Batteries can provide a steady energy flow but limited in time and may require costly maintenance operations for replacement. Energy harvesting sources can provide potentially endless
In addition to the elements described above, the platform can include an installer device to assist the field operators to find a suitable installation place
ISBN NO : 978 - 1502893314
One of the most important requirements is
energy but unpredictable in time, which may impact node operation. Also, the requirements of these sources
may
increase
node,
packaging
and
International Association of Engineering and Technology for Skill Development6 96
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
deployment costs. Considering all these, the battery
on LCD screen and also if the temperature increased
powered nodes may improve application cost and
beyond threshold voltage then it will send the alert
reliability if their energy consumption can be
message to the authorized person’s mobile through
satisfied using a small battery that does not require
GSM network.
replacement during node lifetime.
Fig.4: Block diagram of Monitoring Section
V.DEVICE IMPLEMENTATION In the following are presented the most
Fig.3: Block diagram of Node section
important In this node section, Node1 send the reading
platform
implementation devices
that
are
choices based
for
the
on
the
of temperature to Node2 then to Node3 then updated in
monitoring
section
by
Zigbee
wireless
transmission. In monitoring section it will send alert
requirements in Sections III and IV and are suitable for long-term environmental monitoring
messages to the authorized person by using GSM internet of applications.
transmission. Similarly at Node2, it has temperature reading. After some delay it will send to Node3 then to the monitoring section. Then to the authorized person.
A. Sensor Node Implementation: Fig. 3 shows several sensor nodes designed for longterm environmental monitoring applications. The node for in situ wildfire monitoring is optimized for
Similarly at Node3 will send the reading to the monitoring section then to the authorized person
cost since the reference application typically requires a high number of nodes (up to tens of thousands).
through GSM.
B. MONITORING SECTION: The
monitoring
section
receives
the
environmental readings from the nodes and displays
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development7 97
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
coordinator implements a priority-based service preemption allowing higher priority service requests to interrupt and take over the gateway control from any lower priority service requests currently being served. This improves the gateway forwarding time of alert messages, for instance. The application tasks implement specific functionalities for the application, such as the message queue, field message handling, sensor node status, field message post processing, RPC, etc. They
Fig.5: (a) firmware structure for reference
are implemented as round-robin scheduled co-
application and (b) operation state flow
routines to spare data memory (to save space and
diagram.
costs the gateway uses only the microcontroller internal RAM). Manual configuration during sensor node deployment
The node microcontroller is an 8 bit
is not necessary because the field node IDs are
ATMEL AT89S52 with 4 KB program and 128 bytes
mapped to the state structure using a memory-
data memory, clocked by its internal 11.0592 MHz
efficient associative array. The node IDs are added as
crystel oscillator (to reduce the costs and energy
they become active in gateway range up to
consumption, since it does not need accurate
1000 sensor nodes and 10 peer gateways, while
timings). The full custom 2 KB program has the
obsolete or old entries are automatically reused when
structure in Fig. 5(a). A minimal operating system
needed.
supports the operation of the main program loop shown in Fig. 5(b) and provides the necessary interface with the node hardware, support for node self-tests, and the communication protocol.
B. Gateway Node Implementation: Fig. 6 shows the layers of the full custom software structure of the gateway. The top-level operation is controlled by an application coordinator. On the one hand, it accepts service requests from various gateway tasks (e.g., as reaction to internal or external events, such as message queue nearly full or alert
message
received
from
field
sensors,
Fig.6: Gateway firmware block diagram. In
fact,
gateways
deployed
inside
respectively).On the other hand, the coordinator triggers the execution of the tasks needed to satisfy the service request currently served. Also, the
ISBN NO : 978 - 1502893314
sewages
for
level
monitoring
applications
receiving data from one sensor node and no
International Association of Engineering and Technology for Skill Development8 98
Proceedings of International Conference on Advancements in Engineering and Technology
peers operate for one year on 19 Ah batteries,
field
which
theoretical
communication segments, with latency-energy
calculations above. It is also worth noting that
trade-offs, and the fast and ubiquitous end user
the gateway average current can be further
field
reduced by using the hardware SPI port to
applications). The full custom server software
interface
has the structure shown in Fig. 8. It provides
is
consistent
with
the
with
radio
the
devices
and
by
data.
data
It
www.iaetsd.in
bridges
access
(by
the
low
humans
power
or
IoT
programming the latter to autonomously scan for
interfaces for:
incoming packets instead of the software-
• field nodes (gateways);
controlled LPL over a software SPI port
• the operators and supervisors for each field;
emulation used currently.
• various alert channels; • external access for other IoT systems. Each interface has a processing unit that includes, e.g., the protocol drivers. A central engine controls the server operation and the access to the main database. It is written in Java, uses a MySQL database and runs on a
Fig.7: Block structure of the deployment
Linux operating system. Two protocols are used to interface with the field nodes (gateways) for
device. an
energy-efficient
communication
over
The repeater node uses the gateway unreliable connections: normal and service (boot design with unused hardware and software loader) operation. The normal operation protocol components removed. acknowledges each event upon reception for an
VI. APPLICATION SERVER incremental release of gateway memory The main purpose of a WSN application server is to receive, store, and provide access to
ISBN NO : 978 - 1502893314
even
for
prematurely
interrupted
communications. Messages and acknowledges
International Association of Engineering and Technology for Skill Development9 99
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
can be sent asynchronously to improve the
its lifetime. For example, Fig. 12 shows some
utilization
typical deployments for the reference application
of
high
latency
communication
channels.
nodes. Node deployment can be a complex,
Time
is
time-consuming, error-prone, and manpower-
avoided at every communication level. The
intensive operation, especially for applications
gateways timestamp the field messages and
with a large number of nodes. Thus, it needs to
events using their relative time and the server
be guided by automatic checks, to provide quick
converts it to real-world time using an offset
and easy to understand feedback to field
calculated
gateway
operators, and to avoid deployment-time sensor
communication session. The protocol for the
or gateway node configuration. The check of
boot loader mode is stateless, optimized for
node connectivity with the network is important
large data block transfers and does not use
for star topologies and especially for transmit-
acknowledges. The gateway maintains the
only nodes (like the reference application sensor
transfer state and incrementally checks and
nodes). These nodes cannot use alternative
builds the firmware image. An interrupted
message routing if the direct link with the
transfer can also be resumed with minimal
gatewayis lost or becomes unstable.
at
synchronization
the
begin
of
overhead
the
overhead.
The
deployment
procedure
of
the
sensor node of the reusable WSN platform takes
VII. FIELD DEPLOYMENT
into account the unidirectional communication capabilities of the sensor nodes. It is also
PROCEDURE designed to avoid user input and deploymentThe node deployment procedure of the time configurations on the one hand, and a fast WSN platform aims to install each node in a field automatic
assessment
of
the
deployment
location both close to the application-defined position and reliable concurrent neighbor node position and that ensures a good operation over deployment on the
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development10 100
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
other hand. The sensor nodes are temporarily
deployment state, (b) display position suitability.
switched to deployment operation by activating
The deployment device collects all the data, and
their on-board REED switch using a permanent
computes and
magnet in the deployment device, as shown in
displays an assessment of deployment position
Fig.8(a). This one-bit near field communication
suitability. No gateway or node configuration is
(NFC) ensures a fast, reliable, input-free node
required and the procedure can be repeated
selectivity. Its device ID is collected by the
until a suitable deployment position is found.
deployment device that listens only for strong deployment messages. These correspond to nodes within just a few meters providing an
VIII.RESULTS effective insulation from collecting IDs of nearby Power supply circuit schematic: concurrent node deployments. The gateways that receive the sensor node deployment messages report the link quality with the node [see Fig. 8(b)].
Node section schematic:
Fig.8: Field deployment of sensor nodes: (a) use deployment device magnet to set to deployment state, (b) display position suitability.
Field deployment of sensor nodes: (a)
Monitoring Section Schematic:
use deployment device magnet to set to
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development11 101
Proceedings of International Conference on Advancements in Engineering and Technology
IX. CONCLUSION In proposed method power consumption will be reduced.
Long range
communication
will
be
provided. The security is high. The application requirements for low cost, high number of sensors, fast deployment, long lifetime, low maintenance, and high quality of service are considered in the specification and design of the WSN platform and of all its components.
REFERENCES [1] K. Romer and F. Mattern, “The design space of wireless sensor networks,” IEEE Wireless Commun., vol. 11, no. 6, pp. 54–61, Dec. 2004. [2] I. Talzi, A. Hasler, S. Gruber, and C. Tschudin, “Permasense: Investigating permafrost with a WSN in the Swiss Alps,” in Proc. 4th Workshop Embedded Netw. Sensors, New York, 2007, pp. 8–12. [3] P. Harrop and R. Das,Wireless sensor networks 2010–2020, IDTechEx Ltd, Cambridge, U.K., 2010. [4] N. Burri, P. von Rickenbach, and R. Wattenhofer, “Dozer: Ultra-low power data gathering in sensor
ISBN NO : 978 - 1502893314
www.iaetsd.in
networks,” in Inf. Process. Sensor Netw., Apr. 2007, pp. 450–459. [5] I. Dietrich and F. Dressler, “On the lifetime of wireless sensor networks,” ACM Trans. Senor Netw., vol. 5, no. 1, pp. 5:1–5:39, Feb. 2009. [6] B. Yahya and J. Ben-Othman, “Towards a classification of energy aware MAC protocols for wireless sensor networks,” Wireless Commun. Mobile Comput., vol. 9, no. 12, pp. 1572–1607, 2009. [7] J. Yang and X. Li, “Design and implementation of low-power wireless sensor networks for environmental monitoring,” Wireless Commun., Netw. Inf. Security, pp. 593–597, Jun. 2010. [8] K. Martinez, P. Padhy, A. Elsaify, G. Zou, A. Riddoch, J. Hart, and H. Ong, “Deploying a sensor network in an extreme environment,” Sensor Netw., Ubiquitous, Trustworthy Comput., vol. 1, pp. 8–8, Jun. 2006. [9] A. Hasler, I. Talzi, C. Tschudin, and S. Gruber, “Wireless sensor networks in permafrost research— Concept, requirements, implementation and challenges,” in Proc. 9th Int. Conf. Permafrost, Jun. 2008, vol. 1, pp. 669–674. [10] J. Beutel, S. Gruber, A. Hasler, R. Lim, A. Meier, C. Plessl, I. Talzi, L. Thiele, C. Tschudin, M. Woehrle, and M. Yuecel, “PermaDAQ: A scientific instrument for precision sensing and data recovery in environmental extremes,” in Inf. Process. Sensor Netw., Apr. 2009, pp. 265–276. [11] G. Werner-Allen, K. Lorincz, J. Johnson, J. Lees, and M. Welsh, “Fidelity and yield in a volcano
International Association of Engineering and Technology for Skill Development12 102
Proceedings of International Conference on Advancements in Engineering and Technology
www.iaetsd.in
monitoring sensor network,” in Proc. 7th Symp. Operat. Syst. Design Implement., Berkeley, CA, 2006, pp. 381–396. [12] G. Barrenetxea, F. Ingelrest, G. Schaefer, and M. Vetterli, “The hitchhiker’s guide to successful wireless sensor network deployments,” in Proc. 6th ACM Conf. Embedded Netw. Sensor Syst., New York, 2008, pp. 43–56.
ISBN NO : 978 - 1502893314
International Association of Engineering and Technology for Skill Development13 103