In the modern world, billions of physical sensors are used for various dedications: Environment Monitoring, Healthcare, Education, Defense, Manufacturing, Smart Home, Agriculture Precision and others. Nonetheless, they are frequently utilized by their own applications and thereby snubbing the significant possibilities of sharing the resources in order to ensure the availability and performance of physical sensors. This paper assumes that the immense power of the Cloud can only be fully exploited if it is impeccably integrated into our physical lives. The principal merit of this work is a novel architecture where users can share several types of physical sensors easily and consequently many new services can be provided via a virtualized structure that allows allocation of sensor resources to different users and applications under flexible usage scenarios within which users can easily collect, access, process, visualize, archive, share and search large amounts of sensor data from different applications. Moreover, an implementation has been achieved using Arduino-Atmega328 as hardware platform and Eucalyptus/Open Stack with Orchestra-Juju for Private Sensor Cloud. Then this private Cloud has been connected to some famous public clouds such as Amazon EC2, ThingSpeak, SensorCloud and Pachube. The testing was successful at 80%. The recommendation for future work would be to improve the effectiveness of virtual sensors by applying optimization techniques and other methods.

1. International Journal of Research in Computer Science
eISSN 2249-8265 Volume 3 Issue 1 (2013) pp. 19-25
www.ijorcs.org, A Unit of White Globe Publications
doi: 10.7815/ijorcs. 31.2013.057
FROM PHYSICAL TO VIRTUAL WIRELESS
SENSOR NETWORKS USING CLOUD COMPUTING
Maki Matandiko Rutakemwa
PhD Student, Computer Science, Christ University Bangalore, INDIA
Email: makinsoft@gmail.com, makimatandiko.rutakemwa@christuniversity.in
Abstract: In the modern world, billions of physical But the two hallmark features of sensor networks,
sensors are used for various dedications: Environment namely customized network applications and the
Monitoring, Healthcare, Education, Defense, collaborative in-network processing, are not
Manufacturing, Smart Home, Agriculture Precision achievable beyond the boundary of the users'
and others. Nonetheless, they are frequently utilized by administrative domains (except for limited scope data
their own applications and thereby snubbing the sharing through Internet gateways).
significant possibilities of sharing the resources in
We argue that even quite mature networking and
order to ensure the availability and performance of
duty cycling protocols for sensor networks exists, but
physical sensors. This paper assumes that the immense
approaches to wireless sensor network sharing and
power of the Cloud can only be fully exploited if it is
management are still immature.
impeccably integrated into our physical lives. The
principal merit of this work is a novel architecture In particular, typical wireless sensor networks are
where users can share several types of physical designed and deployed to serve a single application.
sensors easily and consequently many new services Indeed, the common approach in the design of sensor
can be provided via a virtualized structure that allows networks is to deploy networks that are fit-for-purpose
allocation of sensor resources to different users and with the primary aim of supporting a single application
applications under flexible usage scenarios within that belongs to a single authority (usually the owner of
which users can easily collect, access, process, the infrastructure)[13]. While this is a sensible
visualize, archive, share and search large amounts of approach for short-term and small-scale deployments,
sensor data from different applications. Moreover, an in sensor network deployments that consist of
implementation has been achieved using Arduino- thousands of nodes with a life span of multiple years,
Atmega328 as hardware platform and inducing high costs of deployment and maintenance,
Eucalyptus/Open Stack with Orchestra-Juju for the single application approach can lead to inefficient
Private Sensor Cloud. Then this private Cloud has use of resources and low cost-benefit results.
been connected to some famous public clouds such as Moreover, the requirement for dedicated sensing
Amazon EC2, ThingSpeak, SensorCloud and Pachube. infrastructure to support new applications belonging to
The testing was successful at 80%. The different organizations can lead to unnecessary
recommendation for future work would be to improve replication of sensing infrastructure. One example that
the effectiveness of virtual sensors by applying illustrates this problem is the deployment of
optimization techniques and other methods. temperature sensors on a single environment by
different authorities (Government, University, Social
Keywords: Virtual Wireless Sensor Networks,
Agency, Hospital and others.
Ubiquitous Computing, Cloud Computing
In this work we propose a departure from the notion
I. INTRODUCTION of sensor networks aimed at supporting a single
application and serving a single user. We introduce a
Wireless sensor networks have been traditionally
tactic that is based on the separation of substructure
designed to be privately owned and used. Therefore,
and application ownership.
an increasing number of sensor networks have been
deployed to monitor a variety of conditions and The primary objective of this work is to create a
situations. At the same time, more and more framework that allows sensor network infrastructures
applications are starting to rely on the data from sensor to be shared among multiple applications that can
networks to provide users with (near) real-time potentially belong to different authorities. By
information and conditions. This increasing demand of achieving this level of partaking, sensing
users for accurate information about natural and infrastructures can be viewed as an accessible resource
surrounding phenomena is creating a business case for that can be dynamically re-purposed and re-
application providers.
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2. 20 Maki Matandiko Rutakemwa
programmed by different authorities, in order to support for multiple gateways. Most communication is
support multiple applications. done by addressing individual devices. As device
addresses are related to the gateway being used,
The main task in apprehending this journey is the
changing the gateway on the fly is difficult.Users need
design of a novel wireless sensor network architecture
to know the specifications of different kinds of
that supports multiple applications, dynamically
physical sensors.
uploaded by different owners and simultaneously
running over a shared infrastructure. OGC (Open Geospatial Consortium) [9] defined
Sensor Modeling Language (SensorML) [1] to provide
In this work we illustrate our efforts in exploring
standard models and an XML encoding for physical
this vision. The key characteristics of our approach
sensors’ description and measurement processes.
are:
SensorML can represent the metadata for any physical
i. A virtualization layer that is running on each sensor
sensor (such as the type of physical sensor, the
node abstracts the access to sensor resources and
location, and the accuracy). We used SensorML to
allows the management of these resources through
describe the metadata of physical sensors. We have
policies expressed by the infrastructure owner.
added the mapping between physical sensors and
ii. A runtime environment on each node that allows
virtual sensors to describe how to translate commands
multiple applications to run inside each node.
coming from users to virtual sensors into commands
iii. A policy based application deployment that enables
for the corresponding physical sensors.
multiple applications to be deployed over the shared
infrastructure. Although there are many kinds of physical sensors,
no application uses all of them. Each application needs
The following sections offer an overview of the
sufficient physical sensors for its requirements (such as
architecture and a description of our implementation.
physical sensors in a certain location). A
We have discussed the related work in Section 2. publish/subscribe mechanism [11] is used to select
We present an overview of our proposed architecture physical sensors in [8]. When there are multiple sensor
in Section 3, the details of our implementation are in networks, each sensor network publishes sensor data
Section 4 and conclude while projecting future and metadata that describes the type of physical
research opportunities in Section. sensors. Each application subscribes to one or more
sensor networks to receive a real-time data stream
II. RELATED WORKS from their physical sensors. Such publish/subscribe
mechanism allows each application to select only a
There have been a few of studies on the
particular type of physical sensors it collects data from.
virtualization of physical wireless sensor networks.
Sensor-Cloud infrastructure makes virtual sensors
Naturally, the design we propose here shares some of
from multiple physical sensors. Because every virtual
the design goals that are common to other research
sensor is not created from a sensor network, the
projects, while addressing unique problems that are
grouping is more flexible. Users can select groups of
complementary in nature.
virtual sensors or virtual sensors.
The goal of the urban participatory sensing project
Users should check whether the physical sensors
at the Center for Embedded Networked Sensing
are available and detect physical sensors’ faults for
(CENS) is to engage sensors built into portable devices
keeping the quality of the data coming from physical
such as mobile phones and PDAs in sharing their
sensors. FIND [13] provided a novel method to detect
capabilities [10]. A tiered architecture and related
physical sensors with data faults. FIND ranks the
protocols for people-centric urban sensing is under
physical sensors based on their sensing readings as
development as part of the MetroSense project at
well as their physical distances from an event. FIND
Dartmouth, which involves mobile devices in
considers a physical sensor(s) faulty if there is a
opportunistic interactions with wireless Internet
significant mismatch between the sensor data rank and
gateways and available static sensornet infrastructure
the distance rank. This approach focuses on detecting
[5].
physical sensor(s) faults, while we focus on
Mires [6] is a publish/subscribe architecture for monitoring the virtual sensors. Because there is a
WSNs. Basically sensors only publish readings if the relationship between the status of a virtual sensor and
user has subscribed to the specific sensor reading. the status of its sensors, the virtual sensor will also
Messages can be aggregated in cluster heads. report incorrect results if the linked physical sensors
Subscriptions are issued from the sink node (typically are faulty. The users of the cloud computing service
directly connected to a PC), which then receives all check the status of their virtual servers, not the status
publications. of the linked physical server. We also focus on
TinySIP [7] supports session semantics, monitoring the status of virtual sensors.
publish/subscribe, and instant messaging. It offers
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3. From Physical to Virtual Wireless Sensor Networks using Cloud Computing 21
III. VIRTUAL WIRELESS SENSOR NETWORK
INFRASTRUCTURE
Let us now explore how one can temporarily
“borrow” several nodes from several separate domains,
virtual sensors that extend the area of coverage beyond
some physical boundary. Figure 1: Virtual vs Physical Sensors
A. Assumptions Standardization: Different kinds of physical sensors have
Our motivation is to explore the possibilities of different specifications. Each physical sensor provides its
forming scalable virtual wireless sensor network under own functions for control and data collection. Standard
mechanism enables users to access sensors without
the following design assumptions:
concern for the differences among the physical sensors.
−A group of users (private, corporate and/or Standard functions for virtual sensors, are used so that
Government) is willing to deploy sensor node the users can access the virtual sensors with the
hardware to cover areas under their power. standardized functions. Cloud infrastructure translates the
− There exists a level of willingness from all members standard functions for the virtual sensors into specific
of the group to share the sensing and processing functions for the different kinds of physical sensors.
capabilities of their physical sensors’ infrastructure This virtualization implies the following layers of the
as needed, without interruption. architecture :
− A typical user belonging to the group often borrows
− A virtualization layer that is running on each sensor
sensor node capabilities from parts of other sensor
network infrastructure to form a virtual sensor node, abstracts access to sensor resources and allows
network over a desired area of coverage. the management of these resources through policies
expressed by the infrastructure owner.
− The rules of sharing are dictated by the owner of the
− A runtime environment on each node that allows
resource and at no time the sensing task of a local or
remote user violates the authority, privacy and multiple applications to run inside each node.
security of the provider. − A policy based application deployment that enables
− Optionally, a supporting business model accounts multiple application to be deployed over the shared
for balancing the cost of sharing resources (such as infrastructure.
hardware and battery costs) between private and
community use.
When users request virtual sensors, the Cloud
infrastructure automatically provisions them from their
templates. Users can control their virtual sensors
directly or via their Web browsers. Cloud
infrastructure also provides the users with monitoring
functions for the virtual sensors.
B. Steps
The steps to be achieved in the process are:
Virtualization: There are various kinds of scattered
physical sensors. Virtual sensor enables the use of
sensors without worrying about the locations and the
specifications of physical sensors. Fig.2 describes the
relationships between virtual sensors and physical Figure 2: Application – Architecture
sensors. Each virtual sensor is created from one or
more physical sensors. Users can create virtual sensors
and freely use them as if they owned sensors. For
example, they can activate or inactivate their virtual
sensors, check their status, and set the frequency of
data collection from them. If multiple users freely
control the physical sensors, some inconsistent
commands may be issued. The users can freely control
their own virtual sensors by virtualizing the physical
sensors as virtual sensors. Figure 3: Mapping Physical - Virtual Sensors
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4. 22 Maki Matandiko Rutakemwa
C. Major Actors
Sensor Owner: A sensor owner is an actor who owns
his physical sensors. A sensor owner allows others to
use those physical sensors through Cloud
infrastructure. A sensor owner registers the physical
sensors with their properties to the Cloud. The owner
deletes the registration of them when s/he quits sharing
them.
Cloud Administrator: is the actor who manages the
Cloud Infrastructure service. The administrator Figure 5: Arduino Uno Atmega 328, Arduino Ethernet
manages the IT resources for the virtual sensors, Shield, LDR Sensor, LM35 Sensor
monitoring, and the user interfaces.
Figure 6: Arduino Uno, Arduino Ethernet Shield and
sensors connected to the System running Ubuntu 11.10
Figure 4: Federation of Clouds - Cloud Administrator
End User: An end user is an actor with one or more
applications or services that use the sensor data. An
end user requests the use of virtual sensor that satisfies
the requirements from the templates. The user can
control her/his virtual sensors directly or via a Web
browser. The user can monitor the status of the virtual
sensors. When they become unnecessary, the user can
release them. The end users can use the virtual sensors
by paying for usage and with no detailed knowledge
about the physical sensors.
IV. IMPLEMENTATION AND DEVELOPMENT Figure 7: Ubuntu 11.10 with Eucalyptus connected to the
hardware for Private Cloud with virtual sensors
− Using Arduino Uno Atmega 328 and Arduino Shield
along with an LDR sensor and a LM35 sensor, a
prototype of the architecture has been implemented
and tested as shown in Figure 6.
− Firstly Ubuntu 11.10 has been installed on 2 systems
to constitute a private cloud. To this cloud the two
physical sensors have been connected using the
Arduino Shield, Figure 7.
− Next, the private cloud based mainly on Eucalyptus
structure was connected to several public clouds
such as Pachube, ThingSpeak, Amazon EC2,
SensorCloud and Github shown in Figure 8.
Figure 8: Connection to Pachube from Private Cloud
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5. From Physical to Virtual Wireless Sensor Networks using Cloud Computing 23
Figure 9: Temperature and Light Graphs on Pachube after sending readings from physical sensors
Figure 10: Connection to ThingSpeak Public Cloud with LDR readings graph generation
Figure 11: Connection to SensorCloud Public Cloud
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6. 24 Maki Matandiko Rutakemwa
Figure 12: Temperature readings sent to ThingSpeak Public Cloud
V. CONCLUSION [2] J. Hill, R. Szewczyk, A. Woo, S. Hollar, D. Culler, K.
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7. From Physical to Virtual Wireless Sensor Networks using Cloud Computing 25
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How to cite
Maki Matandiko Rutakemwa, "From Physical to Virtual Wireless Sensor Networks using Cloud Computing".
International Journal of Research in Computer Science, 3 (1): pp. 19-25, January 2013. doi: 10.7815/ijorcs.
31.2013.057
www.ijorcs.org