Sensory environmental monitoring

Introduction

A sensor network (from English sensor network) is a network of very small computers ("nodes"), equipped with sensors, that collaborate on a common task or tasks.

Sensor networks are made up of a group of sensors with certain sensitive and wireless acting capabilities, which allow the formation of ad hoc networks, without pre-established physical infrastructure or central administration.

Wireless sensor networks (in English, wireless sensor networks, abbreviated WSN), also called wireless sensor and actuator networks, WSAN, are spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sounds, pressure, etc. and to cooperatively pass their data over the network to other locations. Most modern networks are bidirectional, allowing control of sensor activity.

A mobile wireless sensor network (MWSN) is a wireless sensor network (WSN) in which the sensor nodes are mobile. MWSNs are smaller than their predecessors. MWSNs are much more versatile than static sensor networks and can be deployed in any scenario and cope with rapid technological changes.

These wireless sensor and actuator networks are used in many industrial and consumer fields, such as industrial process monitoring and control, machine health monitoring, cyber-physical systems, home automation, environmental sensing, etc.

They are characterized by their ease of deployment and by being self-configurable, being able to become a transmitter or receiver at any time, offering routing services between nodes without direct vision, as well as recording data referring to the local sensors of each node. Another of their characteristics is their efficient energy management, which allows them to obtain a high rate of autonomy that makes them fully operational[1].

The increasing miniaturization of computers gave birth to the idea of developing extremely small and cheap computers that communicate wirelessly and organize autonomously. The idea of these networks is to randomly distribute these nodes over a large territory, which the nodes observe until their energy resources are exhausted. The attributes “small”, “cheap” and “autonomous” made the idea known as smart dust (smart dust)[[2]]( Fabs_all.jsp%3Farnumber%3D6550437).

Sensory environmental monitoring

Introduction

A sensor network (from English sensor network) is a network of very small computers ("nodes"), equipped with sensors, that collaborate on a common task or tasks.

Characteristics of a sensor network

Sensor networks have a series of their own characteristics and others adapted from Ad hoc networks:

• - Dynamic Topology: In a sensor network, the topology is changing and they have to adapt to be able to communicate new acquired data.

• - Channel variability: The radio channel is a highly variable channel in which there are a series of phenomena such as attenuation, fast fading, slow fading and interference that can produce errors in the data.

• - No network infrastructure is used: A sensor network does not need any infrastructure to operate, since its nodes can act as senders, receivers or routers of the information. However, it is necessary to highlight in the concept of sensor network the figure of the collector node (also called sink node), which is the node that collects the information and by which the information normally generated is collected in discrete time. This information is generally acquired by a computer connected to this node and it is the computer that has the possibility of transmitting the data through wireless or wired technologies as the case may be.

• - Error tolerance: A sensor device within a sensor network must be able to continue functioning despite having errors in its own system.

• - Multi-hop or broadcast communications: In sensor applications, the use of a protocol that allows multi-hop communications is always characteristic, such as AODV, DSDV, EWMA or others, although it is also very common to use broadcast-based messaging.

• - Energy consumption: It is one of the most sensitive factors because they have to combine autonomy with process capacity, since they currently have a limited energy unit. A sensor node must have an ultra-low consumption processor as well as a radio transceiver with the same characteristic. To this we must add software that also combines this characteristic, making consumption even more restrictive.

• - Hardware limitations: In order to achieve adjusted consumption, it is essential that the hardware be as simple as possible, as well as its radio transceiver, this leaves us with limited processing capacity.

• - Production costs: Given that the nature of a sensor network has to be very high in number, in order to obtain data reliably, the sensor nodes, once their application is defined, are economical to make if they are manufactured in large quantities.

Security in wireless sensor networks

A wireless network uses radio signals to exchange data between two or more physical devices, usually called nodes on the network. The lack of wires allows most limitations of traditional cable networks to be overcome, allowing deployment in hostile environments or mobile scenarios. When the nodes do not depend on any pre-existing infrastructure, wireless networks take the name of wireless ad hoc networks. In this case, communications rely on the nodes' ability to form a multi-hop radio network.[6].

In general terms, several vulnerabilities can be identified in ad hoc networks, and at a very abstract level they can be related to one of the following topics:[7].

• - Channel vulnerability.

The channel can be spied on and injected with fake or forwarded messages on the network.

• - Vulnerability of the nodes.

If an adversary gains full access to a node, they can steal sensitive information, reprogram the node and change its behavior, or physically damage hardware to terminate the node.

The growth in the use and popularity of wireless sensor networks has created concerns regarding their security. Users do not want to reveal their data to unauthorized people who could make malicious use of the disclosed information. This concern is even more relevant for wireless environments where anyone can listen to a message sent by radio frequency.[8].

Therefore, even a useful and convenient system might not be attractive to users if it is not secure. To address this problem, WSN researchers have implemented several security protocols to be used in sensor networks. Examples of such protocols are TinySec and TinyECC.

TinySec, one of the well-known security link layer that uses CBC as its default mode of operation, but studies carried out by the Korea Military Academy and the University of Virginia reveal that security protocols are not being adjusted for these networks in wireless environments. Likewise, studies are being carried out to improve encryption protocols and MAC modes of operation in such a way as to increase security without reducing performance.[9].

References

[1] ↑ Anonimo, . (2001). «Largest Tiny Network Yet - Large-Scale Demonstration of Self-Organizing Wireless Sensor Networks». Consultado el 18 februario 2006.: http://webs.cs.berkeley.edu/800demo/

[2] ↑ J. Hill, D. Culler (2001). «A Wireless Embedded Sensor Architecture for System-Level Optimization». -. - (-). -.: http://citeseer.ist.psu.edu/hill01wireless.html

[3] ↑ J. Rabaey, J. Ammer, J. L. da Silva Jr., D. Patel (2000). «PicoRadio: Ad-hoc Wireless Networking of Ubiquitous Low-Energy Sensor/Monitor Nodes». -. - (-). -.: http://citeseer.ist.psu.edu/550622.html

[4] ↑ J. M. Kahn, R. H. Katz, K. S. J. Pister (1999). «Next Century Challenges: Mobile Networking for "Smart Dust"». -. - (-). -.: http://citeseer.ist.psu.edu/kahn99next.html

[5] ↑ G. Asada, M. Dong, T. S. Lin, F. Newberg, G. Pottie, W. J. Kaiser (1998). «Wireless Integrated Network Sensors: Low Power Systems on a Chip». -. - (-). -.: http://citeseer.ist.psu.edu/278712.html

[6] ↑ Di Pietro, R.; Guarino, S.; Verde, N. V.; Domingo-Ferrer, J. (12 de septiembre de 2014). «Security in wireless ad-hoc networks – A survey». Computer Communications 51: 1. doi:10.1016/j.comcom.2014.06.003. |fechaacceso= requiere |url= (ayuda).: https://dx.doi.org/10.1016%2Fj.comcom.2014.06.003

[7] ↑ Di Pietro, R.; Guarino, S.; Verde, N. V.; Domingo-Ferrer, J. (12 de septiembre de 2014). «Security in wireless ad-hoc networks – A survey». Computer Communications 51: 2. doi:10.1016/j.comcom.2014.06.003. |fechaacceso= requiere |url= (ayuda).: https://dx.doi.org/10.1016%2Fj.comcom.2014.06.003

[8] ↑ Lee, Jongdeog; Kapitanova, Krasimira; Son, Sang H. (3 de diciembre de 2010). «The price of security in wireless sensor networks». Computer Networks 54 (17): 2967. doi:10.1016/j.comnet.2010.05.011. |fechaacceso= requiere |url= (ayuda).: https://dx.doi.org/10.1016%2Fj.comnet.2010.05.011

[9] ↑ Lee, Jongdeog; Kapitanova, Krasimira; Son, Sang H. (3 de diciembre de 2010). «The price of security in wireless sensor networks». Computer Networks 54 (17): 2925. doi:10.1016/j.comnet.2010.05.011. |fechaacceso= requiere |url= (ayuda).: https://dx.doi.org/10.1016%2Fj.comnet.2010.05.011

Characteristics of a sensor network

Sensor networks have a series of their own characteristics and others adapted from Ad hoc networks:

• - Dynamic Topology: In a sensor network, the topology is changing and they have to adapt to be able to communicate new acquired data.

• - Error tolerance: A sensor device within a sensor network must be able to continue functioning despite having errors in its own system.

Security in wireless sensor networks

In general terms, several vulnerabilities can be identified in ad hoc networks, and at a very abstract level they can be related to one of the following topics:[7].

• - Channel vulnerability.

The channel can be spied on and injected with fake or forwarded messages on the network.

• - Vulnerability of the nodes.

If an adversary gains full access to a node, they can steal sensitive information, reprogram the node and change its behavior, or physically damage hardware to terminate the node.

References

[2] ↑ J. Hill, D. Culler (2001). «A Wireless Embedded Sensor Architecture for System-Level Optimization». -. - (-). -.: http://citeseer.ist.psu.edu/hill01wireless.html

[4] ↑ J. M. Kahn, R. H. Katz, K. S. J. Pister (1999). «Next Century Challenges: Mobile Networking for "Smart Dust"». -. - (-). -.: http://citeseer.ist.psu.edu/kahn99next.html

Navegación

Sensory environmental monitoring

Introduction

Sensory environmental monitoring

Introduction

History

Application areas

Characteristics of a sensor network

Security in wireless sensor networks

References

History

Application areas

Characteristics of a sensor network

Security in wireless sensor networks

References