172 Software Networks
and the Internet. Finally, we shall touch on a few ideas about one of
the most rapidly developing types of networks: medical sensor
networks, which could potentially affect seven billion people, and
constitute a truly enormous potential market.
6.17. Sensor networks
A sensor network is defined as a set of interconnected sensors, with
each sensor having a transmitter-receiver. Sensor networks form a
new generation of networks with specific properties, which do not fit
into the framework of conventional architectures. However, the dawn
of the Internet of Things has altered our view of sensor networks,
which may, of course, still constitute a closed system, but also connect
to the Internet.
The miniaturization of the sensors poses problems in terms of
communication and energy resources. The sensor needs to be
sufficiently intelligent to gather the required information and transmit
it correctly. In addition, the sensor’s processor must not be used too
intensively, so as to consume as little energy as possible. Thus, it must
incorporate reactive elements, rather than cognitive ones. Finally, in
order to ensure a good data rate, the range of the transmitter-receivers
must necessarily be small – around ten meters. Therefore, the
establishment of a sensor network poses problems of routing, error
control and power management.
Very special sensors are involved in what we call “smart dust”.
These dust particles, which are practically invisible, have a radio
device in addition to performing the computations relating to the
internal sensor.
From the standpoint of communication, the environment of IP is
too intensive, leading to an excessive data rate and overconsumption.
Solutions derived from terrestrial networks, or industrial real-time
networks, offer a better compromise between efficiency and power
consumed. As there may be hundreds of such sensors per square
meter, IPv6 routing represents one obvious solution to deal with the
problem of addresses. However, the IP environment is cumbersome,
www.it-ebooks.info
and the Internet. Finally, we shall touch on a few ideas about one of
the most rapidly developing types of networks: medical sensor
networks, which could potentially affect seven billion people, and
constitute a truly enormous potential market.
6.17. Sensor networks
A sensor network is defined as a set of interconnected sensors, with
each sensor having a transmitter-receiver. Sensor networks form a
new generation of networks with specific properties, which do not fit
into the framework of conventional architectures. However, the dawn
of the Internet of Things has altered our view of sensor networks,
which may, of course, still constitute a closed system, but also connect
to the Internet.
The miniaturization of the sensors poses problems in terms of
communication and energy resources. The sensor needs to be
sufficiently intelligent to gather the required information and transmit
it correctly. In addition, the sensor’s processor must not be used too
intensively, so as to consume as little energy as possible. Thus, it must
incorporate reactive elements, rather than cognitive ones. Finally, in
order to ensure a good data rate, the range of the transmitter-receivers
must necessarily be small – around ten meters. Therefore, the
establishment of a sensor network poses problems of routing, error
control and power management.
Very special sensors are involved in what we call “smart dust”.
These dust particles, which are practically invisible, have a radio
device in addition to performing the computations relating to the
internal sensor.
From the standpoint of communication, the environment of IP is
too intensive, leading to an excessive data rate and overconsumption.
Solutions derived from terrestrial networks, or industrial real-time
networks, offer a better compromise between efficiency and power
consumed. As there may be hundreds of such sensors per square
meter, IPv6 routing represents one obvious solution to deal with the
problem of addresses. However, the IP environment is cumbersome,
www.it-ebooks.info