1 IoT Fundamentals: Definitions, Architectures, Challenges, and Promises
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– There are other sensors and controllers available and the choice of which one
to be used depends on the problem to be solved and the resources available.
There are several factors to consider when selecting a sensor. What are its
lifetime maintenance costs? Can it be mounted on existing infrastructure?
What is the cost of operation? Can it store its own data, or must it be
transmitted to the cloud immediately? If such a connection is needed, is it
available? How can this sensor interoperate with other such sensors? Can
it scale? Once these questions are answered, then a tradeoff analysis can
be conducted and the appropriate sensors can be selected. This is another
reason why it is more efficient for the different departments of a city to work
in concert, as they can leverage sensors and infrastructure to solve multiple
problems.
• City Layer: The next layer is the city layer. This is above the street layer
and provides the connectivity for the myriad devices in use at the lower layer.
This means the network routers and switches are at this layer along with the
communications protocols that allow the connected devices to exchange data.
This is also the edge layer and the start of data processing. Some sensor data will
be time sensitive, while others must be cleaned or reordered before transmission
to the higher levels. A resilient and reliable network is therefore a necessity
at this layer. Often, the networking equipment will be placed outdoors or in a
harsh environment and therefore must be designed to work under inhospitable
conditions. A malfunction at this layer may cause automated false alarms due to
missing or mishandled data.
• Data Center Layer: When the data has been collected at the edge and transmitted,
possibly over different transport protocols, it is delivered to the next layer up, the
data center layer. This is where the final analysis is performed, and the results
of these analytics are stored for further use. Therefore, analytics, storage, and
some method of making results available are the primary functions at this layer.
As previously discussed, the cloud plays a major role at this stage, providing the
required storage and processing power.
• Services Layer: The services layer is the final layer in the Internet of Things
smart city model. At this point, the results of the sensor data are provided to
applications that make use of it – for example, a visualization tool to show the
real-time status of traffic in the city. City managers, law enforcement, and private
citizens should all have access to the data. City managers will want to ensure
that the city is running smoothly and could use the data to find opportunities to
conserve energy, for instance, or to check on the status of waste removal in a
given neighborhood. Law enforcement could be verifying that tolls were paid or
the payment made for the use of a public parking space, among other things. A
private citizen could be looking for an open parking space or for the speediest
path to the other side of the city. Once the sensors are in place and the data made
available, then the city is ready to reap the benefits of the Internet of Things.
35
– There are other sensors and controllers available and the choice of which one
to be used depends on the problem to be solved and the resources available.
There are several factors to consider when selecting a sensor. What are its
lifetime maintenance costs? Can it be mounted on existing infrastructure?
What is the cost of operation? Can it store its own data, or must it be
transmitted to the cloud immediately? If such a connection is needed, is it
available? How can this sensor interoperate with other such sensors? Can
it scale? Once these questions are answered, then a tradeoff analysis can
be conducted and the appropriate sensors can be selected. This is another
reason why it is more efficient for the different departments of a city to work
in concert, as they can leverage sensors and infrastructure to solve multiple
problems.
• City Layer: The next layer is the city layer. This is above the street layer
and provides the connectivity for the myriad devices in use at the lower layer.
This means the network routers and switches are at this layer along with the
communications protocols that allow the connected devices to exchange data.
This is also the edge layer and the start of data processing. Some sensor data will
be time sensitive, while others must be cleaned or reordered before transmission
to the higher levels. A resilient and reliable network is therefore a necessity
at this layer. Often, the networking equipment will be placed outdoors or in a
harsh environment and therefore must be designed to work under inhospitable
conditions. A malfunction at this layer may cause automated false alarms due to
missing or mishandled data.
• Data Center Layer: When the data has been collected at the edge and transmitted,
possibly over different transport protocols, it is delivered to the next layer up, the
data center layer. This is where the final analysis is performed, and the results
of these analytics are stored for further use. Therefore, analytics, storage, and
some method of making results available are the primary functions at this layer.
As previously discussed, the cloud plays a major role at this stage, providing the
required storage and processing power.
• Services Layer: The services layer is the final layer in the Internet of Things
smart city model. At this point, the results of the sensor data are provided to
applications that make use of it – for example, a visualization tool to show the
real-time status of traffic in the city. City managers, law enforcement, and private
citizens should all have access to the data. City managers will want to ensure
that the city is running smoothly and could use the data to find opportunities to
conserve energy, for instance, or to check on the status of waste removal in a
given neighborhood. Law enforcement could be verifying that tolls were paid or
the payment made for the use of a public parking space, among other things. A
private citizen could be looking for an open parking space or for the speediest
path to the other side of the city. Once the sensors are in place and the data made
available, then the city is ready to reap the benefits of the Internet of Things.