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E. Fraccaroli and D. Quaglia
• finding the best assignment (according to given metrics) between software
tasks and hosting nodes by taking into account tasks’ requirements and nodes’
capabilities;
• finding the best set (according to given metrics) of network protocols by taking
into account communication requirements and the presence of a legacy network
infrastructure.
The last distinguishing feature is a strict relationship with the environment. In
many IoT applications, the position of “things” is a constraint for the network.
For instance, networked sensors and actuators should be placed where data should
be acquired, or action should be performed, respectively. This fact affects the
communication architecture significantly. For instance, the position of smart meters
requires the use of radio-frequency bands that can propagate through thick walls.
Finally, the number and position of nodes affect the communications among them
and application performance.
3.2 The Simplified ISO/OSI Reference Model and IoT
This section is devoted to introducing the main telecommunication concepts. It starts
by defining some terms that will be used in the following text. Then, the telecommunication layered architecture is described with the various communication functions.
Finally, the main standardization bodies are introduced.
3.2.1 Fundamental Terminology
3.2.1.1 Network Nodes
A network consists of nodes exchanging data over links. Nodes that host applications
are called end nodes, while nodes that connect links to create the network are called
intermediate systems. Nodes are connected to link through interfaces. In IoT applications, the term Machine-to-Machine (M2M) communications is very common to
emphasize that communications takes place between unmanned “things” and not
people using computers.
3.2.1.2 Links and Topologies
Each link is made of a physical medium, e.g., a radio-frequency band, a copper wire,
or an optical fiber. The physical medium and, optionally, some protocols over it
represent the so-called channel which can be considered an abstract view of the link.
A link can move data in a single direction (unidirectional link), in both directions
E. Fraccaroli and D. Quaglia
• finding the best assignment (according to given metrics) between software
tasks and hosting nodes by taking into account tasks’ requirements and nodes’
capabilities;
• finding the best set (according to given metrics) of network protocols by taking
into account communication requirements and the presence of a legacy network
infrastructure.
The last distinguishing feature is a strict relationship with the environment. In
many IoT applications, the position of “things” is a constraint for the network.
For instance, networked sensors and actuators should be placed where data should
be acquired, or action should be performed, respectively. This fact affects the
communication architecture significantly. For instance, the position of smart meters
requires the use of radio-frequency bands that can propagate through thick walls.
Finally, the number and position of nodes affect the communications among them
and application performance.
3.2 The Simplified ISO/OSI Reference Model and IoT
This section is devoted to introducing the main telecommunication concepts. It starts
by defining some terms that will be used in the following text. Then, the telecommunication layered architecture is described with the various communication functions.
Finally, the main standardization bodies are introduced.
3.2.1 Fundamental Terminology
3.2.1.1 Network Nodes
A network consists of nodes exchanging data over links. Nodes that host applications
are called end nodes, while nodes that connect links to create the network are called
intermediate systems. Nodes are connected to link through interfaces. In IoT applications, the term Machine-to-Machine (M2M) communications is very common to
emphasize that communications takes place between unmanned “things” and not
people using computers.
3.2.1.2 Links and Topologies
Each link is made of a physical medium, e.g., a radio-frequency band, a copper wire,
or an optical fiber. The physical medium and, optionally, some protocols over it
represent the so-called channel which can be considered an abstract view of the link.
A link can move data in a single direction (unidirectional link), in both directions