Internet of Things – Architecture © - 92 -
adds a translation functionality for converting IP to 6LoWPAN, TCP to UDP,
HTTP to CoAP and vice versa.
This gateway configuration may be used in the recurring example to let the
Mote Runner Node communicate using ZigBee technology with the Alarm
Service deployed in a server farm thanks to the two gateways.
While the actual configuration of the different protocol stacks is out of the scope
of the model, the overall behaviour of the system can be modelled according to
the five interoperability aspects described above.
3.6.3.2 Virtual configuration
In this configuration the IoT Communication Model aims at describing the
overall communication behaviour of a system, where the actual communication
path is virtualised by tunnelling the communication using a second protocol
stack.
Figure 22 : Virtual configuration for multiple protocol stacks.Figure 22 exemplifies the modelling of a system behaviour using a virtual
configuration: here, there is an inner communication path composed of an
Ethernet network and a WiFi network using a bridging block and an outer
communication path that is independent of the inner path and allows for the two
application layers to communicate. Such a scheme is usually realised using
virtual private network solutions.
3.6.4 Channel model for IoT communication
This model aims at detailing and modelling the content of the channel in the
Shannon-Weaver model in the context of the IoT domain. This model does not
pretend to capture every possible characteristic of IoT technologies, but
provides a common ground to be used to compute overall system performance
and for benchmarking. Further models have to be considered in order to
account for more specific physical aspects.