Internet of Things – Architecture © - 95 -
Figure 27 : IoT channel for communication constrained to unconstrained networks.An additional case consists of a channel formed by two constrained networks
intermediated by an unconstrained network. A common implementation of this
case us the most important in the IoT: the one involving two constrained
networks linked by the Internet (see Figure 28 ).
Figure 28 : IoT channel for communication over two constrained networks intermediated
by the Internet.
What makes IoT very peculiar is the nature of the constrained networks it relies
on. Such networks are formed by constrained Devices and the communication
between the Devices can:
Be based on different protocols; Require additional processing in the gateways.It is important to point out that the characteristics of each network can have a
noticeable impact on the overall end-to-end communication.
In the previous section we tackled the channel capacity using the Shannon-
Hartley theorem and the min operation in order to aggregate multiple hops.
Obviously the channel capacity is not the only important metric when modelling
the IoT communication.