Page 402 - Unleashing the potenti al of the Internet of Things

4 Unleashing the potential of the Internet of Things

• Actuator:

– It requests the necessary sensed data and reference values from the gates via the ad-hoc
network.

– It requests from the SCN controllers via the central communication channel aggregate
values, which are necessary for a decision but cannot be calculated by the actuator itself.
– It receives from the gates via the ad-hoc network the requested sensed data and reference
values and calculates the other necessary reference values and aggregate values.
– It receives from the SCN controllers via the central communication channel the requested
aggregate values.
– It forms the appropriate control commands.

– It transmits to the SCN controllers information about its own status via the central
communication channel.
• Mote:

– It receives requests from the SCN controllers and the gates via the SCN infrastructure about
sensed data or reference values.

– It transmits the requested data to the SCN controllers and the gates via the SCN
infrastructure.

7.3.2.3 Decision-making process

The decision-making process follows the following procedure:
1) The necessary sensed data, reference values and aggregated values are kept in the SCN
controllers' memory and regularly updated.
2) Each gate forwards sensed data and reference values from the motes to the actuators.

3) Each actuator sends requests for sensed data and reference values to the gates, and then
stores the received ones in memory. The data requests can be of different types, such as
broadcast request (the gates send data of all motes on demand to the actuator), threshold-
exceeding request (gates send data only of the motes whose sensed data exceed some
thresholds), etc.
4) Some other reference values can be regularly computed as needed by the actuators based on
received sensed data and reference values.
5) Each actuator needs to have the up-to-date aggregate values necessary to make a decision.
These aggregate values can be computed by the actuator itself or fetched from the SCN
controllers.
6) Each actuator forms a control command depending on the aggregate values.

An example of flow chart for ad-hoc configuration is shown in Figure 7-5.

388 Rec. ITU-T Y.4250/Y.2222 (04/2013)