Page 398 - 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 motes via the SCN
infrastructure.
– It requests from the SCN controllers via the central communication channel the aggregate
values which are necessary for decision making but cannot be calculated by the actuator
itself.
– It receives from the motes via the SCN infrastructure 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 actuators via the SCN infrastructure
about sensed data or reference values.

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

7.2.3 Decision-making process
The decision-making process follows the following procedure:

1) The necessary sensed data, reference values and aggregate values are kept in the SCN
controllers' memory and regularly updated.

2) Each actuator sends requests for sensed data and reference values to the motes, and then
stores the received ones in memory. The data requests can be of different types, such as
broadcast requests (all motes send data on demand to actuators via the SCN infrastructure),
or threshold-exceeding requests (only motes whose sensed data exceed some thresholds
send data), etc.
3) Some other reference values can be computed as needed by the actuators based on received
sensed data and reference values.

4) 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.
5) Each actuator forms a control command depending on the aggregate values.

Two examples of flow charts for decentralized configuration are shown in Figures 7-2 and 7-3.
In the first example, actuators use aggregate values received from the SCN controllers (data flow 2)
and aggregate values calculated using reference values received from motes (data flow 1).
In the second example, actuators use only aggregate values calculated using reference values
received from motes (data flow 1). There is no influence of the SCN controllers on the decision-
making process. The SCN controllers only calculate (data flow 2) and store in memory aggregate
values for the purpose of interoperation with external systems and the authorized personnel
administrating the SCN.

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