Table 2 Scenarios’ variable description and quantifier

Density represents the quantity of sensors placed in one area.

When the area has a single sensor, it is classified as “0.” If the area has up to five sensors, it is defined as “1”; over 5 and under 15 sensors, a “2” is allocated, and the density is “3” when there are more than 15 sensors in an area.

This is the thing’s ability to change location in an area.

“0” is attributed for a static sensor. If the sensor can change its location in a predefined route, it is classified as “1.” When the sensor has the ability to move across areas, it is given a “2.” And in the case of large changes, as in a city scale, it is represented as “3.”

This reflects the sensor’s data refresh rate. A higher refresh rate makes the data register more critical.

Data refresh rate over 5 min are classified as,“0”; between 1 and 5 min as “1”; each minute as “2,” and real-time “3.”

This denotes for the variety of data types and sensors in the context.

Just one sensor with one data type is represented by “0.” A sensor with various data type is classified as “1”; various sensors with one data type are labeled “2,” and various sensors with various data type are classified as “3.”

This is the geographical displacement of the things.

A single room is represented as “0”; a single store building as “1”; more than one store building as “2”; “3” represents a smart city.

This variable registers the degree of interaction of the thing with a human being.

Ranges from “ 0—not related” when the device is independent of human input, “1—weakly related” when the device/thing is used or held by a human, “2—moderately related” when the sensor is a wearable device, or “3—totally related” when it is a direct input interface (neurotransmitter) or implanted chip.

This represents the capability of a thing in the system to act.

Ranges from “sensor only” (0), “self-acting/self-reconfiguring” (1), “acts in the environment” (2) to “acts on an external thing or human being” (3).