To illustrate and build a reference domain model for a very generic scenario of any IOT solution; below table describes all the entities that are required to define by solution architect:
| Entity In Domain Model | Description |
|---|---|
| User | – A human being or a service or an application or a software agent. – Different types of users and associated roles are not included in the IOT Domain Model. |
| Physical Entity | Physical entity can be a living being or any other item like car, store, logistic items, electronics appliances etc. |
| Virtual entity | – The digital representation of a physical entity is called virtual entity or digital artifacts. – The same physical entity can be associated with several virtual entities. – Virtual Entity has two basic properties: 1. This is the digital representation of a physical entity. 2. This is the synchronized representation of properties/aspects of physical entities. A. Digital Representation: – Each virtual entity has a very unique id. – Virtual Entities can be classified into two types: 1. Active Digital Artifacts (ADA): Any running software, agents or services that access other Resources or Services. 2. Passive Digital Artifacts (PDA): Passive software like database entries. B. Synchronized Representation: It means that digital parameters of virtual entities represent characteristics of physical entities. Therefore, change of either entity (virtual/physical) will affect the other. Example: Manual locking the door will change the property/parameter of home automation software (virtual entity). Similarly, triggering the event to lock the door in home automation software will also triggered electric lock of door (physical entity). |
| Augmented Entity | – Composition of one virtual entity and associated physical entity. – Actually, it enables every object to become part of the digital process. – It is also regarded as a “thing” in the Internet of Things. |
| Devices | Basically, it is either an extension of virtual entities or extension of physical entities. Here, extension means generating a paired couple of virtual and physical entities. It means a device that bridges both virtual and physical entities. To build such devices, we have to provide or add capabilities like monitoring, sensing, actuation, computation, storage and processing. – In IOT Domain, there are 3 types of such devices: 1. Sensors 2. Tags 3. Actuators |
| Resource | – These are the software components that enable virtual entities to interact with physical entities. – There are two types of resources identified: 1. On-Device Resources: Resources deployed on physical devices like executable for accessing, processing and storing information, or controlling actuators. 2. Network Resources: Resources deployed on a network like back end or cloud. – Virtual entities can also be associated with Resources to enable interaction with associated physical entities. |
| Service | – In case of heterogeneous resources, a service is required to provide open and standard interfaces so that interaction with resources & devices associated with Physical entities can be achieved. – A virtual entity can be associated with one service or multiple services. – Multiple instances of a service are also possible in the model. |
Note: Here, Interaction can be done by calling services that either retrieve information or act on a physical entity to meet the goal of the user.
Interaction can be done between:
- Human User and Physical entities.
- As well as between Active Digital Artifact and Physical entity.
Technology 