Basic Concepts of IoT domain model - Week 2 - Lecture 3 & 4 Flashcards
In IoT is a user always human?
No, can be human or an (Active) digital artefact
- A service, application or a software agent that interacts with a physical entity
What is a physical entity?
Any physical object or part of the environemtn that can be identified
E.g. Humans, animals, rooms, store, cards, trucks, logistics chain items, computers, electronic appliances, clothes
What is a virtual entity?
Digital artefacts, either active or passive
Passive Digital Artefacts (PDA) are passive software elements such as database entries that can be Digital representations of the physical entity
Active Digital Artefacts (ADA) are running software applications or Services that may access other services or resources
Each virtual entity must have one and only one ID that identifies it univocally
A virtual entity is associated with and represents only one physical entity
A physical entity can be associated with many virtual entities
Ideally virtual entities are synchronised representations of a given set of properties of the physical entity. Synchronisation means that relevant digital parameters representing the characteristics of the Physical Entity are updated upon any change of the physical entity.
What are devices typically categorised into?
Sensors that provide information, knowledge or data about the physical entity they monitor. In this context, this ranges from the identity of the physical entity to measurements of the physical state of the physical entity
Tags, used to identify physical entities, to which the tags are usually physically attached
Actuators which can modify the physical state of a physical entity
What is primary identification vs secondary identification?
Primary identification is where tangible features of a PE are utilised
extraction and derivation of physical characteristics could be done by a camera and related software. In physical spaces, a GPS or indoor location device can capture the coordinates of the PE
Secondary identification is where tags or labels are attached to the PE. These tags could be RFID or as simple as barcodes
In IoT what are resources?
Software components that provide data from or are used in the actuation on Physical Entities
What are the two types of resource?
On-device resources
- Software locally deployed on the device associated with the Physical Entity. Examples include executable code for accessing, processing and storing sensor information and controlling actuators
Network resources are resources available somewhere in the network
- Back-end or cloud based databases
What are services in IoT
Services expose resources and offer the necessary functionalities for interacting with the resources / devices associated with physical entities
Relates between resources and virtual entities are modelled as associations between virtual entities and services
Interaction with services is done via the network
What is an augmented entity?
The “things” of the internet of things. A physical entity in the physical world that includes server hardware devices (typically, physically attached / integrated / embedded to it) and its representation with at least one virtual entity in the digital world
What are the possible serviceType values for associations?
INFORMATION if the service provides the attribute value to be read
ACTUATION if the service allows the attribute value of be set, as resulting in a corresponding change in the physical world
What is the role of the communication model?
Help the definition of the functional components in the communication functional group of the functional model
Derive communication best-practices based on system requirements
List some functional requirements
Lifetime of devices
Responsiveness
- Frequency of data reporting, invocation of services, etc…
Robustness
- How much data loss is permitted
Sensor related
- Sampling Freq, processing capabilities -> level of reasoning
- Characteristics of the monitored phenomenon/quantity
- Accuracy, power, signal conditioning, sensitivity to environmental conditions
Actuator related
- Response time, power, processing capabilities
List some non-functional requirements
Regulations
- Device deployment, RF related regulations, e.g. TX power, frequency band
Installation, maintenance, accessibility
Physical constrains
- Size and weight limits
- Integration of electronics
- Antenna size
- Power supply available
Cost
- Component cost, integrated devices
Cost of £1 per device pretty good, £1000 device means you can’t scale your system
Different countries use different frequencies for various reasons, might work in UK and France but not in the Middle East
What are the steps of the IoT design methodology?
Objective and requirements
- Define purpose and requirements of the IoT system
Process Model Specification
- Define the use cases
Domain model specification
- Define physical entities, Virtual Entities, Resources and services
Information model specification
- Define the structure (e.g. relations, attributes) of all of the information of the IoT system
Service specifications
- Map process and information model to services and define service specifications
IoT Level Specification
- Define the IoT deployment level
NOT COVERED
Functional View specification
- Map IoT level for the system
Operational View Specification
- Define communication options, service hosting options, storage options, device options
Device & Component integration
- Integrate devices, develop and integrate the components
Application Development
- Develop applications
What is a level 1 IoT system?
Typically applicable for low cost and low complexity systems
Example: home automation system
Used when only local deployment should be used. Internet access is provided so that the application can be accessed remotely
