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This webpage contains the definitions for the main concepts used in the IoT-A project. In paticular, this page should be used as a common reference while reading all the project deliverables for finding explanations about the terminology. Finally, this webpage will be updated upon each major deliverable release.




Active Digital Entity

Any type of active code or software program, usually acting according to aBusiness Logic.



“An actuator is a mechanical device for moving or controlling a mechanism or system. It takes energy, usually transported by air, electric current, or liquid, and converts that into some kind of motion.”



An address is used for locating and accessing – “talking to” – a Device, aResource, or a Service. In some cases, the ID and the Address can be the same, but conceptually they are different.


Application Software

“Software that provides an application service to the user. It is specific to an application in the multimedia and/or hypermedia domain and is composed of programs and data”.

[ETSI- ETR173]

Architectural Reference Model

The IoT-A architectural reference model follows the definition of the IoT reference model and combines it with the related IoT reference architecture. Furthermore, it describes the methodology with which the reference model and the reference architecture are derived, including the use of internal and external stakeholder requirements.



“The fundamental organization of a system embodied in its components, their relationships to each other, and to the environment, and the principles guiding its design and evolution”.


Architecture Vision

”A high-level, aspirational view of the target architecture.”



Stakeholder Aspirations are statements that express the expectations and desires of the various stakeholders for the services that the final [system] implementation will provide.”


Augmented Entity

The composition of a Physical Entity together with its Virtual Entity.



An association establishes the relation between a service and resource on the one hand and a Physical Entityon the other hand.


AutoID and Mobility Technologies

“Automatic Identification and Mobility (AIM) technologies are a diverse family of technologies that share the common purpose of identifying, tracking, recording, storing and communicating essential business, personal, or product data.  In most cases, AIM technologies serve as the front end of enterprise software systems, providing fast and accurate collection and entry of data.

AIM technologies include a wide range of solutions, each with different data capacities, form factors, capabilities, and "best practice" uses.

AIM technologies also include mobile computing devices that facilitate the collection, manipulation, or communication of data from data carriers as well as through operator entry of data via voice, touch screens or key pads.

Each member of the AIM technology family has its own specific benefits and limitations -- meaning there is no "best" technology.  Rather, applications may be best served by one or more AIM technologies.  Multiple AIM technologies are often used in combination to provide enterprise-wide solutions to business issues.

Most AIM technologies are defined by international and national technical standards.  International, national or industry application standards also exist to define the use of AIM technologies.”


Business Logic

Goal or behaviour of a system involving Things serving a particular business purpose. Business Logic can define the behaviour of a single Thing, a group of Things, or a complete business process.


Communication Model

The communication model aims at defining the main communication paradigms for connecting elements, as, in the IoT-A case, defined in the domain model. This model provides a set of communication rules to build interoperable stacks, together with insights about the main interactions among the elements of the domain model.


Constrained Network

A constrained network is a network of devices with restricted capabilities regarding storage, computing power, and / or transfer rate.



Anything that has the capability to affect a Physical Entity, like changing its state or moving it.



A credential is a record that contains the authentication information (credentials) required to connect to a resource. Most credentials contain an user name and password.



Technical physical component (hardware) with communication capabilities to other IT systems. A device can be either attached to or embedded inside a Physical Entity, or monitor a Physical Entity in its vicinity.


Digital Entity

Any computational or data element of an IT-based system.



Discovery is a service to find unknown resources/entities/services based on a rough specification of the desired result. It may be utilized by a human or anotherservice. Credentials for authorization are considered when executing the discovery.


Domain Model

“A domain model describes objects belonging to a particular area of interest. The domain model also defines attributes of those objects, such as name and identifier. The domain model defines relationships between objects such as “instruments produce data sets”. Besides describing a domain, domain models also help to facilitate correlative use and exchange of data between domains”.

[CCSDS 312.0-G-0]

Energy-harvesting Technologies

Energy-harvesting (also known as power harvesting or energy scavenging) is the process by which energy is derived from external sources (e.g., solar power, thermal energy, wind energy, salinity gradients, and kinetic energy), captured, and stored. Frequently, this term is applied when speaking about small, wireless autonomous devices, like those used in wearable electronics and wireless sensor networks.

Traditionally, electrical power has been generated in large, centralized plants powered by fossil fuels, nuclear fission or flowing water. Large-scale ambient energy, such as sun, wind and tides, is widely available but technologies do not exist to capture it with great efficiency. Energy harvesters currently do not produce sufficient energy to perform mechanical work, but instead provide very small amount of power for powering low-energy electronics. While the input fuel to large scale generation costs money (oil, coal, etc.), the "fuel" for energy harvesters is naturally present and is therefore considered free. For example, temperature gradients exist from the operation of a combustion engine and in urban areas, there is also a large amount of electromagnetic energy in the environment because of radio and television broadcasting”.

[Wikipedia EH]


A Gateway is a forwarding element, enabling various local networks to be connected.



Global Storage

Storage that contains global information about many entities of interest. Access to the global storage is available over the Internet.



A human that either physically interacts with Physical Entities or records information about them, or both.



Properties of an entity that makes it definable and recognizable.


Identifier (ID)

Artificially generated or natural feature used to disambiguate things from each other. There can be several Ids for the same Physical Entity. The set of Ids is an attribute of an Physical Entity.


Information Model

“An information model is a representation of concepts, relationships, constraints, rules, and operations to specify data semantics for a chosen domain of discourse. The advantage of using an information model is that it can provide sharable, stable, and organized structure of information requirements for the domain context.

The information model is an abstract representation of entities which can be real objects such as devices in a network or logical such as the entities used in a billing system. Typically, the information model provides formalism to the description of a specific domain without constraining how that description is mapped to an actual implementation. Thus, different mappings can be derived from the same information model. Such mappings are called data models.”


Infrastructure Services

Specific services that are essential for any IoT implementation to work properly. Such services provide support for essential features of the IoT.



“Named set of operations that characterize the behaviour of an entity.”



“The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (TCP/IP) to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks of local to global scope that are linked by a broad array of electronic and optical networking technologies. The Internet carries a vast array of information resources andservices, most notably the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support electronic mail.

Most traditional communications media, such as telephone and televisionservices, are reshaped or redefined using the technologies of the Internet, giving rise to services such as Voice over Internet Protocol (VoIP) and IPTV. Newspaper publishing has been reshaped into Web sites, blogging, and web feeds. The Internet has enabled or accelerated the creation of new forms ofhuman interactions through instant messaging, Internet forums, and social networking sites.

The Internet has no centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own standards. Only the overreaching definitions of the two principal name spaces in the Internet, the Internet-protocol address space and the domain-name system, are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols (IPv4 and IPv6) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise.”

[Wikipedia IN]

Internet of Things (IoT)

The global network connecting any smart object.



“The ability to share information and services. The ability of two or more systems or components to exchange and use information. The ability of systems to provide and receive services from other systems and to use the services so interchanged to enable them to operate effectively together.”


IoT Service

Software component enabling interaction with resources through a well-defined interface. Can be orchestrated together with non-IoT services (e.g., enterprise services). Interaction with the service is done via the network.


Local Storage

Special type of resource that contains information about one or only a fewentities in the vicinity of a device.


Location Technologies

All technologies whose primary purpose is to establish and communicate the location of a device e.g. GPS, RTLS, etc.



In contrast to discoverylook-up is a service that addresses exiting knownresources using a key or identifier.


M2M (also referred to as machine to machine)

“The automatic communications between devices without humanintervention. It often refers to a system of remote sensors that is continuously transmitting data to a central system. Agricultural weather sensing systems, automatic meter reading and RFID tags are examples.”



“A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM.Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.

Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, and toys. By reducing the size and cost compared to a design that uses a separate microprocessor, memory, and input/output devices, microcontrollers make it economical to digitally control even more devices and processes. Mixed signal microcontrollers are common, integrating analog components needed to control non-digital electronic systems”.

[Wikipedia MC]

Network resource

Resource hosted somewhere in the network, e.g., in the cloud.


Next-Generation Networks (NGN)

“Packet-based network able to provide telecommunication services and able to make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies”

[ETSI TR 102 477]


Anything that has the capability to monitor a Physical Entity, like its state or location.


On-device Resource

Resource hosted inside a Device and enabling access to the Device and thus to the related Physical Entity.



The operator owns administration rights on the services it provides and/or on the entities it owns, is able to negotiate partnerships with equivalent counterparts and define policies specifying how a service can be accessed by users.


Passive Digital Entities

A digital representation of something stored in an IT-based system.


Physical Entity

Any physical object that is relevant from a user or application perspective.


Perspective (also referred to as architectural perspective)

“Architectural perspective is a collection of activities, checklists, tactics and guidelines to guide the process of ensuring that a system exhibits a particular set of closely related quality properties that require consideration across a number of the system’s architectural views.”



Information Privacy is the interest an individual has in controlling, or at least significantly influencing, the handling of data about themselves.


Reference Architecture

A reference architecture is an architectural design pattern that indicates how an abstract set of mechanisms and relationships realises a predetermined set of requirements. It captures the essence of the architecture of a collection of systems. The main purpose of a reference architecture is to provide guidance for the development of architectures. One or more reference architectures may be derived from a common reference model, to address different purposes/usages to which the Reference Model may be targeted.


Reference Model

“A reference model is an abstract framework for understanding significant relationships among the entities of some environment. It enables the development of specific reference or concrete architectures using consistent standards or specifications supporting that environment. A reference model consists of a minimal set of unifying concepts, axioms and relationships within a particular problem domain, and is independent of specific standards, technologies, implementations, or other concrete details. A reference model may be used as a basis for education and explaining standards to non-specialists.”



Service by which a given ID is associated with a set ofAddresses of information and interaction Services. Information services allow querying, changing and adding information about the thing in question, while interaction services enable direct interaction with the thing by accessing the Resources of the associated Devices. Based on a priori knowledge.



Computational element that gives access to information about or actuation capabilities on a Physical Entity.



“A quantitative statement of business need that must be met by a particulararchitecture or work package.”



“The use of electromagnetic or inductive coupling in the radio frequency portion of the spectrum to communicate to or from a tag through a variety of modulation and encoding schemes to uniquely read the identity of an RF Tag.”

[ISO/IEC 19762]


A sensor is a special Device that perceives certain characteristics of the real world and transfers them into a digital representation.




"The correct term is 'information security' and typically information security comprises three component parts:

  • Confidentiality. Assurance that information is shared only among authorised persons or organisations. Breaches of confidentiality can occur when data is not handled in a manner appropriate to safeguard the confidentiality of the information concerned. Such disclosure can take place by word of mouth, by printing, copying, e-mailing or creating documents and other data etc.;
  • Integrity. Assurance that the information is authentic and complete. Ensuring that information can be relied upon to be sufficiently accurate for its purpose. The term 'integrity' is used frequently when considering information security as it represents one of the primary indicators of information security (or lack of it). The integrity of data is not only whether the data is 'correct', but whether it can be trusted and relied upon;
  • Availability. Assurance that the systems responsible for delivering, storing and processing information are accessible when needed, by those who need them.




"Services are the mechanism by which needs and capabilities are brought together"


Stakeholder (also referred to as system stakeholder)

“An individual, team, or organization (or classes thereof) with interests in, or concerns relative to, a system.”



Special type of Resource that stores information coming from resources and provides information about Entities. They may also include services to process the information stored by the resource. As Storages are Resources, they can be deployed either on-device or in the network.



“A collection of components organized to accomplish a specific function or set of functions.”



Label or other physical object used to identify the Physical Entity to which it is attached.



Generally speaking, any physical object. In the term ‘Internet of Things’ however, it denotes the same concept as a Physical Entity.


Unconstrained Network

An unconstrained network is a network of devices with no restriction on capabilities such as storage, computing power, and / or transfer rate.



Human or any Active Digital Entity that is interested in interacting with a particular physical object.



“The representation of a related set of concerns. A view is what is seen from a viewpoint. An architecture view may be represented by a model to demonstrate to stakeholders their areas of interest in the architecture. Aview does not have to be visual or graphical in nature”.



“A definition of the perspective from which a view is taken. It is a specification of the conventions for constructing and using a view (often by means of an appropriate schema or template). A view is what you see; aviewpoint is where you are looking from - the vantage point or perspective that determines what you see”.


Virtual Entity

Computational or data element representing a Physical Entity. Virtual Entities can be either Active or Passive Digital Entities.


Wireless communication technologies

“Wireless communication is the transfer of information over a distance without the use of enhanced electrical conductors or "wires". The distances involved may be short (a few meters as in television remote control) or long (thousands or millions of kilometres for radio communications). When the context is clear, the term is often shortened to "wireless". Wireless communication is generally considered to be a branch of telecommunications.”

[Wikipedia WI]

Wireline communication technologies

“A term associated with a network or terminal that uses metallic wire conductors (and/or optical fibres) for telecommunications.”


Wireless Sensors and Actuators Network

“Wireless sensor and actuator networks (WSANs) are networks of nodes that sense and, potentially, control their environment. They communicate the information through wireless links enabling interaction between people or computers and the surrounding environment.”



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