IoT Domain Sub model– Functional Model

Definition

  • It defines the main functionality and their interactions.
  • It is based on following three principles or concepts:
    • Abstract:
      • It is not tied to any technology, application domain or implementation.
      • It does not explain different functional components that make up different functional groups.
    • Define Functional Groups and their interactions.
    • Functional View:
      • It defines runtime functional components of the system, that covers following aspects:
        • Responsibilities of functional components.
        • Default functions of functional components.
        • Main interfaces of functional components.
        • Primary interactions of functional components.

Functional Model defines two types of functional groups:

1. Longitudinal Functionality Group:

Functionalities are limited to that specific group only and are not required by any other functional groups. These functional groups are spread lengthwise in overall model and their interaction is also manly two way longitudinal.

Below are the 7 longitudinal Functional Groups:

  1. Application
  2. Service Organization
  3. IoT Process Management
  4. Virtual Entity
  5. IoT Service
  6. Communication
  7. Device

2. Transversal Functionality Group:

Functionalities are required to be implemented almost in all functional groups, therefore these are spread across all functional groups. Example: Security and Management

Below are the 2 transversal Functional Groups:

  1. Security
  2. Management

Brief explanation of above mentioned functional groups:

1. IoT Process Management Functional Groups:

  • It provides necessary functional aspects to integrate the specific concept of IoT system with business process. This helps enterprises to make sure IoT Sub-System adhering the common & new industry standards and best practices like BPMN 2.0 (Business Process Model and Notation). So that an isolated and proprietary “IoT” solution is not required to establish.
  • As the reliability and accountability of sensor data providing information of virtual entity along with processing capabilities of devices are major aspects of business process, IoT process management helps to hide the IoT specific implementation at lower level to enable smooth integration.
  • While practical realization is done then bu sines process policies covering permissions, prohibitions and obligation aspects; are required to address in IoT Process management.
  • IoT Process Management FG are dependent on Service Organization FG for the execution of business process by finding, binding and invoking specific services.

2. Service Organization Functional Groups:

  • It acts as communication hub among other Functional groups because its primary responsibility to composing (combining multiple basic services to get response of a request) and orchestrating services at various abstraction level so that requests coming from IoT Process Management FG or external application can link to right services as well also link with associated entities by utilizing Virtual Entity FG & IoT Service FG.
  • It also acts as brokerage of services so that Services can subscribe to other services available in system.

3. Virtual Entity Functional Groups:

It contains following functionalities :

1. It has functions for interacting with IoT System having multiple Virtual entities.

2. It also has functionalities for discovering and looking up services that provide information about Virtual Entities.

3. It also has functionalities to managing the static association & dynamic association of moving and non moving Physical entities(virtual entities).

4. IoT Service Functional Groups:

  • It contains functionalities to discover, look-up and name resolution of IoT Services.

5. Communication Functional Groups:

  • It contains various communication schemes based on technologies and also provides interfaces to interact with IoT Services FG.
  • These functional groups consider following aspects related to communication:
  • Data Representation
  • End to End path information
  • Addressing issues
  • Network Management
  • Device Specific features
  • Protocol Translation
  • Context Passing functionalities

6. Management Functional Groups:

  • It contains all functionalities that are required to govern any IoT System. It covers below four high level goals:

1. Cost Reduction: It should covers maximum use cases or users to avoid creation of different solutions for different use cases. It also covers the capturing of data to know the current cost.

2. Attending unexpected usage issues: It covers the knowledge of system state and strategies to address along with mitigation of unforeseen situations like: link failure, queue overload, devices are not working, introduction of error into system and emergency situation like stopping a train or moving complete system into energy saving mode.

3. Fault handling:

It covers to address the unpredictability of future failures that includes below goals:

  • Prediction of failures
  • Detection of existing failures
  • Reduction of effects of failures
  • Repair

4. Flexibility:

  • It covers to address the changes in requirements so no new system is required to prepare when user requirements change.
  • It also includes management of membership, ownership, their administration, defining rules & rights and accompanying information of the given entity to the IoT system.

7. Security:

It covers security and privacy of IoT system that includes:

  • Initial registration of client into system securely to make sure only legitimate clients are allowed to login into system.
  • Keeping user information protected and anonymous while accessing resources or services.
  • Legitimate interaction occurs between peers that are statically authorized or trusted to interact with each other.
  • Secure and data integrity protections.

IoT Domain Sub model– Information Model

Definition

  • It defines the structure of all information of Virtual Entities only at conceptual level and not at concrete level. In other words, it covers all aspects of adding information in the data. Here, structure covers attributes, relations and services that helps to know what, who, where, and when.
  • The detailed representation of information is not covered in this model.

This model covers following details (elements & their association) and of modelling of virtual entities:

1. Virtual Entity has attributes with name and its type.

  • Each virtual entity has a unique id or type i.e human, a car, or a temperature sensor.
  • A virtual entity can have zero to many attributes.

2. Attribute can have one or more values.

  • Each attribute has a name, a type (semantics) and one to many values.

3. Value has meta information(Meta data)

  • Value can further also have more values and each value has zero or many meta data. A virtual container keeps grouping of a value and associated zero or many meta data.

4. Meta Data might help to define other information like:

  • Time stamp (what time information is defined)
  • Location (Location where measurement took place
  • Quality (Quality of measurement) etc.

Meta data can itself have additional meta data i.e unit

5. Association between Virtual entity and Service description for specific attributes. Service allows to read attribute value or set the value based on changes in physical entity.

6. Services description describes services and associated interface. It also contains resource description that covers functionality of resource those are exposed by service.

7. Resource Description describes a resource and also contains description of device on which resource is hosted.

IoT Platform – MainFlux

Description

  • It is on premise and cloud (or hybrid) based IoT Platform that provides:
  1. Device management
  2. Data aggregation and data management
  3. Connectivity and message routing
  4. Event management
  5. User Interface
  6. Core analytics
  • It is developed by considering following three main entities:
  1. Users : These are real users who can access and manage resources (CRUD).
  2. Things : These are devices & applications part of the IoT solution.
  3. Channels : These are communication channels to exchange messages.
  • It uses *NATS as a main messaging system.
  • It can be run on gateway as well as on cloud at the same time. It provides below services to deploy on gateway for having communication with MainFlux on cloud.
  1. Agents: It is a service to manage a gateway that is connected to MainFlux on cloud. It allows you to send commands to the gateway and receive responses.
  2. Export: It is a service that allows sending messages from one MainFlux cloud to another. It also allows sending messages from the gateway to MainFlux cloud.
  • MainFlux provides following major functionalities:
  1. Provisioning: It is a configuration of IoT Platform for creating & setting-up different entities (users, channels & things).
  2. Messaging: Publishing messages from things to channels using protocols (HTTP/MQTT/CoAP/WebSocket)
  3. Storage: Supporting multiple databases (CassandraDB/MongoDB/InfluxDB/PostgreSQL) to store messages.
  4. Security: Establishes secure connections when users or things are communicating with other entities proper certificates are required to set.
  5. Authentication: Using keys or TLS mutual authentication.
  6. Authorization: Setting policies to control permissions for users, things and channels. Mainflux uses *Ory Keto server.
  7. Group based authentication: Allows group based authentication for users & things.
  8. Bootstrap: Supports self restarting process based on conditions set. Devices can trigger bootstrapping if conditions are matched.
  9. Tracing: Supports for generating profiling and monitoring applications as well as helps in debugging. Mainflux uses the *Jaeger tracing framework. It also uses Grafana, Prometheus and OpenTracing for instrumentation purposes.
  10. Twin Services: Supports digital twins functionality.
  11. Benchmarking: To generate large traffic & measure performance third party tool MZBench is used.
  12. Container-based deployment using Docker and Kubernetes.

MainFlux architecture contains following services mentioned in table 1.0

ServiceDescription
usersThis service provides APIs to Manages users by allowing following major activities: New Account Registration Obtaining access tokens and verify them
thingsThis service provides APIs to manage resources (things & channels) by allowing following activities: Provision new things Create new channels Connect things and channels
http-adapterThis service provides APIs to send messages.
mqtt-adapterThis service provides MQTT APIs to send messages.
coap-adapterThis service provides CoAP APIs to send messages.
opcua-adapterThis service provides OPCUA APIs to exchange data. This sits between Mainflux IoT System & OPC-US server.
lora-adapterThis service provides Lora APIs to exchange data. This sits between Mainflux IoT System & OPC-US server. It uses MQTT protocols.
mainflux-cliThis service provides APIs for command line interface. Cli makes it easy to manage users, things, channels and messages.
Table 1.0

*NATS : It is an open source messaging system. It provides servers and also has client libraries (multiple languages) for interacting with servers. It is scalable and high in performance. It is also used in cloud based solutions.

*OPCUA(OPC Unified Architecture) is an open standard to exchange data from sensors to cloud applications. It is cross platform.

*Ory Keto is a permission and authorization server.

*Jaeger tracing system is an open-source tracing system for microservices

Is it open source?

Yes

https://github.com/mainflux/mainflux

Supported Messaging & Security protocols

  • HTTP/HTTPS
  • MQTT
  • WebSocket
  • CoAP
  • TLS

Supported Networks

  • BLE
  • Ethernet (eth0)
  • LoRaWAN

Supported technologies & tools

  • Docker
  • Kubernetes
  • Swagger

Supported Languages

  • Go
  • *Protobuf (Protocol Buffers)

*Protobuf : It is a mechanism that allows us to serialize and de-serialize data. It is language & platform neutral so that different programs written in different languages on different platforms can send & receive data without writing additional code. It has its own compiler and specification.

Supported Databases

  • CassandraDB
  • MongoDB
  • InfluxDB
  • PostgreSQL

Supported OS

Supports all major OS

Domains where it is used and can be used

Applicable in all domains where IoT solution can be implemented.