Bounded Contexts
After the event storming session, the following contexts have been identified:
- Auth
- User
- Monitoring
- Alarm
- Notification
- Location
In the following sections, each context will be described in detail.
Auth
Responsible for managing the authentication and authorization of the users. It also is responsible for managing the permissions of the users.
Ubiquitous Language
| Term | Meaning | Synonyms |
|---|---|---|
| Role | Role assigned to a specific user, only two values are admitted: Admin and Guardian | - |
| Admin | A user with the maximum level of authority. It can manage permissions of other Guardian users | - |
| Guardian | A user that can only view the video stream and visualize the data produced by sensors to which he has access | Monitor |
| User | Either an admin or a guardian | - |
| Permission | A grant to consult devices in a particular location | - |
Events
Inbound Events
The Auth bounded context does not receive any event from the other contexts.
Outbound Events
- LocationMonitoringGranted: event that is sent when a user is granted permission to monitor a location
- LocationMonitoringDenied: event that is sent when a user is denied permission to monitor a location
- UserLoggedIn: event that is sent when a user is authenticated
Users
This context is responsible for managing the users of the system, in particular, nothing regarding the authentication process but only the management of the user registry.
Ubiquitous Language
| Term | Meaning | Synonyms |
|---|---|---|
| User | Generic term to refer to anyone registered to the system | - |
| Contact | Contact on which the specific user will be notified when one anomaly occurs | - |
| Contact Type | Contact type of a single contact, two values are admitted: SMS and EMAIL | - |
Events
Inbound Events
The Users bounded context does not receive any event from the other contexts.
Outbound Events
- UserAdded: sent when a user is created
- UserDeleted: sent when a user is updated
- UserUpdated: sent when a user is updated
- UserContactsModified: sent when a user contact is modified
Monitoring
It is responsible for managing the devices and the data they produce. This context is responsible for consulting the data produced by the devices, their configurations and everything regarding the WoT interactions.
Ubiquitous Language
| Term | Meaning | Synonyms |
|---|---|---|
| Camera | Device that records an environment and transmit the stream to the system | Video Camera |
| Sensor | Device sensing data from an environment (e.g. temperature) | - |
| Device | Either a Camera or a Sensor | - |
| Sensor/Camera settings | User-modifiable configuration of data relative to a specific device | - |
| Transmission interval | The amount of time between to consecutive measurement transmission in ms | - |
| Capability | What a sensor is able to perceive and transmit | - |
| Video Stream | Stream of video data produced by a camera | Stream, Transmission |
| Measurement | Data produced by a sensor | Environment data, Sensor data |
| Numerical measurement | A Measurement with a single numerical value and a Measurement Type | - |
| Measurement Type | A physical dimension with its unit of measure (e.g. temperature in Celsius) | - |
Events
Inbound Events
- MeasurementReceived: triggered when a new measurement is received
- VideoStreamReceived: triggered when a new video stream is received
Outbound Events
- DeviceAdded: sent when a device is added
- DeviceDeleted: sent when a device is deleted
- DeviceSettingsModified: sent when some device settings are modified
- DeviceEnabled: sent when a device is enabled
- DeviceDisabled: sent when a device is disabled
- MeasurementStored: sent when a measurement is stored
Alarm
Responsible for managing the alarms in the overall system. It is also responsible for the object recognition feature of the system.
Ubiquitous Language
| Term | Meaning | Synonyms |
|---|---|---|
| Security rule | A condition that if not satisfied will trigger an anomaly | Rule |
| Intrusion rule | A condition that specify that in a video stream no object of a specific object class can be recognized | - |
| Object class | Type of object that the system is able to recognize | Category, Object |
| Range rule | A condition that will trigger an outlier if the value of a numerical measurement is out of a specific range | - |
| Anomaly | Is either an intrusion or an outlier | - |
| Detection | Recognition of an object | - |
| Intrusion | Detection of an object in contrast with a particular intrusion rule | - |
| Outlier | Numerical measurement with a value in contrast with a particular range rule | - |
Events
Inbound Events
- MeasurementReceived: triggered when a device sends a new measurement
- VideoStreamReceived: triggered when a camera sends the video stream
Outbound Events
- SecurityRuleAdded: sent when a security rule is added
- SecurityRuleDeleted: sent when a security rule is deleted
- SecurityRuleModified: sent when a security rule is modified
- SecurityRuleEnabled: sent when a security rule is enabled
- SecurityRuleDisabled: sent when a security rule is disabled
- SecurityRuleViolation: sent when a security rule is violated
- AnalyzingStarted: sent when the system starts analyzing a video stream
- ObjectDetected: sent when an object is detected in a video frame
- AnomalyDetected: sent when an anomaly is detected
- AnomalyStored: sent when an anomaly is stored
Location
Responsible for the location management of the system.
Ubiquitous Language
| Term | Meaning | Synonyms |
|---|---|---|
| Building | Coarse grained concept of location referring to a structure (e.g. home, warehouse) | - |
| Room | Fine grained concept of location referring to a single space (e.g. living room, entrance, exit) | - |
| Location | Generic term to refer to a place | - |
Events
Inbound Events
The Location bounded context does not receive any event from the other contexts.
Outbound Events
- LocationAdded: sent when a new location is added
- LocationRemoved: sent when a location is removed
Notification
Responsible for managing the notifications of the system. It is responsible for sending notifications to the users when particular events occur.
Ubiquitous Language
| Term | Meaning | Synonyms |
|---|---|---|
| Notification | Message sent to a user using its recipient's | Alert |
| Outlier Notification | Notification regarding an Outlier anomaly | - |
| Intrusion Notification | Notification regarding an Intrusion anomaly | - |
| Notification Type | Type of notification | - |
| Real-time Notification | Notification sent in real-time to the user | - |
| Recipient | The notification target user's contact |
Events
Inbound Events
- AnomalyDetected: received when an anomaly is detected
Outbound Events
- NotificationSent: sent when a notification is sent
Model Integrity Patterns
Each bounded context is isolated and has its own vision of domain entities. For this reason, is necessary to define model integrity patterns to ensure that the data is consistent across the contexts.
In the following are listed the DDD patterns used in the system:
- Shared Kernel: that collects the shared entities between the contexts (Domain Events and some common Entities)
- Conformist: that allows the contexts to share the same entity but with different representations
Context Map
The following context map shows the relationships between the contexts.
