Use case 8
Central point for the dissemination of traffic light information.
This use case is deprecated.
The Case of use 8 is dedicated to the distribution of traffic light information between the producers of this type of information and the consumers, through the DGT 3.0 platform. The services implementing this architecture allow synchronous and asynchronous data exchange.The former will be used for sending static information, affected by few changes, such as the topology of the junctions (MAPEM messages). The latter are needed for sending dynamic information, related to the status of crossings and traffic light phase changes. All requests to the API must be sent to the following URL (base URL):
To publish information a REST API is available with the following methods provided: getAvailableAreas (GET) Obtain the list of available areas in the system. Only the areas that are registered at the time of the query will be returned. getTopology (POST) Allows to download the latest topology in force for a given or planned geographical area. General details for making a request:
The subscription to the service in use case 8 will be done using the MQTT protocol. MQTT (MQ Telemetry Transport) is a messaging protocol used as a simple and lightweight method for transferring data to/from low power devices. The protocol supports a single messaging pattern, the Publish-Subscribe pattern: each message is published to a topic that must be subscribed to in order to receive the information. The subscription to the service of this use case should be through the following inbound or outbound topics:
- ~~Inbound: you will receive messages from the SIS.~~
- ~~Output: Will publish messages accessible to the CIS.~~
See more information and a connection example here.
Information published in the development environment changes throughout the day, so that the consumer interface can be tested. This information contains the SPAT messages. For more information regarding the consumption of traffic light events, the following documentation can be consulted: