# Scenario Database

Each scenario to be simulated with Eclipse MOSAIC requires a database which contains information about the road infrastructure and routes the vehicles drive on. This information is used by various federates. For example, the SUMO federate needs to know initial routes for vehicles, and the Application Simulator requires detailed information about the road infrastructure to provide applications with methods for route calculation. For this purpose, an embedded SQLite database is used which is placed in the application folder of the scenario. This database consists of the following tables:

### Database tables

Database Name Description
Node Contains all Nodes of the road network such as junctions and nodes describing the geometry of a road. Each node is identified by an unique ID (long).(refer to http://wiki.openstreetmap.org/wiki/Node)
Way Provides various properties for each way of the road network.(refer to http://wiki.openstreetmap.org/wiki/Way
WayConsistsOf Provides a list of nodes for each way of the road network.
Connection Contains a list of all connections of the road network including the way it originally is part of. Each connection describes an directed edge between two junctions in the road network.
ConnectionConsistsOf Provides a list of nodes each connection consists of.
Restriction Provides information about turn restrictions. Each turn restriction is described by a from-connection, a via-node, and a to-connection. This data is used for route calculation purposes.
Roundabouts
RoundaboutConsistsOf
Route Contains a list of all routes known for the simulation scenario. All routes referenced in the Mapping configuration must be presentin this table.
Building
BuildingCorner
Provides information about buildings alongside the road network, e.g. for visualization purposes, occlusion models , or sophisticated communication simulation models.
Properties Contains the version of the Eclipse MOSAIC installation which was initially used to create the database.

This section describes the model of the road network used by various components of Eclipse MOSAIC. In the next figure various nodes and connections can be seen. A node is either a junction or describes the geometry of a road. A connection is a directed edge between two junction nodes. That also means, that two separate connections exists for a road segment which can be traversed in both directions. Each connection consists of at least two nodes (start and end junction node). Between those nodes, other nodes can exist which describe the curvature of the road segment. Furthermore, each connection has a reference to its originating way, which may consist of various connections. A way contains further properties, such as the maximum speed or the type of the road.

Nodes and ways are identified by unique IDs derived from the base OSM network file. Connections, however, are not part of the OSM standard and their identifiers are generated during the import. Each connection ID consists of three parts (using the string pattern aaa_bbb_ccc):

• aaa - ID of the originating way
• bbb - ID of the node the connection starts at.
• ccc - ID of the node the connection ends in.