-- Definition -- A network element which represents a continuous path in the network without any branches. The element has a defined beginning and end and every position on the link sequence is identifiable with one single parameter such as length. -- Description -- EXAMPLE A link sequence may represent a route.
-- Definition -- Abstract base type representing phenomena located at or along a network element. This base type provides general properties to associate the network-related phenomena (network properties) with the network elements. -- Description -- In the simplest case (NetworkReference), the network property applies to the whole network element. In the case of a Link, the spatial reference may be restricted to part of the Link by using a linear reference. ISO/TC 211 is currently in the early stages of developing a standard for Linear Referencing (ISO 19148). A simple mechanism to express linear references is provided in this version of the network model; it is expected that the model will be extended once ISO 19148 is stable. The current simple model requires for all linear references two expressions representing a distance from the start of the Link along its curve geometry. The network property applies to the part of the Link between fromPosition and toPosition.
-- Definition -- Represents a reference between two elements in the same network. -- Description -- The cross reference may represent the case where two elements are different representations of the same spatial object.
-- Definition -- Abstract base type representing an element in a network. Every element in a network provides some function that is of interest in the network.
-- Definition -- A collection of link sequences and/or individual links that has a specific function or significance in a network. -- Description -- NOTE This spatial object type supports the aggregation of links to form objects with branches, loops, parallel sequences of links, gaps, etc. EXAMPLE A dual carriageway road, as a collection of the two link sequences that represent each carriageway.
-- Definition -- Abstract base type representing a linear network element that may be used as a target in linear referencing.
-- Definition -- Represents a significant position in the network that always occurs at the beginning or the end of a link. -- Description -- NOTE if a topological representation of the network is used the road node is either a topological connection between two or more links or the termination of a ink. If a geometric representation of the network is used road nodes are represented by points or alternatively another geometric shape. [EuroRoadS]
-- Definition -- Represents a logical connection between two or more network elements in different networks. -- Description -- In the case where the networks are in different spatial data sets, a network connection object may exist in both data sets.
-- Definition -- Curvilinear network element that connects two positions and represents a homogeneous path in the network. The connected positions may be represented as nodes.
-- Definition -- Indicator which of two or more intersecting elements is/are below and which is/are above, to be used if elevation coordinates are not present or cannot be trusted. -- Description -- NOTE 1 In most cases, the number of elements will be two. NOTE 2 In the normal case this is when elements intersect in the x/y-plane when the z coordinate is not present or is not accurate enough.
-- Definition -- A network is a collection of network elements. -- Description -- The reason for collecting certain elements in a certain network may vary (e.g. connected elements for the same mode of transport)
-- Definition -- A network reference that is restricted to part of a linear network element. The part is the part of the network element between fromPosition and toPosition.
-- Definition -- A network reference that is restricted to a point on a linear network element. The point is the location on the network element at the position atPosition along the network.