an Association has been removed or a previously sent Association
has changed.o If the subscription is successful, the user will always get an updated
set of Associations fitting the subscription. Unsubscribe to look-up of Associations
o The use case is initiated by a user of the system. The user has
previously subscribed to receive notifications about Associations
between the Virtual Entity identified by its VE Identifier and services
fitting the VE Service Specification.o The assumption is that the user knows the subscription identifier of
the subscription assigned by the VE Resolution.o In this use case, the subscription to the VE Resolution identified by
the subscription identifier is cancelled.o If the unsubscription is successful, the user will no longer receive
notifications concerning the Associations between the Virtual Entity
identified by its VE Identifier and services fitting the VE Service
Specification. Discover associations based on Virtual Entity specification and Virtual
Entity service specification
o This use case is initiated by a user. The user wants to discover
Physical Entities through their corresponding Virtual Entities. These
Virtual Entities can provide information about the Physical Entity or
trigger actuations on the physical counterpart of the Virtual Entity.o The assumption is that the user does not know the virtual identities of
these Virtual Entities, but knows what kind of Virtual Entities and what
kind of associated services are required.o In this use case, Virtual Entity Resolution enables the user to discover
relevant associations. Virtual entities are specified through a virtual-
entity specification, and the requirements for the associated service
are specified in the virtual-entity-service specification. As a result, the
user then receives fitting associations.o If the discovery is successful, the use gets the virtual identities of
fitting Virtual Entities together with the identifiers of required services,
whose description can then be looked up through the IoT Service
Resolution. Subscribe to discovery of Associations based on VE Specification and
VE Service Specification
o The use case is initiated by a user of the system, i.e., a hHuman User
or an Active Digital Artefact. The user wants to be asynchronously