ce. The state space of an agent is defined by its object resource model. The object resource model is created by integrating all service resource models that concern the agent. This integration requires that two additional types of relations are added, called abstraction resource relations (arr) and external resource relations (err). Abstraction resource relations define the mapping between resources in service resource models on different abstraction levels, while external resource relations are relations between resources in service resource models on the same abstraction level. In Fig. 6.18 we take the CNPC as an example. We will try to produce an object resource model for this agent. CNPC object resource model AR and err arr abstraction resource relations Route Route err external resource relations Fig. 6.18 An object resource model interconnects service resource models 6.2 A Service Network Modelling Case By fragmenting the original resource model for the connection network into sep- arate service resource models, each resource controller sees only a part of the con- nection network. None of the controllers have control over relations in the resource system between such parts. For example, the access route manager and the core route manager know which routes exist and which channels are busy and idle, but they do not know how channel endpoints are connected to connection endpoints and to switch positions. Neither do the switch controllers know which positions are connected to which routes and channels. This knowledge is added to the exist- ing service resource models as external resource relations (err). In Fig. 6.19 these relations are defined, using the general notation for resources used by the CNPC (in order to simplify the model, access routes and internal routes are depicted together in one service resource model). AccessRoute Switch SwitchRoute or InternalRoute*)' conTo conTo 1,2,30 conTo Channel Position Channel AR and IR models SR model Instances: AR1-AR6, IR1 Instances: SR1 external resource relati