Abstract: Different designers of a structure exchange information on their plans (models) with each other. This information is exchanged by reference data which may be in another format than what the designer's application is using. To facilitate a designer to maintain correspondence between his/her model and models handled by different designers, when the reference data is read and an entity is recognized in the data, geometric characteristics of the entity are calculated, and an identifier is formed for the entity by means of the geometric characteristics. The identifier is stored in the model, and it can be used to identify the entity as long as the entity remains unchanged although reference data is updated.

Abstract: Different designers of a structure exchange information on their plans (models) with each other. This information is exchanged by reference data which may be in another format than what the designer's application is using. To facilitate a designer to maintain correspondence between his/her model and models handled by different designers, when the reference data is read and an entity is recognized in the data, geometric characteristics of the entity are calculated, and an identifier is formed for the entity by means of the geometric characteristics. The identifier is stored in the model, and it can be used to identify the entity as long as the entity remains unchanged although reference data is updated.

Abstract: A network arrangement and a method for connecting a message-based system (using message-based synchronization) with an external system by converting the synchronization status received from the external system into the internal synchronization status of the message-based system in an interface node of the message-based system in such a manner that the level in the internal synchronization hierarchy of the message-based system (as indicated by the internal synchronization status) rises or falls corresponding to a corresponding rise or fall of a predetermined magnitude occurring in the synchronization status of the external system.

Abstract: A hierarchical synchronization method and equipment for a node in a telecommunications system employing message-based synchronization and comprising a plurality of nodes interconnected by transmission lines. Signals containing synchronization messages having a synchronization signature are interchanged with neighboring nodes, the synchronization signature indicating the priority of the respective signal in the internal synchronization hierarchy of the telecommunications system and containing a distance parameter representing a distance to a master source of synchronization and a master node parameter indicating an original synchronization source. The node synchronizes with the one of signals received from the neighboring nodes which has the highest priority in the internal synchronization hierarchy. A synchronization list is maintained, the list comprising, on the highest level, the synchronization signature of the signal with which the node is synchronized.

Abstract: In a hierarchical synchronization method for a telecommunications system employing message-based synchronization, in order that a node can recover from the loss of synchronization: (a) a list is formed for each mode interface unit from the group of interfaces appropriate for synchronization in such a way that of the interfaces connected to neighboring nodes, the list only comprises interfaces connected to a neighboring node which, if selected as the node timing source, does not change the synchronization signature transmitted by the node, (b) the node interface units monitor the operation of the control unit of their own node in order to detect whether the node has lost its control unit, (c) if a synchronization signature received by an interface on the synchronization list changes in such a way that the node outgoing signature should be changed and that change occurs when the interface unit has changed and that change occurs when the interface unit has detected the loss of the node control unit, the interfac

Abstract: A method of hierarchical synchronization for a telecommunications system employing message-based synchronization, the system having a plurality of nodes interconnected by transmission lines, wherein the nodes interchange signals containing synchronization messages each having a synchronization signature indicating a priority of the corresponding signal in an internal synchronization hierarchy of the system, and wherein a node is forced to enter into a predetermined standard state in a change situation in order to prevent the selection of faulty synchronization messages.

Abstract: The method for synchronizing the nodes in a telecommunications system utilizing a hierarchical message-based synchronization. The object is to make all the nodes in the system operate at the same clock frequency by letting the system synchronize itself with a single master clock source. The system nodes interchange synchronization messages indicating its priority in the internal synchronization hierarchy of the system. There are several transmission lines between two nodes and the same synchronization signature is transmitted over more than one of these transmission lines. The node copies the signature received from one interface connected to a node in such way that it also applies to the other interfaces connected to the same neighboring node. Thereafter comparing means perform comparison of the signatures and selection of synchronization source.

Abstract: A hierarchical synchronization method for a telecommunications system employing message-based synchronization and a telecommunications system employing message-based synchronization and including a plurality of nodes interconnected by transmission lines (A, B). In the method, the nodes interchange signals containing synchronization messages with information on the priority of the respective signal in the internal synchronization hierarchy of the system. In order to shorten the time periods of state transitions occurring in system failures without any risk of losing synchronization, a transmission line between two nodes is monitored to verify its bidirectionality, and as soon as the bidirectionality of the line cannot be verified, the use of the line for synchronization is prohibited.

Abstract: A method for connecting a system utilizing message-based synchronization with an external system. The message-based system includes a plurality of nodes interchanging signals containing synchronization messages with information about the priority of the respective signal in the internal synchronization hierarchy of the system. For the external system to be able to utilize the message-based system as well as possible with respect to timing, synchronization status data in the internal format of the external system is transmitted from the interface node of the system utilizing message-based synchronization to the external system.

Abstract: A network arrangement including a system employing message-based synchronization and having a plurality of nodes interchanging signals containing synchronization messages with information about the priority of the respective signal in the internal synchronization hierarchy of the system. In order that the system can, even as far as synchronization is concerned, be connected to an external device or network to which the message-based synchronization employed in the system is unknown, a signal entering the system from an external synchronization source is assigned a selectable standard signature indicating the priority of the signal from the external synchronization source with respect to the internal signals of the system, the priority indicated by the signature being selectable separately for each signal entering the system.