Abstract: The invention relates generally to procedures facilitating the routing in a network-structured telecommunications network. In the network structure according to the invention, connections are established by using a predetermined partial group of connections forming a tree topology. Advantageously the number of said predetermined tree topologies is more than one, in which case the node starting the setup of the connection chooses the tree topology to be used in establishing the connection in question. Thus the advantages offered by the tree topology can be flexibly utilised in a network-structured telecommunications network.

Abstract: In a network structure according to the invention for realising a radio extension of an ATM network, only part of the switches of the ATM network are provided with functions required for supporting wireless terminals. In between these wireless-specific switches, there are provided individual connections in order to distribute control and management information. The wireless-specific switches and the individual connections therebetween form a parallel, tree-like PNNI node structure in relation to the rest of the ATM network, so that the wireless-specific switches belong, in addition to said PNNI node structure, also to the node structure of the regular ATM network. With a structure like this, the additions required by the support of wireless terminals in the PNNI protocol remain very slight.

Abstract: In a connection-oriented telecommunication system, when a connection set-up message addressed to a mobile terminal or subscriber arrives at a first switch (12)that supports a mobility management of mobile terminals, the switch, upon detecting that the set-up message is addressed to a wireless terminal, makes a decision on whether a temporary address of the terminal is inquired in a normal manner of the home network or not. The decision is made substantially on the basis of the resources needed for the connection. The information the decision is based on is available to the switch (12)that supports mobility management at latest at the time when the connection set-up message arrives at the switch. The information may be included in the connection set-up message, or it may be information stored in the system or consisting of parameter information generated of selected events, for example.