Alcatel

J&uuml;rgen Sienel

Dieter Kopp

A method for establishing a digital communication link between an originating subscriber terminal and at least one called subscriber terminal, said method being better adapted to the transmission bandwidth used by a subscriber, has the following steps: First, a provisional link at a standard transmission rate from the originating subscriber terminal to the called subscriber is requested from a switching center. That provisional link is then established by the switching center. Next, a new, lower value for the transmission rate is selected by the originating subscriber terminal. That new value is then agreed upon with the switching center. Lastly, the latter switches the transmission rate of the provisional link over to the new, lower value, thus completing establishment of the communication link. The invention can advantageously be used in a telecommunications network, which for example operates according to the ISDN standard, to economize on transmission capacity and reduce call charges.

Method for establishing a communication link, subscriber terminal and switching center

Call connections by way of the Internet (internet telephony) are less expensive than ones by way of an open telephone network. However, no fixed transmission rates are guaranteed in the Internet, which can lead to losses in the quality of transmitted speech signals. A device (V) for establishing a call connection between two subscriber terminals (T T ) has a first interface (IF ) to a packet-switched data network (INET) and means (IP, KOMP) for establishing connections by way of the packet-switched data network (INET) as well as a second interface (IF ) to a connection-oriented telecommunication network (PSTN), in which a transmission channel with a predetermined transmission band width can be furnished. By means of a monitoring device (MON), the device (V) determines a current data throughput in the data network (INET). A control device (SW) of the device (V) compares the current data throughput with a predetermined threshold value and controls the establishment of connections in such a way that the call connection is established by way of the data network (INET) when the data throughput lies above the threshold value and is established by way of the telecommunication network (PSTN) when the data throughput lies below the threshold value.

Growing community of inventors

Leonberg, Germany

Jürgen Sienel

Growing community of inventors

Leonberg, Germany

J&uuml;rgen Sienel

Jürgen Sienel