Communications System, Method for Controlling a Communications System, Network Access Device and Method for Controlling A Network Access Device

A communications system comprising:

• a first communications network;
• a second communications network;
• a third communications network;
• a subscriber device;
• and
• a network access device to which a network layer address is assigned, wherein the network access device is configured to permit access by the first communications network to the third communications network and access by the second communications network to the third communications network,
• wherein the communications system has a communications link between the subscriber device and the third communications network by means of the first communications network and by means of the network access device, wherein the network layer address of the network access device is used during the transmission of data by means of the first communications link, and
• wherein the network access device has a control device which is configured to release the first communications link and to set up a second communications link between the subscriber device and the third communications network by means of the second communications network and by means of the network access device, wherein the network layer address of the network access device is used during the transmission of data by means of the second communications link.

A method for controlling a communications system which has a first communications network, a second communications network, a third communications network, a subscriber device and a network access device to which a network layer address is assigned and which permits access by the first communications network to the third communications network and access by the second communications network to the third communications network, wherein the method comprises:

• using the network layer address of the network access device during the transmission of data by means of a first communications link which is provided between the subscriber device and the third communications network by means of the first communications network and by means of the network access device;
• the network access device releasing the first communications link;
• the network access device setting up a second communications link between the subscriber device and the third communications network by means of the second communications network and by means of the network access device;
• and
• using the network layer address of the network access device during the transmission of data by means of the second communications link.

A network access device of a communications system comprising:

• a first communications network;
• a second communications network;
• a third communications network;
• a subscriber device,
• wherein a network layer address is assigned to the network access device, and the network access device is configured to permit access by the first communications network to the third communications network and access by the second communications network to the third communications network;
• and
• a control device which is configured to release a first communications link, wherein the first communication link is provided between the subscriber device and the third communications network by means of the first communications network and by means of the network access device, wherein the network layer address of the network access device is used during the transmission of data by means of the first communications link, and which control device is also configured to set up a second communications link between the subscriber device and the third communications network by means of the second communications network and by means of the network access device, wherein the network layer address of the network access device is used during the transmission of data by means of the second communications link.

A communications system comprising:

• a first communications network;
• a second communications network;
• a third communications network;
• a subscriber device;
• and
• a network access means, which has a network layer address assigned thereto, for permitting access by the first communications network to the third communications network and access by the second communications network to the third communications network,
• wherein the communications system has a communications link between the subscriber device and the third communications network via the first communications network and via the network access means, wherein the network layer address of the network access means is used during the transmission of data via the first communications link, and
• wherein the network access means has a control means for releasing the first communications link and for setting up a second communications link between the subscriber device and the third communications network via the second communications network and via the network access means, wherein the network layer address of the network access means is used during the transmission of data via the second communications link.