Abstract: The disclosure relates to accessing a communication system. In accordance with the disclosed method a communication device communicating in a first access system based on an address is transferred to a second access system. The communication device sends an indication that the same address is to be used in the second access system, where after, if proxy mobility is available for the address, the same address is used for communications in the second access system.

Abstract: A system and method of maintaining an always-on application client communication is provided. An application programming interface implemented on a device hosting an always-on application client determines if network-based keep-alive functionality exists in a network where the device operates. If network-based keep-alive functionality exists, a network element is instructed to transmit keep-alive messages to the application server on behalf of the device. The network element can be implemented in or as a variety of existing network elements, e.g., as a GPRS gateway serving node or a standalone keep-alive network element. Alternatively, an application server communicatively connected to the always-on application client may query whether network-based keep-alive functionality exists. If network-based keep-alive functionality exists, the application server negotiates with the always-on application client to determine an application-specific mechanism for implementing the network-based keep-alive functionality.

Abstract: The present invention relates to a method for informing changed link properties in a system in which a mobile node is communicating by IP (Internet Protocol) with a correspondent node and utilizing a first link layer configuration. A need to change link layer communication to use a second link layer configuration is detected. Property information indicating a link layer property applied or to be applied in communication utilizing the second link layer configuration is defined. The property information is transmitted to the correspondent node. At least one setting for communication between the correspondent node and the mobile node is adapted in the correspondent node on the basis of the received property information.

Abstract: The disclosure relates to accessing a communication system. In accordance with the disclosed method a communication device communicating in a first access system based on an address is transferred to a second access system. The communication device sends an indication that the same address is to be used in the second access system, where after, if proxy mobility is available for the address, the same address is used for communications in the second access system.

Abstract: A system and method of maintaining an always-on application client communication is provided. An application programming interface implemented on a device hosting an always-on application client determines if network-based keep-alive functionality exists in a network where the device operates. If network-based keep-alive functionality exists, a network element is instructed to transmit keep-alive messages to the application server on behalf of the device. The network element can be implemented in or as a variety of existing network elements, e.g., as a GPRS gateway serving node or a standalone keep-alive network element. Alternatively, an application server communicatively connected to the always-on application client may query whether network-based keep-alive functionality exists. If network-based keep-alive functionality exists, the application server negotiates with the always-on application client to determine an application-specific mechanism for implementing the network-based keep-alive functionality.

Abstract: The present invention relates to a method for informing changed link properties in a system in which a mobile node is communicating by IP (Internet Protocol) with a correspondent node and utilizing a first link layer configuration. A need to change link layer communication to use a second link layer configuration is detected. Property information indicating a link layer property applied or to be applied in communication utilizing the second link layer configuration is defined. The property information is transmitted to the correspondent node. At least one setting for communication between the correspondent node and the mobile node is adapted in the correspondent node on the basis of the received property information.