Method and nodes for handling a UE which has moved from an old location to a new location

A method for handling a user equipment (UE), the method comprising:

• storing, by a subscriber server, first UE context information for the UE, the first UE context information for the UE comprising first mobility node information comprising a first mobility node identifier identifying a first mobility node;
• after storing the first UE context information, the subscriber server receiving second UE context information for the UE, wherein the second UE context information was transmitted by a second mobility node and comprises second mobility node information comprising a second mobility node identifier identifying the second mobility node;
• in response to receiving the second UE context information transmitted by the second mobility node, the subscriber server retrieving the stored UE context information comprising the first mobility node information;
• and
• the subscriber server determining whether to transmit a cancel location message to the first mobility node based on the retrieved UE context information, wherein
• the step of determining whether to transmit a cancel location message to the first mobility node based on the retrieved UE context information comprises:
• the subscriber server determining whether the retrieved UE context information indicates that the first mobility node is stateless;
• and
• the subscriber server deciding to refrain from transmitting the cancel location message to the first mobility node as a result of the subscriber server determining that the retrieved UE context information indicates that the first mobility node is stateless, wherein the first mobility node is stateless if there is no need to update the first mobility node during a subsequent mobility procedure with respect to the UE.

A first mobility node for handling a user equipment (UE) which has moved from a first location to a second location, the first mobility node being adapted to:

• send toward a common database a request for UE context information stored in the common database;
• after sending the request for the UE context information stored in the common database, receive a response to the request, wherein the response to the request was transmitted by the common database and the response comprises the requested UE context information and the requested UE context information comprises first mobility node information identifying the first mobility node or a second mobility node, wherein the common database is neither a Mobility Management Node (MME) nor a Serving GPRS Support Node (SGSN) and is not a component of either a MME or a SGSN;
• determine whether the first mobility node information included in the UE context information obtained from the common database identifies the first mobility node;
• and
• as a result of determining that the first mobility node information does not identify the first mobility node, transmit updated UE context information comprising second mobility node information identifying the first mobility node.

A subscriber server for handling a user equipment (UE) which has moved from an old location to a new location, the subscriber server being adapted to:

• store first UE context information for the UE, the first UE context information for the UE comprising first mobility node information comprising a first mobility node identifier identifying a first mobility node;
• retrieve the UE context information comprising the first mobility node information after receiving second UE context information for the UE transmitted by a second mobility node;
• and
• determine whether to transmit a cancel location message to the first mobility node based on the retrieved UE context information, wherein
• the subscriber server is configured to determine whether to transmit the cancel location message to the first mobility node based on the retrieved UE context information by performing a process comprising:
• determining whether the retrieved UE context information indicates that the first mobility node is stateless;
• and
• deciding to refrain from transmitting the cancel location message to the first mobility node as a result of determining that the retrieved UE context information indicates that the first mobility node is stateless, wherein the first mobility node is stateless if there is no need to update the first mobility node during a subsequent mobility procedure with respect to the UE.

A method for handling a user equipment (UE), the method comprising:

• a first mobility node sending toward a common database a request for UE context information stored in the common database;
• after sending the request for the UE context information stored in the common database, the first mobility node receiving a response to the request, wherein the response to the request was transmitted by the common database and the response comprises the requested UE context information, and a gateway was serving the UE before the UE context information was received, the UE context information comprising first mobility node information identifying the first mobility node or another mobility node;
• the first mobility node determining whether the first mobility node information included in the UE context information obtained from the common database identifies the first mobility node;
• the first mobility node selecting a gateway to serve the UE;
• the first mobility node determining whether the selected gateway is a different gateway than the gateway that was serving the UE before the UE context information was retrieved;
• and
• as a result of selecting the gateway to serve the UE and determining that the selected gateway is a different gateway than the gateway that was serving the UE before the UE context information was obtained, the first mobility node initiating the set-up of a tunnel between the selected gateway and another gateway, wherein
• the common database is neither a Mobility Management Node (MME) nor a Serving GPRS Support Node (SGSN) and is not a component of either a MME or a SGSN.

A first mobility node, the first mobility node being adapted to:

• receive a message indicating that a user equipment (UE) has moved to a new location;
• after receiving the message indicating that the UE has moved to the new location, send toward a common database a request for UE context information stored in the common database;
• after sending the request for the UE context information stored in the common database, receive a response to the request, wherein the response to the request was transmitted by the common database and the response comprises the requested UE context information, and a gateway was serving the UE before the message was received, the UE context information comprising first mobility node information identifying the first mobility node or a second mobility node;
• determine whether the first mobility node information included in the UE context information obtained from the common database identifies the first mobility node;
• select a gateway to serve the UE;
• determine whether the selected gateway is a different gateway than the gateway that was serving the UE before the UE context information was obtained;
• and
• as a result of selecting the gateway to serve the UE and determining that the selected gateway is a different gateway than the gateway that was serving the UE before the UE context information was obtained, initiate the set-up of a tunnel between the selected gateway and another gateway, wherein
• the common database is neither a Mobility Management Node (MME) nor a Serving GPRS Support Node (SGSN) and is not a component of either a MME or a SGSN.