Methods, apparatuses, computer programs and computer program products for user plane integrity protection during X2 handover

A method of operating a radio access network, RAN, node of a wireless communication system, comprising:

• receiving, at the RAN node, a handover request to handover a user equipment, UE, from a source node, the handover request including a user plane integrity protection, UP IP, policy associated with the UE;
• preparing a path switch request, the path switch request comprising the UP IP policy associated with the UE;
• and
• transmitting the path switch request to a core network function of the wireless communication system,
• wherein the UP IP policy comprises a first UP IP policy, the method further comprising:
• receiving a path switch request acknowledgement from the core network function, wherein the path switch request acknowledgement comprises a second UP IP policy;
• in response to the core network function determining that the first UP IP policy does not match the second UP IP policy, receiving the second UP IP policy;
• and
• performing UP IP activation with the UE based on the second UP IP policy.

A method of operating a core network node of a wireless communication system, comprising:

• receiving a path switch request from a target node, the path switch request comprising a user plane integrity protection, UP IP, policy associated with a user equipment, UE;
• transmitting a path switch request acknowledgement to the target node, wherein the path switch request acknowledgement is generated based on the UP IP policy and UE capability information;
• and
• in response to determining that the received UP IP policy does match the stored UP IP policy, preparing the path switch request acknowledgement to include the UE capability information without including the stored UP IP policy to the target node in the path switch request acknowledgement.

A radio access network, RAN, node comprising:

• processing circuitry;
• and
• memory coupled with the processing circuitry, wherein the memory includes instructions that when executed by the processing circuitry causes the RAN node to:
• prepare, at the RAN node, a handover request to handover a user equipment, UE, to a target node, the handover request including a user plane integrity protection, UP IP, policy associated with the UE;
• and
• transmit the handover request to the target node;
• wherein the handover request comprises a UP IP policy including UP IP activation status for each radio bearer established with the UE in a packet data network, PDN, connection, and wherein the handover request further comprises UE capability information indicating UE support for UP IP.

A radio access network, RAN, node comprising:

• processing circuitry;
• and
• memory coupled with the processing circuitry, wherein the memory includes instructions that when executed by the processing circuitry causes the RAN node to perform operations comprising:
• receiving, at the RAN node, a handover request to handover a user equipment, UE, from a source node, the handover request including a user plane integrity protection, UP IP, policy associated with the UE;
• preparing a path switch request, the path switch request comprising the UP IP policy associated with the UE;
• and
• transmitting the path switch request to a core network function of the wireless communication system,
• wherein the UP IP policy comprises a first UP IP policy, the operations further comprising:
• receiving a path switch request acknowledgement from the core network function, wherein the path switch request acknowledgement comprises a second UP IP policy;
• in response to the core network function determining that the first UP IP policy does not match the second UP IP policy, receiving the second UP IP policy;
• and
• performing UP IP activation with the UE based on the second UP IP policy.

A core network, CN, node comprising:

• processing circuitry;
• and
• memory coupled with the processing circuitry, wherein the memory includes instructions that when executed by the processing circuitry causes the CN node to:
• receive a path switch request from a target node, the path switch request comprising a user plane integrity protection, UP IP, policy associated with a user equipment, UE;
• transmit a path switch request acknowledgement to the target node, wherein the path switch request acknowledgement is generated based on the UP IP policy and UE capability information;
• and
• in response to determining that the received UP IP policy does match the stored UP IP policy, prepare the path switch request acknowledgement to include the UE capability information without including the stored UP IP policy to the target node in the path switch request acknowledgement.