Inter Base Station Handover with Dual Active Protocol Stack

A method of handover performed by a wireless device configured with first and second logical connections for communicating with a source base station, the method comprising:

• receiving a handover command while the wireless device is configured to perform packet duplication wherein the wireless device exchanges duplicate packets with one or more source base stations in a source base station group using first and second logical connections;
• responsive to the handover command, configuring dual active protocol stacks (DAPS) with the source base station group and a target base station group respectively for both the first and second logical connections;
• maintaining, during the handover, the first logical connection and second logical connections with dual protocol stacks for the source base station group and the target base station group;
• releasing the first and second logical connections with the source base station group to complete the handover and reconfiguring the wireless device for packet duplication with the target base station group wherein the wireless device exchanges duplicate packets with one or more target base stations in the target base station group using the first and second logical connections.

A method implemented by a source base station group to handover a wireless device configured for packet duplication to a target base station group, the method comprising:

• determining a need to handover a wireless device;
• sending a handover command to the wireless device to initiate handover to the target base station group while the wireless device is configured for packet duplication wherein the wireless device exchanges duplicate packets with the source base station group using first and second logical connections;
• and
• maintaining the first logical connection and the second logical connection with the wireless device while the wireless device establishes DAPSs for both the first and second logical connections with the target base station group;
• and
• receiving a handover message from the target base station group indicating successful handover;
• and
• responsive to the handover message, releasing the first logical connection and second logical connection with the wireless device.

A wireless device configured with first and second logical connections for communicating with a source base station group, the wireless device comprising:

• communication circuitry for communicating with base stations in a wireless communication network;
• and
• processing circuitry operatively coupled to the communication circuitry and configured to:
• receive a handover command while the wireless device is configured to perform packet duplication wherein the wireless device exchanges duplicate packets with one or more source base stations in a source base station group using first and second logical connections;
• responsive to the handover command, configure dual active protocol stacks (DAPS) with the source base station group and a target base station group respectively for both the first and second logical connections;
• maintain, during the handover, the first logical connection and second logical connections with dual protocol stacks for the source base station group and the target base station group;
• release the first and second logical connections with the source base station group to complete the handover and reconfiguring the wireless device for packet duplication with the target base station group wherein the wireless device exchanges duplicate packets with one or more target base stations in the target base station group using the first and second logical connections.

A source base station group configured to handover a wireless device for packet duplication to a target base station group, the source base station group comprising:

• communication circuitry for communicating with a wireless device in a wireless communication network;
• and
• processing circuitry operatively coupled to the communication circuitry and configured to:
• determine a need to handover a wireless device;
• send a handover command to the wireless device to initiate handover to the target base station group while the wireless device is configured for packet duplication wherein the wireless device exchanges duplicate packets with the source base station group using first and second logical connections;
• and
• maintain the first logical connection and the second logical connection with the wireless device while the wireless device duplicates the first and second logical connections with a target base station group;
• and
• receive a handover message from the target base station group indicating successful handover;
• and
• responsive to the handover message, release the first logical connection and second logical connections with the wireless device.

A target base station group configured to handover wireless device configured for packet duplication from a source base station group, the target base station group comprising:

• communication circuitry for communicating with a wireless device in a wireless communication network;
• and
• processing circuitry operatively coupled to the communication circuitry and configured to:
• receive a handover request message for a wireless device configured to perform packet duplication wherein the wireless device exchanges duplicate packets with the source base station group using first and second logical connections;
• responsive to the handover request message, establish dual active protocol stacks (DAPS) at a target base station group for both the first and second logical connections while the wireless device continues to exchange data with the source base station group;
• and
• send a release command to the wireless device to release the first and second logical connections with the source base station group (20S, 500) to complete the handover.