Method and apparatus for recovery of link failure during handover in TD-SCDMA systems

A method of wireless communications, comprising:

• determining, by a user equipment (UE), that a first handover from a source base station to a target base station has failed;
• performing, by the UE, a second handover from the source base station to a first neighbor base station different from the source base station and from the target base station by:
• a. sending a signal to the first neighbor base station;
• and
• b. receiving a return signal from the first neighbor base station;
• sending a message, by the UE, to the neighbor base station to cause a radio resource setup between the first neighbor base station and a radio network controller (RNC);
• and receiving, by the UE, a connection resetup message in response to determining the first handover has failed and a Physical Channel Reconfiguration message from the RNC, the Physical Channel Reconfiguration message having an instruction to perform a third handover to a second neighbor base station that is different from the first neighbor base station and from the target base station, the third handover being performed by sending a sync code to the second neighbor base station and receiving an acknowledgement message from the second neighbor base station.

An apparatus for wireless communication, comprising:

• means for determining, by a user equipment (UE), that a first handover from a source base station to a target base station has failed;
• means for receiving, by the UE, a connection resetup message in response to determining the first handover has failed;
• means for performing, by the UE, a second handover from the source base station to a first neighbor base station different from the source base station and from the target base station in response to receiving the connection resetup message;
• and
• means for receiving, by the UE, a Physical Channel Reconfiguration message from a radio network controller (RNC), the Physical Channel Reconfiguration message having instructions for performing a third handover to a second neighbor base station that is different from the first neighbor base station and from the target base station, the third handover being performed by sending a sync code to the second neighbor base station and receiving an acknowledgement message from the second neighbor base station.

An apparatus of wireless communications, comprising:

• means for determining, by a user equipment (UE), that a first handover from a source base station to a target base station has failed;
• means for performing, by the UE, a second handover from the source base station to a first neighbor base station different from the source base station and from the target base station by:
• a. sending a signal to the first neighbor base station;
• and
• b. receiving a return signal from the first neighbor base station;
• means for sending a message, by the UE, to the neighbor base station to cause a radio resource setup between the first neighbor base station and a radio network controller (RNC);
• and
• means for receiving, by the UE, a connection resetup message in response to determining the first handover has failed and a Physical Channel Reconfiguration message from the RNC, the Physical Channel Reconfiguration message having an instruction to perform a third handover to a second neighbor base station that is different from the first neighbor base station and from the target base station, the third handover being performed by sending a sync code to the second neighbor base station and receiving an acknowledgement message from the second neighbor base station.

A computer program product, comprising:

• a non-transitory computer-readable medium comprising code for:
• determining, by a user equipment (UE), that a first handover from a source base station to a target base station has failed;
• receiving, by the UE, a connection resetup message in response to determining the first handover has failed;
• performing, by the UE, a second handover from the source base station to a first neighbor base station different from the source base station and from the target base station;
• and
• receiving, by the UE, a Physical Channel Reconfiguration message from a radio network controller (RNC), the Physical Channel Reconfiguration message having instructions for performing a third handover to a second neighbor base station that is different from the first neighbor base station and from the target base station, the third handover being performed by sending a sync code to the second neighbor base station and receiving an acknowledgement message from the second neighbor base station.

A computer program product, comprising:

• a non-transitory computer-readable medium comprising code for:
• determining, by a user equipment (UE), that a first handover from a source base station to a target base station has failed;
• performing, by the UE, a second handover from the source base station to a first neighbor base station different from the source base station and from the target base station by:
• a. sending a signal to the first neighbor base station;
• and
• b. receiving a return signal from the first neighbor base station;
• sending a message, by the UE, to the neighbor base station to cause a radio resource setup between the first neighbor base station and a radio network controller (RNC);
• and
• receiving, by the UE, a connection resetup message in response to determining the first handover has failed and a Physical Channel Reconfiguration message from the RNC, the Physical Channel Reconfiguration message having an instruction to perform a third handover to a second neighbor base station that is different from the first neighbor base station and from the target base station, the third handover being performed by sending a sync code to the second neighbor base station and receiving an acknowledgement message from the second neighbor base station.

An apparatus for wireless communication, comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured to:
• determine, by a user equipment (UE), that a first handover from a source base station to a target base station has failed;
• receive, by the UE, a connection resetup message in response to determining the first handover has failed;
• perform, by the UE, a second handover from the source base station to a first neighbor base station different from the source base station and from the target base station in response to receiving the connection resetup message;
• and
• receive, by the UE, a Physical Channel Reconfiguration message from a radio network controller (RNC), the Physical Channel Reconfiguration message having instructions for performing a third handover to a second neighbor base station that is different from the first neighbor base station and from the target base station, the third handover being performed by sending a sync code to the second neighbor base station and receiving an acknowledgement message from the second neighbor base station.

An apparatus for wireless communication, comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured to:
• determine, by the user equipment (UE), that a first handover from a source base station to a target base station has failed;
• perform, by the UE, a second handover from the source base station to a first neighbor cell of a neighbor base station different from the source base station and from the target base station by:
• a. sending a signal to the first neighbor base station;
• and
• b. receiving a return signal from the first neighbor base station;
• send a message, by the UE, to the neighbor base station to cause a radio resource setup between the first neighbor base station and a radio network controller (RNC);
• and
• receive a connection resetup message in response to determining the first handover has failed and a Physical Channel Reconfiguration message from the RNC, the Physical Channel Reconfiguration message having an instruction to perform a third handover to a second neighbor base station that is different from the first neighbor base station and from the target base station, the third handover being performed by sending a sync code to the second neighbor base station and receiving an acknowledgement message from the second neighbor base station.