METHOD AND APPARATUS FOR CONSISTENT LBT FAILURE DETECTION AND RECOVERY IN CELL HANDOVER
A method and apparatus for consistent LBT failure detection and recovery in cell handover. The method is applicable to a terminal equipment and includes receiving a consistent LBT failure indication during cell handover, and suspending data transmission and/or reception with a network device and/or suspending consistent LBT failure detection and recovery during the cell handover.
1 . An apparatus for consistent LBT failure detection and recovery in cell handover, applicable to a terminal equipment, the apparatus comprising:
a memory; and
a processor coupled to the memory and configured to:
receive a consistent uplink LBT failure indication from a target MAC or a source MAC; and
when the consistent uplink LBT failure indication is received from the source MAC, suspend data transmission and reception with a source network device; and
when the consistent uplink LBT failure indication is received from the target MAC and a timer for the cell handover being not operated, consider radio link failure to be detected for a target MCG.
2 . The apparatus according to claim 1 , wherein the cell handover comprises:
dual active protocol stack (DAPS) handover, or
dual active protocol stack (DAPS) handover and non-DAPS handover, or
non-DAPS handover.
3 . The apparatus according to claim 1 , wherein,
the processor, when the consistent uplink LBT failure indication is received from the source MAC during the cell handover, suspend the data transmission and reception with the source network device.
4 . The apparatus according to claim 1 , wherein,
the received consistent uplink LBT failure indication is from an MAC layer of the terminal equipment.
5 . The apparatus according to claim 4 , wherein the received consistent uplink LBT failure indication is from at least one of a source MAC entity and a target MAC entity of the terminal equipment.
6 . The apparatus according to claim 1 , wherein the processor is further configured to suspend consistent LBT failure detection and recovery during the cell handover when a situation is at least one of the following:
suspending indicating LBT failure by a physical layer to an MAC layer;
not triggering consistent LBT failure by an MAC layer;
not indicating consistent LBT failure by an MAC layer to a higher layer; and
radio link failure occurring, a timer used for cell handover being not operated, and initiating connection reestablishment; or the timer being operated, radio link failure occurring, and not initiating connection reestablishment.
7 . The apparatus according to claim 1 , wherein
the processor is further configured to:
complete the cell handover; and
recover a consistent LBT failure detection and recovery mechanism.
8 . The apparatus according to claim 7 , wherein that the processor recovers the consistent LBT failure detection and recovery mechanism comprises at least one of the following:
indicating an LBT failure by a physical layer to an MAC layer when an indication of recovering consistent LBT failure detection and recovery is received and LBT fails;
for a serving cell configured with an LBT failure recovery configuration parameter, triggering consistent LBT failure on a BWP of the serving cell by an MAC entity when an indication of recovering consistent LBT failure detection and recovery is received, an LBT failure indication is received from a lower layer and an LBT counter is greater than or equal to a maximum value of LBT failure; and
indicating consistent LBT failure by the MAC entity to a higher layer when a serving cell in which consistent LBT failure is triggered is a special cell, an indication of recovering consistent LBT failure detection and recovery is received, and consistent LBT failure has been triggered in all uplink BWPs configured with physical random access channel (PRACH) occasions on same carrier in the serving cell.
9 . The apparatus according to claim 7 , wherein that the processor recovers the LBT failure detection and recovery mechanism further comprises:
indicating a lower layer by a RRC layer to recover consistent LBT failure detection and recovery when RRC handover is completed or when the terminal equipment is synchronized to a second cell, the second cell being a target cell.
10 . The apparatus according to claim 1 , wherein the apparatus further comprises:
a receiver configured to receive an RRC reconfiguration message from a first network device, the RRC reconfiguration message comprising configuration information on LBT failure detection and recovery, and the first network device being the source network device, wherein
the consistent uplink LBT failure indication is indication according to the configuration information.
11 . The apparatus according to claim 10 , wherein,
the configuration information on LBT failure detection and recovery comprises first configuration information and/or second configuration information, the first configuration information being related to LBT failure detection and recovery of a first cell, and the second configuration information being related to LBT failure detection and recovery of a second cell,
the first cell being a cell belonging to the source network device, and the second cell being a cell belonging to a target network device.
12 . The apparatus according to claim 11 , wherein,
the source MAC entity of the terminal equipment performs LBT failure detection and recovery on the first cell according to the first configuration information; and/or
the target MAC entity of the terminal equipment performs LBT failure detection and recovery on the second cell according to the second configuration information.
13 . A network device, comprising:
a processor configured to configure a configuration information on LBT failure detection and recovery; and
a transmitter configured to transmit a Radio Resource Control message including the configuration information to a terminal equipment, wherein
the processor is further configured to:
control to cause the terminal equipment to suspend data transmission and reception with a source network device when a consistent uplink LBT failure indication is received from the source MAC, and
control to cause the terminal equipment to consider radio link failure to be detected for a target MCG when the consistent uplink LBT failure indication is received from the target MAC and a timer for the cell handover being not operated.
14 . The network device according to claim 13 , wherein,
the consistent uplink LBT failure indication is indication according to the configuration information.
15 . The network device according to claim 14 , wherein,
the configuration information on LBT failure detection and recovery comprises first configuration information and/or second configuration information, the first configuration information being related to LBT failure detection and recovery of a first cell, and the second configuration information being related to LBT failure detection and recovery of a second cell,
the first cell being a cell belonging to a source network device, and the second cell being a cell belonging to a target network device.
16 . The network device according to claim 14 , wherein the network device further comprises:
a receiver configured to receive a transmitted handover request acknowledgement message from a second network device, the second network device being a target network device.
17 . The network device according to claim 16 , wherein,
the handover request acknowledgement message comprises information needed in accessing to a target cell and configuration information on LBT failure detection and recovery, the configuration information on LBT failure detection and recovery being configuration information on performing LBT failure detection and recovery on a cell in the target network device by the terminal equipment.
18 . A communications system, comprising a terminal equipment and/or a network device, the terminal equipment comprising:
an apparatus for consistent LBT failure detection and recovery in cell handover, applicable to a terminal equipment, the apparatus comprising:
a memory; and
a processor coupled to the memory and configured to:
receive a consistent uplink LBT failure indication from a target MAC or a source MAC; and
when the consistent uplink LBT failure indication is received from the source MAC, suspend data transmission and reception with a source network device; and
when the consistent uplink LBT failure indication is received from the target MAC and a timer for the cell handover being not operated, consider radio link failure to be detected for a target MCG, and
a network device, comprising:
a processor configured to configure a configuration information on LBT failure detection and recovery; and
a transmitter configured to transmit a Radio Resource Control message including the configuration information to a terminal equipment, wherein
the processor is further configured to:
control to cause the terminal equipment to suspend data transmission and reception with a source network device when a consistent uplink LBT failure indication is received from the source MAC, and
control to cause the terminal equipment to consider radio link failure to be detected for a target MCG when the consistent uplink LBT failure indication is received from the target MAC and a timer for the cell handover being not operated.