Method and device used for monitoring a radio link status in wireless communication
The present application provides a method and device for wireless communications. The first node transmits a first radio signal, the first radio signal carries a first data unit; receives a first status report, the first status report indicates whether the first data unit set is successfully received; maintains a first variable of the first data unit; maintains a second variable; herein, the first status report indicates a negative confirmation for the first data unit; the maintaining a first variable of the first data unit comprises: when the first data unit is considered a first retransmission, setting a value of a first variable of the first data unit to 0; the maintaining a second variable comprises: when all conditions in the first condition set are met, a value of the second variable being increased by 1. The present application effectively monitors radio link.
1 . A user equipment (UE) for wireless communications, the UE comprising:
a transceiver; and
a processor, wherein the transceiver and the processor are configured to:
transmit a radio signal comprising a data unit,
receive, at a Radio Link Control Protocol (RLC) entity of the UE, a status report associated with a data unit set comprising the data unit,
on a condition that the status report indicates a negative confirmation for the data unit, determine that the data unit is a first retransmission,
maintain a first variable associated with the data unit,
set the first variable to zero based upon determining that the data unit is a first retransmission,
maintain a second variable,
determine that a value of the first variable is less than a first threshold and the data unit is indicated to be discarded, wherein the first threshold is associated with the RLC entity,
increment the second variable by 1 based upon determining that the value of the first variable is less than a first threshold and the data unit is indicated to be discarded, and
on a condition that the status report indicates a positive confirmation for any data unit in the data unit set, set the value of the second variable to 0.
2 . The UE according to claim 1 , wherein the transceiver and the processor are further configured to:
determine that the value of the first variable of the data unit is equal to the first threshold, and
transmit, to an upper layer of the UE, a first indication indicating reaching a maximum number of retransmissions.
3 . The UE according to claim 1 , wherein the transceiver and the processor are further configured to:
determine that the value of the second variable is equal to a second threshold, and
transmit a second indication to an upper layer of the UE, wherein the second threshold is configured by a network or pre-configured, and wherein the second indication is used to trigger a radio link failure.
4 . The UE according to claim 1 , wherein the transceiver and the processor are further configured to:
receive a Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) at a PDCP sublayer,
start a first timer,
when the first timer expires, transmit a third indication to the RLC entity, wherein the PDCP SDU is used to generate the data unit, and wherein the third indication is used to indicate discarding the data unit.
5 . The UE according to claim 4 , wherein the transceiver and the processor are further configured to:
as a response to receiving the third indication, discard the data unit, wherein the RLC entity is associated with a first-type radio bearer, and wherein the data unit belongs to the first-type radio bearer.
6 . The UE according to claim 1 , wherein maintaining the first variable comprises:
determining that the data unit is not considered the first retransmission and is not pending for retransmission, and the first variable has not been increased due to another negative confirmation in the status report, incrementing the value of the first variable by 1.
7 . A base station for wireless communications, the base station comprising:
a transceiver; and
a processor, wherein the transceiver and the processor are configured to:
receive a radio signal, the radio signal carrying a data unit,
transmit a status report to a Radio Link Control Protocol (RLC) entity of a user equipment (UE), wherein the status report indicates whether a data unit set is successfully received, and wherein the data unit set comprises the data unit, and wherein:
a first variable associated with the data unit is maintained,
a second variable is maintained,
the status report indicates a negative confirmation for the data unit, and the status report indicating the negative confirmation for the data unit is considered retransmission for the data unit,
a first variable of the data unit being maintained comprises: when the data unit is considered a first retransmission, a value of the first variable of the data unit being set to 0,
the second variable being maintained comprises: when all conditions in a first condition set are met, increasing the value of the second variable being increased by 1, and when the status report indicates a positive confirmation for any data unit in the data unit set, the value of the second variable is set to 0,
the first condition set comprises that the value of the first variable of the data unit is less than a first threshold and the data unit is indicated to be discarded, and
the first threshold is configured to the RLC entity.
8 . The base station according to claim 7 , wherein when the value of the first variable of the data unit is equal to the first threshold, a first indication is transmitted to an upper layer of a transmitter of the radio signal, and the first indication indicates reaching a maximum number of retransmissions.
9 . The base station according to claim 7 , wherein when the value of the second variable is equal to a second threshold, a second indication is transmitted to an upper layer of a transmitter of the radio signal, and wherein the second threshold is configured by a network or pre-configured, and wherein the second indication is used to trigger a radio link failure.
10 . The base station according to claim 7 , wherein when a Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) is received at a PDCP sublayer, a first timer is started, and wherein when the first timer expires, a third indication is transmitted to the RLC entity, and wherein the PDCP SDU is used to generate the data unit, and the third indication is used to indicate discarding the data unit.
11 . The base station according to claim 10 , wherein as a response to receiving the third indication, the data unit is discarded, and wherein, the RLC entity is associated with a first-type radio bearer, and the first condition set comprises the data unit belonging to the first-type radio bearer.
12 . A method in a user equipment (UE) for wireless communications, the method comprising:
transmitting a radio signal comprising a data unit;
receiving, at a Radio Link Control Protocol (RLC) entity of the UE, a status report associated with a data unit set comprising the data unit;
on a condition that the status report indicates a negative confirmation for the data unit, determining that the data unit is a first retransmission;
maintaining a first variable associated with the data unit,
setting the first variable to zero based upon determining that the data unit is a first retransmission,
maintaining a second variable,
determining that the first variable is less than a first threshold and the data unit is indicated to be discarded, wherein the first threshold is configured to the RLC entity;
incrementing the second variable by 1 based upon determining that a value of the first variable is less than a first threshold and the data unit is indicated to be discarded; and
on a condition that the status report indicates a positive confirmation for any data unit in the data unit set, setting the value of the second variable to 0.
13 . The method in the UE according to claim 12 , further comprising:
determining that the value of the first variable of the data unit is equal to the first threshold; and
transmitting, to an upper layer of the UE, a first indication indicating reaching a maximum number of retransmissions.
14 . The method in the UE according to claim 12 , further comprising:
determining that the value of the second variable is equal to a second threshold, and
transmitting a second indication to a upper layer of the UE, wherein the second threshold is configured by a network or pre-configured, and wherein the second indication is used to trigger a radio link failure.
15 . The method in the UE according to claim 12 , further comprising:
receiving a Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) at a PDCP sublayer;
starting a first timer; and
when the first timer expires, transmitting a third indication to the RLC entity, wherein the PDCP SDU is used to generate the data unit, and wherein the third indication is used to indicate discarding the data unit.
16 . The method in the UE according to claim 15 , further comprising:
as a response to receiving the third indication, discarding the data unit, wherein the RLC entity is associated with a first-type radio bearer, and wherein the data unit belongs to the first-type radio bearer.
17 . The method in the UE according to claim 12 , wherein maintaining the first variable of the data unit comprises:
determining the data unit is not considered the first retransmission and is not pending for retransmission, and the first variable has not been increased due to another negative confirmation in the status report, incrementing the value of the first variable by 1.