Method and apparatus for operating buffer state report in wireless communication system
A method of supporting a buffer status report (BSR) associated with a device-to-device (D2D) communication includes: establishing a radio resource control (RRC) connection with an evolved NodeB (eNB) and receiving configuration information associated with a D2D communication from the eNB, the configuration information including information of a resource allocation mode for a D2D data transmission and information of a timer associated with a BSR for a D2D data transmission; determining, by a user equipment (UE), a radio link failure (RLF), the RLF being associated with a connection problem of the RRC connection; initializing a re-establishment process for the RRC connection; canceling all BSRs for a D2D data transmission in response to the determined RLF, the canceled BSRs for a D2D data transmission being associated with a D2D data transmission scheduled by the eNB; and initializing the timer associated with a BSR for a D2D data transmission.
1. A method comprising:
receiving, by a wireless user device from a base station, one or more messages comprising information of a resource allocation mode for direct data transmission between wireless user devices;
determining, by the wireless user device, a radio link failure (RLF) associated with a radio resource control (RRC) connection; and
based on the determined RLF:
canceling buffer status reports (BSRs) for direct data transmission, wherein the canceled BSRs for direct data transmission are associated with at least one direct data transmission, between wireless user devices, scheduled by the base station;
selecting, based on a configuration parameter indicating a plurality of resources of a resource pool via which the wireless user device is allowed to transmit data to at least one wireless user device in an exceptional condition, at least one resource associated with the exceptional condition; and
transmitting, via the at least one resource associated with the exceptional condition, data to a second wireless user device.
2. The method of claim 1 , further comprising initializing, based on the determined RLF, a timer associated with the BSRs for direct data transmission.
3. The method of claim 2 , wherein initializing of the timer associated with the BSRs for direct data transmission comprises:
initializing a periodic BSR-timer and a retransmission BSR-timer (retx BSR-timer).
4. The method of claim 3 , wherein initializing of the periodic BSR-timer and the retx BSR-timer comprises:
stopping the periodic BSR-timer and the retx BSR-timer; and
resetting timer values of the periodic BSR-timer and the retx BSR-timer.
5. The method of claim 1 , further comprising:
receiving information of a resource selection mode; and
changing, based on the determined RLF, from the resource allocation mode to the resource selection mode,
wherein in the resource allocation mode, the base station schedules resources for direct data transmission between wireless user devices.
6. The method of claim 1 , further comprising:
determining, based on an occurrence of the exceptional condition, a change from the resource allocation mode to a resource selection mode,
wherein an exceptional condition comprises at least one of:
an RLF;
an initialization of a re-establishment process for the RRC connection has been initiated; and
a T311 timer associated with the re-establishment process for the RRC connection has been started.
7. The method of claim 1 , further comprising:
receiving, via a System Information Block (SIB) or a broadcast channel, the configuration parameter indicating the plurality of resources of the resource pool via which the wireless user device is allowed to transmit data to at least one wireless user device in the exceptional condition.
8. The method of claim 1 , further comprising initializing a re-establishment process for the RRC connection.
9. A wireless user device comprising:
an antenna;
a transceiver to communicate with a base station via the antenna; one or more processors; and
memory storing instructions that, when executed by the one or more processors, cause the wireless user device to:
receive, from the base station, one or more messages comprising information of a resource allocation mode for direct data transmission between wireless user devices;
determine a radio link failure (RLF) associated with a radio resource control (RRC) connection; and
based on the determined RLF:
cancel buffer status reports (BSR s) for direct data transmission, wherein the canceled BSRs for direct data transmission are associated with at least one direct data transmission, between wireless user devices, scheduled by the base station;
select, based on a configuration parameter indicating a plurality of resources of a resource pool via which the wireless user device is allowed to transmit data to at least one wireless user device in an exceptional condition, at least one resource associated with the exceptional condition; and
transmit, via the at least one resource associated with the exceptional condition, data to a second wireless user device.
10. The wireless user device of claim 9 , wherein the instructions, when executed by the one or more processors, cause the wireless user device to initialize, based on the determined RLF, a timer associated with the BSRs for direct data transmission.
11. The wireless user device of claim 10 , wherein the instructions, when executed by the one or more processors, cause the wireless user device to initialize the timer by initializing a periodic BSR-timer and a retransmission BSR-timer (retx BSR-timer).
12. The wireless user device of claim 11 , wherein the instructions, when executed by the one or more processors, cause the wireless user device to initialize the periodic BSR-timer and the retx BSR-timer by:
stopping the periodic BSR-timer and the retx BSR-timer; and
resetting timer values of the periodic BSR-timer and the retx BSR-timer.
13. The wireless user device of claim 10 , wherein the instructions, when executed by the one or more processors, cause the wireless user device to:
receive information of a resource selection mode; and
change, based on the determined RLF, from the resource allocation mode to the resource selection mode,
wherein in the resource allocation mode, the base station schedules resources for direct data transmission between wireless user devices.
14. The wireless user device of claim 10 , wherein the instructions, when executed by the one or more processors, cause the wireless user device to:
determine, based on an occurrence of the exceptional condition, a change from the resource allocation mode to a resource selection mode,
wherein an exceptional condition comprises at least one of:
an RLF;
an initialization of a re-establishment process for the RRC connection has been initiated; and
a T311 timer associated with the re-establishment process for the RRC connection has been started.
15. A method comprising:
receiving, by a wireless user device from a base station, one or more messages comprising information of a resource allocation mode for direct data transmission between wireless user devices;
triggering, while the wireless user device is operating in the resource allocation mode, a buffer status report (BSR) for direct data transmission;
determining, after the triggering, that a timer associated with a handover of the wireless user device is running; and
based on the determining that the timer associated with the handover of the wireless user device is running:
canceling BSRs for direct data transmission, wherein the canceled BSRs for direct data transmission are associated with at least one direct data transmission, between wireless user devices, scheduled by the base station and associated with the resource allocation mode;
selecting, based on a configuration parameter indicating a plurality of resources of a resource pool via which the wireless user device is allowed to transmit data to at least one wireless user device in an exceptional condition, at least one resource associated with the exceptional condition; and
transmitting, via the at least one resource associated with the exceptional condition, data to a second wireless user device.
16. The method of claim 15 , further comprising:
receiving at least one of:
a radio resource control (RRC) reconfiguration message comprising mobility control information, or
a cell change order message; and
starting, based on the RRC reconfiguration message or the cell change order message, the timer associated with the handover of the wireless user device.
17. The method of claim 15 , wherein the timer associated with the handover of the wireless user device comprises a T304 timer.
18. The method of claim 15 , further comprising:
stopping, after completing the handover, the timer associated with the handover of the wireless user device; and
changing, based on the stopping the timer, from a resource selection mode to the resource allocation mode.
19. The method of claim 15 , further comprising:
determining, based on an occurrence of the exceptional condition, a change from the resource allocation mode to a resource selection mode,
wherein the exceptional condition comprises: a T304 timer associated with the handover has been started.
20. The method of claim 15 , further comprising:
receiving, via a System Information Block (SIB) or a broadcast channel, the configuration parameter indicating the plurality of resources of the resource pool via which the wireless user device is allowed to transmit data to at least one wireless user device in the exceptional condition.