Buffer status reporting in a mobile communication system
An invention relates to methods for transmitting a buffer status report (BSR) in a mobile communication system, more particularly to the definition of rules for triggering, generating and transmitting BSRs. The invention also relates to a data transmission method utilizing new rules to decide data of which radio bearers is transmitted within a given transmission time interval. Moreover, the invention relates to scheduling method for radio resources that is taking into account additional scheduling-relevant information from the buffer status reporting and/or data transmission method. To avoid unnecessary grants from the network and to suggest an advanced handling of data transmissions the invention suggests a buffer status reporting and data transmission schemes that take into account the scheduling mode of data of radio bearers pending for transmission to decide whether to report on it in a buffer status report, respectively, whether to multiplex the data to a transport block for transmission.
1. A method implemented in a mobile communication system including a mobile terminal and a base station, the method comprising:
the base station transmitting to the mobile station a semi-persistent scheduling configuration via physical downlink control channel (PDCCH) signaling;
the mobile terminal receiving from the base station the semi-persistent scheduling configuration via the PDCCH signaling;
when semi-persistent scheduling is not activated, the mobile terminal transmitting to the base station a scheduling request to request uplink resources for uplink transmission including uplink transmission of a buffer status report;
when semi-persistent scheduling is activated, the mobile terminal checking a setup information element of a logical channel as part of a buffer status reporting procedure to determine whether to trigger a scheduling request for the logical channel;
when the mobile terminal determines to trigger the scheduling request, the mobile terminal transmitting the scheduling request to the base station for the logical channel; and
when the mobile terminal determines not to trigger the scheduling request, the mobile terminal not transmitting the scheduling request to the base station;
wherein the mobile communication system is selectively operable in one of at least a dynamic scheduling mode, in which radio resources are dynamically allocated by dynamic grants, and a semi-persistent scheduling mode, in which radio resources are allocated on a semi-persistent basis by semi-persistent scheduling grants.
2. The method according to claim 1 , wherein the setup information element of the logical channel indicates that a buffer status report is not triggered.
3. The method according to claim 2 , wherein the setup information element of the logical channel indicates that the buffer status report is not triggered despite that data has become available for the logical channel.
4. The method according to claim 2 , wherein the setup information element of the logical channel indicates that the buffer status report is not triggered due to activation of the semi-persistent scheduling.
5. The method according to claim 1 , wherein the mobile terminal determines to trigger the scheduling request when the setup information element of the logical channel indicates activation of the semi-persistent scheduling.
6. The method according to claim 1 , wherein the mobile terminal determines to trigger the scheduling request when the setup information element of the logical channel indicates that data has become available for the logical channel.
7. The method according to claim 1 , further comprising:
when semi-persistent scheduling is not activated, no uplink resources are allocated for a transmission time interval, and a buffer status report has not been triggered, the mobile terminal transmitting to the base station the scheduling request to request uplink resources for uplink transmission of a buffer status report.
8. The method according to claim 1 , further comprising:
the mobile terminal considering an activation status of semi-persistent resource allocation to determine whether to trigger the buffer status report.
9. The method according to claim 1 , further comprising:
the mobile terminal considering a scheduling mode status to determine on which logical channel to report in the buffer status report.
10. The method according to claim 9 , wherein the scheduling mode status is an activation of the semi-persistent scheduling or a deactivation of the semi-persistent scheduling.
11. A mobile communication system comprising:
a base station configured to transmit a semi-persistent scheduling configuration via physical downlink control channel (PDCCH) signaling, and
a mobile terminal including:
a receiver configured to receive the PDCCH signaling including the semi-persistent scheduling configuration,
a controller configured to cause the mobile terminal to selectively operate, based on the PDCCH signaling, in one of at least a dynamic scheduling mode, in which radio resources are dynamically allocated by dynamic grants, and a semi-persistent scheduling mode, in which radio resources are allocated on a semi-persistent basis by semi-persistent scheduling grants, and
a transmitter configured to transmit a scheduling request to the base station to request uplink resources for uplink transmission including uplink transmission of a buffer status report,
wherein the controller of the mobile terminal is configured to:
when semi-persistent scheduling is not activated, cause the transmitter to transmit the scheduling request,
when semi-persistent scheduling is activated, check a setup information element of a logical channel as part of a buffer status reporting procedure to determine whether to trigger a scheduling request for the logical channel,
when determining to trigger the scheduling request, cause the transmitter to transmit the scheduling request for the logical channel, and
when determining not to trigger the scheduling request, not cause the transmitter to transmit the scheduling request.
12. The mobile communication system according to claim 11 , wherein the setup information element of the logical channel indicates that a buffer status report is not triggered.
13. The mobile communication system according to claim 12 , wherein the setup information element of the logical channel indicates that the buffer status report is not triggered despite that data has become available for the logical channel.
14. The mobile communication system according to claim 12 , wherein the setup information element of the logical channel indicates that the buffer status report is not triggered due to activation of the semi-persistent scheduling.
15. The mobile communication system according to claim 11 , wherein the controller of the mobile terminal determines to trigger the scheduling request when the setup information element of the logical channel indicates activation of the semi-persistent scheduling.
16. The mobile communication system according to claim 11 , wherein the controller of the mobile terminal determines to trigger the scheduling request when the setup information element of the logical channel indicates that data has become available for the logical channel.
17. The mobile communication system according to claim 11 , wherein
the controller of the mobile terminal causes the transmitter to transmit to the base station the scheduling request to request uplink resources for uplink transmission of a buffer status report, when semi-persistent scheduling is not activated, no uplink resources are allocated for a transmission time interval, and a buffer status report has not been triggered.
18. The mobile communication system according to claim 11 , wherein
the controller of the mobile terminal considers an activation status of semi-persistent resource allocation to determine whether to trigger the buffer status report.
19. The mobile communication system according to claim 11 , wherein
the controller of the mobile terminal considers a scheduling mode status to determine on which logical channel to report in the buffer status report.
20. The mobile communication system according to claim 19 , wherein the scheduling mode status is an activation of the semi-persistent scheduling or a deactivation of the semi-persistent scheduling.