Apparatus and method for operating a communications device in a mobile communications network
View Patent ↗Apparatus and a method for handling discard of a service data unit in universal mobile telecommunications system user equipment. Strategies for the radio resource control entity to handle discard of a service data unit by the radio link control entity are presented.
1. A method of operating a user equipment (UE) configurable for use in a Universal Mobile Telecommunications System (UMTS), the UE comprising a physical layer, a user layer, a radio resource control (RRC) layer, and a radio link control (RLC) layer compliant for use in a UMTS, comprising:
submitting, from the RRC layer, an SDU to the RLC layer for transmission;
measuring elapsed time since the SDU was submitted in the RRC layer;
detecting that the elapsed time has reaching a predetermined timeout value;
causing the RRC layer to resubmit the previously submitted SDU to the RLC layer;
measuring the elapsed time since the resubmitted SDU was resubmitted to the RLC layer;
repeating the resubmission and associated elapsed time at most N times; and
causing the RRC layer to submit a failure response message for the ongoing procedure to the RLC layer for transmission, if there have been N resubmissions.
2. The method of claim 1 comprising:
setting an operating mode wherein an acknowledgement of successful reception of said SDU is awaited.
3. The method of claim 1 wherein N=0.
4. The method of claim 1 wherein when a RADIO_BEARER_RECONFIGURATION procedure is being undertaken, the failure response message submitted by the RRC layer is a RADIO_BEARER_RECONFIGURATION_FAILURE message.
5. A user equipment (UE) configurable for use in a Universal Mobile Telecommunications System (UMTS), the UE comprising a physical layer, a user layer, a radio resource control (RRC) layer, and a radio link control (RLC) layer compliant for use in a UMTS, the user equipment being arranged to:
submit, from the RRC layer, an SDU to the RLC layer for transmission;
measure elapsed time since the SDU was submitted in the RRC layer;
detect that the elapsed time has reaching a predetermined timeout value;
cause the RRC layer to resubmit the previously submitted SDU to the RLC layer;
measure the elapsed time since the resubmitted SDU was resubmitted to the RLC layer;
repeat the resubmission and associated elapsed time at most N times; and
cause the RRC layer to submit a failure response message for the ongoing procedure to the RLC layer for transmission, if there have been N resubmissions.
6. The user equipment of claim 5 further arranged to:
setting an operating mode wherein an acknowledgement of successful reception of said SDU is awaited.
7. The user equipment of claim 5 wherein N=0.
8. The user equipment of claim 5 wherein when a RADIO_BEARER_RECONFIGURATION procedure is being undertaken, the failure response message submitted by the RRC layer is a RADIO_BEARER_RECONFIGURATION_FAILURE message.