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 an unrecoverable error message 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. 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;
causing the RRC layer to submit a first message, the first message different than the SDU, to the RLC layer for transmission if there have been N resubmissions; and
receiving, by the UE, a second message after having transmitted the first message, where the second message is configured for use by the UE in setting itself to a known state.
5. The method of claim 4 wherein the first message is a CELL UPDATE message and the second message is a CELL UPDATE CONFIRM message.
6. The method of claim 4 comprising:
setting an operating mode wherein an acknowledgement of successful reception of said SDU is awaited.
7. The method of claim 4 wherein N=0.
8. 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 release any connection where the connection represents a peer connection to equivalent layers outside of the UE.
9. The method of claim 8 comprising:
setting an operating mode wherein an acknowledgement of successful reception of said SDU is awaited.
10. The method of claim 8 wherein N=0.
11. The method of claim 8 comprising:
entering idle mode after releasing the RRC connections.