Method for dropping packet data, radio communication device, and mobile communication system
A control method in a mobile communication system, that includes configuring a discard timer corresponding to a service data unit (SDU) for discarding the SDU according to a value of the timer; maintaining the value of the discard timer corresponding to the SDU when a handover is performed without restarting or resetting the value of the discard timer; and discarding the corresponding SDU when the maintained value of the discard timer reaches a given value.
1. A control method in a mobile communication system, comprising:
storing service data units (SDUs);
discarding the SDUs according to a value of a discard timer corresponding to the SDUs;
transferring the SDUs from a source base station to a target base station and transferring the value of the discard timer corresponding to the SDUs to be transferred when a handover is performed;
wherein the target base station sets a new value of the discard timer for the transferred SDUs with the transferred value of the discard timer or the transferred value of the discard timer corrected with a transfer delay time, and when the new value of the discard timer reaches a given value, discards the corresponding SDUs.
2. The control method according to claim 1 , wherein the source base station transfers the value of the discard timer by using a SDU reception state reporting protocol or a time stamp field included in a SDU transfer protocol header.
3. The control method as defined in claim 1 , wherein the SDU is a Packet Data Convergence Protocol (PDCP) SDU.
4. A control method in a mobile communication system, comprising:
storing service data units (SDUs);
discarding the SDUs according to a value of a discard timer corresponding to the SDUs;
transferring the SDUs from a source base station to a target base station, and correcting the value of the discard timer corresponding to the SDUs to be transferred with a transfer delay time and then transferring the value of the discard timer when a handover is performed,
wherein the target base station sets a new value of the discard timer for the corresponding SDUs with the corrected value of the discard timer transferred thereto, and when the value of the discard timer reaches a given value, discards the corresponding SDUs.
5. The control method as defined in claim 4 , wherein the SDU is a Packet Data Convergence Protocol (PDCP) SDU.