APPARATUS AND METHOD FOR TRANSMITTING/RECEIVING CIPHERED PACKET IN MOBILE COMMUNICATION SYSTEM

• US 20080123655A1
• Filed: 11/15/2007
• Published: 05/29/2008
• Est. Priority Date: 11/15/2006
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: JEONG, Kyeong-In, VAN LIESHOUT, Gert Jan, KIM, Seong-Hun, VAN DER VELDE, Himke
• Application Number:
  US11/940,783
• Publication Number:
  US 20080123655A1
• Time in Patent Office: Days
• US Class Current: 370/394
• CPC Class Codes: H04L 1/1867 Arrangements specially adapted for the transmitter end
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04W 12/037 of the control plane, e.g. signalling traffic
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365

Abstract

Provided is an apparatus and method for transmitting/receiving a ciphered packet in a mobile communication system. The apparatus and method perform a reset of a Packet Data Convergence Protocol (PDCP) in connection with transmission/reception of a ciphered packet including a compressed header, thereby preventing packet loss from occurring, and minimizing waste of limited transmission resources.

Claims

1. A method for transmitting/receiving a ciphered packet in a mobile communication system, the method comprising the steps of:

sensing, by a receiving-side Packet Data Convergence Protocol (PDCP) entity, that header restoration of a received packet has failed, and transmitting a PDCP reset message to a transmitting-side PDCP entity;

when receiving the PDCP reset message, transmitting, by the transmitting-side PDCP entity, a response message that includes a new hyper-frame number used for ciphering of a compressed header to the receiving-side PDCP entity; and

receiving, by the receiving-side PDCP entity, the response message, and deciphering packets received after PDCP reset by means of the new hyper-frame number.

2. The method as claimed in claim 1, wherein when a header-restored packet is not output from a header decompressor, although the receiving-side PDCP entity has input a packet to the header decompressor, the receiving-side PDCP entity determines that the header restoration of the packet has failed.

3. The method as claimed in claim 1, wherein, in transmitting the PDCP reset message to the transmitting-side PDCP entity, the receiving-side PDCP entity transmits the PDCP reset message to the transmitting-side PDCP entity through a receiving-side Radio Link Control (RLC) entity in a form of a control message.

4. The method as claimed in claim 1, further comprising, when the transmitting-side PDCP entity has received the PDCP reset message, discarding, by the transmitting-side PDCP entity, PDCP data stored in an RLC transmission buffer.

5. The method as claimed in claim 1, further comprising stopping, by the transmitting-side PDCP entity, transmission of the PDCP data pre-stored in a transmission buffer until the transmitting-side PDCP entity receives packets including the newly set hyper-frame number.

6. The method as claimed in claim 1, wherein the hyper-frame number corresponds to most significant bits having a predetermined length, among PDCP count parameters set corresponding to serial numbers of the packets.

7. The method as claimed in claim 3, further comprising transmitting, by the receiving-side RLC entity, the PDCP reset message to a transmitting-side RLC entity after inserting the PDCP reset message into an RLC STOP message, and stopping, by the transmitting-side RLC entity, transmission when the transmitting-side RLC entity has received the RLC STOP message.

8. A method for transmitting/receiving a ciphered packet in a mobile communication system, the method comprising the steps of:

sensing, by a receiving-side Packet Data Convergence Protocol (PDCP) entity, a failure of header restoration of a received packet;

when the header restoration of the received packet has failed, transmitting, by the receiving-side PDCP entity, a message informing that PDCP re-establishment is required to a transmitting-side Radio Resource Control (RRC) entity through a receiving-side RRC entity; and

performing, by the receiving-side RRC entity and the transmitting-side RRC entity, the PDCP re-establishment.

9. The method as claimed in claim 8, further comprising when the header restoration of the received packet has failed, increasing or decreasing, by the receiving-side PDCP entity, a hyper-frame number by one in connection with deciphering of the received packet, and performing synchronization with a hyper-frame number of a transmitting-side PDCP entity.

10. The method as claimed in claim 8, wherein, in sensing a failure of the header restoration of the received packet, the receiving-side PDCP entity determines that the header restoration of the received packet has failed, when a header-decompressed packet is not output from a header decompressor although the receiving-side PDCP entity has input the received packet to the header decompressor.

11. The method as claimed in claim 8, wherein transmitting the message informing that PDCP re-establishment is required comprises:

reporting, by the receiving-side PDCP entity, an error occurrence to the receiving-side RRC entity when sensing that the synchronization has failed;

transmitting, by the receiving-side RRC entity, an identifier representing a packet error occurrence to a receiving-side RLC entity;

transmitting, by the receiving-side RLC entity, a packet transmission stop message to a transmitting-side RLC entity, after inserting the packet transmission stop message into an RLC control message; and

transmitting, by the receiving-side RRC entity, a message reporting that PDCP re-establishment is required to the transmitting-side RRC entity, performing PDCP re-establishment, and transmitting PDCP re-establishment packets that are newly configured through the performance of PDCP re-establishment.

12. The method as claimed in claim 11, further comprising a step of discarding, by the receiving-side RLC entity, the packets stored in a reception buffer.

13. A method for transmitting/receiving a ciphered packet in a mobile communication system, the method comprising:

determining, by a receiving apparatus, to initialize a Packet Data Convergence Protocol (PDCP) when sensing that deciphering of a received packet has failed, and transmitting a Layer 2 RESET REQUEST message including a serial number of a highest packet, a header of which has been decompressed without error, to a transmitting apparatus;

performing, by the transmitting apparatus, PDCP reset in response to the Layer 2 RESET REQUEST message, newly determining a hyper-frame number in connection with ciphering for transmission of a packet next to a packet with the serial number, and transmitting a Layer 2 RESET RESPONSE message including the newly determined hyper-frame number to the receiving apparatus; and

performing, by the receiving apparatus, deciphering with respect to packets next to the packet of the serial number, by means of the newly determined hyper-frame number, thereby receiving the packets.

14. The method as claimed in claim 13, wherein the serial number of the highest packet corresponds to a value one higher than a highest serial number, among serial numbers of packets determined to have been normally received by the receiving apparatus.

15. An apparatus for transmitting a ciphered packet in a mobile communication system, the apparatus comprising:

a Packet Data Convergence Protocol (PDCP) controller for receiving a message for PDCP reset setting from a Radio Link Control (RLC) controller, setting a hyper-frame number corresponding to ciphering of the packet, and performing a control operation such that the hyper-frame number is inserted into a response message and is transmitted; and

a transmission buffer for storing and discarding packets according to an instruction of the PDCP controller.

16. The apparatus as claimed in claim 15, further comprising the RLC controller, which creates the response message including a PDCP reset message and transmits the response message through a control message to a receiving apparatus, according to an instruction of the PDCP controller.

17. The apparatus as claimed in claim 15, wherein the RLC controller transmits a control packet including the newly set hyper frame number through the control message to a receiving apparatus.

18. The apparatus as claimed in claim 16, wherein the RLC controller receives a PDCP reset message through an RLC control message from the receiving apparatus.

19. The apparatus as claimed in claim 15, further comprising a Radio Resource Control (RRC) message processor for receiving a message to request PDCP re-establishment from a receiving apparatus, and controlling a header compressor and a ciphering unit.

20. An apparatus for receiving a ciphered packet in a mobile communication system, the apparatus comprising:

a Packet Data Convergence Protocol (PDCP) controller for performing header restoration with respect to received packets including a compressed header, determining PDCP reset when it is sensed that the restoration has failed, and receiving a response message that includes a hyper-frame number newly determined corresponding to the PDCP reset from a transmitting apparatus; and

a Radio Link Control (RLC) controller for notifying the transmitting apparatus of the PDCP reset through a control message, and storing or discarding the received packet according to a control of the PDCP controller.

21. The apparatus as claimed in claim 20, wherein, when a header-decompressed packet is not output from a header decompressor although the PDCP controller has input a packet to the header decompressor, the PDCP controller determines that header restoration of the packet has failed.

22. The apparatus as claimed in claim 20, wherein the PDCP controller creates and transmits an identifier representing a packet restoration failure to a Radio Resource Control (RRC) entity after sensing that the header restoration has failed.

23. The apparatus as claimed in claim 22, the PDCP controller performs a correction of the hyper-frame number after sensing that the header restoration n has failed.

24. The apparatus as claimed in claim 22, further comprising an RRC message processor for receiving the identifier, creating an RRC message requesting PDCP re-establishment, and transmitting the created RRC message to the transmitting apparatus.