Method and apparatus for PCDP discard

• US 10,630,819 B2
• Filed: 05/01/2017
• Issued: 04/21/2020
• Est. Priority Date: 10/01/2007
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Sammour, Mohammed, Terry, Stephen E.
• Primary Examiner(s): Ng, Christine
• Application Number:
  US15/583,420
• Publication Number:
  US 20170237837A1
• Time in Patent Office: 1,086 Days
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 28/0205 at the air interface dynamic wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 80/02 Data link layer protocols

Abstract

A method and apparatus for discarding a packet data convergence protocol (PDCP) service data unit (SDU) are disclosed. A PDCP layer sets a timer and discards a PDCP SDU upon expiration of the timer. The timer may be set upon receiving the PDCP SDU from an upper layer or upon submitting the PDCP SDU to a lower layer for transmission. The timer and a radio link control (RLC) discard timer may be coordinated. Alternatively, the PDCP layer may discard the PDCP SDU based on a notification from an RLC layer or based on a PDCP status report.

Claims

1. A method for discarding a packet data convergence protocol (PDCP) packet, the method comprising:

a PDCP entity starting a timer on a condition of receiving a PDCP service data unit (SDU) from an upper layer, wherein a threshold value of the timer is configured at a radio resource control (RRC) layer, and wherein the threshold value of the timer is configured on a per-radio bearer (RB) basis;

the PDCP entity processing the PDCP SDU to form a PDCP protocol data unit (PDU);

the PDCP entity sending the PDCP PDU to a radio link control (RLC) entity;

on a condition that the timer expires, the PDCP entity discarding the PDCP SDU;

the PDCP entity sending an indication of the discard to the RLC entity; and

the RLC entity discarding an RLC SDU associated with the PDCP PDU based on the indication.

2. The method as in claim 1, wherein the PDCP entity processing the PDCP SDU to form the PDCP PDU comprises the PDCP entity adding a PDCP sequence number to the PDCP SDU and the PDCP entity performing header compression on the PDCP SDU.

3. The method as in claim 1, wherein a value for the timer associated with the PDCP SDU is preserved during a PDCP re-establishment procedure.

4. A wireless transmit receive unit (WTRU) comprising:

a radio link control (RLC) entity; and

a packet data convergence protocol (PDCP) entity, wherein;

the PDCP entity is configured to;

start a timer on a condition that the PDCP entity receives a PDCP service data unit (SDU) from an upper layer entity, wherein a threshold value of the timer is configured at a radio resource control (RRC) layer, and wherein the threshold value of the timer is configured on a per-radio bearer (RB) basis;

process the PDCP SDU to form a PDCP protocol data unit (PDU);

send the PDCP PDU to the RLC entity;

on a condition that the timer expires, discard the PDCP SDU; and

send an indication of the discard to the RLC entity; and

the RLC entity is configured to;

discard an RLC SDU associated with the PDCP PDU based on the indication.

5. The WTRU as in claim 4, wherein the PDCP entity is further configured to process the PDCP SDU to form the PDCP PDU by being configured to add a PDCP sequence number to the PDCP SDU and perform header compression on the PDCP SDU.

6. The WTRU as in claim 4, wherein the PDCP entity is further configured to preserve a value for the timer associated with the PDCP SDU during a PDCP re-establishment procedure.