DELAYED ACKNOWLEDGEMENT TRANSMISSION METHOD AND APPARATUS IN MOBILE COMMUNICATION SYSTEM

• US 20120281570A1
• Filed: 05/03/2012
• Published: 11/08/2012
• Est. Priority Date: 05/03/2011
• Status: Active Grant

• Current Assignee: Industry Academic Cooperation Foundation, Samsung Electronics Co. Ltd.
• Original Assignee: Industry Academic Cooperation Foundation, Samsung Electronics Co. Ltd.
• Inventors: JUNG, Jungsoo, KIM, Youngyong, AHN, Woojin, YOON, Gangjin
• Granted Patent: US 9,413,495 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection

Abstract

A delayed acknowledgement transmission method and an apparatus are provided for improving communication performance of a system and a terminal by delaying an ACKnowledgement (ACK) transmission of the terminal in a handover procedure. The method includes transmitting an acknowledgement corresponding to a segment immediately upon receipt of the segment, detecting a delay condition event which is triggered when a difference between a signal strength of the source base station and a neighboring base station is equal to or greater than a predefined offset, calculating a delay value for delaying acknowledgement transmission corresponding to the segment received after detecting the delay condition event, and transmitting the segment received after the detection of the delay condition event by delaying by as much as a time corresponding to the delay value. The apparatus is capable of avoiding a router'"'"'s performance degradation and reducing a packet transmission delay and packet loss.

Claims

1. An acknowledgement transmission method of a terminal connected to a source base station in a mobile communication system, the method comprising:

transmitting an acknowledgement corresponding to a segment immediately upon receipt of the segment;

detecting a delay condition event which is triggered when a difference between a signal strength of the source base station and a neighboring base station is equal to or greater than a predefined offset;

calculating, when the delay condition event is detected, a delay value for delaying acknowledgement transmission corresponding to the segment received after detecting the delay condition event; and

transmitting the segment received after the detection of the delay condition event by delaying by as much as a time corresponding to the delay value.

2. The method of claim 1, further comprising:

transmitting, when a delay termination event is detected after the delay condition event, the acknowledgement corresponding to the segment received after the detection of the delay termination event without delay.

4. The method of claim 2, wherein the delay termination event comprises an event triggered by the terminal detaching from the source base station.

5. The method of claim 2, wherein the delay condition event is detecting an event A3.

6. The method of claim 5, wherein the delay termination event includes at least one of detecting an event A5, an event A2 in state of the event A3, and the event A3 in state of an event A4.

7. The method of claim 1, wherein the calculating of the delay value comprises:

calculating a number of segments expected to be received before the terminal detaches from the source base station after the detection of the delay condition event;

calculating a forwarding time to be taken for segment forwarding in a handover; and

obtaining the delay value to be applied to the segment to be received after the detection of the delay condition event based on the number of segments and the forwarding time.

3. The method of claim 3, further comprising:

transmitting, when a delay termination event is detected after the delay condition event, the acknowledgement corresponding to the segment already received but not yet acknowledged immediately.

8. A terminal for transmitting an acknowledgement in a mobile communication system in which a terminal is connected to a source base station, the terminal comprising:

an event detector for detecting a delay condition event which is triggered when a difference between a signal strength of the source base station and a neighboring base station is equal to or greater than a predefined offset;

a delay calculator for calculating, when the delay condition event is detected, a delay value for delaying acknowledgement transmission corresponding to the segment received after detecting the delay condition event; and

a radio communication unit for transmitting the acknowledgement corresponding to the segment received before the detection of the delay condition without delay and the acknowledgement corresponding to the segment received after the detection of the delay condition with as much delay as the calculated delay value.

9. The terminal of claim 8, wherein the radio communication unit transmits, when a delay termination event is detected after the delay condition event, the acknowledgement corresponding to the segment received after the detection of the delay termination event without delay.

10. The terminal of claim 9, wherein the radio communication unit transmits, when a delay termination event is detected after the delay condition event, the acknowledgement corresponding to the segment already received but not yet acknowledged immediately.

11. The terminal of claim 9, wherein the delay termination event comprises an event triggered by the terminal detaching from the source base station.

12. The terminal of claim 9, wherein the delay condition event is detecting an event A3.

13. The terminal of claim 12, wherein the delay termination event includes at least one of detecting an event A5, an event A2 in state of the event A3, and the event A3 in state of an event A4.

14. The terminal of claim 8, wherein the delay calculator calculates a number of segments expected to be received before the terminal detaches from the source base station after the detection of the delay condition event, calculates a forwarding time to be taken for segment forwarding in a handover, and calculates the delay value to be applied to the segment to be received after the detection of the delay condition event based on the number of segments and the forwarding time.