Method and apparatus for transmitting packet by using indirect acknowledgement timer in wired/wireless integrated network

• US 7,233,572 B2
• Filed: 06/28/2002
• Issued: 06/19/2007
• Est. Priority Date: 12/26/2001
• Status: Expired due to Fees

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Ahn, Jae Young, Kim, Yun Joo, Lee, Mee Jeong
• Primary Examiner(s): Kizou; Hassan
• Assistant Examiner(s): SOL, ANTHONY M
• Application Number:
  US10/183,348
• Publication Number:
  US 20030117992A1
• Time in Patent Office: 1,817 Days
• Field of Search: None
• US Class Current: 370/236
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 1/1835 Buffer management
• CPC Class Codes: H04L 1/1848 Time-out mechanisms
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 47/28 in relation to timing considerations
• CPC Class Codes: H04W 28/0231 based on communication conditions dynamic wireless traffic scheduling definition based on channel quality criteria H04W72/54
• CPC Class Codes: H04W 28/0273 adapting protocols for flow control or congestion control to wireless environment, e.g. adapting transmission control protocol [TCP] wireless network protocols or protocol adaptations to wireless operation, e.g. wireless application protocol H04W80/00
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A packet transmission apparatus and method is disclosed. The present invention transmits data packets without relaying a duplicate acknowledgement packet by equipping an indirect acknowledgement timer at a buffer, generating/transmitting the indirect acknowledgement packet of the first arrived acknowledgment packet base on the indirect acknowledgement timer and implementing an indirect acknowledgement method to a snoop protocol for overcoming problems of the transmission control protocol (TCP) in the wireless network environment. The present invention effectively utilizes resources of the wireless link, which is wasted during recovering lost packet in the conventional snoop protocol. The present invention also reduces a required size of the buffer of the base station by allowing a partially-generation of the indirect acknowledgement packet.

Claims

1. A method for transmitting a packet in a packet transmission apparatus connected to a transmitter through a wired link and connected to a receiver through a wireless link, comprising the steps of:

a) setting up an indirect acknowledgement timer to a data packet received from the transmitter, storing the data packet into a buffer and transmitting the data packet to the receiver;

b) updating a size of the buffer based on an acknowledgement packet received from the receiver and treating the data packet received from the transmitter; and

c) transmitting an indirect acknowledgement packet to the transmitter according to a state of the buffer in case an acknowledgement packet is not received from the receiver until the indirect acknowledgement timer is elapsed, wherein step b) includes the steps of;

b1) if the acknowledgment packet is a new acknowledgement packet, changing a size of the buffer by calculating a round trip time (RTT) of the wireless link;

b2) deleting the data packet corresponding to the acknowledgement packet received from the buffer;

b3) setting up the indirect acknowledgement timer to a data packet stored in the buffer, which is the next data packet of the deleted data packet; and

b4) determining whether the indirect acknowledgement packet of the data packet corresponding to said received acknowledgement packet is transmitted, and if the indirect acknowledgement packet is not transmitted, transmitting the received acknowledgement packet to the transmitter.

2. The method as recited in claim 1, wherein said step b), if the received acknowledgement packet is the first duplicate acknowledgement packet, includes the steps of:

b1) retransmitting a data packet corresponding to the received acknowledgement packet, if the data packet is stored in the buffer; and

b2) counting the received duplicate acknowledgement packets.

3. The method as recited in claim 1, wherein the size of the buffer is updated according to a value calculated by an equation as:

$\mathrm{Size}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{buffer}<br><br>,\left(\mathrm{treshold}\right)=\frac{\mathrm{RTT}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{wireless}<br><br><br><br>\mathrm{link}+\mathrm{retransmission}<br><br><br><br>\mathrm{time}<br><br><br><br>\mathrm{out}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{base}<br><br><br><br>\mathrm{station}}{\mathrm{RTT}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{wireless}<br><br><br><br>\mathrm{link}}.$

4. The method as recited in claim 1, wherein said step c) includes the steps of:

c1) in case the buffer is not overflowed, generating an indirect acknowledgement packet corresponding to data packet of which the indirect acknowledgement timer is elapsed and transmitting the indirect acknowledgement packet to the transmitter; and

c2) establishing an indirect acknowledgement timer to a data packet stored in the buffer, which is a next data packet of the data packet of which the indirect acknowledgment timer is elapsed.

5. The method as recited in claim 1 wherein, said step a) includes the steps of:

a1) recording an arrival time of the received data packet from the transmitter and storing the received data packet into the buffer;

a2) establishing the indirect acknowledgement timer to the received data packet in case the number of stored data packets in the buffer is not greater than “

1”

; and

a3) transmitting the received data packet to the receiver.

6. The method as recited in claim 5, wherein said step a) further includes the step a4), in case the received data packet from the transmitter is not new data packet, setting up a new number of local retransmission and transmitting the received data packet to the receiver.

7. The method as recited in claim 5, wherein said step a) further comprises the step a4), in case the received data packet from the transmitter is not orderly received data packet, encapsulating a congestion information into header of the received data packet header and transmitting the received data packet to the receiver.

8. A packet transmission apparatus connected to a transmitter through a wired link and connected to a receiver through a wireless link, comprising:

a transceiver for the transmitter connected with the transmitter through the wired link, for receiving a data packet and transmitting an acknowledgement packet or an indirect acknowledgement packet;

a transceiver for the receiver connected with the receiver through the wireless link, for transmitting a data packet and receiving the acknowledgement packet;

a buffer for storing a data packet received from the transmitter; and

an indirect acknowledgement controller for establishing an indirect acknowledgement timer to a data packet stored in said buffer, setting up a size of the buffer based on the acknowledgement packet received from the transceiver for the receiver and generating an indirect acknowledgement packet according to whether the buffer is overflowed in case the acknowledgement packet is not received from the receiver until the indirect acknowledgement timer is elapsed,

wherein said indirect acknowledgement controller, in case the received acknowledgement packet from the receiver is a new acknowledgement packet, includes;

an updating means for updating the size of the buffer by calculating a round trip time (RTT) of the wireless link based on the received acknowledgement packet;

a deletion means for deleting data packet corresponding to the received acknowledgement packet from the buffer;

an establishment means for establishing the indirect acknowledgement timer to the data packet, which is a next stored data packet of the deleted data packet; and

a determination means for determining whether the indirect acknowledgement packet of the data packet corresponding to the received acknowledgement packet is already transmitted to the transmitter and transmitting the received acknowledgement packet if the indirect acknowledgment packet is not transmitted.

9. The apparatus as recited in claim 8, further comprising a duplicate acknowledgement controller for determining whether the received acknowledgement packet is a duplicate acknowledgement packet, retransmitting a data packet corresponding to the received acknowledgement packet in case the received acknowledgement packet is the first duplicate acknowledgement packet and the data packet is stored in the buffer and counting a number of received duplicate acknowledgement packet.

10. The apparatus as recited in claim 8, wherein the updating means updates a size of buffer according to a value calculated by an equation as:

$\mathrm{Size}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{buffer}=\frac{\mathrm{RTT}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{wireless}<br><br><br><br>\mathrm{link}+\mathrm{retransmission}<br><br><br><br>\mathrm{time}<br><br><br><br>\mathrm{out}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{base}<br><br><br><br>\mathrm{station}}{\mathrm{RTT}<br><br><br><br>\mathrm{of}<br><br><br><br>\mathrm{wireless}<br><br><br><br>\mathrm{link}}.$

11. The apparatus as recited in claim 8, wherein said indirect acknowledgement controller includes:

an indirect acknowledgement packet generation means for generating an indirect acknowledgement packet of a data packet of which an indirect acknowledgement timer is elapsed in case the received acknowledgement packet from the receiver is not transmitted until the indirect acknowledgement timer is elapsed and the buffer is not overflowed; and

an establishing means for establishing the indirect acknowledgement timer of a data packet which is a next data packet of the data packet of which the indirect acknowledgement timer is elapsed in the buffer.

12. The apparatus as recited in claim 8, wherein said indirect acknowledgement controller includes:

a record means for recording an arrival time of the data packet received from the transmitter; and

an establishment means for establishing the indirect acknowledgement timer of the received data packet in case a number of data packet in the buffer is not greater than “

1”

.

13. The apparatus as recited in claim 8, wherein said indirect acknowledgement controller updates a number of local retransmission in case the received data packet from the transmitter is not new data packet, and transmits the received data packet to said transceiver for the receiver.

14. The apparatus as recited in claim 8, wherein said indirect acknowledgement controller encapsulates a congestion information into a header of the received data packet in case the received data packet from the transmitter is not received orderly, and transmits the received data packet to said transceiver for the receiver.

15. A computer-readable medium storing instructions for executing a method for transmitting a packet in a packet transmission apparatus, the method comprising the steps of:

a) setting up an indirect acknowledgement timer to a data packet received from the transmitter, storing the data packet into a buffer and transmitting the data packet to the receiver;

b) updating a size of the buffer based on a acknowledgement packet received from the receiver and treating the data packet received from the transmitter; and

c) transmitting an indirect acknowledgement packet to the transmitter according to a state of the buffer in case an acknowledgement packet is not received from the receiver until the indirect acknowledgement timer is elapsed, wherein step b) includes the steps of;

b1) if the acknowledgment packet is a new acknowledgement packet, changing a size of the buffer by calculating a round trip time (RTT) of the wireless link;

b2) deleting the data packet corresponding to the acknowledgement packet received from the buffer;

b3) setting up the indirect acknowledgement timer to a data packet stored in the buffer, which is the next data packet of the deleted data packet; and

b4) determining whether the indirect acknowledgement packet of the data packet corresponding to said received acknowledgement packet is transmitted, and if the indirect acknowledgement packet is not transmitted, transmitting the received acknowledgement packet to the transmitter.