Apparatus, and associated method, for communicating packet data in a network including a radio-link

• US 20050041581A1
• Filed: 06/28/2004
• Published: 02/24/2005
• Est. Priority Date: 06/01/2000
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Technologies Oy (Nokia Corporation)
• Inventors: Kuusinen, Jarmo, Turunen, Matti
• Granted Patent: US 9,007,123 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters

Abstract

Apparatus, and associated method, for improving packet data communications upon a communication path including a radio-link. Determination is made of the conditions on the radio-link when selecting the optimal size of a transmission window within which to transmit packets of data. And, retransmission time-out values are also selected responsive to the indications of the radio-link conditions.

Claims

1. In a communication system in which packet data is communicated between a first host and a second host upon a communication path, the communication path including a radio-link, an improvement of apparatus for selecting a window size within which to transmit a data packet, said apparatus comprising:

a radio-link status determiner coupled to receive an indication of the radio-link forming a portion of the communication path between the first host and the second host, said radio-link status determiner for determining an indication of a characteristic of the radio-link and for generating a radio-link status indication indicative of the indication of the characteristic determined thereat; and

a window size selector coupled to receive the radio-link status indication generated by said radio-link status determiner, said window size selector for selecting a window size within which to transmit the data packet.

2. The apparatus of claim 1 wherein the indication of the radio-link to which said radio-link status determiner is coupled to receive comprise indications of a packet data throughput rate upon the radio-link.

3. The apparatus of claim 2 wherein the radio-link includes a forward link and a reverse link and wherein the indication of the packet data throughput rate is of at least a selected one of the forward link and the reverse link.

4. The apparatus of claim 3 wherein the indications of the radio-link to which said radio-link status determiner is coupled to receive comprises indications of a RTT (round-trip-time) representative of a time period within which two-way transmission with the first host are determined to be effectuated.

5. The apparatus of claim 4 wherein the communication system is defined by logical layers, the logical layers including an RLC (radio-link control) layer, and wherein the time period of which the RTT is representative corresponds to a round-trip time of communication of a data packet and an acknowledgment thereto less retransmission times at the RLC layer.

6. The apparatus of claim 4 wherein the optimal window size selected by said optimal window size selector is proportional to the indication of the data through put rate and to the RTT.

7. The apparatus of claim 1 wherein the first host comprises a mobile host and the second host comprises a network host and wherein the mobile host is further operable to send a message to the network host, wherein the message includes an offered window field, and wherein a value representative of the optimal window size selected by said optimal window size selector is inserted into the offered window field.

8. The apparatus of claim 7 wherein the network host is operable to receive the message, including the value representative of optimal window size, sent by the mobile host, and to transmit the data packet, the data packet transmitted by the network host within a transmission window of a maximum size corresponding to the optimal window size.

9. The apparatus of claim 1 wherein the first host further comprises a retransmission timer at least for selecting when to retransmit a data packet and wherein said radio-link status determiner is further for determining an indication of a characteristic of the radio-link forming a portion of the communication path and for generating a radio-link quality status indication indicative of the indication of the characteristic determined thereat, a value representative of which is applied to the retransmission timer and responsive to which a time-out value of the retransmission timer is selected.

10. The apparatus of claim 9 wherein the radio-link status indication generated by said radio-link status determiner is representative of changes in the radio-link status between a first selected time and at least a second selected time.

11. The apparatus of claim 10 wherein, if the radio-link status indication is beyond a selected value, the time-out value of the retransmission timer is caused to be increased.

12. The apparatus of claim 11 wherein the communication system is defined by logical layers, the logical layers including an L3CE layer, and wherein the radio-link status indication comprises a RTT (round-trip-time) representative of a time period within which two-way transmissions with the first host at the L3CE layer are determined to be effectuated.

13. The apparatus of claim 12 wherein the time-out value of the retransmission timer is caused to be increased if changes in values of the RTT exceed a multiple of a mean deviation.

14. The apparatus of claim 12 wherein the time-out value of the retransmission timer is caused to be increased if more than a selected number of data packets are communicated upon the communication path without acknowledgment thereto.

15. The apparatus of claim 12 wherein the time-out value of the retransmission timer is caused to be increased during transmission of a selected number of data packets subsequently to be transmitted.

16. The apparatus of claim 1 wherein the first host and the second host are operable to communicate data packets pursuant to a TCP (transmission control protocol) protocol and wherein said radio-link status determiner determines the indication of the throughput quality of TCP-formatted data packets.

17. In a communication system in which packet data is communicated between a first host and a second host upon a communication path, the communication path including a radio-link, and the mobile host having a retransmission timer at least for selecting when to retransmit a data packet, an improvement of apparatus for the first host for selecting a window size within which to transmit the data packet, said apparatus comprising:

a radio-link status determiner coupled to receive indications of the radio-link forming a portion of the communication path between the first host and the second host, said radio-link status determiner for determining an indication of a characteristic of the radio-link and for generating a radio-link quality indication indicative of the indication of the characteristic determined thereat; and

a retransmission timer time-out value selector coupled to receive a value representative of the radio-link status indication generated by said radio-link status determiner, said retransmission timer time-out value selector for selecting a time-out value of the retransmission timer responsive to the value representative of the radio-link status indicators.

18. In a method for communicating packet data between a first host and a second host, the first host and the second host connected together by way of a communication path which includes a radio-link, an improvement of a method for the first host for selecting a window size within which to transmit a data packet, said method comprising:

determining an indication of throughput on the radio-link;

generating a radio-link status indication indicative of the throughput determined during said operation of determining; and

selecting a window size within which to transmit the data packet responsive to a value of the radio-link status indication.

19. The method of claim 18 wherein the first host further comprises a retransmission timer at least for selecting when to retransmit a data packet and wherein said method further comprises the operations of:

determining an indication of radio-link status of the radio-link forming a portion of the communication path;

generating a radio-link status indication indicative of the indication of the radio-link status determined during said operation of determining; and

adjusting a time-out value of the retransmission timer if the radio-link status indication is beyond a selected threshold.

20. The method of claim 19 wherein the radio-link status indication determined during said operation of determining the indication of radio-link status is representative of changes in the radio-link status.

21-22. -22. (Canceled)