Method and system of data packet transmission timing for controlling bandwidth

• US 20030145100A1
• Filed: 01/31/2002
• Published: 07/31/2003
• Est. Priority Date: 01/31/2002
• Status: Active Grant

• Current Assignee: Rateze Remote Mgmt. L.L.C. (Intellectual Ventures LLC)
• Original Assignee: The Fantastic Co. AG
• Inventors: La Cognata, Emanuele, Marchetto, Jarno
• Granted Patent: US 7,539,756 B2
• Time in Patent Office: Days
• US Class Current: 709/233
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/22 Traffic shaping
• CPC Class Codes: H04L 47/28 in relation to timing considerations

Abstract

A method and system for determining a wait time (t_w) to be used between successive transmissions of packets of a content to achieve a selected target bandwidth B_T for the transmission. The wait time between successive packets of a content being transmitted is determined as a function of the selected target bandwidth (B_T) to be achieved during the transmission and the size (P) of the packets based on the algorithm $t_w=\frac{P}{B_T}$

The invention provides bandwidth control at the source (the sending device) without relying on network Quality of Service (QoS) facilities.

Claims

1. A method of using the wait time (t_w) between transmission of successive packets of known packet size (P) of a content to be transmitted to achieve a target bandwidth (B_T) during the transmission comprising the steps of:

selecting a target bandwidth (B_T) sought to be achieved during the transmission;

computing a wait time (t_w) between successive packets of the transmission using the algorithm

$t_w=\frac{P}{B_T};<br><br>\mathrm{and}$

controlling the transmission of the packets using the wait time.

2. The method as claimed in claim 1 wherein the computed wait time t_w that is used is rounded to a time unit.

3. The method as claimed in claim 2 wherein the rounding to the time unit is accomplished by a counter.

4. The method as claimed in claim 1 further comprising the step of:

determining the start time t₁ of transmission of a packet;

determining the end time t₂ of transmission of the packet, and

determining the time used t_used in transmitting the packet as t₂−

t₁.

5. The method as claimed in claim 4 further comprising the steps of:

(a) determining the time used (t_used) in the transmission of a packet;

(b) determining a residual time (t) as t_used−

t_w;

(c) waiting the time t between the end of transmission of one packet to the start of transmission of the next packet.

6. The method as claimed in claim 5 further comprising the step of repeating steps (a), (b) and (c) for each packet transmitted.

7. A method as in claim 5 wherein the residual time t is controlled by:

determining a value of start time t_start, of sending a packet a current time t_now;

performing a loop operation of;

(a) computing a time t_elapsed=t_now−

t_start,

(b) comparing t_elapsed to the residual time t and transmitting the next packet when the value of t_elapsed≧

t.

8. The method as claimed in claim 7 further comprising the steps of computing an error value δ

=t_elapsed−

t and subtracting the value δ

from a later supplied value of t.

9. A method as in claim 5 wherein the computed wait time t_w that is used is rounded to a time unit.

10. A method as in claim 9 wherein the rounding to the time unit is accomplished by a counter.

11. The method of claim 1, including the additional step of selecting the known packet size (P) of the packets to be transmitted.

12. The method of claim 1 wherein the known packet size (P) is provided by an application.

13. Apparatus for using the wait time (t_w) between transmission of successive packets of a content to be transmitted to achieve a target bandwidth B_T during the transmission comprising:

a computer including

a program to control transmission of a content in packets of data;

means to input and receive parameters of the size (P) of the packets to be transmitted and of the desired target bandwidth (B_T);

processing means to calculate a wait time (t_w) between successive packets of the transmission using the algorithm

$t_w=\frac{P}{B_T}<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{and}$

control means to successively transmit the packets with the wait time t_w between the packets.

14. Apparatus as in claim 13 wherein said computer further comprises:

means for determining the start time (t₁) of transmission of a packet;

means for determining the end time (t₂) of transmission of the packet, and means for determining the time used (t_used) in transmitting the packet as t₂−

t₁.

15. Apparatus as in claim 14 wherein said computer further comprises:

first means for determining the time used (t_used) in the transmission of a packet;

second means for determining a residual time t as t_w−

t_used; and

wherein said control means operates to wait the residual time t between the start of transmission of one packet to the start of transmission of the next packet.

16. Apparatus as in claim 15 wherein said first and second determining means operates to determine the residual time t for each packet transmitted and said control means operates to wait the residual time t between the start of transmission of one packet to the start of transmission of the next packet.

17. Apparatus as in claim 16 further comprising means for controlling the residual time t by

determining a value of start time t_start, and a current time t_now

performing a loop operation of:

(a) computing a time t_elapsed=t_now−

t_start, and

(b) comparing t_elapsed to the residual time t and transmitting the next packet when the value of t_elapsed≧

t.

18. Apparatus as in claim 17 further comprising means for computing an error value δ

=t_elapsed−

t and subtracting the value δ

from a later supplied value of t.

19. Apparatus as in claim 13 wherein said control means further comprises a counter that operates on a periodic basis to measure the wait time t_w.

20. Apparatus as in claim 13 wherein said computer operates said control means to compute the wait time t_w based on other measured times.