System and Method for Regulating Bandwidth in a Multicast Video Transmission System
First Claim
1. A video transmitter for communicating with plural video receivers for connecting to corresponding video display devices, the transmitter comprising:
- rate meter for monitoring a current transmission bitrate and a current retransmission bitrate; and
determining means for determining if state changes are needed to alter a retransmission bitrate of the transmitter, wherein the determining means performs the steps of;
determining if (1) a state of the transmitter is “
no tuning” and
(2) the current retransmission bitrate has been greater than a video tune-up start threshold for at least a video tune-up interval;
setting the state of the transmitter to “
tuning up”
if conditions (1) and (2) are true;
determining (3) if the state of the transmitter is “
tuning up” and
(4) the current retransmission bitrate is greater than a video tune-up stop threshold;
setting the state of the transmitter to “
no tuning”
if conditions (3) and (4) are true;
determining if (5) a state of the transmitter is “
no tuning” and
(6) the current retransmission bitrate has been greater than a video tune-down start threshold for at least a video tune-down interval;
setting the state of the transmitter to “
tuning down”
if conditions (5) and (6) are true;
determining (7) if the state of the transmitter is “
tuning down” and
(8) the current retransmission bitrate is less than a video tune-down stop threshold;
setting the state of the transmitter to “
no tuning”
if conditions (7) and (8) are true;
increasing the current retransmission bitrate by a video tune-up step when the state of the transmitter is “
tuning up”
; and
decreasing the current retransmission bitrate by a video tune-down step when the state of the transmitter is “
tuning down”
.
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Accused Products
Abstract
A video transmitter can adaptively alter its transmission rate to plural receivers which receive video via multicast transmission. While the transmitter is initially in the “no tuning state,” the need for a video tune-up state change can be determined by calculating if the current generated A/V retry transmission rate is greater than the video tune-up start threshold and if it was triggered more than the video tune-up interval ago. If so, then the state can be set to “tuning up” and the retransmission rate can be increased by the video tune-up step, as shown in FIG. 7. However, if the state is set to “tuning up” and it is determined that the current generated A/V retry transmission rate is greater than the video tune-up stop threshold, then “tuning-up” is no longer required, and the state is set such that “tuning up” is no longer true such that the state returns to the “no tuning” state. Likewise, the need for a video tune-down state change can be determined by calculating if the current generated A/V retry transmission rate is greater than the video tune-down start threshold and if it was triggered more than the video tune-down interval ago. If so, then the state can be set to “tuning down” and the retransmission rate can be increased by the video tune-down step. However, if the state is set to “tuning down” and it is determined that the current generated A/V retry transmission rate is less than the video tune-down stop threshold, then “tuning-down” is no longer required, and the state is set such that “tuning down” is no longer true and the state returns to the “no tuning” state.
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Citations
6 Claims
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1. A video transmitter for communicating with plural video receivers for connecting to corresponding video display devices, the transmitter comprising:
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rate meter for monitoring a current transmission bitrate and a current retransmission bitrate; and determining means for determining if state changes are needed to alter a retransmission bitrate of the transmitter, wherein the determining means performs the steps of; determining if (1) a state of the transmitter is “
no tuning” and
(2) the current retransmission bitrate has been greater than a video tune-up start threshold for at least a video tune-up interval;setting the state of the transmitter to “
tuning up”
if conditions (1) and (2) are true;determining (3) if the state of the transmitter is “
tuning up” and
(4) the current retransmission bitrate is greater than a video tune-up stop threshold;setting the state of the transmitter to “
no tuning”
if conditions (3) and (4) are true;determining if (5) a state of the transmitter is “
no tuning” and
(6) the current retransmission bitrate has been greater than a video tune-down start threshold for at least a video tune-down interval;setting the state of the transmitter to “
tuning down”
if conditions (5) and (6) are true;determining (7) if the state of the transmitter is “
tuning down” and
(8) the current retransmission bitrate is less than a video tune-down stop threshold;setting the state of the transmitter to “
no tuning”
if conditions (7) and (8) are true;increasing the current retransmission bitrate by a video tune-up step when the state of the transmitter is “
tuning up”
; anddecreasing the current retransmission bitrate by a video tune-down step when the state of the transmitter is “
tuning down”
. - View Dependent Claims (2, 3)
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4. A video system comprising:
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plural video receivers for connecting to corresponding video display devices; and a transmitter for communicating with plural video receivers, the transmitter comprising; a communications interface for communicating with the plural video receivers, a rate meter for monitoring a current transmission bitrate and a current retransmission bitrate, and determining means for determining if state changes are needed to alter a retransmission bitrate of the transmitter, wherein the determining means performs the steps of; determining if (1) a state of the transmitter is “
no tuning” and
(2) the current retransmission bitrate has been greater than a video tune-up start threshold for at least a video tune-up interval;setting the state of the transmitter to “
tuning up”
if conditions (1) and (2) are true;determining (3) if the state of the transmitter is “
turning up” and
(4) the current retransmission bitrate is greater than a video tune-up stop threshold;setting the state of the transmitter to “
no tuning”
if conditions (3) and (4) are true;determining if (5) a state of the transmitter is “
no tuning” and
(6) the current retransmission bitrate has been greater than a video tune-down start threshold for at least a video tune-down interval;setting the state of the transmitter to “
tuning down”
if conditions (5) and (6) are true;determining (7) if the state of the transmitter is “
tuning down” and
(8) the current retransmission bitrate is less than a video tune-down stop threshold;setting the state of the transmitter to “
no tuning”
if conditions (7) and (8) are true;increasing the current retransmission bitrate by a video tune-up step when the state of the transmitter is “
tuning up”
; anddecreasing the current retransmission bitrate by a video tune-down step when the state of the transmitter is “
tuning down”
. - View Dependent Claims (5, 6)
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Specification