System and Method for Regulating Bandwidth in a Multicast Video Transmission System

• US 20090241148A1
• Filed: 10/20/2008
• Published: 09/24/2009
• Est. Priority Date: 10/19/2007
• Status: Active Grant

• Current Assignee: Vertiv IT Systems, Inc. (Vertiv Holdings Co.)
• Original Assignee: Avocent Corporation (Vertiv Holdings Co.)
• Inventors: Lo, Lawrence
• Granted Patent: US 8,533,764 B2
• Time in Patent Office: Days
• US Class Current: 725/81
• CPC Class Codes: H04L 12/2807 Exchanging configuration information on appliance services in a home automation network arrangements for maintenance or administration involving network analysis for automatically determining the actual topology of a network H04L41/12; hardware or software tools for network management using graphical user interfaces H04L41/22; address allocation H04L61/50
• CPC Class Codes: H04L 12/2838 Distribution of signals within a home automation network, e.g. involving splitting/multiplexing signals to/from different paths adaptations of television systems for transmission by electric cable for domestic distribution H04N7/106; hybrid transport H04L12/6418; home network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04L 2012/2849 Audio/video appliances
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5061 Pools of addresses
• CPC Class Codes: H04N 21/4108 characterised by an identification number or address, e.g. local network address protecting specific internal or external computer components using identification number G06F21/73; network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/43615 Interfacing a Home Network, e.g. for connecting the client to a plurality of peripherals home Audio Video Interoperability [HAVI] data switching networks H04L12/2805
• CPC Class Codes: H04N 21/43632 involving a wired protocol, e.g. IEEE 1394 high-speed IEEE 1394 serial bus H04L12/40052
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18
• CPC Class Codes: H04N 21/64322 IP

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.

Claims

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”

.

2. The video transmitter as claimed in claim 1, wherein the video transmitter communicates with the plural video receivers using a wireless communications interface.

3. The video transmitter as claimed in claim 2, wherein the wireless communications interface comprises a communications interface complying with an 802.11 family of wireless protocols.

4. A video system comprising:

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”

; and

decreasing the current retransmission bitrate by a video tune-down step when the state of the transmitter is “

tuning down”

.

5. The video system as claimed in claim 4, wherein communications interface comprises a wireless communications interface.

6. The video system as claimed in claim 4, wherein the wireless communications interface comprises a communications interface complying with an 802.11 family of wireless protocols.