Invention for Quality feedback mechanism to allocate bandwidth in a switched digital system

Invented by Scott M. Davis, Tom Gonder, Paul Brooks, Time Warner Cable Enterprises LLC

The Time Warner Cable Enterprises LLC invention works as follows

In a switched video content-based network, where a head end receives a first set of program streams, but sends to a customer only a subset, the imminence or presence of an inadequate bandwidth condition is determined. In response to the determination, the bit rate of at most one subset selected by subscribers in the local neighborhood of the client can dynamically be decreased by changing the encoding. However, adequate quality is maintained for at least one subset selected by subscribers in the neighbor of client. This is based on an objective quality measurement to address the imminence or presence of insufficient bandwidth.

Background for Quality feedback mechanism to allocate bandwidth in a switched digital system

Many TV programs are now transmitted digitally thanks to digital communications technology. Digital Satellite System (DSS), Digital Broadcast Services, and Advanced Television Standards Committee program streams are digitally formatted according to the Moving Pictures Experts Group 2 standard (MPEG-2). The MPEG-2 standard describes, among other things the methods for video and audio compression that allow multiple programs with different audio feeds to be multiplexed in a stream of transport. An MPEG-2 encoded stream of transport can be decoded by a digital TV receiver, which will extract the desired program.

Compressed video and audio data are usually carried by continuous elementary stream, respectively. These streams are then broken into access units, or packets, creating packetized elementary streams. These packets can be identified by headers that include time stamps to synchronize and are used in MPEG-2 transport streams. Multiple programs with their PESs can be multiplexed to create a single stream for digital broadcasting. PES packets are further subdivided into shorter fixed-size data packets. This allows multiple programs with different clocks to be carried in a transport stream. Transport streams can contain more than just audio and video PESs. They also include other data, such as MPEG-2 program information (sometimes called metadata), that describes the transport stream. A program associated table (PAT), which lists all programs in the transport stream, may be included in MPEG-2 metadata. Each entry in the MPAT points to a program map table (PMT), which lists the elementary streams that make up each program. While some programs are available, others may require encryption or conditional access. This information is typically carried in the MPEG-2 transport stream as metadata.

The fixed-size data packets mentioned in the transport stream all have a packet identification (PID) code. The PID code is shared by all packets in the same elementary stream so that the decoder can choose the appropriate elementary stream and reject the rest. To ensure that each packet is used to decode a stream, packet-continuity counters can be used.

A video content network such as a cable TV network may offer many services, including movies on-demand, paid subscriptions, switched digital video and free on-demand. A user can request the establishment of a session in order to start watching program material. In some instances, the bandwidth may not be sufficient to create the new session or maintain existing sessions. In many cases, it is important to allocate network bandwidth.

A quality feedback mechanism for bandwidth allocation in a switched-digital video system is disclosed.

In one aspect, an example method that is suitable for implementation in a switched video content-based network where a head end receives a first set of program streams and sends to clients only a subset, which includes steps such as determining the at minimum one of imminence or presence of an inadequate bandwidth condition; and dynamically decreasing the bit rate of at most one subset selected by subscribers in the neighbor of client based on an objective quality measurement to address the at the least one subset of program streams chosen by the subscribers in the client

Another aspect is that an apparatus is available for use in a switched video content-based network. A head end receives a first set of program streams, and only sends to clients a subset. This allows the head end to select program streams from subscribers within a specific area of the client. An encoder bank encodes multiple input video streams into a plurality output video streams. The subset of program stream corresponds to the plurality and output video streams. The apparatus includes a video quality sensor system that determines an objective measure for quality for at most the output streams. It also includes an encoder management and video quality sensing systems. A switched digital bandwidth manager is coupled to the encoder management. The switched digital bandwidth manager can determine and signal to encoder management systems at least one of the following: imminence or presence of an inadequate bandwidth condition in the switched video content-based network. The encoder management system responds to the signaling by decreasing the bit rate of at most one subset selected program stream by subscribers in the neighbor of the client. This is done based on the communication from the video quality sensor system, which indicates the objective measure quality.

As used herein, ?facilitating? “Action” can be defined as performing an action, making it easier, assisting in the execution of the action, or causing it to happen. By way of illustration, an action might be made easier by instructions executed on one processor. Remote processors can execute instructions by sending the appropriate data or commands to cause or assist the action to take place.

One or more embodiments or elements of the invention can be implemented as an article of manufacture that includes a machine-readable medium that contains one (or more) programs that when executed execute such step(s); that’s a computer program product that includes a tangible computer-readable recordable medium (or multiple media such as this), with computer usable code for performing the method steps. One or more embodiments or elements of the invention can be implemented as an apparatus that includes a memory and at most one processor. This is operative to perform or facilitate the performance of exemplary method steps. Another aspect of the invention, or elements thereof, can be implemented as means to perform one or more method steps. The means can include a memory and at least one processor that are coupled to the memory and operative to implement the specific techniques described herein.

These and other advantages of the invention will be apparent from the detailed description of the illustrative embodiments of the invention, which should be read in conjunction with the accompanying illustrations.

FIG. “FIG. One or more embodiments can be used to create switched digital networks, as described below. The network 100 comprises (i) one to three data and application origination point 102, (iii), one or two content sources 103; (iii), one or several application distribution servers (104); (v) one (or more) video-on-demand servers (VOD) 105 and (v) consumer or customer premises equipment (CPE). A dynamic bandwidth allocation device (DBWAD 1001) such as a global resource manager is also included. This is a non-limiting example for a session manager. The distribution server(s), 104, VOD server(s), 105, DBWAD 1001, CPE(s), 106 and bearer (e.g. hybrid fiber cable (HFC), network 101) connect to each other. FIG. 1 shows a simple architecture. FIG. 1 is a simplified example of the architecture. However, it will be noted that similar architectures may be used with different origination points, distribution stations, VOD servers and/or CPE device (as well other network topologies), consistent with the invention. FIG. 1A, which is described in more detail below, may be used.

It is important to note that network 101 can include a traditional HFC network, a switched digital network, and other types of video content networks (e.g. fiber-to the-curb (FTTC ), or fiber-tothe-home (FTTH).

The data/application origination points 102 include any medium that permits data and/or apps (such as VOD-based or Watch TV?). Application) to be transferred (for example, over a network that is not separately numbered). These could include a third-party data source, application vendor website (CD-ROM), an external network interface, mass storage device (e.g. Redundant Arrays Of Inexpensive Disks, RAID) system), and others. This transference can be initiated automatically upon one or more specific events (e.g., receipt of a request package or acknowledgement (ACK), or manually.

The application distribution system 104 is a computer system that allows such applications to enter the network system. The networking arts are familiar with distribution servers.

The VOD server105 is a computer system that allows on-demand content to be received from any of the data sources 102 and entered into the network system. These servers can either generate the content locally or act as an intermediary or gateway from distant sources.

The CPE 106 covers any equipment located in customers’ premises (or other suitable locations) that can accessed by a Distribution Server 104; such as set-top terminals (STT), digital sets-top boxes (DSTB), set top box (STB), or just?box? The like.

Referring to FIG. One exemplary embodiment is shown in FIG. 1A. FIG. FIG. 1A shows the typical components and services of the head-end architecture 150. These include billing module 152 and subscriber management system (308 and CPE configuration module 308), cable-modem termination systems (CMTS) and outof-band (OOB), system 156, and LAN(s), 158 and 160 which place the various components in data communications with each other. You will see that the diagram shows a bus or bar LAN topology, but there are many other arrangements, such as a ring, star, and so forth. It will be appreciated that while a bus LAN topology is shown, any number of other arrangements (e.g., ring, star etc.) may be used in accordance with the invention. You will also appreciate that FIG. 1A is a high-level conceptual architecture. Each multi-service operator (MSO), or multiple system operator, may have multiple head end configurations that use custom architectures.

The architecture 150 in FIG. 1A further includes a multiplexer/encrypter/modulator (MEM) 162 coupled to the HFC network 101 adapted to ?condition? Content for transmission over the network. The distribution servers 104 can be connected to the LAN 160. This allows access to the MEM 162 or network 101 via one of the file servers 170. Although the VOD server 105 is coupled to the LAN 158 the architectures that may be used include the VOD servers being associated with a core switching device like an 802.3z Gigabit Internet device or the VOD server being coupled to LAN 160. Information is often carried over multiple channels so the head-end must be modified to obtain the information from different sources. The channels are typically delivered from the CPE 106 to the head-end 150 (or downstream). Multiplexed together at the head-end 150 to the CPE 106 (?downstream?) 1B) through a variety interposed network component.

It will also be acknowledged that multiple servers (broadcast or VOD) can be used and disposed of at different locations if necessary, such as in different server farms. Multiple servers can be used to provide one or more service groups. A single server can be used to feed several service groups in a simple architecture. Another variant uses multiple servers at the same place to feed several service groups. Another variant uses multiple servers located at different locations to feed one or more service group.

In certain instances, material can also be obtained via a satellite feed 1108, but such material is demodulated in block 1106 and decrypted there before being fed to block 162. Access control may be made possible by conditional access system 157. The network management system 1110 could provide the appropriate management functions. Notable is also the fact that signals from MEM 162 as well as upstream signals from network 101 have been split in block 1112 and demodulated. These signals are fed to CMTS 156.

Click here to view the patent on Google Patents.