Fast digital channel changing

• US 20040034863A1
• Filed: 08/13/2002
• Published: 02/19/2004
• Est. Priority Date: 08/13/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Barrett, Peter T., Baldwin, James A.
• Granted Patent: US 8,397,269 B2
• Time in Patent Office: Days
• US Class Current: 725/38
• CPC Class Codes: G01S 1/026 of associated receivers
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1639 the display being based on projection
• CPC Class Codes: G06F 21/305 by remotely controlling device operation
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/74 operating in dual or compartmented mode, i.e. at least one secure mode
• CPC Class Codes: G06F 21/88 Detecting or preventing theft or loss
• CPC Class Codes: G06F 2221/2105 Dual mode as a secondary aspect
• CPC Class Codes: G06F 2221/2115 Third party
• CPC Class Codes: G06F 3/0481 based on specific properties of the displayed interaction object or a metaphor-based environment, e.g. interaction with desktop elements like windows or icons, or assisted by a cursor's changing behaviour or appearance
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 20/10425 by counting out-of-lock events of a PLL
• CPC Class Codes: G11B 20/22 for reducing distortions
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H03L 7/091 the phase or frequency detector using a sampling device H03L7/087 takes precedence
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 10/25754 Star network topology
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access
• CPC Class Codes: H04B 7/2628 : using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2687 : Inter base stations synchronisation
• CPC Class Codes: H04J 13/0077 : Multicode, e.g. multiple codes assigned to one user
• CPC Class Codes: H04J 13/16 : Code allocation
• CPC Class Codes: H04J 3/0655 : using timestamps
• CPC Class Codes: H04J 3/0658 : Clock or time synchronisation among packet nodes
• CPC Class Codes: H04L 1/0002 : by adapting the transmission rate
• CPC Class Codes: H04L 1/0015 : characterised by the adaptation strategy
• CPC Class Codes: H04L 1/0066 : Parallel concatenated codes
• CPC Class Codes: H04L 1/0068 : by puncturing
• CPC Class Codes: H04L 1/1685 : the supervisory signal being transmitted in response to a specific request, e.g. to a polling signal
• CPC Class Codes: H04L 1/1841 : Resequencing
• CPC Class Codes: H04L 1/187 : Details of sliding window management
• CPC Class Codes: H04L 12/417 : with deterministic access, e.g. token passing
• CPC Class Codes: H04L 12/462 : LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 12/4641 : Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 2012/40215 : Controller Area Network CAN
• CPC Class Codes: H04L 2012/40273 : the transportation system being a vehicle
• CPC Class Codes: H04L 25/03038 : with a non-recursive structure H04L25/03031 takes precedence
• CPC Class Codes: H04L 25/4902 : Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 25/4904 : using self-synchronising codes, e.g. split-phase codes
• CPC Class Codes: H04L 25/497 : by correlative coding, e.g. partial response coding or echo modulation coding transmitters and receivers for partial response systems transversal equalizers at the transmitter end H04L25/03343
• CPC Class Codes: H04L 27/156 : with demodulation using temporal properties of the received signal, e.g. detecting pulse width
• CPC Class Codes: H04L 41/06 : Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 41/5009 : Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 41/5087 : wherein the managed service relates to voice services management of VoIP services H04M7/0081
• CPC Class Codes: H04L 43/0829 : Packet loss
• CPC Class Codes: H04L 43/091 : Measuring contribution of individual network components to actual service level
• CPC Class Codes: H04L 43/50 : Testing arrangements
• CPC Class Codes: H04L 45/04 : Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/22 : Alternate routing
• CPC Class Codes: H04L 45/24 : Multipath
• CPC Class Codes: H04L 47/10 : Flow control; Congestion control
• CPC Class Codes: H04L 47/11 : Identifying congestion
• CPC Class Codes: H04L 47/12 : Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/15 : in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/193 : at the transport layer, e.g. TCP related
• CPC Class Codes: H04L 47/2416 : Real-time traffic
• CPC Class Codes: H04L 47/27 : Evaluation or update of window size, e.g. using information derived from acknowledged [ACK] packets
• CPC Class Codes: H04L 47/283 : in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/34 : ensuring sequence integrity, e.g. using sequence numbers
• CPC Class Codes: H04L 47/70 : Admission control; Resource allocation
• CPC Class Codes: H04L 47/72 : using reservation actions during connection setup
• CPC Class Codes: H04L 47/745 : Reaction in network
• CPC Class Codes: H04L 47/765 : triggered by the end-points
• CPC Class Codes: H04L 47/822 : Collecting or measuring resource availability data
• CPC Class Codes: H04L 47/824 : Applicable to portable or mobile terminals
• CPC Class Codes: H04L 49/90 : Buffering arrangements
• CPC Class Codes: H04L 49/9094 : Arrangements for simultaneous transmit and receive, e.g. simultaneous reading/writing from/to the storage element
• CPC Class Codes: H04L 51/04 : Real-time or near real-time messaging, e.g. instant messaging [IM]
• CPC Class Codes: H04L 51/48 : Message addressing, e.g. address format or anonymous messages, aliases
• CPC Class Codes: H04L 51/58 : Message adaptation for wireless communication
• CPC Class Codes: H04L 61/2553 : Binding renewal aspects, e.g. using keep-alive messages
• CPC Class Codes: H04L 65/1016 : IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 65/1043 : Gateway controllers, e.g. media gateway control protocol [MGCP] controllers
• CPC Class Codes: H04L 65/1101 : Session protocols
• CPC Class Codes: H04L 65/1104 : Session initiation protocol [SIP]
• CPC Class Codes: H04L 65/4061 : Push-to services, e.g. push-to-talk or push-to-video
• CPC Class Codes: H04L 65/613 : for the control of the source by the destination control signals issued by the client directed to the server or network components specially adapted for selective content distribution H04N21/637
• CPC Class Codes: H04L 65/70 : Media network packetisation
• CPC Class Codes: H04L 65/765 : intermediate
• CPC Class Codes: H04L 67/1001 : for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1034 : Reaction to server failures by a load balancer
• CPC Class Codes: H04L 69/14 : Multichannel or multilink protocols
• CPC Class Codes: H04L 69/16 : Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 : Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 : In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/166 : IP fragmentation; TCP segmentation
• CPC Class Codes: H04L 69/18 : Multiprotocol handlers, e.g. single devices capable of handling multiple protocols
• CPC Class Codes: H04L 69/40 : for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04L 9/085 : Secret sharing or secret splitting, e.g. threshold schemes
• CPC Class Codes: H04L 9/304 : based on error correction codes, e.g. McEliece
• CPC Class Codes: H04L 9/40 : Network security protocols
• CPC Class Codes: H04M 1/715 : using two or more extensions per line cordless telephones H04M1/725
• CPC Class Codes: H04M 1/724 : User interfaces specially adapted for cordless or mobile telephones
• CPC Class Codes: H04M 1/72415 : for remote control of appliances
• CPC Class Codes: H04M 11/06 : Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04M 3/007 : Access interface units for simultaneous transmission of speech and data, e.g. digital subscriber line [DSL] access interface units DSL access multiplexers H04Q11/0478, and H04L12/2856
• CPC Class Codes: H04M 3/16 : with lock-out or secrecy provision in party-line systems
• CPC Class Codes: H04M 3/42221 : Conversation recording systems at the subscriber's set H04M1/656
• CPC Class Codes: H04M 7/0057 : Services where the data services network provides a telephone service in addition or as an alternative, e.g. for backup purposes, to the telephone service provided by the telephone services network
• CPC Class Codes: H04M 7/1295 : Details of dual tone multiple frequency signalling
• CPC Class Codes: H04N 1/00957 : Compiling jobs, e.g. for batch processing H04N1/3208 takes precedence; program code compilation G06F8/41
• CPC Class Codes: H04N 1/031 : the photodetectors having a one-to-one and optically positive correspondence with the scanned picture elements, e.g. linear contact sensors
• CPC Class Codes: H04N 1/0318 : Integral pick-up heads, i.e. self-contained heads whose basic elements are a light-source, a lens array and a photodetector array which are supported by a single-piece frame
• CPC Class Codes: H04N 1/1934 : Combination of arrays
• CPC Class Codes: H04N 1/1935 : Optical means for mapping the whole or part of a scanned line onto the array
• CPC Class Codes: H04N 1/32106 : separate from the image data, e.g. in a different computer file
• CPC Class Codes: H04N 1/40 : Picture signal circuits H04N1/387 takes precedence
• CPC Class Codes: H04N 19/109 : among a plurality of temporal predictive coding modes
• CPC Class Codes: H04N 19/139 : Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/51 : Motion estimation or motion compensation
• CPC Class Codes: H04N 19/517 : by encoding
• CPC Class Codes: H04N 19/527 : Global motion vector estimation
• CPC Class Codes: H04N 19/625 : using discrete cosine transform [DCT]
• CPC Class Codes: H04N 19/70 : characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/91 : Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
• CPC Class Codes: H04N 21/23418 : involving operations for analysing video streams, e.g. detecting features or characteristics television picture signal circuitry for scene change detection H04N5/147; filtering for image enhancement G06T5/00; methods or arrangements for recognising scenes G06V20/00; arrangements characterised by components specially adapted for monitoring, identification or recognition of video in broadcast systems H04H60/59
• CPC Class Codes: H04N 21/2543 : Billing , e.g. for subscription services payment schemes, architectures or protocols G06Q20/00; e-commerce G06Q30/00; arrangements for billing for the use of broadcast information or broadcast-related information H04H60/21
• CPC Class Codes: H04N 21/2625 : for delaying content or additional data distribution, e.g. because of an extended sport event
• CPC Class Codes: H04N 21/4181 : for conditional access
• CPC Class Codes: H04N 21/426 : Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/433 : Content storage operation, e.g. storage operation in response to a pause request, caching operations
• CPC Class Codes: H04N 21/4331 : Caching operations, e.g. of an advertisement for later insertion during playback
• CPC Class Codes: H04N 21/4383 : Accessing a communication channel
• CPC Class Codes: H04N 21/4384 : involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/4623 : Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/47202 : for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/47211 : for requesting pay-per-view content payment schemes payment architectures or payment protocols G06Q20/00, G07F
• CPC Class Codes: H04N 21/6175 : involving transmission via Internet broadcast-related systems characterised by the transmission system being the Internet H04H60/82
• CPC Class Codes: H04N 21/6187 : involving transmission via a telephone network, e.g. POTS
• CPC Class Codes: H04N 21/6581 : Reference data, e.g. a movie identifier for ordering a movie or a product identifier in a home shopping application
• CPC Class Codes: H04N 21/6582 : Data stored in the client, e.g. viewing habits, hardware capabilities, credit card number arrangements where receivers interact with the broadcast H04H20/38
• CPC Class Codes: H04N 2201/0094 : Multifunctional device, i.e. a device capable of all of reading, reproducing, copying, facsimile transception, file transception
• CPC Class Codes: H04N 2201/02493 : Additional optical elements not otherwise provided for, e.g. filters, polarising plates, masks or apertures
• CPC Class Codes: H04N 2201/03112 : Light source
• CPC Class Codes: H04N 2201/03133 : Window, i.e. a transparent member mounted in the frame
• CPC Class Codes: H04N 2201/03141 : Photodetector lens
• CPC Class Codes: H04N 2201/03145 : Photodetector
• CPC Class Codes: H04N 2201/03187 : Additional optical element
• CPC Class Codes: H04N 2201/3212 : of data relating to a job, e.g. communication, capture or filing of an image
• CPC Class Codes: H04N 2201/3222 : of processing required or performed, e.g. forwarding, urgent or confidential handling
• CPC Class Codes: H04N 2201/3274 : Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 23/57 : Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices
• CPC Class Codes: H04N 23/68 : for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 : based on the image signal
• CPC Class Codes: H04N 23/6812 : based on additional sensors, e.g. acceleration sensors
• CPC Class Codes: H04N 23/683 : performed by a processor, e.g. controlling the readout of an image memory
• CPC Class Codes: H04N 23/684 : performed by controlling the image sensor readout, e.g. by controlling the integration time
• CPC Class Codes: H04N 23/6845 : by combination of a plurality of images sequentially taken
• CPC Class Codes: H04N 5/38 : Transmitter circuitry for the transmission of television signals according to analogue transmission standards H04N5/14 takes precedence
• CPC Class Codes: H04N 5/4448 : for frame-grabbing
• CPC Class Codes: H04N 5/445 : for displaying additional information H04N5/50 takes precedence
• CPC Class Codes: H04N 5/45 : Picture in picture , e.g. displaying simultaneously another television channel in a region of the screen
• CPC Class Codes: H04N 5/46 : for receiving on more than one standard at will deflecting circuits of multi-standard receivers H04N3/27
• CPC Class Codes: H04N 5/50 : Tuning indicators; Automatic tuning control
• CPC Class Codes: H04N 5/64 : Constructional details of receivers, e.g. cabinets or dust covers furniture aspects of television cabinets A47B81/06
• CPC Class Codes: H04N 5/642 : Disposition of sound reproducers
• CPC Class Codes: H04N 5/66 : Transforming electric information into light information scanning details H04N3/00
• CPC Class Codes: H04N 5/76 : Television signal recording
• CPC Class Codes: H04N 5/775 : between a recording apparatus and a television receiver
• CPC Class Codes: H04N 5/85 : on discs or drums
• CPC Class Codes: H04N 5/907 : using static stores, e.g. storage tubes or semiconductor memories H04N5/91 takes precedence
• CPC Class Codes: H04N 7/0112 : one of the standards corresponding to a cinematograph film standard
• CPC Class Codes: H04N 7/0122 : the input and the output signals having different aspect ratios
• CPC Class Codes: H04N 7/163 : by receiver means only
• CPC Class Codes: H04N 7/165 : Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309
• CPC Class Codes: H04N 7/1675 : Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/17327 : with deferred transmission or handling of upstream communications
• CPC Class Codes: H04N 7/17336 : Handling of requests in head-ends
• CPC Class Codes: H04N 9/3129 : scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161
• CPC Class Codes: H04N 9/3141 : Constructional details thereof details not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/642 : Multi-standard receivers
• CPC Class Codes: H04N 9/7925 : for more than one standard
• CPC Class Codes: H04N 9/8042 : involving data reduction
• CPC Class Codes: H04Q 2213/1302 : Relay switches
• CPC Class Codes: H04Q 2213/13039 : Asymmetrical two-way transmission, e.g. ADSL, HDSL
• CPC Class Codes: H04Q 2213/1304 : Coordinate switches, crossbar, 4/2 with relays, coupling field
• CPC Class Codes: H04Q 2213/13076 : Distributing frame, MDF, cross-connect switch
• CPC Class Codes: H04Q 2213/13095 : PIN / Access code, authentication
• CPC Class Codes: H04Q 2213/13109 : Initializing, personal profile
• CPC Class Codes: H04Q 2213/13298 : Local loop systems, access network
• CPC Class Codes: H04Q 2213/13349 : Network management
• CPC Class Codes: H04Q 3/0025 : Provisions for signalling
• CPC Class Codes: H04Q 3/60 : for connecting to satellites or concentrators which connect one or more exchange lines with a group of local lines
• CPC Class Codes: H04W 24/00 : Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/00 : Network traffic management; Network resource management
• CPC Class Codes: H04W 28/18 : Negotiating wireless communication parameters
• CPC Class Codes: H04W 28/26 : Resource reservation
• CPC Class Codes: H04W 36/02 : Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 4/10 : Push-to-Talk [PTT] or Push-On-Call services
• CPC Class Codes: H04W 4/12 : Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 4/14 : Short messaging services, e.g. short message services [SMS] or unstructured supplementary service data [USSD]
• CPC Class Codes: H04W 40/00 : Communication routing or communication path finding
• CPC Class Codes: H04W 40/02 : Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 48/08 : Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0225 : using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: H04W 52/0248 : dependent on the time of the day, e.g. according to expected transmission activity
• CPC Class Codes: H04W 52/0274 : by switching on or off the equipment or parts thereof
• CPC Class Codes: H04W 52/30 : using constraints in the total amount of available transmission power
• CPC Class Codes: H04W 56/00 : Synchronisation arrangements
• CPC Class Codes: H04W 64/00 : Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 68/00 : User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 72/1268 : of uplink data flows
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/52 : based on load
• CPC Class Codes: H04W 74/008 : with additional processing of random access related information at receiving side
• CPC Class Codes: H04W 74/0816 : with collision avoidance
• CPC Class Codes: H04W 74/0833 : Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/12 : Setup of transport tunnels
• CPC Class Codes: H04W 76/18 : Management of setup rejection or failure
• CPC Class Codes: H04W 76/30 : Connection release
• CPC Class Codes: H04W 76/34 : Selective release of ongoing connections
• CPC Class Codes: H04W 76/45 : for Push-to-Talk [PTT] or Push-to-Talk over cellular [PoC] services
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/245 : from a network towards a terminal
• CPC Class Codes: H04W 8/26 : Network addressing or numbering for mobility support
• CPC Class Codes: H04W 8/265 : for initial activation of new user
• CPC Class Codes: H04W 80/00 : Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 84/042 : Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 84/08 : Trunked mobile radio systems
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/085 : Access point devices with remote components
• CPC Class Codes: H04W 88/16 : Gateway arrangements
• CPC Class Codes: H04W 92/02 : Inter-networking arrangements
• CPC Class Codes: H04W 92/12 : between access points and access point controllers
• CPC Class Codes: Y02D 30/70 : in wireless communication networks
• CPC Class Codes: Y10S 370/906 : Fiber data distribution interface, FDDI
• CPC Class Codes: Y10S 370/907 : Synchronous optical network, SONET
• CPC Class Codes: Y10S 707/99943 : Generating database or data structure, e.g. via user interface

Abstract

Fast channel changing in digital-television-based entertainment networks can be implemented, for example, by electing to tune to channels at opportune tuning times. In an exemplary implementation, a method includes: receiving a channel change request that indicates a requested new channel from a client device; preparing a broadcast video data stream of the requested new channel that is offset in time behind a current broadcast time for broadcast video data of the requested new channel; and streaming the broadcast video data stream responsive to the channel change request. In another exemplary implementation, a system includes: a storage device that retains broadcast video data for multiple channels; a video data extractor that accesses the retained broadcast video data and retrieves an intra frame of broadcast video data that is in the past for a requested channel; and a video data distributor that transmits the retrieved intra frame of broadcast video data.

Claims

1. A system for tuning channels in a digital video broadcast network, the system comprising:

a receiver to receive a request to tune to a new channel from a client device; and

a broadcast video extractor to seek for and retrieve a previous complete frame of broadcast video for the new channel from a storage device responsive to the received request.

2. The system as recited in claim 1, further comprising:

a transmitter to transmit the retrieved previous complete frame of broadcast video to the client device to thereby enable the client device to display an image of the new channel.

3. The system as recited in claim 1, further comprising:

a broadcast video booster to access the storage device and retrieve a plurality of incomplete frames of broadcast video that follow the retrieved previous complete frame of broadcast video.

4. The system as recited in claim 1, wherein the retrieved previous complete frame of broadcast video comprises a retrieved most-recently-received complete frame of broadcast video.

5. The system as recited in claim 1, wherein the retrieved previous complete frame of broadcast video is complete such that the client device can decode and cause to be displayed an image thereof without reference to any other frame of broadcast video.

6. A method for tuning channels in a digital video broadcast network, the method comprising actions of:

receiving a request to tune to a requested channel from a client device;

seeking for a previous complete frame of broadcast video for the requested channel;

retrieving the previous complete frame of broadcast video for the requested channel; and

transmitting the previous complete frame of broadcast video for the requested channel to the client device to enable the client device to display an image of the requested channel.

7. A system for accelerating channel changing in a video broadcast environment, the system comprising:

a storage device that retains broadcast video data for a plurality of channels;

a video data extractor that accesses the retained broadcast video data and retrieves an intra frame of broadcast video data that is in the past for a requested channel of the plurality of channels; and

a video data distributor that receives the retrieved intra frame of broadcast video data and transmits the retrieved intra frame of broadcast video data.

8. The system as recited in claim 7, further comprising:

a video data booster that accesses the retained broadcast video data and retrieves a broadcast video data stream that follows the retrieved intra frame of broadcast video data; and

wherein the video data distributor further receives the retrieved broadcast video data stream and transmits the retrieved broadcast video data stream.

9. The system as recited in claim 8, wherein the retrieved broadcast video data stream is of a size that is sufficient to fill a decoding buffer at a client device.

10. The system as recited in claim 7, wherein the video data extractor and the video data distributor comprise software elements of a data center.

11. The system as recited in claim 7, wherein the storage device comprises a disk-based storage array.

12. The system as recited in claim 7, wherein the video data extractor and the video data distributor comprise a combination of one or more of hardware, software, and firmware of a server system.

13. A system for accelerating channel changing in a video broadcast environment, the system comprising:

a storage device that retains broadcast video data for a plurality of channels;

a channel change request handler that receives channel change requests from a plurality of client devices, the channel change requests including requested channels;

a video data extractor that receives the requested channels from the channel change request handler, the video data extractor adapted to access the retained broadcast video data and to retrieve intra frames of broadcast video data that are prior to a current broadcast time for the requested channels;

a video data booster that is adapted to access the retained broadcast video data and to retrieve respective streams of broadcast video data that follow respective ones of the retrieved intra frames of broadcast video data and that are of sufficient size to fill decoding buffers of the plurality of client devices; and

a video data distributor that receives the retrieved intra frames of broadcast video data and the retrieved respective streams of broadcast video data that follow therefrom, the video data distributor adapted to transmit the retrieved intra frames of broadcast video data and the retrieved respective streams of broadcast video data that follow therefrom to the plurality of client devices responsive to the channel change requests.

14. The system as recited in claim 13, further comprising

a network interface that enables the channel change request handler to receive channel change requests from the plurality of client devices and that enables the video data distributor to transmit the retrieved intra frames of broadcast video data and the retrieved respective streams of broadcast video data that follow therefrom to the plurality of client devices.

15. The system as recited in claim 14, wherein the network interface comprises a cable modem termination system (CMTS).

16. The system as recited in claim 14, wherein the network interface comprises at least one component that is adapted to interact with at least one of an Internet protocol (IP)-based network and a digital subscriber line (DSL)-based network.

17. The system as recited in claim 13, wherein the system establishes individual point to point sessions with individual ones of the plurality of client devices.

18. The system as recited in claim 13, wherein the intra frames of broadcast video data are retrieved as being prior to the current broadcast time when the intra frames of broadcast video data arrived at the system prior to the current broadcast time.

19. The system as recited in claim 13, wherein the system comprises a headend of at least one of a cable network and a satellite network.

20. An arrangement for accelerating channel changing, the arrangement comprising:

storage means for storing broadcast video data over time;

extraction means for extracting broadcast video data from the storage means, the extraction means configured to seek backward in time over the broadcast video data until an intra frame of the broadcast video data is located, the extraction means further configured to retrieve the intra frame; and

boosting means for boosting broadcast video data retrieval from the storage means, the boosting means configured to retrieve a stream of the broadcast video data that follows the intra frame, the stream being of a size that is sufficient to fill a decoding buffer of a client device.

21. The arrangement as recited in claim 20, further comprising:

handling means for handling a channel change request from the client device, the channel change request having a requested channel;

the handling means configured to receive the channel change request from the client device, the handling means further configured to provide at least the requested channel to at least the extraction means.

22. The arrangement as recited in claim 21, wherein the channel change request comprises a digital packet transmitted from the client device.

23. The arrangement as recited in claim 21, wherein the extraction means and the boosting means are further configured to retrieve the intra frame and the stream, respectively, from broadcast video data that corresponds to the requested channel in the broadcast video data of the storage means.

24. The arrangement as recited in claim 20, further comprising:

interface means for interfacing with a network, the interface means configured to receive packets via and to transmit packets over the network; and

distribution means for distributing the intra frame and the stream of the broadcast video data to the client device using the interface means.

25. The arrangement as recited in claim 24, wherein the network comprises an Internet protocol (IP)-based network.

26. The arrangement as recited in claim 20, wherein the stream of the broadcast video data comprises at least one predicted frame.

27. A system for accelerating channel changing in a video broadcast environment, the system comprising:

one or more memories, the one or more memories including broadcast video data and electronically-executable instructions;

one or more processors, the one or more processors capable of executing the electronically-executable instructions to perform actions comprising;

receive a request for a new channel from a client device;

access the broadcast video data for the new channel;

seek backward in time along the broadcast video data for the new channel until an intra frame is located;

retrieve the intra frame for the new channel from the broadcast video data; and

transmit the intra frame for the new channel to the client device.

28. The system as recited in claim 27, wherein the one or more memories comprise a first memory and a second memory, the first memory storing the broadcast video data and the second memory storing the electronically-executable instructions.

29. The system as recited in claim 28, wherein the first memory comprises mass memory, and the second memory comprises random access memory (RAM).

30. The system as recited in claim 27, wherein the one or more processors comprise at least part of a server computer.

31. The system as recited in claim 27, wherein the system comprises a data center at a headend of a television-based entertainment network.

32. The system as recited in claim 27, further comprising:

one or more network interfaces, the one or more network interfaces capable of interfacing with at least one network and capable of being controlled by the one or more processors.

33. The system as recited in claim 27, wherein the one or more processors are capable of executing the electronically-executable instructions to perform a further action comprising:

establish a point to point session with the client device across a two way unicast network.

34. The system as recited in claim 27, wherein the one or more processors are capable of executing the electronically-executable instructions to perform further actions comprising:

retrieve a stream of broadcast video data that starts after the intra frame and extends along the broadcast video data for the new channel for a period of time that is sufficient to fill a decoding buffer of the client device; and

transmit the stream of broadcast video data for the new channel to the client device.

35. The system as recited in claim 27, wherein the one or more processors are capable of executing the electronically-executable instructions to perform further actions comprising:

receive current broadcast video data from a broadcast center; and

store the current broadcast video data at the one or more memories.

36. One or more electronically-accessible media comprising instructions that, when executed, direct a server to:

access stored broadcast video data, the stored broadcast video data corresponding to a plurality of channels;

locate for a requested channel an intra frame of broadcast video data that is a most-recently-received intra frame in a portion of the stored broadcast video data that corresponds to the requested channel;

retrieve the located intra frame for the requested channel from the stored broadcast video data; and

send the located intra frame for the requested channel to a client device.

37. The one or more electronically-accessible media as recited in claim 36, further comprising instructions that, when executed, direct the server to:

receive a packet that includes the requested channel from the client device.

38. The one or more electronically-accessible media as recited in claim 36, further comprising instructions that, when executed, direct the server to:

retrieve a stream of broadcast video data that is located immediately following the located intra frame for the requested channel in the portion of the stored broadcast video data that corresponds to the requested channel; and

send the stream for the requested channel to the client device at a transmission rate that exceeds a real-time transmission rate of the broadcast video data.

39. The one or more electronically-accessible media as recited in claim 38, further comprising instructions that, when executed, direct the server to:

retrieve the stream of broadcast video data for the requested channel such that the stream is of a sufficient length so as to fill a decoding buffer of the client device.

40. A method for accelerating channel changing in a video broadcast environment, the method comprising actions of:

receiving, at a client device, a channel change input from a user, the channel change input ordering a change to a requested channel;

sending, from the client device to an upstream node, a channel change request responsive to the channel change input, the channel change request including an indication of the requested channel;

receiving, at the upstream node, the channel change request;

accessing, at the upstream node, a memory that stores retained broadcast video data for a plurality of channels, the plurality of channels including the requested channel;

retrieving, at the upstream node, an intra frame of broadcast video data of the requested channel from the retained broadcast video data, the intra frame of broadcast video data being in the past with respect to a current broadcast time;

sending, from the upstream node to the client device, the intra frame of broadcast video data;

retrieving, at the upstream node, a broadcast video data stream that follows the intra frame of broadcast video data and that is of a size that is sufficient to fill a decoding buffer of the client device;

sending, from the upstream node to the client device, the broadcast video data stream that follows the intra frame of broadcast video data;

receiving, at the client device, the intra frame of broadcast video data; and

receiving, at the client device, the broadcast video data stream that follows the intra frame of broadcast video data.

41. The method as recited in claim 40, further comprising an action of:

causing, at the client device, the intra frame of broadcast video data and the broadcast video data stream that follows the intra frame of broadcast video data to be displayed on a screen associated with the client device.

42. The method as recited in claim 40, wherein the upstream node comprises a headend, and the client device comprises a set-top box.

43. The method as recited in claim 40, wherein both actions of retrieving occur prior to either action of sending from the upstream node.

44. The method as recited in claim 40, wherein the action of receiving, at the client device, the intra frame of broadcast video data occurs prior to the action of sending, from the upstream node to the client device, the broadcast video data stream that follows the intra frame of broadcast video data.

45. One or more electronically-accessible media comprising electronically-executable instructions that, when executed, direct one or more electronic devices to perform the method as recited in claim 40.

46. A method for accelerating channel changing in a video broadcast environment, the method comprising actions of:

receiving a channel change request from a client device, the channel change request indicating a requested new channel;

preparing a broadcast video data stream of the requested new channel that is offset in time behind a current broadcast time for broadcast video data of the requested new channel; and

streaming the broadcast video data stream to the client device responsive to the channel change request.

47. The method as recited in claim 46, wherein the offset in time is due to a difference between the current broadcast time and a time of a most recent intra frame for the broadcast video data of the requested new channel.

48. The method as recited in claim 46, wherein the action of preparing comprises:

accessing a storage device that includes stored broadcast video data of the requested new channel, the stored broadcast video data of the requested new channel including a plurality of intra frames received from a broadcast center.

49. One or more electronically-accessible media comprising electronically-executable instructions that, when executed, direct one or more electronic devices to perform the method as recited in claim 46.

50. A method for a client device for accelerating channel changing, the method comprising actions of:

receiving a channel change input from a user, the channel change input ordering a change to a requested channel;

sending a channel change request responsive to the channel change input, the channel change request including an indication of the requested channel; and

receiving an intra frame of broadcast video data that is prior to a current broadcast time as well as a stream of broadcast video data that follows the intra frame of broadcast video data as a result of the action of sending the channel change request.

51. The method for a client device as recited in claim 50, further comprising an action of:

filling a decoding buffer with the stream of broadcast video data that follows the intra frame of broadcast video data.

52. The method for a client device as recited in claim 50, further comprising actions of:

causing the intra frame of broadcast video data to be displayed on a screen;

decoding the stream of broadcast video data that follows the intra frame of broadcast video data; and

causing the decoded stream of broadcast video data to be displayed on the screen.

53. A headend capable of accelerating channel changing in a video broadcast environment, the headend comprising:

one or more memories, the one or more memories including electronically-executable instructions and stored broadcast video data, the stored broadcast video data including current broadcast video data and non-current broadcast video data;

one or more processors, the one or more processors capable of executing the electronically-executable instructions to perform actions comprising;

receive a request for a new channel from a client device;

access the stored broadcast video data that corresponds to the new channel;

retrieve part of the non-current broadcast video data that corresponds to the new channel from the stored broadcast video data; and

transmit the part of the non-current broadcast video data that corresponds to the new channel to the client device responsive to the request.

54. The headend as recited in claim 53, wherein the part of the non-current broadcast video data comprises at least one intra frame and a plurality of non-intra frames.

55. A method for a headend of a television-based entertainment network, the method comprising actions of:

continuously receiving a stream of broadcast video data for a particular channel;

storing the stream of broadcast video data for the particular channel in a storage device, the stream of broadcast video data including a plurality of intra frames of broadcast video data and a plurality of non-intra frames of broadcast video data;

wherein the plurality of intra frames of broadcast video data include a most-recently-received intra frame of broadcast video data, and the plurality of non-intra frames of broadcast video data include a non-intra frame of broadcast video data that corresponds to a current broadcast time;

receiving a channel change request from a client device, the channel change request indicating a request to change channels to the particular channel;

retrieving the most-recently-received intra frame of broadcast video data and one or more non-intra frames of the plurality of non-intra frames of broadcast video data from the storage device, the one or more non-intra frames of broadcast video data being temporally located after the most-recently-received intra frame of broadcast video data and before the non-intra frame of broadcast video data that corresponds to the current broadcast time; and

sending the most-recently-received intra frame of broadcast video data and the one or more non-intra frames of broadcast video data to the client device responsive to the action of receiving the channel change request.

56. The method for a headend as recited in claim 55, the method comprising a further action of:

sending the non-intra frame of broadcast video data that corresponds to the current broadcast time and any additional non-intra frames of broadcast video data that are between a last non-intra frame of broadcast video data of the one or more non-intra frames of broadcast video data and the non-intra frame of broadcast video data that corresponds to the current broadcast time.

57. One or more electronically-accessible media comprising electronically-executable instructions that, when executed, direct a headend to perform the method as recited in claim 55.

58. A headend that is capable of accelerating channel changing in a video broadcast environment, the headend configured to perform actions comprising:

receiving a channel change request that corresponds to a first time and is directed to a requested channel;

accessing broadcast video data for the requested channel;

retrieving an intra frame of broadcast video data that corresponds to a second time from the broadcast video data for the requested channel, the second time being earlier than the first time;

retrieving broadcast video data frames that follow the intra frame of broadcast video data from the broadcast video data for the requested channel;

sending the intra frame of broadcast video data from the headend; and

sending the broadcast video data frames that follow the intra frame of broadcast video data from the headend.

59. The headend as recited in claim 58, wherein the first time is associated with at least one of a transmission time of the channel change request and a reception time of the channel change request.

60. The headend as recited in claim 58, wherein the intra frame of broadcast video data comprises an intra frame of broadcast video data in accordance with a Moving Pictures Expert Group (MPEG)-compliant scheme.