Prefetched data in a digital broadcast system

• US 6,725,267 B1
• Filed: 11/10/2000
• Issued: 04/20/2004
• Est. Priority Date: 05/31/2000
• Status: Expired due to Fees

• Current Assignee: PrediWave Corp.
• Original Assignee: PrediWave Corp.
• Inventors: Hoang, Khoi
• Primary Examiner(s): Luu, Le Hien
• Assistant Examiner(s): WILLETT, STEPHAN F
• Application Number:
  US09/709,948
• Time in Patent Office: 1,257 Days
• Field of Search: 709/104, 709/217, 709/226, 709/233
• US Class Current: 709/226
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/611 for multicast or broadcast systems for broadcast or conference H04L12/18; arrangements for broadcast or distribution combined with broadcast H04H20/00; arrangements for broadcast applications with a direct linkage to broadcast information or to broadcast space-time H04H60/00; selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS], H04W4/06
• CPC Class Codes: H04L 65/612 for unicast
• 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 67/01 Protocols
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04N 21/2385 Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/262 Content or additional data distribution scheduling, e.g. sending additional data at off-peak times, updating software modules, calculating the carousel transmission frequency, delaying a video stream transmission, generating play-lists scheduling strategies for dispatcher in multiprogramming arrangements G06F9/4881; arrangements for scheduling broadcast services or broadcast-related services H04H60/06; flow control in packet networks H04L47/10; establishing a time schedule or organising the servicing of application requests H04L67/62
• CPC Class Codes: H04N 21/26216 involving the channel capacity, e.g. network bandwidth admission control, resource allocation in open networks H04L12/5692; flow control in packet networks H04L47/10; establishing a schedule or organising the servicing of application requests taking into account QoS H04L67/61
• CPC Class Codes: H04N 21/26233 involving content or additional data duration or size, e.g. length of a movie, size of an executable file
• CPC Class Codes: H04N 21/26241 involving the time of distribution, e.g. the best time of the day for inserting an advertisement or airing a children program
• CPC Class Codes: H04N 21/26275 for distributing content or additional data in a staggered manner, e.g. repeating movies on different channels in a time-staggered manner in a near video on demand system
• CPC Class Codes: H04N 21/4181 for conditional access
• CPC Class Codes: H04N 21/4331 Caching operations, e.g. of an advertisement for later insertion during playback
• CPC Class Codes: H04N 21/472 End-user interface for requesting content, additional data or services; End-user interface for interacting with content, e.g. for content reservation or setting reminders, for requesting event notification, for manipulating displayed content end-user interfaces for retrieving video data from a database G06F16/739; network services for supporting unicast streaming H04L65/612
• CPC Class Codes: H04N 21/47202 for requesting content on demand, e.g. video on demand
• CPC Class Codes: H04N 21/482 End-user interface for program selection broadcast systems using EPGs H04H60/72
• CPC Class Codes: H04N 21/84 Generation or processing of descriptive data, e.g. content descriptors systems specially adapted for using meta-information in broadcast systems H04H60/73
• CPC Class Codes: H04N 21/845 Structuring of content, e.g. decomposing content into time segments
• CPC Class Codes: H04N 7/17318 : Direct or substantially direct transmission and handling of requests
• CPC Class Codes: Y10S 707/99945 : Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99948 : Application of database or data structure, e.g. distributed, multimedia, or image

Abstract

A method for sending data to a client to provide data-on-demand services comprises the steps of: receiving a data file, specifying a time interval, parsing the data file into a plurality of data blocks based on the time interval such that each data block is displayable during a time interval, determining a required number of time slots to send the data file, allocating to each time slot at least a first of the plurality of data blocks and optionally one or more additional data blocks, such that starting from any of the time slots, (i) the data file can be displayed by accessing the first of the plurality of data blocks; (ii) at a consecutive time slot, a next data block sequential to a prior displayed data block is available for displaying; and (iii) repeating step (ii) until all of the plurality of data blocks for the data file has been displayed, and sending the plurality of data blocks based on the allocating step.

Claims

1. A method for sending data to a client to provide data-on-demand services, the method comprising the steps of:

(a) receiving a data file;

(b) specifying a time interval;

(c) parsing said data file into a plurality of data blocks based on said time interval;

(d) prefetching a set of prefetched data blocks from said plurality of data blocks, wherein prefetching said set of prefetched data blocks includes the acts of;

determining a desired reduction in bandwidth that is necessary for transmitting a remaining data blocks of said plurality of data blocks to said client;

determining a desired prefetch delay time that is associated with receiving said set of prefetched data blocks at said client; and

selecting said set of prefetch data blocks based on said desired reduction in bandwidth and said desired prefetch delay time;

(e) sending said set of prefetched data blocks in a dedicated channel; and

(f) transmitting said remaining data blocks of said plurality of data blocks in a transmission channel.

2. An apparatus for scheduling and broadcasting on demand data, the apparatus comprising:

a first channel server suitable for the transmission of digital broadcast data via a first channel;

a second channel server suitable for the transmission of digital broadcast data via a second channel;

a data broadcast controller for;

parsing an on-demand data file into a plurality of blocks of data;

preparing a scheduling matrix comprising said plurality of blocks of data; and

prefetching a set number of blocks of data from said scheduling matrix to form a set number of prefetched blocks of data;

determining a prefetch delay time that is associated with receiving said set number of prefetched blocks of data;

wherein said data broadcast controller reduces a bandwidth necessary for transmission of a remaining blocks of data from said plurality of blocks of data by prefetching said set number of blocks of data; and

a transmitter for transmitting said set number of prefetched blocks of data on said first channel, and transmitting said remaining blocks of data as scheduled in said matrix on said second channel.

3. The apparatus for scheduling and broadcasting on demand data as in claim 2, wherein the data broadcast controller determines an optimal set number of blocks of data to prefetch based on a determined reduction in bandwidth that is necessary for transmitting said remaining blocks of data of said plurality of blocks of data and said determined prefetch delay time that is associated with receiving said optimal set number of blocks of data to prefetch.

4. The apparatus for scheduling and broadcasting on demand data as in claim 3, wherein the data broadcast controller determines the optimal set number of blocks of data to prefetch on an incremental block by block basis.

5. The apparatus for scheduling and broadcasting on demand data as in claim 2, wherein the data broadcast controller prepares a scheduling matrix comprised of blocks of data for a plurality of different on-demand data files.

6. The apparatus for scheduling and broadcasting on demand data as in claim 5, wherein the transmitter transmits a plurality of different on-demand data files on said second channel.

7. The apparatus for scheduling and broadcasting on demand data as in claim 6, wherein the transmitter transmits prefetched data from a plurality of different on-demand data files on said first channel.

8. The apparatus for scheduling and broadcasting on demand data as in claim 2, wherein preview data is transmitted on said first channel.

9. The apparatus for scheduling and broadcasting on demand data as in claim 2, wherein emergency data is transmitted on said first channel.

10. The apparatus for scheduling and broadcasting on demand data as in claim 2, wherein commercial data is transmitted on said first channel.

11. The apparatus for scheduling and broadcasting on demand data as in claim 2, wherein the data broadcast controller randomly selects blocks of data for as preview data to be transmitted on said first channel.

13. The apparatus for scheduling and broadcasting on demand data as in claim 2, wherein the on-demand digital data file is a video on demand data file.

14. The apparatus for scheduling and broadcasting on demand data as in claim 8, wherein the on-demand data file is a web page data file.

12. An apparatus capable of receiving and handling a plurality of digital data services such as VOD and digital broadcast, said apparatus comprising:

a databus;

a first communication device suitable for coupling to a digital broadcast communications medium, said first communication device operable to receive digital broadcast data over at least a first and second channels;

memory bi-directionally coupled to said databus;

a digital data decoder bi-directionally coupled to said databus; and

a central processing unit (CPU) bi-directionally coupled to said databus, said CPU implementing a control process controlling said memory, said digital decoder, and a demodulator, said control process executing instructions for combining the received digital broadcast data from said first and second channels to reproduce an on-demand digital data file;

wherein the received digital broadcast data on said first channel includes prefetched data blocks from said on-demand digital data file and the received digital broadcast data on said second channel includes data blocks from said on-demand digital data file in accordance with a scheduling matrix, and wherein said prefetched data blocks are prefetched based on a determined reduction of bandwidth that is necessary for transmitting the received digital broadcast data on said second channel and a determined prefetch delay time that is associated with transmitting said prefetched data blocks on said first channel.