FAST CHANNEL SWITCHING FOR ENCRYPTED MEDIAFLO MOBILE MULTIMEDIA MULTICAST SYSTEM

• US 20090187946A1
• Filed: 01/23/2008
• Published: 07/23/2009
• Est. Priority Date: 01/23/2008
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Newport Media Inc. (Nexstar Media Group, Inc.)
• Inventors: Yousef, Nabil
• Granted Patent: US 8,230,462 B2
• Time in Patent Office: Days
• US Class Current: 725/46
• CPC Class Codes: H04N 21/23412 for generating or manipulating the scene composition of objects, e.g. MPEG-4 objects
• CPC Class Codes: H04N 21/23895 involving multiplex stream encryption
• CPC Class Codes: H04N 21/25891 being end-user preferences retrieval of video data in a video database based on user preferences G06F16/739; arrangements for recognizing users' preferences H04H60/46; user profiles in network data switching protocols H04L67/306; processing of user preferences or user profiles in wireless networks H04W8/18
• CPC Class Codes: H04N 21/26609 using retrofitting techniques, e.g. by re-encrypting the control words used for pre-encryption
• 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 21/43853 involving multiplex stream decryption arrangements using cryptography for the use of broadcast information or broadcast-related information H04H60/23
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/44209 Monitoring of downstream path of the transmission network originating from a server, e.g. bandwidth variations of a wireless network arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896
• 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 21/4667 Processing of monitored end-user data, e.g. trend analysis based on the log file of viewer selections
• 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

Abstract

Enhancing a stream layer transmission for a MediaFLO™ mobile multimedia multicast system comprising a transmitter and a receiver. Code word (CW) computations are performed on a current channel being accessed by the receiver. A favorite channel that a user is statistically mostly likely to switch to on the receiver at any particular time is anticipated. The Overhead Information Symbols (OIS) for each favorite channel is periodically monitored. The receiver remains in a sleep mode while data bursts are received from non-favorite channels, and then wakes up during data bursts of the favorite channel. The same CW computations are performed on the favorite channel as were being performed on the current channel. A cyclic redundancy check (CRC) is performed once the CW computations are performed upon selecting the favorite channel.

Claims

1. A method of enhancing stream layer transmission for a MediaFLO mobile multimedia multicast system comprising a transmitter and a receiver, wherein a plurality of multicast logical channels (MLC) forming a data frame is sent from said transmitter, wherein each MLC comprises multimedia data streams comprising a stream 0 data packet, a stream 1 data packet, a stream 2 data packet, and parity data bits, and wherein four data frames comprises a super-frame, and wherein each said super-frame comprises time-division multiplexing (TDM) pilots, Overhead Information Symbols (OIS), data, and a Pilot Positioning Channel (PPC);

said receiver performing a process comprising;

performing code word (CW) computations on a current channel being accessed by said receiver;

anticipating a favorite channel that a user is statistically mostly likely to switch to on said receiver at any particular time;

periodically monitoring the OIS for each favorite channel every 2N periods, where N is a crypto period of a CW;

remaining in a sleep mode while data bursts are received from non-favorite channels;

waking up from said sleep mode during data bursts of said favorite channel;

performing the same CW computations being performed on said current channel on said favorite channel; and

performing a cyclic redundancy check (CRC) of said stream 0 data packet once said CW computations are performed upon selecting said favorite channel.

2. The method of claim 1, wherein the anticipating process comprises statistically predicting user channel switching behavior based on past user channel switching behavior.

3. The method of claim 1, wherein the anticipating process comprises selecting a channel immediately up or down with respect to said current channel.

4. The method of claim 1, wherein the anticipating process comprises selecting a channel that was previously viewed immediately prior to selection of said current channel.

5. The method of claim 1, further comprising programming a set of favorite channels from among all channels available for viewing on said receiver, wherein the anticipating process comprises selecting one favorite channel from said set of favorite channels.

6. The method of claim 1, further comprising performing error detection on said multimedia data streams.

7. The method of claim 6, further comprising correcting errors in said multimedia data streams using redundant data stored on a fourth frame of said super-frame.

8. The method of claim 1, wherein a CW is ready for computing in said receiver such that if said favorite channel is selected immediately after said current channel, then decryption of said super-frame begins immediately.

9. A method of enhancing stream layer transmission for a MediaFLO mobile multimedia multicast system comprising a transmitter and a receiver, wherein a plurality of multicast logical channels (MLC) forming a data frame is sent from said transmitter, wherein each MLC comprises multimedia data streams comprising a stream 0 data packet, a stream 1 data packet, a stream 2 data packet, and parity data bits, and wherein four data frames comprises a super-frame, said method comprising:

performing code word (CW) computations on a current channel being accessed by said receiver;

anticipating a favorite channel that a user is statistically mostly likely to switch to on said receiver at any particular time;

periodically monitoring the OIS for each favorite channel;

remaining in a sleep mode while data bursts are received from non-favorite channels;

waking up from said sleep mode during data bursts of said favorite channel;

performing the same CW computations being performed on said current channel on said favorite channel; and

performing a cyclic redundancy check (CRC) of said stream 0 data packet once said CW computations are performed upon selecting said favorite channel.

10. The method of claim 9, wherein the anticipating process comprises statistically predicting user channel switching behavior based on past user channel switching behavior.

11. The method of claim 9, wherein the anticipating process comprises selecting a channel immediately adjacent to said current channel.

12. The method of claim 9, wherein the anticipating process comprises selecting a channel that was previously selected immediately prior to selection of said current channel.

13. The method of claim 9, further comprising:

performing error detection on said multimedia data streams; and

correcting errors in said multimedia data streams using redundant data stored on a fourth frame of said super-frame.

14. A system for enhancing stream layer transmission for a MediaFLO mobile multimedia multicast environment, said system comprising:

a transmitter adapted to send a plurality of multicast logical channels (MLC) forming a data frame, wherein each MLC comprises multimedia data streams comprising a stream 0 data packet, a stream 1 data packet, a stream 2 data packet, and parity data bits, and wherein four data frames comprises a super-frame, and wherein each said super-frame comprises time-division multiplexing (TDM) pilots, Overhead Information Symbols (OIS), data, and a Pilot Positioning Channel (PPC);

a receiver that receives said MLC from said transmitter, wherein said receiver is adapted to;

perform code word (CW) computations on a current channel being accessed by said receiver;

anticipate a favorite channel that a user is statistically mostly likely to switch to on said receiver at any particular time;

periodically monitor the OIS for each favorite channel every 2N periods, where N is a crypto period of a CW;

remain in a sleep mode while data bursts are received from non-favorite channels;

wake up from said sleep mode during data bursts of said favorite channel; and

perform the same CW computations being performed on said current channel on said favorite channel; and

cyclic redundancy check (CRC) hardware on said receiver to perform a CRC of said stream 0 data packet once said CW computations are performed upon selecting said favorite channel.

15. The system of claim 14, wherein the receiver anticipates said favorite channel by statistically predicting user channel switching behavior based on past user channel switching behavior.

16. The system of claim 14, wherein the receiver anticipates said favorite channel by selecting a channel immediately up or down with respect to said current channel.

17. The system of claim 14, wherein the receiver anticipates said favorite channel by selecting a channel that was previously viewed immediately prior to selection of said current channel.

18. The system of claim 14, further comprising an error detection component in said receiver adapted to perform error detection on said multimedia data streams.

19. The system of claim 18, further comprising an error corrector component in said receiver adapted to correct errors in said multimedia data streams using redundant data stored on a fourth frame of said super-frame.

20. The system of claim 14, wherein a CW is ready for computing in said receiver such that if said favorite channel is selected immediately after said current channel, then decryption of said super-frame begins immediately.