Multicasting transmission of multimedia information

• US 7,003,794 B2
• Filed: 02/20/2001
• Issued: 02/21/2006
• Est. Priority Date: 06/27/2000
• Status: Expired due to Fees

• Current Assignee: Runcom Technologies Ltd.
• Original Assignee: Bamboo Mediacasting Ltd. (Runcom Technologies Ltd.)
• Inventors: Arye, Ram
• Primary Examiner(s): Srivastava, Vivek
• Assistant Examiner(s): Ma, Johnny
• Application Number:
  US09/790,082
• Publication Number:
  US 20020002708A1
• Time in Patent Office: 1,827 Days
• Field of Search: 725/73, 725/90, 725 93- 98, 725/86, 725/87, 725/100, 725/151, 370/468, 370/487, 370/4, 370/490, 709/231, 709/232, 709/2, 709/229
• US Class Current: 725/100
• CPC Class Codes: H04N 19/40 using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream
• CPC Class Codes: H04N 21/23424 involving splicing one content stream with another content stream, e.g. for inserting or substituting an advertisement
• CPC Class Codes: H04N 21/234363 by altering the spatial resolution, e.g. for clients with a lower screen resolution
• CPC Class Codes: H04N 21/23439 for generating different versions
• 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 21/44016 involving splicing one content stream with another content stream, e.g. for substituting a video clip
• 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 21/4508 Management of client data or end-user data
• CPC Class Codes: H04N 21/4621 Controlling the complexity of the content stream or additional data, e.g. lowering the resolution or bit-rate of the video stream for a mobile client with a small screen arrangements for using the results of monitoring on user's side in broadcast systems H04H60/65; flow control in packet networks H04L47/10
• CPC Class Codes: H04N 21/6131 involving transmission via a mobile phone network wireless downlink channel access H04W74/006
• CPC Class Codes: H04N 21/6405 Multicasting data broadcast and multicast in packet switching networks H04L12/18

Abstract

A multicasting system for reception of multimedia information comprising: a content switch coupled to a multimedia content source and at least one multimedia smart terminal. The multimedia content source includes a plurality of multimedia contents, wherein each multimedia content is supported by a primary multimedia stream transmitted over a primary dedicated channel having a primary bandwidth. At least one multimedia smart terminal is configured to receive from the content switch over a network each multimedia content as a secondary multimedia stream transmitted over a secondary channel having a secondary bandwidth. The content switch includes a bandwidth scaler configured to scale each primary multimedia stream to a plurality of secondary multimedia sub-streams that are substantially synchronized. The multimedia smart terminal includes a smart terminal sub-stream switch configured to switch among the plurality of secondary multimedia sub-streams in order to select a substantially optimum secondary multimedia sub-stream. The substantially optimum secondary multimedia sub-stream includes a substantially optimum relationship between an error rate level determined at the time of reception of a multimedia content and the quality of reception of a multimedia content.

Claims

1. A multicasting system for reception of multimedia information, said system comprising:

a content switch coupled to a multimedia content source;

said multimedia content source including a plurality N of multimedia contents, each said multimedia content being supported by a primary primary bit rate multimedia stream transmitted over a primary dedicated channel having a primary bandwidth;

N being an integer;

said content switch further including;

a bandwidth scaler configured to scale each said primary primary bit rate multimedia stream transmitted at a primary high bit rate over one said primary dedicated channel having one said primary bandwidth to a plurality K of secondary bit rate secondary multimedia sub-streams, K being an integer, wherein a first secondary bit rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary bit rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary bit rate secondary multimedia sub-stream has a K-th low bit rate, and

at least one multimedia smart terminal, each said multimedia smart terminal configured to receive from said content switch over a network each said multimedia content as a secondary multimedia stream transmitted over a secondary channel having a secondary bandwidth;

wherein at least one said multimedia smart terminal further includes;

a smart terminal sub-stream switch configured to switch between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate;

wherein said substantially optimum secondary_bit_rate secondary multimedia sub-stream includes a substantially optimum relationship between an error rate level determined at the time of reception of said substantially optimum secondary_bit_rate secondary multimedia sub-stream and the quality of reception of a multimedia content supported by said substantially optimum secondary_bit_rate secondary multimedia sub-stream.

2. The system of claim 1, wherein said plurality K of secondary_bit_rate secondary video sub-streams is substantially synchronized, and wherein said smart terminal sub-stream switch further comprises:

a synchronous smart terminal sub-stream switch;

wherein said synchronous smart terminal sub-stream switch is configured to switch between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate;

and wherein said synchronous smart terminal sub-stream switch is configured to substantially synchronize the timing of a transition between a preceding_optimum secondary_bit_rate secondary multimedia sub-stream and a subsequent_optimum secondary_bit_rate secondary multimedia sub-stream to the timing of a set of synchronizing data transmitted by said secondary multimedia stream in order to substantially minimize the loss of data during said transition.

3. The system of claim 2, wherein said synchronous smart terminal sub-stream switch further comprises:

a dynamically loaded database including a look-up table comprising said N multimedia content entries;

wherein for each said content entry n, n being an integer less or equal to N, said look-up table further includes a k number of secondary_bit_rate secondary multimedia sub-streams;

k being an integer less or equal to K; and

wherein for each said secondary_bit_rate secondary multimedia sub-stream said look-up table further includes a lower_error_rate threshold, a higher_error_rate threshold, and a set of synchronizing data.

4. The system of claim 3, wherein said synchronous smart terminal sub-stream switch further comprises:

a switching smart terminal sub-stream means for switching among a plurality of k available secondary_bit_rate secondary multimedia sub-streams in order to select for each said multimedia content a substantially optimum secondary_bit_rate secondary multimedia sub-stream based on said look-up table; and

a synchronous smart terminal sub-stream means for substantially synchronizing the timing of a transition between a preceding_optimum secondary_bit_rate secondary multimedia sub-stream and a subsequent_optimum secondary_bit_rate secondary multimedia sub-stream to the timing of a set of synchronizing data provided by said look-up table in order to substantially minimize the loss of data during said transition.

5. The system of claim 4, wherein said switching smart terminal sub-stream means further includes:

a means for continuously determining a current error rate for a currently employed optimum secondary_bit_rate secondary multimedia sub-stream including a substantially optimum bit rate;

a higher_threshold switching means;

wherein if said substantially optimum secondary_bit_rate secondary multimedia sub-stream has a determined error rate higher than a predetermined higher_error_rate threshold, said higher_threshold switching means switches said content from said substantially optimum secondary_bit_rate secondary multimedia sub-stream to a lower secondary_bit_rate secondary multimedia sub-stream including a lower_low bit rate, wherein said lower_low bit rate is lower than said substantially optimum low bit rate; and

a lower_threshold switching means;

wherein if said substantially optimum secondary_bit_rate secondary multimedia sub-stream has a determined error rate lower than a predetermined lower_error_rate threshold, said lower_threshold switching means switches said content from said substantially optimum secondary_bit_rate secondary multimedia sub-stream to a higher secondary bit_rate secondary multimedia sub-stream including a higher_low bit rate, wherein said higher_low bit rate is lower than said substantially optimum low bit rate.

6. The system of claim 5, wherein said set of synchronizing data further includes a plurality of flags;

said system further including;

a flag means for continuously determining said plurality of flags indicating at least one optimum time moment when said switch from said preceding_optimum secondary_bit_rate secondary multimedia sub-stream to a subsequent_optimum secondary_bit_rate secondary multimedia sub-stream takes place.

7. The system of claim 4, wherein said switching smart terminal sub-stream means further includes:

a means for continuously determining an error rate for said preceding_optimum secondary_bit_rate secondary multimedia sub-stream;

wherein said determined error rate indicates a direction for switching from said preceding_optimum secondary_bit_rate secondary multimedia sub-stream to said subsequent_optimum secondary_bit_rate secondary multimedia sub-stream;

wherein said direction includes an up-down direction if said subsequent_optimum secondary_bit_rate secondary multimedia sub-stream includes a lower bit rate as compared with said preceding_optimum bit rate;

said switch having said up-down direction comprises an up-down switch; and

wherein said direction includes a down-up direction if said subsequent_optimum secondary_bit_rate secondary multimedia sub-stream includes a higher bit rate as compared with said preceding_optimum bit rate;

said switch having said down-up direction comprises a down-up switch;

a prior history switching means for determining a prior switching history including at least one prior up-down or at least one down-up switch; and

for tracking and collecting a set of timing data for each said prior up-down or down-up switch; and

a decision making means for making a decision of whether to make or to delay making a current switch based on said direction for said current switch indicated by said detection means, based on said prior switching history including at least one said prior up-down or at least one said prior down-up switch; and

based on said set of timing data for each said prior up-down or each said prior down-up switch.

8. The system of claim 7, wherein said decision making means further includes:

a means for calculating a number of prior switches over a predetermined time period;

wherein if said number of prior switches over said predetermined time period exceeds a predetermined threshold said decision of whether to make or to delay making a current switch is delayed until said number of prior switches over said predetermined time period goes below said predetermined threshold.

9. The system of claim 3;

wherein said synchronous smart terminal sub-stream switch further comprises;

a receiving multimedia synchronous smart terminal sub-stream switch further including;

a receiving device configured to receive said plurality N of multimedia contents from said content switch over said network, and configured to receive a look-up table comprising said N multimedia content entries;

wherein for each said content entry n, wherein n is an integer less or equal to N, said look-up table further includes a k number of secondary_bit_rate secondary multimedia sub-streams;

wherein k is an integer less or equal to K; and

wherein for each said secondary_bit_rate secondary multimedia sub-stream said look-up table further includes a lower_error_rate threshold, a higher_error_rate threshold, and a set of synchronizing data; and

a smart terminal content switch configured to switch between said plurality N of available multimedia contents based on said look-up table.

10. The system of claim 3;

wherein at least one said multimedia smart terminal further includes;

a transceiver multimedia smart terminal further including;

a transceiver device; and

a smart terminal content switch;

wherein said receiving/transmitting device is configured to receive said plurality N of multimedia contents from said content switch over said network;

and wherein said smart terminal content switch is configured to receive a look-up table comprising said N multimedia content entries;

wherein for each said content entry n, wherein n is an integer less or equal to N, said look-up table further includes a k number of secondary_bit_rate secondary multimedia sub-streams;

wherein k is an integer less or equal to K; and

wherein for each said secondary_bit_rate secondary multimedia sub-stream said look-up table further includes a lower_error_rate threshold, a higher_error_rate threshold, and a set of synchronizing data;

and wherein said receiving/transmitting device is configured to transmit to said content switch the condition of reception of each said received multimedia content.

11. In a multicasting transmission system, wherein a multimedia content source includes a plurality N of multimedia contents, N is an integer, wherein a content switch is coupled to said multimedia content source, and wherein said content switch receives each said multimedia content as a primary multimedia stream transmitted at a primary high bit rate over a primary dedicated channel having a primary bandwidth, wherein said content switch further includes a bandwidth scaler configured to scale each said received primary primary_bit_rate multimedia stream into a plurality K of secondary_bit_rate secondary multimedia sub-streams, K being an integer, wherein a first secondary_bit_rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary_bit_rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary_bit_rate secondary multimedia sub-stream has a K-th low bit rate, and wherein each said secondary_bit_rate secondary multimedia sub-stream is substantially synchronized to one said primary primary_bit_rate multimedia stream;

a multimedia smart terminal configured to receive from said content switch over a network at least one multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth, said multimedia smart terminal further comprises;

a smart terminal sub-stream switch configured to switch between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate;

wherein said substantially optimum secondary_bit_rate secondary multimedia sub-stream includes a substantially optimum relationship between an error rate level determined at the time of reception of said substantially optimum secondary_bit_rate secondary multimedia sub-stream and the quality of reception of a multimedia content supported by said substantially optimum secondary_bit_rate secondary multimedia sub-stream.

12. In a multicasting transmission system of claim 11, wherein said smart terminal sub-stream switch further comprises:

a synchronous smart terminal sub-stream switch;

wherein said synchronous smart terminal sub-stream switch is configured to switch between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate;

and wherein said synchronous smart terminal sub-stream switch is configured to substantially synchronize the timing of a transition between a preceding_optimum secondary_bit_rate secondary multimedia sub-stream and a subsequent_optimum secondary_bit_rate secondary multimedia sub-stream to the timing of a set of synchronizing data transmitted by said secondary multimedia stream in order to substantially minimize the loss of data during said transition.

13. In a multicasting transmission system of claim 12, wherein said synchronous smart terminal sub-stream switch further comprises:

a dynamically loaded database including a look-up table comprising said N multimedia content entries;

wherein for each said content entry n, n being an integer less or equal to N, said look-up table further includes a k number of secondary_bit_rate secondary multimedia sub-streams;

k being an integer less or equal to K; and

wherein for each said secondary_bit_rate secondary multimedia sub-stream said look-up table further includes a lower_error_rate threshold, a higher_error_rate threshold, and a set of synchronizing data.

14. In a multicasting transmission system of claim 13, wherein said synchronous smart terminal sub-stream switch further comprises:

a switching smart terminal sub-stream means for switching among a plurality of k available secondary_bit_rate secondary multimedia sub-streams in order to select for each said multimedia content a substantially optimum secondary_bit_rate secondary multimedia sub-stream based on said look-up table; and

a synchronous smart terminal sub-stream means for substantially synchronizing the timing of a transition between a preceding_optimum secondary_bit_rate secondary multimedia sub-stream and a subsequent_optimum secondary_bit_rate secondary multimedia sub-stream to the timing of a set of synchronizing data provided by said look-up table in order to substantially minimize the loss of data during said transition.

15. In a video multicasting transmission system, wherein a video content source includes a plurality N of video contents, N is an integer, wherein a content switch is coupled to said video content source, and wherein said content switch receives each said video content as a primary video stream transmitted at a primary high bit rate over a primary dedicated channel having a primary bandwidth, wherein said content switch further includes a bandwidth scaler configured to scale each said received primary primary_bit_rate video stream into a plurality K of secondary_bit_rate secondary video sub-streams, K being an integer, wherein a first secondary_bit_rate secondary video sub-stream has a first low bit rate, wherein a second secondary_bit_rate secondary video sub-stream has a second low bit rate, and wherein a K-th secondary_bit_rate secondary video sub-stream has a K-th low bit rate, and wherein each said secondary_bit_rate secondary video sub-stream is substantially synchronized to one said primary primary_bit_rate video stream;

a video smart terminal configured to receive from said content switch over a network at least one video content as a secondary video stream transmitted over a secondary channel having a secondary bandwidth, said video smart terminal further comprises;

a video smart terminal sub-stream switch configured to switch between said plurality K of secondary_bit_rate secondary video sub-streams in order to select a substantially optimum secondary_bit_rate secondary video sub-stream having a substantially optimum low bit rate;

wherein said substantially optimum secondary_bit_rate secondary video sub-stream includes a substantially optimum relationship between an error rate level determined at the time of reception of said substantially optimum secondary_bit_rate secondary video sub-stream and the quality of reception of a video content transmitted by said substantially optimum secondary_bit_rate secondary video sub-stream.

16. In a multicasting transmission system of claim 15, said video smart terminal sub-stream switch further comprising:

a synchronous video smart terminal sub-stream switch;

wherein said synchronous video smart terminal sub-stream switch is configured to switch between said plurality K of secondary_bit_rate secondary video sub-streams in order to select a substantially optimum secondary_bit_rate secondary video sub-stream having a substantially optimum low bit rate;

and wherein said synchronous video smart terminal sub-stream switch is configured to substantially synchronize the timing of a transition between a preceding_optimum secondary_bit_rate secondary video sub-stream and a subsequent_optimum secondary_bit_rate secondary video sub-stream to the timing of a set of synchronizing data transmitted by said secondary_bit_rate secondary video stream in order to substantially minimize the loss of data during said transition.

17. In a multicasting transmission system of claim 16, said synchronous video smart terminal sub-stream switch further comprising:

a dynamically loaded database including a look-up table comprising said N video content entries;

wherein for each said content entry n, wherein n is an integer less or equal to N, said look-up table further includes a k number of secondary_bit_rate secondary video sub-streams;

wherein k is an integer less or equal to K; and

wherein for each said secondary_bit_rate secondary video sub-stream said look-up table further includes a lower_error_rate threshold, a higher_error_rate threshold, and a set of synchronizing data.

18. In a multicasting transmission system of claim 16, said synchronous smart terminal sub-stream switch further comprising:

a switching smart terminal sub-stream means for switching among a plurality of k available secondary_bit_rate secondary video sub-streams in order to select for each said video content a substantially optimum secondary_bit_rate secondary video sub-stream based on said look-up table; and

a synchronous smart terminal sub-stream means for substantially synchronizing the timing of a transition between a preceding_optimum secondary_bit_rate secondary video sub-stream and a subsequent_optimum secondary_bit_rate secondary video sub-stream to the timing of a set of synchronizing data provided by said look-up table in order to substantially minimize the loss of data during said transition.

19. In a multicasting transmission system of claim 16, said primary video stream comprising a compressed video stream further comprising a plurality of independent frames and a plurality of dependent frames;

said plurality of independent frames further comprising a plurality of snapshots, said plurality of dependent frames further comprising a plurality of motion vectors;

wherein a video picture comprises a set of calculated dependent frames, wherein each said calculated dependent frame is calculated by using a set of motion vectors in said dependent frame and a prior independent frame;

wherein each said secondary sub-stream further comprises a plurality of independent frames and a plurality of dependent frames;

wherein said plurality of independent frames in each said sub-stream comprises a plurality of synchronizing data; and

wherein said synchronous smart terminal sub-stream means further includes;

a video means for substantially synchronizing the timing of said transition between a preceding_optimum secondary_bit_rate secondary video sub-stream and a subsequent_optimum secondary_bit_rate secondary video sub-stream to the timing of appearance of a plurality of independent frames in said subsequent_optimum secondary_bit_rate secondary video sub-stream in order to substantially minimize the loss of data during said transition.

20. In a multicasting transmission system of claim 16, said primary video stream comprising a compressed video&

data stream further comprising a plurality of independent frames and a plurality of dependent frames;

said plurality of independent frames further comprising a plurality of snapshots, said plurality of dependent frames further comprising a plurality of motion vectors;

wherein a video picture comprises a set of calculated dependent frames, wherein each said calculated depended frame is calculated by using a set of motion vectors in said dependent frame and a prior independent frame;

wherein each said secondary sub-stream further comprises a plurality of independent frames and a plurality of dependent frames;

wherein said plurality of independent frames in each said sub-stream comprises a plurality of synchronizing data; and

wherein said synchronous smart terminal sub-stream means further includes;

a video&

data means for substantially synchronizing the timing of said transition between a preceding_optimum secondary_bit_rate secondary video sub-stream and a subsequent_optimum secondary_bit_rate secondary video sub-stream to the timing of appearance of a plurality of independent frames in said subsequent_optimum secondary_bit_rate secondary video sub-stream in order to substantially minimize the loss of data during said transition.

21. A method of multicasting reception of multimedia information, said method comprising the steps of:

receiving a plurality N of multimedia contents provided by a multimedia content source by using a content switch coupled to said multimedia content source, wherein each said multimedia content is received as a primary multimedia stream transmitted at a primary bit rate over a primary dedicated channel having a primary bandwidth;

N being an integer;

transmitting over a network each said multimedia content by using said content switch;

wherein each said multimedia content is transmitted as a multimedia stream over a secondary channel having a secondary bandwidth;

wherein said content switch further includes a bandwidth scaler; and

wherein said step of transmitting over said network each said multimedia content further includes the step of;

scaling each said primary primary bit rate multimedia stream transmitted at one said primary high bit rate over one said primary dedicated channel having one said primary bandwidth to a plurality K of secondary bit rate secondary multimedia sub-streams, K being an integer, wherein a first secondary bit rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary bit rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary bit rate secondary multimedia sub-stream has a K-th low bit rate; and

receiving over said network each said multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth by at least one multimedia smart terminal;

wherein at least one said multimedia smart terminal further includes a smart terminal sub-stream switch; and

wherein said step of receiving over said network each said multimedia content by using said smart terminal sub-stream switch further includes the step of;

switching between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate;

wherein said substantially optimum secondary_bit_rate secondary multimedia sub-stream includes a substantially optimum relationship between an error rate level determined at the time of reception of said substantially optimum secondary_bit_rate secondary multimedia sub-stream and the quality of reception of a multimedia content supported by said substantially optimum secondary_bit_rate secondary multimedia sub-stream.

22. A method of multicasting reception of multimedia information, said method comprising the steps of:

receiving a plurality N of multimedia contents provided by a multimedia content source by using a content switch coupled to said multimedia content source, wherein each said multimedia content is received as a primary multimedia stream transmitted at a primary bit rate over a primary dedicated channel having a primary bandwidth;

N being an integer;

transmitting over a network each said multimedia content by using said content switch;

wherein each said multimedia content is transmitted as a multimedia stream over a secondary channel having a secondary bandwidth;

wherein said content switch further includes a bandwidth scaler; and

wherein said step of transmitting over said network each said multimedia content further includes the step of;

scaling each said primary primary bit rate multimedia stream transmitted at one said primary high bit rate over one said primary dedicated channel having one said primary bandwidth to a plurality K of secondary bit rate secondary multimedia sub-streams, K being an integer, wherein a first secondary bit rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary bit rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary bit rate secondary multimedia sub-stream has a K-th low bit rate; and

receiving over said network each said multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth by at least one multimedia smart terminal;

wherein at least one said multimedia smart terminal further includes a synchronous smart terminal sub-stream switch; and

wherein said step of receiving over said network each said multimedia content further includes the steps of;

(A) switching between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate; and

(B) substantially synchronizing the timing of said step (A) to the timing of a set of synchronizing data transmitted by said secondary_bit_rate secondary multimedia stream.

23. A method of multicasting reception of multimedia information, said method comprising the steps of:

receiving a plurality N of multimedia contents provided by a multimedia content source by using a content switch coupled to said multimedia content source, wherein each said multimedia content is received as a primary multimedia stream transmitted at a primary bit rate over a primary dedicated channel having a primary bandwidth;

N being an integer;

transmitting over a network each said multimedia content by using said content switch;

wherein each said multimedia content is transmitted as a multimedia stream over a secondary channel having a secondary bandwidth;

wherein said content switch further includes a bandwidth scaler; and

wherein said step of transmitting over said network each said multimedia content further includes the step of;

scaling each said primary primary bit rate multimedia stream transmitted at one said primary high bit rate over one said primary dedicated channel having one said primary bandwidth to a plurality K of secondary bit rate secondary multimedia sub-streams, K being an integer, wherein a first secondary bit rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary bit rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary bit rate secondary multimedia sub-stream has a K-th low bit rate; and

receiving over said network each said multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth by at least one multimedia smart terminal;

wherein at least one said multimedia smart terminal further includes a synchronous smart terminal sub-stream switch further comprising a dynamically loaded database including a look-up table comprising said N multimedia content entries;

wherein for each said content entry n, wherein n is an integer less or equal to N, said look-up table further includes a k number of secondary_bit_rate secondary multimedia sub-streams;

wherein k is an integer less or equal to K; and

wherein for each said secondary_bit_rate secondary multimedia sub-stream said look-up table further includes a lower_error_rate threshold, a higher_error_rate threshold, and a set of synchronizing data; and

wherein said step of receiving over said network each said multimedia content further includes the steps of;

(A) switching among a plurality of k available secondary_bit_rate secondary multimedia sub-streams in order to select for each said multimedia content a substantially optimum secondary_bit_rate secondary multimedia sub-stream based on said look-up table; and

(B) substantially synchronizing the timing of a transition between a preceding_optimum secondary_bit_rate secondary multimedia sub-stream and a subsequent_optimum secondary_bit_rate secondary multimedia sub-stream to the timing of a set of synchronizing data provided by said look-up table in order to substantially minimize the loss of data during said transition.

24. The method of claim 23, wherein said step (A) further includes the steps of:

(A1) continuously determining a current error rate for a currently employed optimum secondary_bit_rate secondary multimedia sub-stream including a substantially optimum bit rate;

(A2) if said substantially optimum secondary_bit_rate secondary multimedia sub-stream has a determined error rate higher than a predetermined higher_error_rate threshold, switching said content from said substantially optimum secondary_bit_rate secondary multimedia sub-stream to a lower secondary_bit_rate secondary multimedia sub-stream including a lower_low bit rate, wherein said lower_low bit rate is lower than said substantially optimum low bit rate; and

(A3) if said substantially optimum secondary_bit_rate secondary multimedia sub-stream has a determined error rate lower than a predetermined lower_error_rate threshold;

switching said content from said substantially optimum secondary_bit_rate secondary multimedia sub-stream to a higher secondary_bit_rate secondary multimedia sub-stream including a higher_low bit rate, wherein said higher_low bit rate is lower than said substantially optimum low bit rate.

25. The method of claim 23, wherein said step (A) further includes the steps of:

(A4) switching said multimedia content from a first optimum secondary_bit_rate secondary multimedia sub-stream including a first optimum low bit rate to a second optimum secondary_bit_rate secondary multimedia sub-stream including a second optimum low bit rate, wherein the relationship between said second optimum low bit rate and said first optimum low bit rate, that is the bit_rate_direction of a current switch of said multimedia content from said first optimum secondary_bit_rate secondary multimedia sub-stream to said second optimum secondary_bit_rate secondary multimedia sub-stream is determined by the bit_rate_direction of a prior switch.

26. In a multicasting transmission system, wherein a multimedia content source includes a plurality N of multimedia contents, N is an integer, wherein a content switch is coupled to said multimedia content source, and wherein said content switch receives each said multimedia content as a primary multimedia stream transmitted at a primary bit rate over a primary dedicated channel having a primary bandwidth;

wherein said content switch further includes a bandwidth scaler configured to scale each said primary primary_bit_rate multimedia stream transmitted at one said primary high bit rate over one said primary dedicated channel having one said primary bandwidth into a plurality K of secondary_bit_rate secondary multimedia sub-streams, K being an integer, wherein a first secondary_bit_rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary_bit_rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary_bit_rate secondary multimedia sub-stream has a K-th low bit rate, and wherein each said secondary_bit_rate secondary multimedia sub-stream is substantially synchronized to a set of synchronizing data;

said multimedia smart terminal further including smart terminal sub-stream switch;

a method of receiving from said content switch over a network at least one multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth using a receiving multimedia smart terminal further comprising a receiving device and a smart terminal content switch;

said method comprising the steps of;

receiving said plurality N of multimedia contents from said content switch over said network using said receiving device;

switching between said plurality N of available multimedia contents using said smart terminal content switch; and

switching between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate.

27. A multicasting system for wireless reception of multimedia information, said system comprising:

a content switch coupled to a multimedia content source;

wherein said multimedia content source includes a plurality N of multimedia contents, N being an integer, and wherein said content switch receives each said multimedia content over a first wireless network as a primary multimedia stream transmitted at a primary bit rate over a primary dedicated channel having a primary bandwidth; and

at least one multimedia smart terminal, each said multimedia smart terminal configured to receive from said content switch over a wireless network each said multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth;

wherein said content switch further includes;

a bandwidth scaler configured to scale each said primary primary_bit_rate multimedia stream transmitted at one said primary high bit rate over one said primary dedicated channel having one said primary bandwidth to a plurality K of secondary_bit_rate secondary multimedia sub-streams, K being an integer, wherein a first secondary_bit_rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary_bit_rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary_bit_rate secondary multimedia sub-stream has a K-th low bit rate, and wherein each said secondary_bit_rate secondary multimedia sub-stream is substantially synchronized to one said primary primary_bit_rate multimedia stream;

and wherein at least one said multimedia smart terminal further includes;

a smart terminal sub-stream switch configured to switch between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to substantially minimize an error rate level determined at the time of reception of each said secondary_bit_rate secondary multimedia sub-stream.

28. A multicasting system for reception of real-time multimedia information, said system comprising:

a content switch coupled to a multimedia content source;

wherein said multimedia content source includes a plurality N of multimedia contents, N being an integer, and wherein said content switch receives each said multimedia content as a primary multimedia stream transmitted at a primary bit rate over a primary dedicated channel having a primary bandwidth; and

at least one multimedia smart terminal, each said multimedia smart terminal configured to receive from said content switch over a network each said multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth;

wherein said content switch further includes;

a bandwidth scaler configured to scale each said primary primary_bit_rate multimedia stream transmitted at one said primary high bit rate over one said primary dedicated channel having one said primary bandwidth to a plurality K of secondary_bit_rate secondary multimedia sub-streams, K being an integer, wherein a first secondary_bit_rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary_bit_rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary_bit_rate secondary multimedia sub-stream has a K-th low bit rate, and wherein each said secondary_bit_rate secondary multimedia sub-stream is substantially synchronized to one said primary primary_bit_rate multimedia stream;

and wherein at least one said multimedia smart terminal further includes;

a smart terminal sub-stream switch configured to switch between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to substantially minimize an error rate level determined at the time of reception of each said secondary_bit_rate secondary multimedia sub-stream.

29. A multicasting system for reception of multimedia information from a multimedia content source including a plurality N of multimedia contents, N being an integer;

said system comprising;

a content switch means for receiving each said multimedia content transmitted as a primary multimedia stream at a primary bit rate over a primary dedicated channel having a primary bandwidth; and

at least one multimedia smart terminal means for receiving from said content switch over a network each said multimedia content as a multimedia stream transmitted over a secondary channel having a secondary bandwidth;

wherein said content switch means further includes;

a bandwidth scaling means for scaling each said primary primary bit rate multimedia stream transmitted at one said primary high bit rate over one said primary dedicated channel having one said primary bandwidth to a plurality K of secondary bit rate secondary multimedia sub-streams, K being an integer, wherein a first secondary bit rate secondary multimedia sub-stream has a first low bit rate, wherein a second secondary bit rate secondary multimedia sub-stream has a second low bit rate, and wherein a K-th secondary bit rate secondary multimedia sub-stream has a K-th low bit rate, and wherein said plurality K of secondary bit rate secondary multimedia sub-streams is substantially synchronized;

wherein at least one said multimedia smart terminal means further includes;

a smart terminal sub-stream switch means for switching between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate;

wherein said substantially optimum secondary_bit_rate secondary multimedia sub-stream includes a substantially optimum relationship between an error rate level determined at the time of reception of said substantially optimum secondary_bit_rate secondary multimedia sub-stream and the quality of reception of a multimedia content supported by said substantially optimum secondary_bit_rate secondary multimedia sub-stream.

30. The system of claim 29;

wherein said smart terminal sub-stream switch means further comprises;

a synchronous smart terminal sub-stream switch means for switching between said plurality K of secondary_bit_rate secondary multimedia sub-streams in order to select a substantially optimum secondary_bit_rate secondary multimedia sub-stream having a substantially optimum low bit rate; and

for substantially synchronizing the timing of a transition between a preceding_optimum secondary_bit_rate secondary multimedia sub-stream and a subsequent_optimum secondary_bit_rate secondary multimedia sub-stream to the timing of a set of synchronizing data transmitted by each said secondary_bit_rate secondary multimedia sub-stream in order to substantially minimize the loss of data during said transition.