High speed serial data transport between communications hardware modules

• US 7,408,961 B2
• Filed: 04/16/2002
• Issued: 08/05/2008
• Est. Priority Date: 09/13/2001
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Kaku, Vicky B.
• Primary Examiner(s): Orgad; Edan
• Assistant Examiner(s): Wong; Blanche
• Application Number:
  US10/124,610
• Publication Number:
  US 20030056049A1
• Time in Patent Office: 2,303 Days
• Field of Search: 370/537, 370/542
• US Class Current: 370/535
• CPC Class Codes: G06F 13/409 Mechanical coupling back panels H05K7/1438
• CPC Class Codes: H04N 21/23608 Remultiplexing multiplex streams, e.g. involving modifying time stamps or remapping the packet identifiers
• CPC Class Codes: H04N 21/2365 Multiplexing of several video streams
• CPC Class Codes: H04N 21/64322 IP

Abstract

Transcoder multiplexers that transport digital packets, such as MPEG2 packets, between boards in a chassis using a serial differential protocol are disclosed. The disclosed multiplexers achieve data transfer rates at least twice as fast as conventional systems. Digital data packets are thereby efficiently communicated to target processing engines on other boards across the backplane. Prior art requirements for custom backplane designs, together with discrete hardware for sending data in parallel form between boards, are obviated. Instead, a backplane architecture designed specifically for IP data traffic from any slot to any slot is utilized. Also, an improved protocol is applied for transmitting data serially between boards to provide an inexpensive, upgradeable and flexible hardware solution. Preferred embodiments use LVDS transmitter/receiver pairs with high link speeds.

Claims

1. A high speed Internet Protocol communications system for serially transporting digital data between communications hardware comprising:

a chassis for receiving plural boards, the chassis comprising a backplane which includes a control data bus and a serial data bus communicatively linking the plural boards together;

the plural boards comprising an input board for receiving an incoming parallel data stream and transmitting a differential serial data stream to the serial data bus, the input board including a serializer for converting the received parallel data stream into the differential serial data stream and a transmitter for transmitting the differential serial data stream to the serial data bus;

the differential serial data stream comprising encoded video data packets, each of the data packets comprising a header having a target media accelerated processor identifier; and

the plural boards further comprising at least one other board with a serial data receiver and a deserializer, the serial data receiver receiving the differential serial data stream from the serial data bus, and the deserializer converting the received differential serial data stream into an output data stream in accordance with control signals received via the control data bus.

2. The communications system of claim 1, wherein the communications system comprises a transport multiplexer.

3. The communications system of claim 1, wherein the differential serial data stream transported between the communications hardware via the serial data bus comprises MPEG2 encoded data packets, each of the data packets comprising a header having a target media accelerated processor identifier, an MPEG2 data packet and a footer having a time stamp.

4. The communications system of claim 1, wherein

the transmitter is a low voltage differential signal transmitter;

the receiver is a low voltage differential signal receiver; and

data is transported unidirectionally from the transmitter to the receiver.

5. The communications system of claim 1, wherein

the input board comprises eleven low voltage differential signal transmitters;

and the at least one other board comprises four low voltage signal receivers.

6. The communications system of claim 1,

having a rate of serial data transport from the input board to the at least one other board of at least about 324 Mbps;

and

wherein the control data bus comprises a compact peripheral component interconnect (cPCI) data bus.

7. The communications system of claim 1, wherein the at least one other board is a transcoder board comprising a low voltage differential signal receiver with clock recovery for receiving the differential serial data stream via the serial data bus and a media accelerator processor for generating the output data stream therefrom.

8. The communications system of claim 1, wherein the at least one other board is a time division multiplexer board comprising at least one pair of low voltage signal receiver for receiving the differential serial data stream via the serial data bus and at least one media accelerated processor.

9. The communications system of claim 1, wherein the plural boards further comprise a central processing unit (CPU) board that is communicatively linked to the input board via the control data bus.

10. The communications system of claim 9, wherein

the differential serial data stream transported between the plural boards via the serial data bus comprises MPEG2 encoded data packets;

the plural boards further comprise a transcoder board comprising a low voltage differential signal receiver for receiving the differential serial data stream via the serial data bus and a media accelerator processor for generating the output data stream therefrom; and

the input board comprises a field programmable gate array comprising means for;

performing packet identifier filtering and aliasing;

providing the CPU with information relating to the incoming data stream;

buffering the encoded data packets; and

routing the encoded data packets to the media accelerator processor.

11. A system for serially transporting digital data within a transport multiplexer comprising:

a chassis for receiving plural boards, the chassis comprising a backplane which comprises a compact peripheral component interconnect (cPCI) bus and a serial data bus communicatively linking at least one input board to at least one other board;

a central processing unit (CPU) board communicatively linked to the cPCI bus and providing control signals to the cPCI bus;

the at least one input board transmitting a differential serial data stream to the serial data bus in response to receipt of a parallel data stream, the at least one input board comprising a serializer for converting the received parallel data stream into the differential serial data stream and comprising a low voltage differential signal transmitter for transmitting the differential serial data stream to the serial data bus;

the differential serial data stream comprising encoded video data packets, each of the data packets comprising a header having a target media accelerated processor identifier; and

the at least one other board comprising a serial data receiver and a deserializer, the serial data receiver receiving the differential serial data stream from the serial data bus, and the deserializer converting the received differential serial data stream into an output data stream in accordance with control signals received from the CPU board via the cPCI bus.

12. The system of claim 11, wherein the differential serial data stream transported between the input board and the other board via the serial data bus comprises MPEG2 encoded data packets, each of the data packets comprising a header having a target media accelerated processor identifier, an MPEG2 data packet and a footer having a time stamp.

13. The system of claim 11, wherein

the receiver is a low voltage differential signal receiver with clock recovery;

and

data is transported unidirectionally from the transmitter to the receiver.

14. The system of claim 11, wherein

the input board comprises eleven low voltage differential signal transmitters;

and the at least one other board comprises four low voltage signal receivers.

15. The system of claim 11, wherein the at least one other board is a transcoder board comprising a low voltage differential signal receiver for receiving the differential serial data stream via the serial data bus and a media accelerated processor for generating the output data stream therefrom.

16. The system of claim 11, wherein

the system comprises at least two other boards;

and

the input board further comprises;

plural ports for receiving plural input data streams;

means for performing packet identifier filtering and aliasing of the input data streams;

means for capturing control information from the input data streams;

means responsive to receipt of the plural input data streams for transmitting plural independent differential serial data streams to the at least one other board via the serial data bus; and

means for buffering the differential serial data streams to thereby reduce the possibility of data bottlenecks occurring.

17. A system for serially transporting digital data comprising:

means for receiving a parallel data stream, for serializing the parallel data stream and for transmitting the serialized data stream to a serial data bus, the serialized data stream comprising encoded video data packets, each of the data packets comprising a header having a target media accelerated processor identifier; and

means for receiving the serialized data stream via the serial data bus and for converting the received serialized data stream into an output data stream in accordance with control signals received via a control data bus; and

means for communicatively linking a plurality of boards via the control data bus and the serial data bus.

18. The system of claim 17, wherein the serialized data stream transported via the serial data bus comprises MPEG2 encoded data packets, each of the data packets comprising a header having a target media accelerated processor identifier, an MPEG2 data packet and a footer having a time stamp.

19. The system of claim 17, wherein

the means for transmitting comprises a low voltage differential signal transmitter;

the means for receiving the serialized data stream comprises a low voltage differential signal receiver; and

the serialized data stream is transported unidirectionally from the transmitter to the receiver.

20. The system of claim 17, wherein the means for receiving the serialized data stream comprises a transcoder with a low voltage differential signal receiver for receiving the serialized data stream via the serial data bus and a media accelerated processor for generating the output data stream therefrom.

21. A high speed Internet Protocol backplane for communicatively linking an input board having a serializer with an other board having a serial data receiver and a deserializer, the backplane comprising:

a transport multiplexer (TMX);

a compact peripheral component interconnect (cPCI) control data bus of the TMX for delivering control data from the input board to the other board; and

a serial data bus of the TMX for delivering differential serial content data from the input board to the other board, the differential serial content data comprising encoded video data packets, each of the encoded video data packets comprising a header having a target media accelerated processor identifier;

wherein the control data bus and the serial data bus comprise independent communications pathways in the TMX linking the input board and the other board together, the input board being configured to receive parallel content data and to transmit the differential serial content data to the other board via the TMX, and the other board being configured to receive the differential serial content data from the input board via the TMX and to convert the received differential serial content data into output data in accordance with the control data received from the input board via the TMX.

22. A method for serially transporting digital data between a first board and at least one other board within a chassis comprising:

communicatively linking the first board and the at least one other board via a control data bus and a serial data bus;

receiving plural parallel data streams;

specifying a routing configuration for the plural parallel data streams;

serializing the parallel data streams in accordance with the routing configuration;

transmitting the serialized data stream to the serial data bus, the serialized data stream comprising encoded video data packets, each of the data packets comprising a header having a target media accelerated processor identifier;

receiving the serialized data stream via the serial data bus and the control data via the control data bus; and

converting the received serial data stream into an output data stream in accordance with control data received via the control data bus.

23. The method of claim 22, wherein the serialized data stream comprises MPEG2 encoded data packets, each of the data packets comprising a header having a target media accelerated processor (MAP) identifier, an MPEG2 data packet and a footer having a time stamp.

24. The method of claim 22, wherein

transmitting the serialized data stream comprises transmitting a low voltage differential signal;

receiving the serialized data stream comprises receiving the low voltage differential signal; and

the serialized data stream is transported unidirectionally.