High speed multimedia data network

• US 5,995,512 A
• Filed: 01/17/1997
• Issued: 11/30/1999
• Est. Priority Date: 01/17/1997
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Original Assignee: Delco Electronics Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Pogue, Russell Wilbur Jr.
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): HYUN, SOON D
• Application Number:
  US08/785,244
• Time in Patent Office: 1,047 Days
• Field of Search: 370/395, 370/400, 370/401, 370/463, 370/465, 370/466, 370/519, 370/407, 370/420, 370/421, 370/446, 370/252, 370/508, 370/424, 370/425, 370/426, 370/419, 359/118
• US Class Current: 370/419
• CPC Class Codes: H04J 3/0638 Clock or time synchronisation among nodes; Internode synchronisation synchronization for ring networks H04L12/422; data switching networks with synchronous transmission H04L12/43
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles

Abstract

A low cost, high speed multimedia data network is disclosed. The network preferably includes a fiber optic data bus arranged in a star topology configuration. Various types of devices or nodes may be placed in communication with the bus via a specially designed interface. The interface allows a device to communicate with the high speed network without requiring that the device have the processing power to receive and transmit data according to the protocols and demands of the network. The interface may be configured to match the complexity of its associated device. For intelligent devices, the interface may allow some of the network-related functions to be performed by the device itself. For non-intelligent (or "dumb") devices, the interface performs substantially all of the network-related functions. In general, the interface provides the capability of insulating a node from the complexities of the high speed network by receiving data from and providing data to the node according to the node'"'"'s data format, and receiving data from and providing data to the network according to the network'"'"'s data format. The general messaging protocols are designed to facilitate the transfer of data in a star topology configuration, while also facilitating the relatively low cost and flexible implementation of the network.

Claims

1. A communications interface comprising:

a data interface in communication with a node interface port;

a receiver in communication with said data interface and a network data bus;

a transmitter in communication with said data interface and said network data bus;

said data interface receiving network data from the network data bus via said receiver according to a network data format and forwarding such network data to an external node via said node interface port according to a node data format compatible with such external node;

said data interface further receiving external data from said external node via said node interface port according to said node data format and providing such external data to said transmitter according to said network data format;

a controller in communication with said data interface, receiver and transmitter for determining said node data format, said controller having a memory storing configuration information about how to recognize and distinguish various types of network data that may be received by said receiver, when such network data should be received by said receiver, and when the network data bus is available for data transmission by said transmitter;

wherein said receiver detects a network data phase difference by comparing a phase of received network data to an expected phase based on said stored configuration information.

2. The communications interface of claim 1 wherein said receiver advances or delays transmission of received network data to said data interface based on the network phase difference detected by said receiver.

3. A communications interface comprising:

a data interface in communication with a node interface port;

a receiver in communication with said data interface and a network data bus;

a transmitter in communication with said data interface and said network data bus, said transmitter including means for determining an estimate of a propagation delay associated with transmissions from said transmitter through said network data bus, and for adjusting signals transmitted by said transmitter to compensate for said estimated propagation delay, said estimate being determined bv measuring travel time for a signal traveling from said transmitter via said network data bus to said receiver;

said data interface receiving network data from the network data bus via said receiver according to a network data format and forwarding such network to an external node via said node interface port according to a node data format compatible with such external node;

said data interface further receiving external data from said external node via said node interface port according to said node data format and providing such external data to said transmitter according to said network data format.

4. The communications interface of claim 3 further comprising:

a controller having a memory storing configuration information about how to recognize and distinguish various types of network data that may be received by said receiver; and

wherein said receiver detects network data phase differences by comparing the phase of received network data with a phase expected based on said configuration information stored in said controller and advances or delays transmission of received network data to said data interface based on said detected network data phase differences.

5. A communications interface comprising:

a data interface in communication with a node interface port;

a receiver in communication with said data interface and a first transducer that receives light pulses from an optical fiber transmission line of an optical data bus, converts said received light pulses into digital data, and provides said digital data to said receiver;

a transmitter in communication with said data interface and a second transducer that receives digital data from said transmitter, converts said digital data received from said transmitter into light pulses, and provides said light pulses to another optical fiber transmission line of said optical data bus, said transmitter including means for determining an estimate of a propagation delay associated with transmissions from said transmitter via said optical data bus by measuring the time it takes for a signal to travel from said transmitter via said optical data bus to said receiver, and for adiusting signals transmitted by said transmitter to compensate for the estimated propagation delay;

said data interface receiving digital data from said receiver according to a network data format and providing data received from said receiver to an external node according to a node data format compatible with such external node;

said data interface further receiving data from said external node according to said node data format and providing said data received from said external node to said transmitter according to said network data format; and

a controller in communication with said data interface, receiver and transmitter;

said controller containing predetermined node data formats and configures said data interface by providing it with control information associated with one of said predetermined node data formats that allows said data interface to provide data to said external node in one of said predetermined node data formats.

6. A data communications system comprising:

a data communications network that transmits data according to a network data format;

a plurality of nodes, any one of said plurality of nodes transmitting or receiving data according to a node data format used by said one of said plurality of nodes; and

configurable communications interfaces in communication with said network and said plurality of nodes, said communications interfaces passing data from said nodes to said network or from said network to said nodes;

each of said configurable communications interfaces capable of being configured to accept data from an associated node in the node data format of such associated node, transmit data to said network in said network data format, receive data from said network in said network data format, and transmit data to such associated node in the node data format of such associated node; and

a master controller in communication with said network via one of said configurable communications interfaces for transmitting a synchronization symbol to the other of said configurable communications interfaces via the network in time slots assigned by said network data format, said synchronization symbol being used by such other configurable communications interfaces to adjust their frequency timing with respect to said master controller.

7. The system of claim 6 wherein said network data format further comprises:

a start-of-transmission symbol transmitted at the beginning of each of said time slots, said interface using said start-of-transmission symbol to make phase adjustments to each interface'"'"'s phase timing.

8. The system of claim 7 wherein:

the data transmitted by least one of said plurality of nodes to an associated configurable communications interface comprises audio data; and

said audio data is transmitted according to a node data format that is compatible with audio signals.

9. The system of claim 7 wherein:

the data transmitted by least one of said plurality of nodes to an associated configurable communications interface comprises video data; and

said video data is transmitted according to a node data format that is compatible with video signals.

10. A data communications system comprising:

a data communications network that transmits data according to a network data format;

a plurality of nodes, any one of said plurality of nodes transmitting or receiving data according to a node data format used by one of said plurality of nodes; and

configurable communications interfaces in communication with said network and said plurality of nodes, said communications interfaces passing data from said nodes to said network or from said network to said nodes, at least one of said configurable communications interfaces including a transmitter having means for determining an estimate of a propagation delay associated with transmissions from said transmitter via said network by measuring the time it takes for a signal to travel from said transmitter via said network back to said interface, and adjusting signals transmitted by said transmitter to compensate for the estimated propagation delay;

each of said configurable communications interfaces capable of being configured to accept data from an associated node in the node data format of such associated node, transmit data to said network in said network data format, receive data from said network in said network data format, and transmit data to such associated node in the node data format of such associated node.

11. A data communications system comprising:

a data communications network that transmits data according to a network data format;

a plurality of nodes, any one of said plurality of nodes transmitting or receiving data according to a node data format used by one of said plurality of nodes; and

configurable communications interfaces in communication with said network and said plurality of nodes, said communications interfaces passing data from said nodes to said network or from said network to said nodes;

each of said configurable communications interfaces capable of being configured to accept data from an associated node in the node data format of such associated node, transmit data to said network in said network data format, receive data from said network in said network data format, and transmit data to such associated node in the node data format of such associated node,

wherein each of said configurable communications interfaces interrogates said associated node to determine whether such associated node is capable of receiving information about when the network is available for transmission of data, when information on the network should be received and passed to such associated node, and various types of data that may be received from the network, and for providing such information to the associated node if it is determined that the associated node is capable of receiving such information;

wherein one of said plurality of nodes comprises a master controller in communication with said network via one of said configurable communications interfaces for transmitting a synchronization symbol via the network to the other of said configurable communications interfaces, said synchronization symbol being used by such other configurable communications interfaces to synchronize a local clock of each of such interfaces to said master controller.

12. A data communications system comprising:

a data communications network that transmits data according to a network data format;

a plurality of nodes, any one of said plurality of nodes transmitting or receiving data according to a node data format used by one of said plurality of nodes; and

configurable communications interfaces in communication with said network and said plurality of nodes, said communications interfaces passing data from said nodes to said network or from said network to said nodes;

each of said configurable communications interfaces capable of being configured to accept data from an associated node in the node data format of such associated node, transmit data to said network in said network data format, receive data from said network in said network data format, and transmit data to such associated node in the node data format of such associated node; and

a master controller in communication with said network via one of said configurable communications interfaces; and

wherein said one configurable communications interface;

receives clock frequency recovery communications from said master controller, and uses said clock frequency recovery communications to generate its frequency timing relative to said master controller;

receives clock phase recovery communications and uses the clock phase recovery communication to generate its phase timing relative to a reference point on said network; and

enables data reception only after the frequency timing and phase timing have been generated.

13. The system of claim 12 wherein said clock phase recovery communications comprise a start-of-transmission symbol comprising:

a guard interval;

a phase alignment marker having a predetermined pattern known to said one configurable communications interface;

said guard interval used by said one configurable communications interface to allow a time marker for detecting said phase alignment marker.

14. The system of claim 13 wherein:

said phase alignment marker in said phase recovery communication is compared to said known pattern; and

said phase timing is adjusted based on said comparison.

15. The system of claim 12 wherein said one configurable communications interface includes a transmitter, and has an estimate of a propagation delay associated with transmissions from said transmitter, and adjusts signals transmitted by said transmitter to compensate for said estimated propagation delay.

16. The system of claim 15 wherein said one configurable communications interface determines said estimate of said propagation delay.

17. The system of claim 16 wherein said one configurable communications interface determines said estimate by measuring the time it takes for a signal to travel from said transmitter via said network back to said one configurable communications interface.

19. The system of claim 12 wherein said clock frequency recovery communications comprise a synchronization pattern which is fed to a voltage controlled oscillator to generate frequency timing.

18. A data communications svstem comprising:

a data communications network that transmits data according to a network data format;

a plurality of nodes, any one of said plurality of nodes transmitting or receiving data according to a node data format used by one of said plurality of nodes; and

configurable communications interfaces in communication with said network and said plurality of nodes, said communications interfaces passing data from said nodes to said network or from said network to said nodes, and including a transmitter having means for determining an estimate of a propagation delay associated with transmissions from said transmitter via said network by measuring the time it takes for a signal to travel from said transmitter via said network back to said interface, and advancing data sent from said transmitter so that said data is out of phase with a local clock of said one configurable communications interface when sent, but substantially in phase with said local clock when said data is received back at said one configurable communications interface, thereby compensating for the estimated propagation delay;

each of said configurable communications interfaces capable of being configured to accept data from an associated node in the node data format of such associated node, transmit data to said network in said network data format, receive data from said network in said network data format, and transmit data to such associated node in the node data format of such associated node.