Apparatus for and method of predictive time stamping of isochronous data packets transmitted over an IEEE 1394-1995 serial bus network

• US 20060013223A1
• Filed: 09/19/2005
• Published: 01/19/2006
• Est. Priority Date: 03/09/1998
• Status: Active Grant

• Current Assignee: Hisato Shima, Kevin K. Lym, Quan Vu
• Original Assignee: Hisato Shima, Kevin K. Lym, Quan Vu
• Inventors: Shima, Hisato, Vu, Quan, Lym, Kevin K.
• Granted Patent: US 7,561,576 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 12/40058 Isochronous transmission
• CPC Class Codes: H04L 12/40071 Packet processing; Packet format adaptation of digital video signals for transport over a specific network H04N21/2381, H04N21/4363, H04N21/4381; packet switches H04L49/00; intermediate storage or scheduling H04L49/90
• CPC Class Codes: H04L 12/40117 Interconnection of audio or video/imaging devices home automation networks H04L12/2803; bitstream network arrangements specially adapted for distribution of digital video signals H04N7/24
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04N 21/4223 Cameras H04N23/00 takes precedence
• CPC Class Codes: H04N 21/4302 Content synchronisation processes, e.g. decoder synchronisation
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• CPC Class Codes: H04N 21/4363 Adapting the video stream to a specific local network, e.g. a Bluetooth® network
• CPC Class Codes: H04N 21/43632 involving a wired protocol, e.g. IEEE 1394 high-speed IEEE 1394 serial bus H04L12/40052

Abstract

In order to predictively time stamp isochronous data packets transmitted over an IEEE 1394-1995 serial bus network, an application, which is to send a stream of isochronous data packets to a receiving node, first transmits a number of dummy frames each consisting of a number of packets. Preferably, these isochronous data packets make up frames of video data. From these dummy packets, the application obtains the time stamp values within the common isochronous packet (CIP) header of each packet. Using these obtained time stamp values, the application calculates a presentation time value for each data frame to be transmitted. The obtained time stamp value from a transmitted video frame is used to calculate the presentation time for a video frame which is a number of frames ahead within the transmit queue. Once the presentation time value for a frame is calculated, that value is then inserted by the application into the CIP header for the first packet within that frame and the frame is sent to the transmit queue for transmission to the receiving node over the IEEE 1394-1995 serial bus network.

Claims

1-30. -30. (canceled)

31. A method of transmitting data over a network, comprising:

a. transmitting a frame of data from a first node to a second node;

b. timestamping the frame of data with a time stamp value at the second node;

c. determining if the time stamp value is within a correct boundary time for video data;

d. processing the frame of data within the correct boundary of time for video data; and

e. discarding the frame of data not within the correct boundary of time for video data.

32. An application for transmitting data from a computer to a video camera over a serial bus network.

33. An application for obtaining a time stamp value from a previous packet, calculating a time value for a packet to be transmitted a number of packets after the previous packet using the obtained time stamp value and inserting the time value into the packet to be transmitted before the packet to be transmitted is transmitted.