Patents by Inventor Joanna Qun Zang

Joanna Qun Zang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7672230
    Abstract: A dynamic channel change technique is disclosed which may be implemented between nodes and a Head End of an access network. Initially a network device may communicate with the Head End via a first downstream channel and a first upstream channel. When the network device receives a dynamic channel change request which includes instructions for the network device to switch to a second downstream channel, the network device may respond by switching from the first downstream channel to the second downstream channel. Thereafter, the network device may communicate with the Head End via the second downstream channel and first upstream channel. Further, according to a specific embodiment, the dynamic channel change request may also include an upstream channel change request for causing the network device to switch from a first upstream channel to a second upstream channel.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: March 2, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: John T. Chapman, Daniel W. Crocker, Feisal Y. Daruwalla, Joanna Qun Zang, Yong Lu
  • Patent number: 7656890
    Abstract: A dynamic channel change technique is disclosed which may be implemented between nodes and a Head End of an access network. Initially a network device may communicate with the Head End via a first downstream channel and a first upstream channel. When the network device receives a dynamic channel change request which includes instructions for the network device to switch to a second downstream channel, the network device may respond by switching from the first downstream channel to the second downstream channel. Thereafter, the network device may communicate with the Head End via the second downstream channel and first upstream channel. Further, according to a specific embodiment, the dynamic channel change request may also include an upstream channel change request for causing the network device to switch from a first upstream channel to a second upstream channel.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: February 2, 2010
    Assignee: Cisco Technology, Inc.
    Inventors: John T. Chapman, Daniel W. Crocker, Feisal Y. Daruwalla, Joanna Qun Zang, Yong Lu
  • Patent number: 7113484
    Abstract: A dynamic channel change technique is disclosed which may be implemented between nodes and a Head End of an access network. Initially a network device may communicate with the Head End via a first downstream channel and a first upstream channel. When the network device receives a dynamic channel change request which includes instructions for the network device to switch to a second downstream channel, the network device may respond by switching from the first downstream channel to the second downstream channel. Thereafter, the network device may communicate with the Head End via the second downstream channel and first upstream channel. Further, according to a specific embodiment, the dynamic channel change request may also include an upstream channel change request for causing the network device to switch from a first upstream channel to a second upstream channel.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: September 26, 2006
    Assignee: Cisco Technology, Inc.
    Inventors: John T. Chapman, Daniel W. Crocker, Feisal Y. Daruwalla, Joanna Qun Zang, Yong Lu
  • Patent number: 7068712
    Abstract: A CMTS redundancy technique requires at least two CMTS interfaces (e.g., line cards) on one or more CMTS chassis at the head end of a cable network. One of the CMTSs serves as a backup or “protecting” CMTS. When another CMTS (a “working” CMTS) becomes unavailable to service its group of cable modems, the protecting CMTS takes over service to those cable modems. The SWITCHOVER takes place transparently (or nearly transparently) to the cable modems. The protecting CMTS provides service on the same downstream channel as used by the working CMTS. The cable modems need not modify any settings pursuant to their cable modem communication protocol (e.g., DOCSIS ranging). This transparency to the cable modems is realized by keeping the working and protecting CMTSs in synchronization regarding service parameters for the cable modems. In other words, the protecting CMTS maintains a list of current parameters for allowing service to the cable modems.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: June 27, 2006
    Assignee: Cisco Technology, Inc.
    Inventors: Joanna Qun Zang, Feisal Daruwalla, James R. Forster, Guenter E. Roeck, Joseph O'Donnell, John Chen, Mark Millet
  • Patent number: 7058007
    Abstract: A protection CMTS is available to immediately service a cable modem should that modem's service from a working CMTS fail for any reason. To speed the service transfer (cutover) from the working CMTS to the protection CMTS, the cable modem may preregister with the protection CMTS well before the cutover becomes necessary. The cable modem's registration with both the working CMTS and the protection CMTS preferably employs a single IP address, so that the cable modem need not obtain a new IP address during cutover. While the cable modem may register with both the working CMTS and the protection CMTS, the devices are designed or configured so that only the working CMTS injects a host route for the cable modem into the appropriate routing protocol. Only after cutover to the protection CMTS does the protection CMTS inject its host route.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: June 6, 2006
    Assignee: Cisco Technology, Inc.
    Inventors: Feisal Daruwalla, James R. Forster, Guenter E. Roeck, Joanna Qun Zang, Yong Lu
  • Patent number: RE44661
    Abstract: A protection CMTS is available to immediately service a cable modem should that modem's service from a working CMTS fail for any reason. To speed the service transfer (cutover) from the working CMTS to the protection CMTS, the cable modem may preregister with the protection CMTS well before the cutover becomes necessary. The cable modem's registration with both the working CMTS and the protection CMTS preferably employs a single IP address, so that the cable modem need not obtain a new IP address during cutover. While the cable modem may register with both the working CMTS and the protection CMTS, the devices are designed or configured so that only the working CMTS injects a host route for the cable modem into the appropriate routing protocol. Only after cutover to the protection CMTS does the protection CMTS inject its host route.
    Type: Grant
    Filed: December 6, 2006
    Date of Patent: December 24, 2013
    Assignee: Cisco Technology, Inc.
    Inventors: Feisal Daruwalla, James R. Forster, Guenter E. Roeck, John T. Chapman, Joanna Qun Zang, Yong Lu