3com Corporation

Michael R Mannette

Douglas Newlin

Kurt W Steinbrenner

A method and system for synchronizing two clocks of a first and second device. Successive synchronization messages are sent from the first device to the second device. Each synchronization message has a timestamp. Each message is received at the second device and the period between successive timestamps is determined. The period of the second clock of the second device is also determined. The period between timestamps is compared with the period of the second clock of the second device. The period of said second clock is adjusted based upon the comparison.

Clock synchronization of HFC telephone equipment

An apparatus, method and system are provided for multimedia access network channel management, such as channel management in a hybrid fiber-coaxial cable network, for voice (telephony), video, fax and data transmission. The preferred system embodiment includes a plurality of cable telephony modems (CTMs), for such voice (telephony), video, fax and data transmission, and includes a cable modem termination system (CMTS). For upstream communication from the CTMs to the CMTS, the network provides a plurality of channels, formed by a combination of FDM and TDMA. When a CMTS receives an multimedia network access message having a comparative priority from a CTM, the CMTS determines whether there is a first channel which is available from the plurality of channels, and if so, assigns a first transmission corresponding to the multimedia network access message to the first channel. When there is no available first channel, the CMTS determines whether there is a second transmission on a second channel which is moveable to a third channel, and if so, reassigns the second transmission to the third channel and assigns the first transmission corresponding to the multimedia network access message to the second channel. When there is no available first channel and no second transmission which is moveable, the CMTS determines whether there is a third transmission on an assigned channel having a lower comparative priority than the comparative priority of the multimedia network access message, and when there is a third transmission, the CMTS removes the third transmission from the assigned channel to form a vacated channel, and assigns the transmission corresponding to the multimedia network access message to the vacated channel.

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Rolling Meadows, IL, United States of America

Michael R Mannette