Open cable digital broadcasting system having multiple DSG channel and method for acquiring home DSG channel in the same system

A method for acquiring a home data over cable service interface specifications set-top box gateway (DSG) channel in an open cable digital broadcasting receiver, comprising:

• a first step of searching for a downstream channel to a cable modem termination system (CMTS);
• a second step of determining whether an upstream channel to the CMTS is successful;
• a third step of converting to a DSG uni-directional downstream mode when the upstream channel search fails in the second step;
• a fourth step of determining whether DSG data is received from all servers;
• a fifth step of determining whether the channel is a multiple DSG channel when the DSG data is received in the fourth step;
• a sixth step of determining whether an upstream channel restoration function for the same channel is performed to more than a preset maximum extent when the channel is determined to be the multiple DSG channel in the fifth step;
• and
• a seventh step of performing a downstream channel restoration function when the upstream channel restoration function for the same channel is performed to more than the preset maximum extent in the sixth step.

An open cable digital broadcasting system, comprising:

• at least one cable modem termination system (CMTS) having an upstream band and a downstream band;
• a network distributor for transmitting downstream data received from the CMTS to a cable modem in correspondence to the downstream band, and for transmitting upstream data received from the cable modem to the CMTS in correspondence to the upstream band;
• and
• a cable modem for transmitting the upstream data to the network distributor through the upstream band in correspondence to upstream data transmission information after identifying the upstream data transmission information from the downstream data when receiving the downstream data through the network distributor.

An open cable digital broadcasting system, comprising:

• a dynamic host configuration protocol (DHCP) server for assigning a media access protocol (MAP) Internet protocol (IP) address to a cable modem through a previously assigned media access control (MAC) address;
• at least one cable modem termination system (CMTS) having an upstream band and a downstream band;
• and
• a cable modem for setting channels of upstream and downstream data, and for transmitting upstream and downstream data to the CMTS when it is determined that the MAP IP address is assigned by the DHCP and that the MAP IP address is assigned.