Method for simultaneously transmitting/receiving upstream and downstream signals using remote PHY architecture and apparatus for the same

An apparatus for simultaneously transmitting upstream and downstream signals, comprising:

• a system core configured to determine whether to divide frequencies based on a determination that signal interference occurs among multiple cable modems connected to a cable network, and when it is determined to divide the frequencies, categorize the multiple cable modems into multiple groups so that signal interference occurs in each group, but signal interference does not occur between groups, and configured to divide the frequencies in accordance with a number of the groups, and set transmission bands for the multiple groups so that an upstream band of one group of the multiple groups overlaps with a downstream band of another group of the multiple groups, the system core being located at a headend of the cable network;
• and
• a remote PHY device located at an optical network terminal of the cable network and configured to cancel self-interference signals for respective groups based on the transmission bands,
• wherein the remote PHY device detects at least one of the self-interference signals for respective groups and self-interference signals for respective cable modems by comparing a first downstream signal that does not pass through the cable network with a second downstream signal that is input after being combined with an upstream signal based on a circulator.