Method and system for service group management in a cable network

A system comprising:

• circuitry for use in a cable modem termination system (CMTS), said circuitry comprising a network interface and a processor wherein:
• said processor is configured to determine, for a plurality of cable modems served by said CMTS, a corresponding plurality of signal-to-noise ratio (SNR) related metrics;
• said processor is configured to assign said plurality of cable modems among a plurality of service groups based on said plurality of SNR-related metrics;
• said processor is configured to generate, for each one of said plurality of service groups, a composite SNR-related metric based at least in part on a worst-case SNR profile of said plurality of SNR-related metrics corresponding to said one of said plurality of service groups;
• said processor is configured to select physical layer communication parameters to be used for communicating with said one of said plurality of service groups based on said composite SNR-related metric;
• and
• said network interface is configured to communicate with a portion of said plurality of cable modems corresponding to said one of said plurality of service groups using the selected physical layer communication parameters.