Overview
The motivation for the SFDX frequency plan is to provide an option for an FDX operation with a legacy band that aligns with the upstream spectrum of DOCSIS 3.1 high-split CMs. It may minimize disruption for operators who start with substantial deployments of D3.1 high-split CMs, and then deploy FDX CMs, since high-split CMs’ access to upstream frequencies is unaffected. This approach expands the upstream legacy band from 5 MHz to 204 MHz and starts the FDX band at 258 MHz and continuing to the downstream upper band edge of the cable plant. In this paper, the features, and benefits of the SFDX frequency plan are described, and changes to CableLabs D4.0 Physical layer specification [1] are reviewed and explained.
