DOCSIS 3.1 Channel Headroom Calculator

This DOCSIS® 3.1 Headroom Calculator performs a headroom calculation for the Transmit Channel Set according to DOCSIS® 3.1 Physical Layer Specification [CM-SP-PHYv3.1-I20-230419].

'Headroom' is the difference between CM maximum power transmit capabilities and its actual transmit power. Due to the fact that DOCSIS 3.1 modems are capable of bonding multiple channels into the Transmit Channel Set, there are 2 different headroom calculations: Overall Transmit Channel Set Headroom and Headroom for each Transmit Channel. Additionally, we calculate the Worst Parameters across all the channels in the Transmit Channel Set.

For the cases where the CMTS RX Power is different that CMTS Set Point, adjustments calculated for all the applicable parameters.

For additional information please refer to "SCTE-2023 - Technical Paper: Cable Modem Transmit Headroom Resiliency Management".

Channel Configuration

# Channel type Reported TX power, dBmV Channel width, MHz Integration Bandwidth, MHz CMTS setpoint RX, dB CMTS actual RX, dB