Cable Modem Power Reduction via DOCSIS Mode Switching
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Solution Overview
Problem
Cable modems that provide telephony features need to reduce power consumption during battery backup mode to maximize operating time, as current solutions do not efficiently manage power usage during battery operation.
Innovation Solution
The cable modem switches from multi-channel DOCSIS 3.0 operation to single-channel DOCSIS 2.0 operation when the external power fails, shutting down high-power wideband ADC and tuner circuits and activating lower-power narrowband ADC and tuner circuits, and adjusting the programmable gain amplifier to reduce current draw.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the cable modem operates in multi-channel DOCSIS 3.0 mode with wideband ADC and tuner circuits, then data transmission capability is improved, but power consumption increases
Solution Approach 1:
The cable modem dynamically switches between DOCSIS 3.0 multi-channel mode and DOCSIS 2.0 single-channel mode based on power availability. When battery backup is detected, the system transitions from high-performance wideband circuits to low-power narrowband circuits, making the operational characteristics adjustable rather than fixed
Solution Approach 2:
The system changes operational parameters by switching channel configurations from multi-channel to single-channel and adjusting ADC bandwidth from wideband to narrowband. This parameter change reduces the operational bandwidth and processing requirements, thereby reducing power consumption during battery operation
2Reliability
If the cable modem uses battery backup during power failure, then service continuity is improved, but operating duration is limited by power consumption
Solution Approach 1:
The system dynamically adapts its operational mode based on power source availability. Upon detecting battery backup, it transitions to a power-saving configuration that extends operating duration while maintaining essential VoIP telephony services, thereby prolonging the time the system can operate reliably on battery power
3Use of energy by moving object
If the cable modem shuts down wideband ADC and tuner circuits during battery operation, then power consumption is reduced, but data transmission capability deteriorates
Solution Approach 1:
The system extracts and removes the high-power wideband ADC and tuner circuits from active operation during battery backup mode. By taking out these power-intensive components and relying on lower-power narrowband alternatives, the system reduces overall power consumption while maintaining essential communication functionality
Solution Approach 2:
The system applies different operational qualities to different functional components. During battery operation, essential VoIP functions maintain adequate performance while non-essential high-bandwidth data transmission capabilities are reduced. This local differentiation of quality allows the system to prioritize critical services over optional services under power constraints
Data Source
AI summary
A novel apparatus and method of reduced power consumption for battery backup operation of a communication device such as a cable modem. When the cable modem senses a failure of the external power source it requests from the cable head-end to switch from multi-channel DOCSIS 3.0 operation to single-channel DOCSIS 2.0 operation. In response to approval by the cable head-end, the cable modem shuts down multi-channel circuits in the PHY such as the wideband analog to digital converter (ADC) which is normally used during multi-channel operation. In its place, it activates narrowband circuitry such as a narrowband ADC which consumes far less power. Tuner filter circuits are also swapped to match the reduced bandwidth requirements of battery backup operation. To further reduce power, the narrower bandwidth requirements during battery backup operation permit the linearity of a programmable gain amplifier (PGA) in the upstream path to be reduced.