Networked End Device Sleep Mode Clock Tolerance Alignment
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Solution Overview
Problem
Traditional systems for networked devices face inefficiencies in sleep mode operation due to constant scanning for device availability, leading to excessive RF traffic and reduced battery life, especially when devices wake up simultaneously or have varying operation frequencies based on environment or battery status.
Innovation Solution
The solution involves end devices sending clock tolerance information and sleep mode requests to a central unit, which adjusts scanning times and determines appropriate sleep modes based on energy usage, aligning wake-up times with scanning periods and prioritizing devices for reduced energy consumption and extended battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the central unit constantly scans networked devices to verify availability, then device connectivity is maintained, but energy consumption increases and battery life decreases
Solution Approach 1:
The central unit performs scanning operations periodically at scheduled intervals rather than continuously, allowing devices to enter sleep mode between scan cycles. This periodic scanning maintains device connectivity verification while significantly reducing energy consumption compared to constant scanning.
Solution Approach 2:
The system pre-schedules scan times and device wake-up times in advance, aligning them to ensure devices are awake when scans occur. This preliminary coordination allows devices to sleep confidently during known scan-free periods, reducing energy consumption while maintaining reliability.
2Productivity
If devices wake up simultaneously for scanning, then connectivity verification is efficient, but network traffic congestion increases
Solution Approach 1:
The system segments the network device population into different groups with staggered wake-up schedules. Instead of all devices waking simultaneously, devices are divided into time slots or groups that wake at different intervals, distributing network traffic over time and preventing congestion while maintaining verification efficiency.
Solution Approach 2:
The wake-up schedule for each device is made dynamic rather than static, allowing the system to adjust individual device wake times based on network conditions, device priorities, and traffic patterns. This dynamic scheduling optimizes both verification efficiency and traffic distribution.
3Duration of action of stationary object
If devices use fixed wake-up intervals to save energy, then battery life is extended, but clock accuracy variations cause missed wake-up times
Solution Approach 1:
The system incorporates feedback mechanisms where devices report their actual wake-up times and clock status to the central unit. The central unit uses this feedback to adjust and resynchronize device schedules, compensating for clock drift and accuracy variations while maintaining energy-saving sleep intervals.
Solution Approach 2:
The system changes the wake-up time parameter dynamically based on individual device clock accuracy measurements. Devices with poorer clock accuracy are given more frequent wake-up opportunities or larger time windows, while devices with high accuracy can use longer intervals, optimizing both battery life and wake-up reliability for each device.
Data Source
AI summary
A technique provides apparatuses, methods, and computer readable media for sending sleep information from an end device to a central unit of a network, in which the wake-up time of the end device is aligned to the scanning time for the central unit. The technique addresses at least two considerations: the clock accuracy of the end device is accounted for, and the reason that the end device requests sleep mode operation is provided. To address the above considerations, the end device may send its clock tolerance information and/or request for sleep mode (RSM) command to the central unit once the end device is connected via the network. The central unit may then adjust the scanning time based on the clock tolerance information. If the central unit receives a response from the end device during the adjusted scanning time, the central unit deems that the end device is still connected.