Wake-Up Receiver PPDU Format for Ultra-Low Power IoT
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Solution Overview
Problem
The IEEE 802.11ah standard, while providing low power features, is inadequate for applications requiring ultra-low power consumption and low latency during power-save mode, particularly in IoT devices that need extended network lifetime.
Innovation Solution
The introduction of a wake-up receiver PPDU format based on the IEEE 802.11ah standard, using a simple modulation scheme like OOK with repetition, allows for a low-power wake-up mechanism that reduces power consumption by using a wake-up receiver to activate the main radio only when data is available, thereby extending network operation lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If IEEE 802.11ah standard power save mode is used, then power consumption is reduced, but latency increases and power consumption cannot reach ultra-low levels
Solution Approach 1:
The receiver is segmented into two independent parts: a low-power wake-up receiver that consumes minimal energy and a main radio that handles full data communication. The wake-up receiver operates continuously at ultra-low power to detect wake-up signals, while the main radio remains in deep sleep mode until activated, thereby achieving both ultra-low power consumption and low latency response.
Solution Approach 2:
A wake-up signal acts as an intermediary between the external environment and the main radio system. This signal mediates the transition from deep sleep to active state, allowing the system to respond quickly to external events without continuously operating the power-hungry main radio, thus resolving the contradiction between low power consumption and low latency.
2Loss of time
If main radio is activated frequently to check for data, then latency is reduced, but power consumption increases
Solution Approach 1:
The receiver functionality is divided between a continuously active wake-up receiver and a periodically activated main radio. The wake-up receiver handles frequent signal detection at ultra-low power, while the main radio activates only when needed to process actual data, eliminating the need for frequent high-power activations and thus reducing overall power consumption while maintaining low latency.
Solution Approach 2:
The main radio operates in periodic cycles rather than continuously or with frequent activations. It remains in deep sleep mode and wakes up periodically to check for data, synchronized with the wake-up signal mechanism. This periodic operation reduces average power consumption while maintaining acceptable latency performance.
3Use of energy by moving object
If wake-up receiver is used to activate main radio only when data is available, then power consumption is reduced, but device complexity increases
Solution Approach 1:
The receiver is segmented into functionally distinct components: a simple wake-up receiver for signal detection and a main radio for data processing. This segmentation allows each component to be optimized independently, with the wake-up receiver being simpler and lower power, while the main radio handles complex processing only when activated, thus managing overall device complexity effectively.
Solution Approach 2:
The wake-up receiver implements a simplified version of the radio reception functionality, copying only the essential signal detection capabilities needed to wake up the main radio. This simplified copy reduces complexity and power consumption while the full functionality resides in the main radio, which operates only when needed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution significantly reduces power consumption and prolongs network lifetime while maintaining low latency, enabling IoT devices to operate efficiently with frequent wake-ups without interfering with legacy devices.
Implementation Method 1
using a simple modulation scheme like OOK with repetition
Data Source
AI summary
A method performed by a wireless device operating in a wireless network. The method includes generating a physical layer protocol data unit (PPDU) that includes a preamble portion and a data portion, wherein the preamble portion includes a signal field, wherein the signal field includes a bit that is set to binary ‘0’ to indicate that the data portion of the PPDU includes a wake-up receiver preamble and wake-up receiver data. The method further includes wirelessly transmitting the PPDU.