Wake-Up Transceiver Reduces Uplink Latency in Sleep Mode APs
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Solution Overview
Problem
In wireless local area networks (WLANs), there is a significant challenge in reducing transmission latency due to the high energy consumption and sleep mode operations of access points (APs) and stations (STAs), particularly when APs enter energy save modes, leading to increased transmission latency for uplink data packets.
Innovation Solution
A wake-up method is introduced where a STA determines the sleep state of an AP and transmits a wake-up frame to its wake-up transceiver, allowing the AP to wake up its main transceiver, thereby reducing transmission latency by enabling immediate data transmission during sleep periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the AP enters sleep mode to save energy, then energy consumption is reduced, but uplink data transmission latency increases
Solution Approach 1:
The AP's transceiver is divided into two independent parts: a main transceiver that consumes high power and a wake-up transceiver that consumes low power. The main transceiver can be turned off during sleep mode while the wake-up transceiver remains active to receive wake-up frames, enabling the AP to respond to uplink data transmission requests without fully waking the main transceiver immediately.
Solution Approach 2:
The wake-up transceiver acts as an intermediary between the external environment (wake-up frames from STAs) and the main transceiver. It receives and processes wake-up frames, then activates the main transceiver only when necessary, thereby reducing the main transceiver's idle listening energy consumption while maintaining the ability to respond to uplink data requests.
2Loss of time
If the AP wakes up immediately to receive uplink data, then transmission latency is reduced, but energy consumption increases
Solution Approach 1:
The system dynamically adjusts the operational state of the main transceiver based on actual communication needs. The wake-up transceiver continuously monitors for wake-up frames in a low-power state, and only activates the high-power main transceiver when a wake-up frame is detected, creating a dynamic power management strategy that adapts to traffic conditions.
Solution Approach 2:
The AP operates in periodic cycles between sleep mode and active mode. During sleep mode, only the low-power wake-up transceiver is active. When a wake-up frame is received, the main transceiver is activated for a brief period to handle the uplink data transmission, then returns to sleep mode, creating a periodic on-off pattern that reduces overall energy consumption.
Data Source
AI summary
This application provides a wake-up method, a station, and an access point. The method is performed in a communications system. The communications system can include an access point (AP) and at least one station (STA). The AP includes a wake-up transceiver (WUR) and a main transceiver. The method can include determining, by a first STA, that the AP is in a sleep state, where when the AP is in the sleep state, the main transceiver of the AP is in an off state. The method can also include transmitting, by the first STA, a wake-up frame to the WUR of the AP, where the wake-up frame triggers the WUR of the AP to wake up the main transceiver of the AP. Therefore, an uplink data transmission latency can be reduced.