Wireless LAN System Information Update via Probe Request Response
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Solution Overview
Problem
In IEEE 802.11 WLAN systems, as the number of devices increases, channel access times lengthen, degrading overall system performance and impeding power saving, especially in machine-to-machine (M2M) communication scenarios where many devices communicate a small amount of data at low rates.
Innovation Solution
A method and apparatus for updating system information using a probe request and response mechanism, where a station (STA) transmits a probe request frame with a change sequence field when the received change sequence from an access point (AP) differs from its stored value, and the AP responds with a probe response frame containing updated system information and the current change sequence field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all system information is broadcast periodically to ensure devices have updated information, then system information reliability is improved, but channel overhead increases and power consumption increases
Solution Approach 1:
The patent extracts only the essential system information that has changed from the periodic broadcast, transmitting it through probe request/response frames. This allows devices to receive updated information without receiving the complete system information set, thereby reducing channel overhead and power consumption while maintaining reliability.
Solution Approach 2:
Instead of continuous periodic broadcasting of all system information, the patent implements event-driven periodic action where probe requests are sent only when system information changes are detected. This reduces unnecessary transmissions and associated power consumption while ensuring devices receive updates when needed.
2Loss of time
If system information is broadcast frequently to ensure devices have latest updates, then system information currency is improved, but channel overhead increases and interference increases
Solution Approach 1:
The patent extracts and transmits only the changed portions of system information through probe request/response frames rather than broadcasting complete system information frequently. This reduces channel overhead and minimizes interference while ensuring devices receive timely updates on changes.
Solution Approach 2:
The patent implements a feedback mechanism where devices send probe requests to query system information changes, and the access point responds with updated information only when changes have occurred. This feedback-driven approach ensures information currency without unnecessary frequent broadcasts, reducing interference.
3Measurement precision
If devices continuously monitor for system information updates, then system information accuracy is improved, but power consumption increases
Solution Approach 1:
The patent implements preliminary action by having devices send probe requests only when they need to check for system information changes, rather than continuously monitoring. The access point maintains system information change status ready for query, allowing devices to obtain accurate information on-demand without continuous power-consuming monitoring.
Solution Approach 2:
Devices perform self-service by autonomously determining when to send probe requests based on their need for system information updates. This on-demand approach allows devices to maintain accurate system information without continuous power-consuming monitoring, as they can query updates only when necessary for their operation.
Data Source
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AI summary
The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for updating system information in a wireless LAN system. A method for a station (STA) to update system information in a wireless communication system according to one embodiment of the present invention comprises the steps of: if the value of a change sequence field received by the STA from an access point (AP) is different from the value of the change sequence field stored in the STA, transmitting, to the AP, a probe request frame including the change sequence field set to the value of the change sequence field stored in the STA; and a step of receiving, from the AP, a probe response frame responding to the probe request frame including the change sequence field.