Wireless Channel Access via Beacon TIM and PS-Poll RAW
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Solution Overview
Problem
Current wireless LAN systems face challenges in reducing unnecessary power consumption and transmission delays due to contention-based channel access operations, and there is a need for a method to allow additional channel access attempts when initial attempts are unsuccessful.
Innovation Solution
The proposed solution involves an enhanced channel access method in wireless LAN systems, where a new extended slot time is used for channel access operations, and a new frame format, such as the NDP PS-Poll frame, is employed to minimize collisions and power consumption. Each station is assigned a specific PS-Poll interval based on a TIM element, allowing only indicated stations to access the channel, thereby reducing unnecessary power usage and increasing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If contention-based channel access operation is used in wireless LAN systems, then channel access is achieved, but unnecessary power consumption and transmission delay occur
Solution Approach 1:
The patent applies preliminary action by having the access point transmit a beacon frame containing a TIM element before the actual data transmission. This beacon frame preliminarily indicates which stations have data to receive, allowing stations to wake up, check the TIM element, and only access the channel if needed. This prevents unnecessary channel access attempts and power consumption by sleeping stations.
Solution Approach 2:
The patent implements periodic action through the periodic transmission of beacon frames at predetermined intervals. The TIM element is included in these periodic beacon frames, creating a rhythmic cycle where stations periodically wake up to check for data availability. This periodic mechanism ensures efficient power management while maintaining channel access efficiency.
2Productivity
If contention-based channel access operation is used in wireless LAN systems, then channel access is achieved, but transmission delay increases
Solution Approach 1:
The access point performs preliminary action by transmitting the beacon frame with TIM element information before data transmission. This allows stations to prepare in advance by checking whether they have data to receive, eliminating unnecessary contention and reducing transmission delay for stations that do have data.
Solution Approach 2:
The TIM element provides feedback information to stations about data availability at the access point. This feedback mechanism allows stations to make informed decisions about whether to access the channel, reducing unnecessary transmissions and minimizing delay for stations that need to transmit.
3Adaptability or versatility
If all stations attempt channel access in any time slot, then channel access opportunity is maximized, but collisions increase and power consumption rises
Solution Approach 1:
The patent applies local quality by differentiating the channel access behavior based on individual station needs indicated by the TIM element. Instead of uniform access opportunities for all stations, the system provides targeted access opportunities only to stations that have data to receive, as indicated by their presence in the TIM element. This reduces collisions and power consumption while maintaining access opportunities for active stations.
4Use of energy by moving object
If no channel access attempt is made after initial failure, then power consumption is reduced, but transmission opportunity is lost
Solution Approach 1:
The TIM element provides feedback information that indicates whether a station has data to receive. This feedback mechanism allows stations to make informed decisions about whether to attempt channel access, ensuring that transmission opportunities are not lost while avoiding unnecessary power consumption for stations without data.
Data Source
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AI summary
Disclosed is a method for a station (STA) for accessing a channel in a wireless communication system. The method for a STA for accessing a channel in a wireless communication system comprises the steps of: receiving a beacon frame comprising a traffic indicator map (TIM); and transmitting a power save (PS)-Poll frame if buffered traffic is indicated by TIM to the STA, wherein the PS-Poll frame is transmitted during a PS-Poll dedicated restricted access window (RAW) by and/or during an additional RAW, the PS-Poll dedicated RAW being allocated to transmit the PS-Poll frame, and the additional RAW being additionally allocated subsequent to the PS-Poll-dedicated RAW.