Cascaded Trigger Frames for Random Access Contention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high-density wireless network deployments, existing technologies face inefficiencies in channel access and power saving due to the high number of devices competing for the wireless medium, particularly in scenarios like hotspots and cellular offloading, where data rates are lower and system efficiency becomes more critical.
Innovation Solution
The implementation of a High Efficiency Wireless Local Area Network (HEW) system that uses a master station to schedule HEW stations for non-contention based communication during a control period, employing orthogonal frequency division multiple access (OFDMA) and other multiple access techniques, along with a beacon frame that includes random access trigger frames to allocate channel resources efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple devices compete for wireless medium using traditional contention-based access, then devices can access the channel independently, but system efficiency deteriorates in high-density scenarios due to increased contention and collisions
Solution Approach 1:
The access point acts as an intermediary that coordinates channel access for multiple stations. Instead of devices competing directly with each other, the AP receives uplink data from multiple STAs, performs downlink scheduling, and manages resource allocation, thereby eliminating contention while maintaining independent access capability for each device.
Solution Approach 2:
The system enables stations to indicate their downlink reception needs through buffer status reports and traffic indication maps, allowing the network to self-adjust resource allocation based on actual demand. This reduces unnecessary transmissions and improves overall system efficiency in high-density scenarios.
2Use of energy by moving object
If traditional power save mechanisms are used in high-density networks, then devices can save power by sleeping, but channel access efficiency deteriorates due to frequent wake-ups and contention during active periods
Solution Approach 1:
The access point performs downlink scheduling in advance during control periods, allocating resources and notifying stations of upcoming data transmissions. This allows stations to enter power save mode confidently, knowing exactly when to wake up for data reception, eliminating the need for frequent contention-based channel access during sleep intervals.
Solution Approach 2:
The system implements periodic control periods followed by data transmission periods, with stations synchronized to wake up at predetermined intervals. This periodic structure allows devices to remain in low-power state during control periods and only activate during scheduled data reception, improving both power efficiency and channel access predictability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Embodiments of a user station (STA), access point (AP), and method for random access contention in a wireless network are generally described herein. The STA may receive, from the AP, a beacon frame for a beacon interval. The STA may further receive a first random access Trigger Frame (TF) that indicates a first allocation of channel resources for random access contention by STAs during a first uplink transmission period of the beacon interval. The beacon frame may include a transmission timing for the first random access TF and a first TF cascade type for the first random access TF. The first TF cascade type may indicate whether a next TF is a random access TF or a scheduled access TF.