Secondary Channel Spatial Reuse in Wireless Networks
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Solution Overview
Problem
The IEEE 802.11ax standard does not effectively manage traffic from overlapping basic service sets (OBSSs) to avoid unnecessary contention when accessing channels, particularly secondary channels, leading to inefficient use of frequency-spectrum resources in densely deployed wireless local-area networks (WLANs).
Innovation Solution
Implementing a method where a wireless device within a spatial reuse group (SRG) detects and stores the channel bandwidth and receive duration time of a wideband data unit from an overlapping BSS, applying a higher SRG OBSS power density threshold on secondary channels within that bandwidth to prevent misidentification of channels as busy, thereby allowing spatial reuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the default OBSS_PD level is applied on secondary channels, then channel access is conservatively managed, but channel availability decreases due to misidentification of channels as busy
Solution Approach 1:
The patent applies different OBSS_PD thresholds to different channels based on local conditions. Specifically, when a wideband data unit is detected on a secondary channel, the patent applies a higher (more permissive) OBSS_PD threshold only to that specific secondary channel, while maintaining the default threshold on other channels. This localized adjustment allows channel 1x0 to be correctly identified as available for spatial reuse, while other channels maintain conservative access control.
2Device complexity
If the primary channel OBSS_PD level is applied on secondary channels, then consistent power density control is achieved, but spatial reuse efficiency decreases due to unnecessary contention
Solution Approach 1:
The patent introduces local variation in OBSS_PD threshold application. When a wideband data unit is detected on a secondary channel, the patent applies a higher OBSS_PD threshold specifically to that secondary channel, rather than uniformly applying the primary channel's OBSS_PD level across all secondary channels. This enables stations to correctly identify available channels for spatial reuse without unnecessary contention, improving overall network throughput.
3Reliability
If weaker inter-BSS signals cause secondary channels to be identified as busy, then channel access control is maintained, but network performance decreases due to reduced spatial reuse
Solution Approach 1:
The patent dynamically changes the OBSS_PD threshold parameter based on detected signal conditions. When a wideband data unit is detected on a secondary channel, the patent adjusts the OBSS_PD threshold to a higher value for that specific channel, allowing weaker inter-BSS signals to be correctly identified as available rather than treating them as busy. This parameter adaptation enables spatial reuse opportunities to be captured, improving network performance while maintaining adequate access control.
Data Source
AI summary
A data unit (e.g., a physical layer convergence procedure (PLCP) protocol data unit (PPDU)) is detected at a first wireless device of a basic service set (BSS). The data unit was sent on a channel from a second wireless device of an overlapping basic service set (OBSS). The data unit is wide-bandwidth, occupying both a primary channel and a secondary channel of the wireless network. The first and second wireless devices are within a same spatial reuse group (SRG). The first wireless device stores the channel bandwidth of the data unit and a receive duration time of the data unit. During the receive duration time of the data unit, a SRG OBSS power density threshold is applied on the secondary channels that are within the channel bandwidth of the data unit, instead of applying a non-SRG OBSS power density threshold on those secondary channels.