In the earlier 802.11ah standard, a novel power save mechanism targeted to address power save requirements of IoT devices which normally would desire longer sleep times was devised. This method or feature was named as Target Wake Time. In this feature, the Access Point could allow the 802.11 stations to wake up at predefined instances […]
PSR-based Spatial Reuse operation – MAC settings
An 802.11ax Station indicates support for PSR based spatial reuse transmission by setting the PSR based SR Support subfield to 1 in the HE PHY capabilities information element. An 802.11ax Station indicates support for PSR based spatial reuse reception by setting the PSR responder subfield to 1 in the HE MAC capabilities Information field in […]
PSRR PPDU and PSR-based Spatial Reuse
Another method of Spatial Reuse that has been defined in the standard is Parameterized Spatial Reuse (PSR) operation. The operation is dependent on the receive of a PSRR PPDU packet. It is important to understand the definition of PSRR PPDU. What is a PSRR PPDU? The full-form of the PSRR PPDU stands for Parameterized Spatial […]
OBSS PD Example Operation
The below figure taken from the standard illustrates OBSS PD operation in 802.11ax: The above steps for STA SR S2 is best described from the standard and is posted below (from the 802.11ax standard): Receives the PPDU from S1 and, if it classifies the PPDU as inter-BSS PPDU, ignores the PPDU using OBSS PD-based spatial […]
Transmit Power Restriction Period and TX Power Level for OBSS PD operation
When a non-AP Station determines to set an OBSS PD level and ignores an OBSS packet according to the rules defined by the 802.11ax standard, the 802.11 station has to begin an “OBSS PD SR transmit power restriction” period. The transmit power restriction period will be terminated once the current TX opportunity that the station […]
OBSS PD level requirements for OBSS PD operation
The 802.11ax standard which adheres to OBSS PD operation should also conform to certain minimum and maximum OBSS PD levels and transmit power constraints. The station should conform to operate within the OBSS PD min/max values and also cannot transmit at the maximum power it is possible to transmit a packet. The transmit power is […]
OBSS PD SRG Packet procedures in 802.11ax
The below 802.11ax describes the basic rules and checks to not update the Basic NAV timer or issue a PHY Reset for a OBSS SRG PD Level. The standard also defines further “NOTES” which define SRG OBSS-PD operation in the same section (Section 26.10.2.3 802.11ax standard). The interested reader should go through the section. OBSS […]
OBSS PD Non-SRG Packet procedures in 802.11ax
The 802.11ax describes the following operation for PHYreset for a detected OBSS packet or not update the Station’s Basic NAV timer based on the below rules maintaining a non-SRG OBSS PD Level: There are further “NOTES” provided which describes non-SRG operation in 802.11ax in the same section (section 26.10.2.2 of the 802.11ax standard). The interested […]
OBSS Packet Detect Threshold Spatial Reuse
For the interested reader – refer Spatial Reuse Operation and Spatial Reuse Groups for a brief on the idea of spatial reuse and what a spatial group consists of. As we discussed in the earlier articles, It is possible to configure a different Carrier Sense Threshold for Overlapping BSS such that the Signal detect threshold […]