WiFi NDPA Frame Structure for Multi-AP Joint Sounding
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Solution Overview
Problem
Existing WiFi standards lack efficient frame formats and methods for Multi-Access Point (M-AP) Joint Sounding, particularly in supporting MIMO-based coordination schemes involving multiple APs and STAs, leading to issues like incorrect frame recognition, inadequate parameter indication, and inefficient resource utilization.
Innovation Solution
A new frame format for Null Data Packet Announcement (NDPA) frames is introduced, featuring a broadcast TA indication, M-AP Set ID, and AP IDs to prevent legacy device decoding, and separate fields for STS and AP information, allowing flexible parameter indication and efficient recognition of multiple transmitters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a new frame format for NDPA is introduced to support multiple APs and STAs, then the capability to identify multiple transmitters and flexible parameter indication is improved, but the device complexity and difficulty of detecting and measuring increase
Solution Approach 1:
The NDPA frame is segmented into distinct modules: M-AP Set Info Subblock for identifying the set of participating APs, multiple STA Info Subblocks for indicating different STAs, and per-STA AP Info Subfields for flexible parameter indication. This segmentation allows the frame to systematically handle multiple APs and STAs while maintaining structured organization, resolving the contradiction between enhanced adaptability and increased complexity.
2Reliability
If a new frame format with M-AP Set ID and AP IDs is used, then the reliability of frame recognition is improved, but the loss of time for processing and the difficulty of detecting and measuring increase
Solution Approach 1:
The M-AP Set ID and AP IDs are pre-defined and pre-synchronized among all participating APs and STAs before the actual sounding procedure. This preliminary configuration allows receiving devices to quickly match incoming frames against known identifiers without extensive processing, thereby maintaining high recognition reliability while minimizing time loss.
3Adaptability or versatility
If separate fields for STS and AP information are introduced, then the adaptability for flexible parameter indication is improved, but the device complexity increases
Solution Approach 1:
The frame format incorporates dynamic field structures where the presence and content of STS and AP information fields are determined by a sounding parameter indication mechanism. This allows the frame to adapt its structure based on the specific sounding requirements, providing flexible parameter indication while avoiding the transmission of unnecessary information that would increase complexity.
Data Source
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AI summary
The present disclosure relates to a network device for announcing a Multi-Access Point, M- AP, Joint channel sounding procedure in a WiFi network for acquiring channel state information between multiple Access Points (APs), which belong to a same M-AP set, and multiple stations associated with at least one of those multiple APs, wherein the network device is an Access Point of a subset of the M-AP set which subset includes APs that are configured to transmit an announcement frame, the network device comprising: a processor configured to provide the announcement frame of the M-AP Joint channel sounding procedure, wherein the announcement frame comprises an identification of the M-AP set and identifications of the APs, associated to the subset of the M-AP set which subset of APs is configured to transmit the announcement frame; and a transceiver configured to transmit the announcement frame.