Description

802.11n (Wi-Fi 4, ratified 2009) is the standard most early CSI papers use because the canonical intel-5300 and Atheros tools (see atheros-csi-tool) target it. It introduced MIMO (up to 4x4 spatial streams) and 40 MHz channels, and its OFDM frame structure (LTF / HT-LTF training fields) is what every commodity CSI extractor parses. Despite being two generations behind the deployed state of the art, 802.11n remains the lingua franca of CSI research — most published datasets and most baselines are 802.11n.

Specs / capabilities

  • 2.4 GHz and 5 GHz bands
  • 20 MHz (56 OFDM subcarriers, 52 data) or 40 MHz (114 / 108) channels
  • Up to 4x4 MIMO (most CSI tools cap at 3x3 for the IWL5300)
  • HT-LTF training symbols allow per-subcarrier per-(Tx, Rx) channel estimation
  • PHY rate up to 600 Mbps

Tooling

  • intel-5300 + Linux 802.11n CSI Tool (decimated to 30 subcarriers)
  • atheros-csi-tool (full 56 / 114 subcarriers)
  • esp32 (single-stream 64 subcarriers)

Used by (papers)

  • The default standard in pre-2019 CSI literature

14 vault papers run on this hardwar

Titles and DOIs only — no abstracts, no analyses.

  • Precise Power Delay Profiling with Commodity WiFi 2015 DOI ↗
  • Gait recognition using wifi signals 2016 DOI ↗
  • Predictable 802.11 packet delivery from wireless channel measurements 2010 DOI ↗
  • A Survey on Human Behavior Recognition Using Channel State Information 2019 DOI ↗
  • WiFi CSI-Based Device-free Multi-room Presence Detection using Conditional Recurrent Network 2021 DOI ↗
  • A Non Intrusive Human Presence Detection Methodology Based on Channel State Information of Wi-Fi Networks 2023 DOI ↗
  • A Non Intrusive Human Presence Detection Methodology Based on Channel State Information of Wi-Fi Networks 2023 DOI ↗
  • Exposing the CSI: A Systematic Investigation of CSI-based Wi-Fi Sensing Capabilities and Limitations 2023 DOI ↗
  • Device-Free Passive Identity Identification via WiFi Signals 2017 DOI ↗
  • Implementing Wi-Fi CSI-based room-level occupancy Estimation: an experimental study in multi-zone residential environments 2025 DOI ↗
  • Device-Free Wireless Sensing for Gesture Recognition Based on Complementary CSI Amplitude and Phase 2024 DOI ↗
  • BLE Can See: A Reinforcement Learning Approach for RF-based Indoor Occupancy Detection 2021 DOI ↗
  • Komondor: a Wireless Network Simulator for Next-Generation High-Density WLANs 2019 DOI ↗
  • A Survey on Detection, Tracking and Identification in Radio Frequency-Based Device-Free Localization 2019 DOI ↗