W WiSenseHub
← Home

For health, home, and education

What WiFi sensing measures

Channel State Information (CSI) records how people and objects alter WiFi paths for research on motion, presence, location, and breathing.

See a real signal I already have data
01

From a room to a pattern

See how movement changes a WiFi link, then compare a quiet room with walking.

Person walking through a living room between a WiFi transmitter and receiver TX RX
CSI at the receiver
Amplitude
Phase
One WiFi link

Movement changes what arrives at the receiver.

CSI records how the room and a moving person change a known signal across WiFi subcarriers.

Amplitude
How strongly each subcarrier arrived
Phase
How much each subcarrier shifted
CSI amplitude plot recorded in an empty room

Empty room. The bands remain relatively steady over time.

CSI amplitude plot recorded while a person walks

Walking. Motion disturbs the pattern across time and receiver links.

WiSenseHub previews from Exposing the CSI (CC BY-SA 4.0). Color shows CSI amplitude.

How to read it

Timeleft to right

Subcarriersfrequency slices

ColorCSI amplitude

Four terms you will see in WiFi sensing papers
CSI
Fine-grained channel measurements across time, frequency, and antenna links.
Subcarrier
One small frequency slice inside a WiFi channel.
Amplitude
The strength of the measured channel response.
Phase
The signal shift, which often needs calibration before analysis.
02

Begin with your question

Choose the question closest to your work, then inspect datasets collected for it.

Presence and care

Is someone present, moving, or at risk of falling?

Separate empty-room, routine movement, and fall-like events. Health results remain experimental.

See a fall dataset →
Activity and interaction

How is a person moving?

Learn labeled patterns for walking, sitting, and gestures.

See activity data →
Location and home context

Where is activity happening?

Compare receivers or locations for presence and indoor localization.

See localization data →
Repeated small motion

Can the signal track a breathing pattern?

Track subtle periodic motion in controlled recordings.

See NIST BreatheSmart →

Picture the use case

Every study starts with a person, setting, and label.

Older adult walking with a cane inside a furnished home
Illustrative labels
Walking
Sit to stand
Mobility & safety

Walking, sit-to-stand, and controlled fall-like events.

Explore mobility data → Photo by Mehmet Turgut Kirkgoz via Pexels.
Person sleeping in a quiet bedroom
Illustrative labels
Quiet breathing
Body movement
Breathing & sleep

Subtle repeated motion during sleep or rest.

Explore breathing data → Photo by cottonbro studio via Pexels.
Person performing a squat exercise in a living room
Illustrative labels
Stand
Squat
Activity & interaction

Gestures and actions such as standing or squatting.

Explore activity data → Photo by Ron Lach via Pexels.
03

What WiSenseHub does with the data

Turn varied files, axes, and labels into a consistent research view.

  1. 1

    Choose

    Match task, setting, and hardware.

  2. 2

    Standardize

    Create named arrays, labels, masks, and provenance.

  3. 3

    Inspect

    Check shape, time, missing values, and coverage.

  4. 4

    Analyze

    Build task views and reproducible splits.

04

A classroom route

Use the signal comparison as a short lab or outreach activity.

Start with two labeled traces; introduce CSI structure after students describe what changed.

  1. ObserveCompare empty-room and movement traces.
  2. DescribeName the time, subcarrier, and receiver axes.
  3. TestStandardize a sample and compare labels.
05

Read further

  1. OverviewHuman Activity Sensing with Wireless SignalsOpen article →
  2. CSI basicsWiFi Sensing with Channel State InformationOpen PDF →
  3. HealthVital Signs Monitoring Based on WiFi CSI DataOpen article →
  4. Real plotsDICHASUS dataset detailsView plots →
  5. LimitsExposing the CSIOpen paper →