Wi-Fi Aware (NAN) throughput significantly degraded when iPhone is associated to a Wi-Fi network; disabling Wi-Fi from Control Center roughly doubles transfer speed

Summary

We are observing that Wi-Fi Aware data transfer throughput on iPhone is heavily impacted by the device's Wi-Fi association state and by surrounding RF interference. When Wi-Fi is turned off from Control Center, Wi-Fi Aware throughput increases to roughly 2x (or higher) compared to when the device remains associated to a Wi-Fi network. We would like to confirm whether this is expected behavior or a system-level bug.

Log

  • Feedback ID: FB23454477

Environment

  • Device: iPhone
  • Feature under test: Wi-Fi Aware (NAN) data path transfer

Steps to Reproduce

  1. Connect the iPhone to a Wi-Fi network (associate to an AP).
  2. Establish a Wi-Fi Aware (NAN) data-path session with a peer device.
  3. Start a sustained data transfer and measure the steady-state throughput.
  4. Repeat the measurement in two RF conditions: a. Clean RF environment (no other surrounding Wi-Fi/BLE devices nearby). b. Congested / high-interference RF environment.
  5. Turn Wi-Fi off from the Control Center pull-down menu (leave the peer/session as before).
  6. Repeat the same Wi-Fi Aware transfer and measure throughput again.

Observed Behavior

Scenario 1 — Wi-Fi connected (associated to an AP)

  • Clean RF environment (Wi-Fi connected, no other surrounding Wi-Fi/BLE devices nearby):
    • Wi-Fi Aware transfer throughput is approximately 20 MB/s.
  • Congested / high-interference RF environment:
    • Wi-Fi Aware transfer throughput drops to approximately 8 MB/s.
  • Reference log: sysdiagnose_2026.06.28_21-05-09+0800_iPhone-OS_iPhone_23F81.tar.gz

Scenario 2 — Wi-Fi turned off via Control Center

  • After turning Wi-Fi off from the Control Center pull-down menu, the Wi-Fi Aware transfer throughput increases to 2x or higher compared to Scenario 1.
  • Reference log: sysdiagnose_2026.06.28_21-15-00+0800_iPhone-OS_iPhone_23F81.tar.gz

Expected Behavior

Wi-Fi Aware throughput should not be significantly constrained by the device's Wi-Fi association state. We expect comparable Wi-Fi Aware performance regardless of whether the device is associated to a Wi-Fi network, since disabling Wi-Fi should not be required to achieve full Wi-Fi Aware data-path throughput.

Questions for Apple

  1. Is the throughput reduction while associated to a Wi-Fi network expected behavior (e.g., due to time-sharing/channel scheduling between the infrastructure connection and the Wi-Fi Aware data path)?
  2. If this is by design, are there recommended APIs, configurations, or best practices to maintain higher Wi-Fi Aware throughput while the device remains connected to Wi-Fi?
  3. If this is not expected, we believe this is a system-level bug and would appreciate guidance on a fix or workaround.
Wi-Fi Aware (NAN) throughput significantly degraded when iPhone is associated to a Wi-Fi network; disabling Wi-Fi from Control Center roughly doubles transfer speed
 
 
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