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Comment by pabs3

4 years ago

Why do network scans spike latency? Seems like a WiFi firmware bug to me. I wonder if it happens with open source WiFi firmware like ath9k_htc.fw

https://github.com/qca/open-ath9k-htc-firmware

It does not.

The latency is also massively better -- I surgically implanted an "ancient" ath9k into my laptop and 5ghz wifi latencies dropped 6x compared to the "modern" broadcom chip on the laptop's motherboard. Still getting 300mbit/sec.

All it cost me was the left speaker, removed to make space for the superior wifi card with open-source firmware.

Kinda makes you go "hrm."

Wifi chipsets can't scan networks and do regular wifi-y stuff at the same time.

  • That seems odd, when they can connect to 2 networks at the same time

    • Only if either (a) both networks use the same channel or (b) the networks use different bands (i.e. one is 5ghz and the other is 2.4ghz).

      In order to scan usefully you need to listen on more than one channel from each band. Hence, the interruptions.

      I suppose in theory if you were using a 5ghz network you could scan all the 2.4ghz frequencies. In practice there is little demand for this, so the proprietary firmwares don't support it (at least some, and often all, of the scan routine happens in firmware).

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