How would I use a Trendnet TEW-648UBM wifi usb dongle in master mode to transform the Pi into an access point? (I am using Raspbian)


The dongle seems to work out of the box; it loads the driver 8192cu, and can scan and connect to networks.

However, when i try to use it in master mode i get:

Error for wireless request "Set Mode" (8B06) :
    SET failed on device wlan0 ; Operation not permitted.

The same error occurs when I use other iwconfig commands, such as txpower.

I also tried to use an open source driver provided by Realtek, RTL8188C_8192C_USB_linux_v3.4.4_4749.20121105, but honestly I have no idea how to use it, and am afraid that if I install the driver, it will break the distribution



Following the advices received here, i found out that in the last wheezy the kernel module is ok, as well as wpa-supplicant (unless you want WPS support). The only things that have to be replaced are hostapd and the wireless-tools.

So simply uninstall wireless-tools and hostapd, then download the realtek package, and make/make install both wireless-tools and hostap

after, it will work as described in the tutorial linked by BigCowPi.

Just a note: using iwconfig directly now works for setting the card in master mode, but it still fails when using it to set the txpower. This might be a limitation of the driver, i don't know. I would appreciate if somebody could comment on that.

1 Answer 1


I has the same problem with my Edimax Nano USB wifi adapter. I have a guide on my blog to setting that up as a wireless AP with a workaround for RTL 8188 chipsets.

If you don't want to visit my blog, here is a link to the guide I used originally.

  • Thank you very much. I think this will solve the problems. Mind if i ask you also whether for you iwconfig works to set the txpower to 0, or lower in general? thanks!
    – Pa_
    Mar 29, 2013 at 10:43
  • I haven't tried this - when I get chance, I'll try it and let you know.
    – BigCowPi
    Mar 29, 2013 at 18:03

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