Re: Problems associating with RTL8188CE

Larry Finger
2011-12-15T19:50:42Z

On 12/15/2011 12:41 PM, Tim Gardner wrote:
> On 12/14/2011 05:50 PM, Larry Finger wrote:
>> Tim,
>>
>> I did the live test with the Dec. 14 build of 12.04 (64 bit). It
>> connected with my WNDR3300 with no difficulty. I tested all 4 modes
>> supported by the AP. All worked.
>>
>> I assume that an installation would work the same as the live version,
>> but that is easy for you to test.
>>
>> Larry
>>
>
> Here are the 3 modes I was able to successfully test on my WNDR3300 as an open AP:
>
> * Up to 270Mbps at 2.4Ghz
> 11N Channel: 03/2.422Ghz
> in this mode only the 11N SSID is beaconed.
> iperf: 11.2 Mbps average over 120 seconds, high of 26.2 Mbps, low of 6.71
>
> * Up to 270Mbps at 5Ghz & 54Mbps at 2.4Ghz
> 11N Channel: 36 / 5.180Ghz
> 11G Channel: auto
> in this mode only the G beacon can be seen (which makes sense)
> iperf: 14.3 Mbps average over 120 seconds, high of 28.5 Mbps, low of 8.97
>
> * Up to 130Mbps at 2.4Ghz
> 11N Channel: 03/2.422Ghz
> in this mode only the 11N SSID is beaconed.
> iperf: 16.0 Mbps average over 120 seconds, high of 28.9 Mbps, low of 7.44
>
> This mode would not acquire a beacon using the rtl8192ce:
>
> * Up to 130Mbps at 5Ghz & 54Mbps at 2.4Ghz
> 11N Channel: 36 / 5.180Ghz
> 11G Channel: auto
> in this mode no beacon can be seen.
>
> I verified using a MacBook Air under OS/X that the N SSID was appearing on the 5
> Ghz channel, but couldn't see the G beacon. Maybe its a bug in the WNDR3300.

I had never used the "auto" channel setting before. When I set my AP to the same
configuration as yours (130/54 and 36/auto), it sent the 802.11n beacon in the
2.4GHz channel. The 11G SSID was not seen; however, I could connect to the AP on
channel 1. When I switched to 11G channel 1, rather than auto, then I saw the
11G SSID in the beacon. I then tested the 5G band using a Dell DW1450 (p54usb)
dual-band device. The 11N SSID was present on channel 36 using auto or channel 1.

There may be a bug in the WNDR3300 firmware. Sometimes when I switched from
channel 1 to auto for the 2G band, that band would beacon the 11G SSID, and
other times, it would beacon the 11N SSID. I have not determined a pattern. The
11N SSID is always shown on the selected 5G channel. I could, however, connect
the RTL8188CE to whatever SSID the AP was sending on the 2.4GHz band.

Curiouser and curiouser,

Larry