Re: Problems associating with RTL8188CE

[Tim Gardner <tim.gardner@canonical.com>]

On 12/15/2011 12:50 PM, Larry Finger wrote:
> 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

Yep - specifying a _fixed_ channel for 'Up to 130Mbps at 5Ghz & 54Mbps 
at 2.4Ghz' allowed a connection using the G beacon. I have not verified 
using a 5Ghz capable adapter that its also beaconing on channel 36.

rtg
-- 
Tim Gardner tim.gardner@canonical.com