Wireless Access

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New Contributor
Posts: 2
Registered: ‎12-10-2012

Microsoft Surface Pro & Power Save Aware Scan

Has anyone noticed any issues with Microsoft Surface Pro's with "Power Save Aware Scan" in ARM enabled?

 

I noticed this post via Microsoft:

 

When an 802.11 wireless network adapter that is set to use power save mode wants to enter a sleep state, the adapter indicates this intention to the wireless AP. The adapter does this by setting the power save option in its packets or in the 802.11 frames that it sends to the wireless AP. In this scenario, the following behavior should occur:

1.       When the wireless AP receives the frames that have the power save option set, the wireless AP determines that the client network adapter that sent the frames wants to enter a power saving state.
2.       The wireless AP then buffers packets that are destined for the client network adapter.
3.       When the radio of the client network adapter turns on, the client network adapter then communicates with the AP to retrieve the buffered packets.
This behavior enables the wireless network adapter to use less power and to wake up periodically at the correct time to receive network traffic from the AP.
If the wireless AP does not support this feature correctly, the wireless AP continues to send packets to the client network adapter even if the client network adapter radio is turned off. Therefore, these packets are lost. In this scenario, the symptoms that you experience may vary depending on the phase of the wireless connection in which these packets are lost.

MVP
Posts: 4,307
Registered: ‎07-20-2011

Re: Microsoft Surface Pro & Power Save Aware Scan

 

What version of AOS you have installed ?

 

We experienced similar issues with a 6.2.x.x

Thank you

Victor Fabian
Lead Mobility Engineer @ Integration Partners
AMFX | ACMX | ACDX | ACCX | CWAP | CWDP | CWNA
New Contributor
Posts: 2
Registered: ‎12-10-2012

Re: Microsoft Surface Pro & Power Save Aware Scan

I am currently running 6.2.1.0.

Guru Elite
Posts: 21,490
Registered: ‎03-29-2007

Re: Microsoft Surface Pro & Power Save Aware Scan

jwdicker,

 

The power save aware scan was put into place years ago to specifically deal with an issue with Intel 2600 chipset that we believe they have since fixed.  I am not aware of any device that requires this checkbox to function properly outside of the 2600 (I could be wrong).  If you feel the Microsoft surface pro has a problem, please feel free to uncheck this box.



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

MVP
Posts: 4,307
Registered: ‎07-20-2011

Re: Microsoft Surface Pro & Power Save Aware Scan

[ Edited ]
What type of APs are you using ?

What band is the surface using when this occurs ?
Thank you

Victor Fabian
Lead Mobility Engineer @ Integration Partners
AMFX | ACMX | ACDX | ACCX | CWAP | CWDP | CWNA
Guru Elite
Posts: 21,490
Registered: ‎03-29-2007

Re: Microsoft Surface Pro & Power Save Aware Scan

[ Edited ]

jwdicker wrote:

Has anyone noticed any issues with Microsoft Surface Pro's with "Power Save Aware Scan" in ARM enabled?

 

I noticed this post via Microsoft:

 

When an 802.11 wireless network adapter that is set to use power save mode wants to enter a sleep state, the adapter indicates this intention to the wireless AP. The adapter does this by setting the power save option in its packets or in the 802.11 frames that it sends to the wireless AP. In this scenario, the following behavior should occur:

1.       When the wireless AP receives the frames that have the power save option set, the wireless AP determines that the client network adapter that sent the frames wants to enter a power saving state.
2.       The wireless AP then buffers packets that are destined for the client network adapter.
3.       When the radio of the client network adapter turns on, the client network adapter then communicates with the AP to retrieve the buffered packets.
This behavior enables the wireless network adapter to use less power and to wake up periodically at the correct time to receive network traffic from the AP.
If the wireless AP does not support this feature correctly, the wireless AP continues to send packets to the client network adapter even if the client network adapter radio is turned off. Therefore, these packets are lost. In this scenario, the symptoms that you experience may vary depending on the phase of the wireless connection in which these packets are lost.


jwdicker,

 

Power Save is part of the 802.11 standard (http://www.youtube.com/watch?v=uph5Sg1z81Y) and all enterprise access points support this.  The power-save aware mechanism in the ARM profile is an addition to this and it should not affect standard 802.11 power save.  With that being said, if all of your other clients are not having a problem, in general, the problem is not with your infrastructure or with power save in general.  I would say open a support case to determine exactly what is going on with your specific client.  New clients come along all the time and there is always fine tuning done on the drivers to determine what is wrong.  Opening a support case will prevent you from chasing in the wrong direction.  Hopefully other customers with the surface will chime in on what they found so that you can get some relief with your issue.  The "show ap debug client-table ap-name <name of ap>" command will show you clients going in and out of power save to demonstrate that this is supported.  Do you have a specific issue, or is this a question about what you read?

 

(Aruba3600) #show ap debug client-table ap-name AP-125-Home

Client Table
------------
MAC                ESSID                    BSSID              Assoc_State  HT_State  AID  PS_State    UAPSD            Tx_Pkts  Rx_Pkts  PS_Qlen  Tx_Retries  Tx_Rate  Rx_Rate  Last_ACK_SNR  Last_Rx_SNR  TX_Chains  Tx_Timestamp              Rx_Timestamp              MFP Status (C,R)
---                -----                    -----              -----------  --------  ---  --------    -----            -------  -------  -------  ----------  -------  -------  ------------  -----------  ---------  ------------              ------------              ----------------
00:1a:1e:1d:c0:f1  3FEEF727-4ACE-4586-9817  00:1a:1e:20:82:f0  Associated   WS        0x1  Awake       (0,0,0,0,N/A,0)  1370565  2752724  0        46332       78       104      27            26           2[0x3]     Sun May 26 11:16:07 2013  Sun May 26 11:16:07 2013  (0,0)
5c:da:d4:24:a9:9e  CatchMe                  00:1a:1e:20:82:e0  Associated   None      0x2  Awake       (0,0,0,0,N/A,0)  30628    37937    0        789         54       54       42            40           2[0x5]     Sun May 26 11:15:46 2013  Sun May 26 11:15:46 2013  (0,0)
44:2a:60:c3:b8:fe  CatchMe                  00:1a:1e:20:82:e0  Associated   M         0x4  Power-save  (0,0,0,0,N/A,0)  1731     10879    0        26          65       65       31            31           2[0x5]     Sun May 26 11:15:45 2013  Sun May 26 11:15:46 2013  (0,0)
10:bf:48:e8:1e:17  CatchMe                  00:1a:1e:20:82:e0  Associated             0x1  Power-save  (0,0,0,0,N/A,0)  15037    50328    0        256         65       65       36            37           2[0x5]     Sun May 26 11:15:42 2013  Sun May 26 11:15:42 2013  (0,0)
e8:92:a4:96:6f:43  CatchMe                  00:1a:1e:20:82:e0  Associated             0x3  Power-save  (0,0,0,0,N/A,0)  17366    52154    0        17          65       6        52            50           2[0x5]     Sun May 26 11:15:30 2013  Sun May 26 11:15:42 2013  (0,0)
                                                                                                                                                                                                                                                                           
UAPSD:(VO,VI,BK,BE,Max SP,Q Len)
HT Flags: A - LDPC Coding; W - 40Mhz; S - Short GI HT40; s - Short GI HT20
          D - Delayed BA; G - Greenfield; R - Dynamic SM PS
          Q - Static SM PS; N - A-MPDU disabled; B - TX STBC
          b - RX STBC; M - Max A-MSDU; I - HT40 Intolerant

(Aruba3600) #  

 

 



Colin Joseph
Aruba Customer Engineering

Looking for an Answer? Search the Community Knowledge Base Here: Community Knowledge Base

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