From mboxrd@z Thu Jan 1 00:00:00 1970 From: sandeep suresh Date: Thu, 31 Mar 2016 09:49:42 +0000 (UTC) Subject: [ath9k-devel] Queries on Power Save Mode in Ath9k References: <2125500467.348105.1459417782137.JavaMail.yahoo.ref@mail.yahoo.com> Message-ID: <2125500467.348105.1459417782137.JavaMail.yahoo@mail.yahoo.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ath9k-devel@lists.ath9k.org Dear Experts,?This is regarding the power save mode capabilities in ath9k driver from:http://linuxwireless.org/en/developers/Documentation/ieee80211/power-savings/and wanted to clarify some doubts: a. TBTT and "beacon interval" are relevant to WiFi-AP only?b. "Listen interval" is relevant to WiFi- Station only?c. "DTIM Period" is relevant to WiFi-AP and "DTIM Count" is relevant to WiFi-Station only?d. In the section of "Listen Interval" it is mentioned, "After the listen interval the AP ?does not guarantee it will buffer frames for the station anymore and may discard them" Reference to buffer frame is: (a) Unicast, (b) Multi-cast, (c)Broadcast, (d) All of theme. For retrieving buffered unicast frames from AP, Stations has to send a Power Save Poll (PS-Poll) control frame. Is PS-Poll to be sent even for retrieving buffered multicast and broadcast frames? Let us assume that there are 2 multicast and 2 broadcast frames buffered in WiFi-AP. The "DTIM interval" = 2 and "beacon interval" = 100 settings in WiFi-AP.f. DTIM count in the DTIM field of WiFi-AP beacon will count down every beacon. When DTIM count becomes '0', all the 4 frames are transmitted by WiFi-AP. This will happen after 200ms. The WiFi-Station should catch the beacon in which the DTIM count field is zero, followed by which? ?the station will be able to receive all the 4 packets. Is this correct?g. Now assume that WiFi-Client misses the beacon reception with "DTIM count" = 0 because of interference from any other potential 2.4GHz devices in the neighborhood. Will it loose all the 4 frames? Or the 4 frames will be repeated every DTIM interval by AP? That means every 200ms, DTIM count will countdown to zero and all the 4 buffered frames will be transmitted.h. If WiFi-AP repeats transmission of buffered 4 frames every "DTIM interval", how long does the WiFi-AP continue to do this (any timeout?) as this will generate additional wifi traffic? Thanks & regardsSandeep.? ? -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.ath9k.org/pipermail/ath9k-devel/attachments/20160331/909e424a/attachment.htm