Return-path: Received: from mail-ig0-f176.google.com ([209.85.213.176]:35032 "EHLO mail-ig0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751538AbaLRQVG (ORCPT ); Thu, 18 Dec 2014 11:21:06 -0500 Received: by mail-ig0-f176.google.com with SMTP id l13so1212176iga.15 for ; Thu, 18 Dec 2014 08:21:05 -0800 (PST) MIME-Version: 1.0 Date: Thu, 18 Dec 2014 17:21:05 +0100 Message-ID: (sfid-20141218_172138_179004_778AEDF0) Subject: DFS CAC time From: Helmut Schaa To: linux-wireless Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, Using ath10k I get the following when checking the CAC times for an ETSI regulatory domain: iw list | grep CAC -B 2 * 5260 MHz [52] (20.0 dBm) (radar detection) DFS state: available (for 342 sec) DFS CAC time: 60000 ms * 5280 MHz [56] (20.0 dBm) (radar detection) DFS state: available (for 342 sec) DFS CAC time: 60000 ms * 5300 MHz [60] (20.0 dBm) (radar detection) DFS state: available (for 342 sec) DFS CAC time: 60000 ms * 5320 MHz [64] (20.0 dBm) (radar detection) DFS state: available (for 342 sec) DFS CAC time: 60000 ms * 5500 MHz [100] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5520 MHz [104] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5540 MHz [108] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5560 MHz [112] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5580 MHz [116] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5600 MHz [120] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5620 MHz [124] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5640 MHz [128] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5660 MHz [132] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5680 MHz [136] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms * 5700 MHz [140] (27.0 dBm) (radar detection) DFS state: usable (for 408 sec) DFS CAC time: 60000 ms So, every channel has a CAC time of 60 seconds. Checking version 1.7.2 of the ETSI regulation indicates that we might need some modifications to cfg80211: >From [1] page 79: "NOTE 1: For channels whose nominal bandwidth falls completely or partly within the band 5 600 MHz to 5 650 MHz, the Channel Availability Check Time shall be 10 minutes. NOTE 2: For channels whose nominal bandwidth falls completely or partly within the band 5 600 MHz to 5 650 MHz, the Off-Channel CAC Time shall be within the range 1 hour to 24 hours." So, for these channels we should select a longer initial CAC time. Is anyone aware of this issue? Thanks, Helmut [1] http://www.etsi.org/deliver/etsi_en/301800_301899/301893/01.07.02_20/en_301893v010702a.pdf