Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:53956 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751523Ab0JMWbc (ORCPT ); Wed, 13 Oct 2010 18:31:32 -0400 Received: by fxm4 with SMTP id 4so2042024fxm.19 for ; Wed, 13 Oct 2010 15:31:31 -0700 (PDT) MIME-Version: 1.0 Date: Wed, 13 Oct 2010 17:31:31 -0500 Message-ID: Subject: estimated_retx ? From: Joel Fernandes To: linux-wireless@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, I was wondering what the meaning of this line of code in mesh_hwmp.c in function airtime_link_metric_get is: estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err)); The computation is : 1 / ( 1 - error rate ) Does the variable name imply "estimated retransmissions" ? Also the err variable is calculated as a moving average based on the ACK of every frame tx. It is my understanding that err should be error rate (no.of bit errors per second). How then can a moving average be considered as errors *per second* ? thanks, Joel