Return-Path: Message-ID: <3FF9D546.9040005@csr.com> Date: Mon, 05 Jan 2004 21:21:10 +0000 From: Steven Singer MIME-Version: 1.0 To: Marcel Holtmann CC: Florian Echtler , Olivier Bornet , BlueZ Mailing List Subject: Re: [Bluez-devel] bthid cvs question References: <1071020597.10655.4.camel@pegasus> <20031210080259.GF26896@smartdata.ch> <1071065922.10655.60.camel@pegasus> <1071969925.2684.5.camel@pegasus> <3FF99466.8080209@csr.com> <1073329354.2508.26.camel@pegasus> In-Reply-To: <1073329354.2508.26.camel@pegasus> Content-Type: text/plain; charset=us-ascii; format=flowed List-ID: Marcel Holtmann wrote: >>A lot of devices use page scan repetition mode R2 by default as it's the >>lowest power mode. > > the most device I have seen are using R1 by default and the only R2 are > my HID devices. Headsets can use R2. Basically any battery powered device that needs to be connectable for long periods of time will be a candidate for using R2. > I am no baseband expert, so let me see if I understand you right. In the > case we don't know the page scan repetition mode we should use R2 in > prefer of R1 or even R0? Correct. > Does this have disadvantages if the devices is > in R1 or R0 mode? I ask because we found that connecting with R1 by > default gives us a significant page time improvement. The disadvantage of always using R2 is that you connect more slowly to unknown devices than you might do if you used R1. The advantage of using R2 is that you can connect to all devices. If you use R1 then there may be many devices out there that you cannot connect to (or that you connect to unreliably). The worst case baseband connection times for different scenarios are: slave sr \ master psrm R0 R1 R2 R0 0.20s 1.28s 2.56s R1 infinity 2.56s 3.84s R2 infinity infinity 5.12s > If only R2 makes sense in case that we don't the exact value, somebody > should bring up an errata to the HCI working group ;) The note from the baseband needs to be moved up to the HCI spec. - Steven -- ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept by MIMEsweeper for the presence of computer viruses. www.mimesweeper.com **********************************************************************