Return-Path: Cc: linux-bluetooth@vger.kernel.org Message-Id: <97A79091-A35F-4A53-8AAF-DCD527C574DA@holtmann.org> From: Marcel Holtmann To: David Merrill In-Reply-To: Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Mime-Version: 1.0 (Apple Message framework v929.2) Subject: Re: one "talker" multiple "listeners" possible for inquiry scan with RSSI? Date: Mon, 24 Nov 2008 03:51:26 +0100 References: Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi David, > I am getting to know bluez, reading the BT spec, playing with pybluez > - and I have a multi-adapter question I hope someone may know the > answer to. > > I want to capture the RSSI from a mobile phone from several Bluetooth > radio dongles on a linux system, so I can try to estimate where the > mobile phone is. I find that when I have all radios doing inquiry > scans with RSSI at the same time, it generates a lot of radio traffic, > and WiFi in the area slows down. > > So I'm wondering, can I have one radio initiate the inquiry scan with > RSSI, and have the other 5 radios just listen for the replies from the > mobile phone without "talking"? Could this be accomplished just by > setting the hardware address of the "listeners" to match the address > of the "talker", then they would receive the replies - or is there > some hand-shaking / delivery guarantee algorithm that is required that > would not be possible if the listeners remain quiet? the simple answer is no. It is not how Bluetooth works. For more details you should get a book on Bluetooth that explains how the radio/ baseband actually works. Regards Marcel