Return-Path: <cyrus@holtmann.org>
Subject: Re: Read RSSI through Management Interface?
From: Marcel Holtmann <marcel@holtmann.org>
To: Claudio Takahasi <claudio.takahasi@openbossa.org>
Cc: BlueZ development <linux-bluetooth@vger.kernel.org>,
	"Gustavo F. Padovan" <padovan@profusion.mobi>,
	Johan Hedberg <johan.hedberg@nokia.com>
In-Reply-To: <BANLkTinpSJeozeWCcYCBeQ=sxKU5SJSrSQ@mail.gmail.com>
References: <BANLkTinpSJeozeWCcYCBeQ=sxKU5SJSrSQ@mail.gmail.com>
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Date: Wed, 20 Apr 2011 20:36:35 -0700
Message-ID: <1303356995.15916.8.camel@aeonflux>
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Sender: linux-bluetooth-owner@vger.kernel.org
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Hi Claudio,

> we need to read the RSSI of LE and basic rate connections to implement
> the Proximity profile. RSSI included in the advertising packets can't
> be used for Proximity, it requires an "active" connection.
> 
> Here are some suggestions:
> 
> 1. Add a new command to mgmt interface to add a given address into a
> RSSI "monitoring list".
>    When the connection is established the kernel will automatically
> track the RSSI of the connection on regular intervals sending
> HCI_Read_RSSI. Read RSSI value can be reported through a new event in
> the management interface

the HCI_Read_RSSI on basic rate is a useless command since it depends
highly on the power control. Especially since all Bluetooth chips try to
keep this one optimized.

The RSSI from an active connection does not really give us much. And in
addition we have a lot of legacy BR chips just plain failing this
command and returning static data. How do you plan to address this?

Regards

Marcel