Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.2 \(3112\)) Subject: Re: [RFC][PATCH] Add Set Advertising Parameters command From: Marcel Holtmann In-Reply-To: Date: Tue, 16 Feb 2016 10:42:02 -0800 Cc: BlueZ development Message-Id: <589AC9D1-63F1-44AE-AC9C-C34213995B0B@holtmann.org> References: <20160216130927.GA10374@vps217108.ovh.net>

To: Barry Byford <31baz66@gmail.com> Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Barry, >>> --- >>> doc/mgmt-api.txt | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>> 1 file changed, 67 insertions(+) >>> >>> diff --git a/doc/mgmt-api.txt b/doc/mgmt-api.txt >>> index 731a088..4b842fd 100644 >>> --- a/doc/mgmt-api.txt >>> +++ b/doc/mgmt-api.txt >>> @@ -2596,6 +2596,7 @@ Add Advertising Command >>> 4 Add TX Power field to Adv_Data >>> 5 Add Appearance field to Scan_Rsp >>> 6 Add Local Name in Scan_Rsp >>> + 7 Pending Parameters >>> >>> When the connectable flag is set, then the controller will use >>> undirected connectable advertising. The value of the connectable >>> @@ -2623,6 +2624,12 @@ Add Advertising Command >>> supported to provide less air traffic for devices implementing >>> broadcaster role. >>> >>> + If the Pending Parameters flag is set, the Advertising Instance >>> + will only be queued when the Set Advertising Parameters command >>> + is issued, with the correct Instance identifier. If the next >>> + command is not a Set Advertising Parameters commmand, the current >>> + Advertising Instance is cancelled. >>> + >> >> this is an API design, I prefer to not support. It is really complicated and does not feel like a clean design. >> >>> The Duration parameter configures the length of an Instance. The >>> value is in seconds. >>> >>> @@ -2680,6 +2687,66 @@ Add Advertising Command >>> Invalid Index >>> >>> >>> +Set Advertising Parameters Command >>> +================================== >>> + >>> + Command Code: 0x003f >>> + Controller Index: >>> + Command Parameters: Instance (1 Octet) >>> + Adv_Interval_min (2 Octets) >>> + Adv_Interval_max (2 Octets) >>> + Return Parameters: >>> + >>> + This command is used to set advertising parameters for a Bluetooth >>> + Low Energy controller. >>> + >>> + This command can be used to configure global advertising parameters >>> + that will be applied for advertising issued by the Set Advertising >>> + command. >>> + >>> + This command can also be used to configure single Advertising >>> + Instances. In that case, the parameters applied for the Advertising >>> + Instance will override global Advertising Parameters when the >>> + Adversiting Instance is running. >>> + >>> + When configuring an Advertising Instance, the Instance must have >>> + been added with the flag "Pending parameters". The Advertising >>> + Instance will be added to queue only when the Set Advertising >>> + Parameters will be issued. >>> + >>> + The Instance parameter designates what we want to configure. >>> + If the Instance parameter is 0, the Advertising Parameters apply >>> + globally, for both the advertising issued with the Set Adverting >>> + and the Advertising Instances issued with Add Averting. >> >> I wonder if we actually want to include the Instance parameter at all here. I mean, why not just have some global setting for advertising parameters and just run with it. >> >> However would fine grained per instance setting actually help you? If you have an instance with a higher interval it will consume the extra power. >> >> And honestly if we ever really need super fine grained control, then I rather design an Add Enhanced Advertising command after we figured out what we really want. Especially looking forward on the next Bluetooth specification, I prefer not to lock myself in at this point in time. >> >> So if we want to add a global Set Advertising Parameters similar to Set Scan Parameters then I am fine with that, but anything more complex seems not the right solution at this point. >> >> Regards >> >> Marcel >> > > On the Eddystone beacons they have 3 different frame types and a > typical installation might broadcast two frame types. The suggestion > is that the two fame types would be interleaved and the Eddystone-TLM > frame type would be broadcast less frequently than Eddystone-URL for > example. Would having this parameter per instance allow this to be > done? the duration of an advertisement is already part of our instances. The advertising max/min interval is a the link-layer intervals the controller might choose on when to put the advertising packets on the air. There is no tight control anyway. It is a suggestion. And I think that kind of suggestion can be global. For Eddystone, the existing duration parameter should already do exactly what you need. Regards Marcel