[Thali-talk] Thali for Android

Mon Jul 20 16:34:02 EDT 2015

Hi Yaron,

Thanks for all these precious informations and sorry to answer  so late.
We refine our project in a  rescue system composed of an centralized app (
rescue server) to coordinate operations and smartphone app (rescue
companion) which sends position,  through predefined messages, to the
centralized one.
So what we need is a high latency mesh : Companion wants to send message to
the server, if it can't see it he gives a copy to others companions. Then
if others companions can't see server they will give a copy to others etc,
 until the message arrive to server.

To achieve this goal, we need to :
- send messages to devices without interaction of the user. BtConApp seems
to permit that but only between two devices.
- use simultaneous connections to broadcast messages
- use an opportunistic routing protocol for mesh networks
- run companion app as a background service on  an Android stock rom.

 I intend to built a layer over BtConApp which permits to manage
simultaneous connections and route messages to the server.

I hope that everything is clear despite my basic english.

Best,

Anthony

2015-06-30 0:20 GMT+02:00 Yaron Goland <yarong at microsoft.com>:

>  Hi Anthony, there are two questions in your email so I'll address them
> separately.
>
> The first, and I suspect most important, question is - does Thali support
> some kind of relay capability? In other words if user A wants to send a
> message to user C and they aren't in range can user A send the message to
> user B who will send it to user C? In other words, are we creating a mesh?
>
> To answer that first question we have to recognize the two different kinds
> of mesh, high latency and low latency.
>
> Most folks when they say 'mesh' mean low latency. In other words, user A
> would expect to, real time, relay bytes via user B to get to user C. This
> only works in scenarios where everyone is close to each other. Right now we
> have no plans to support low latency meshes. The reason is that we are
> right now focused on battery operated devices and with modern batteries
> trying to run a low latency mesh isn't really feasible. In all but the most
> limited circumstances one's battery will get eaten.
>
> The other flavor of mesh are high latency meshes. These are really just
> store and forward networks. In this scenario user A would give a copy of
> their messages for User C to user user B. User A is hoping that User B will
> see User C before they do. This can be thought of as a variant of a gossip
> protocol. We are thinking about potentially supporting this in Thali but we
> have done no work on it yet. The main thing we are trying to figure out is
> how useful it would be in the real world. Are people really in situations
> where they have enough intermediaries to make it worth it?
>
> For right now we only support 1:1 replication. And how we support that
> replication actually takes us to your second question.
>
> The second question is - do you have to use Cordova?
>
> The answer is no, but it is trickier than that. Thali's "native" runtime
> is node.js. All the work we did in Android (and iOS) are to build native
> libraries that then plug into our node.js runtime (JXCore) where they can
> be used.
>
> At the moment the way we put node.js on the Android phone is by using a
> cordova plugin. But that is absolutely not a requirement. We will be
> refactoring it so that it can run as a stand alone node.js instance that
> you can call from your Android app and talk to over localhost. But we are a
> few releases from doing that.
>
> The reason why we use Node.js is because that is where we run PouchDB, a
> Javascript implementation of CouchDB. That is our database and we use the
> CouchDB replication protocol to let us replicate content between two users.
>
> So, for example, if users A, B and C are all working in the same DB then
> user A can make a change to that DB locally, synch those changes over to
> user B who can then synch those changes over to user C.
>
> I know that sounds like a high latency mesh and in a sense it sorta,
> kinda, is. But typically in high latency meshes users transfer data for
> other users without knowing who the user is or what the data is. In our
> model data is only shared between people who have chosen to work in the
> same DB and where folks have access to that DB.
>
> Now, just in case this email hasn't made your head explode yet, we will be
> adding in ACLs and using them for filtered replication. So, for example,
> User A could add in a message to the DB intended for user C but not user B.
> In that case when User A synchs with user B, user B won't get that record.
> But this means that user C won't see the record until they are able to
> directly synch with User A since the ACLs prevented a copy from going to
> User B. Hence why I don't really call this a low latency mesh.
>
> Did any of that actually make sense or did I just confuse you even more?
>
> Thanks,
>
>      Yaron
>
>
>
>
>  ------------------------------
> *From:* Thali-talk <thali-talk-bounces at thaliproject.org> on behalf of
> Brian Lambert <blambert at microsoft.com>
> *Sent:* Tuesday, June 16, 2015 7:40 PM
> *To:* Anthony smgh; thali-talk at thaliproject.org
> *Subject:* Re: [Thali-talk] Thali for Android
>
>
> Hi Anthony,
>
>
>
> Thanks for your note.
>
>
>
> It turns out that the author of BTConnectorLib, who would be the most
> helpful person to respond to this for you, is on holiday this week.
>
>
>
> We’ll make sure he sees this message upon his return and he’ll get back to
> you then.
>
>
>
> Best,
>
>
>
> Brian Lambert
>
>
>
> *From:* Thali-talk [mailto:thali-talk-bounces at thaliproject.org] *On
> Behalf Of *Anthony smgh
> *Sent:* Tuesday, June 16, 2015 6:17 PM
> *To:* thali-talk at thaliproject.org
> *Subject:* [Thali-talk] Thali for Android
>
>
>
> Hello all,
>
>
>
> I make studies at CNAM Toulouse in France and as a part of a school
> project i would like to develop an android app which allow to notify user
> about danger or people in danger particularly  when no network
> infrastructure is available.
>
>
>
> I researched about messaging over an wireless mesh network using
> Wifi-Direct on Android and I recently found Thali project which seems to
> have all features needed for my project . I read the documentation at
> http://thaliproject.org/ and https://github.com/thaliproject/ . I tested
> BTConApp and everything works great between two devices.
>
> Now, i would like to use Thali with more devices (> 3 ) in order to see
> how messages travel on the mesh network .
>
> I don't understand clearly if i  shoud use BTConnectorLib or Cordova
> plugin and if Thali offers already  any routing capabilities or not yet.
> Can you tell me more about that ?
>
>
>
> Thanks for sharing your work.
>
>
>
> Anthony
>
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