[HOT] Smartphones using wifi in the field If you ain't in the field or techie ignore this post.

john whelan jwhelan0112 at gmail.com
Thu Feb 18 01:55:03 UTC 2016


A few more bits of the puzzle.  I don't have a good solution at the
moment.  The PBX software works but needs some techincal expertise.  ie I
played with it for a few hours before grasping it, but the right ten year
old child would probably have no difficulties.

I've set up a couple of TP-link 4300 routers as a test commotion mesh
network and I have three windows 10 laptops two running pro and one home
and a desktop to play with besides the machines I use normaly.  I connected
the laptops to the routers via cat 5 cables to reduce any problems with
wifi etc.  ie which router am I connected to?

I was unable to ping any windows laptops that were not directly connected
to the same router.  Same as the Android devices if they are on the same
router serval runs fine, cross the Commotion mesh network forget it.

Then I wiped one of the laptops and installed FreePBX.  The installation
was fairly smooth and I now have Asterisk running on the lap top.  I can
ping this client machine from anywhere in the Commotion network so
obviously there is something about win 10 home and pro and android devices
that stops them being seen across the network.

On an i7 laptop the cpu load for one call is minimal.  It's a second hand
Dell mil spec machine.  The nice thing is that SIP software is available
for many operating systems.  The tatty thing is there is jargon involved
and each user must be added mannually.  With Android devices running SIP
software I could connect to either node and thence to the Unix box running
Asterisk.  The FreePBX overlay is quite nice but you need second machine
with browser to control the Asterix PBX and it wants to call home across
the internet for all sorts of things but it is usable without.  It does
need an internet connection when you set it up though.

In the field support would be a major issue.

So it looks like to run Serval through Commotion Commontion would need to
be modified to allow clients to see each other in the same way as serval
can see clients through the mesh extender or it needs some sort of server
which knows about all the serval clients so they could communicate in the
same manner as the PBX software.

Still having got a unix box lying around, now I can create a SERVAL mesh
extender mesh network.

Cheerio John

On 11 February 2016 at 22:33, Eric Christensen <eric at christensenplace.us>
wrote:

> On Monday, February 08, 2016 06:54:55 PM john whelan wrote:
> > I'm seeing different groups have different requirements here and cost is
> a
> > major driver.
>
> I used to be a network engineer and still do a fair amount of network
> architecture.  That said, I fully agree with your statement regarding
> solidifying the requirements at the very beginning.
>
> There are many solutions available to build wireless networks.  Some are
> more
> expensive than others, obviously, and expense does not equal quality or
> ease
> of use.  I'm fond of the Ubiquiti network gear for building point-to-point
> links using their proprietary TDMA protocol (prevents blind-transmitter and
> stations trying to talk over one another).  These devices also support
> traditional WiFi (802.11abg...) for point-to-multipoint connections to the
> clients.  Since WiFi is pretty much ubiquitous on our consumer devices
> this is
> likely the easiest way to connect to computers and smartphones.  Mesh
> networks
> are also nice as they provide additional availability options although not
> all
> mesh protocols are equal.
>
> The next fun is the applications.  My gut reaction is to suggest all open
> source software and stick to what people know.  You can always use postfix
> and
> dovecot for email, owncloud for sharing and managing files, and httpd for
> websites (and asterisk for voice communications and jabber for IM
> and...).  To
> me it's very important to keep this data as local as possible.  The last
> thing
> you want to do is tie up your WAN connection (wide area network: connection
> between cities or backhaul to the Internet) for data that is simply going
> between local computers.  Keep your WAN connection for exchanging
> information
> between disparate local area networks (LANs).  You should be able to host
> email, owncloud, and httpd on a small laptop or desktop computer locally to
> help keep the traffic on the WAN to a minimum and provide faster access to
> data
> locally.  Also, you want applications on the smartphones and computers that
> can cache changes locally and sync them later when network connectivity is
> available.  I know that OSMAND allows you to hold changes and notes offline
> until you are ready to upload them.  This is a bit plus when you are out
> and
> about without network connectivity.
>
> I guess my greatest curiosity would be committing data to and retrieving
> data
> from the OSM network.  Is there a way to easily host this data locally,
> accepting changes from clients, and then send diffs back up to the OSM
> servers
> and also receive diffs of changes from OSM.  Again, with everyone needing
> to
> update their maps with the latest changes I think this would be very
> important.  Having all the mapping data available on the LAN for whatever
> app
> they are using means only having to download the data once over the WAN
> saving
> the valuable bandwidth.  It also improves speeds for the users.  I just
> don't
> know how to do this piece of the puzzle.
>
> FWIW, the One Laptop Per Child (OLPC) folks developed a pretty neat mesh
> networking system that is built into their OLPC laptops.  They laptops
> create
> a mesh network on their own and if one laptop has access to the master
> server
> or the Internet those resources are automatically shared with everyone
> else.
> I don't know anything about the protocol or implementation (it's on my todo
> list) but it's developed to just work; always nice for a emergency/tactical
> network.
>
> --Eric
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