Re: [dispatch] SIP and GSM/UMTS with OpenBTS

[[e-mail] (Dale R. Worley)]

> From: "Ralph A. Schmid, dk5ras" <[e-mail]>

(Is there a reason you insert so many blank lines?)

> So imagine a village, a few hundred people living there, most of
> them owning mobile phones for communication when they travel to the
> town for work or for trading goods - but at home those phones are
> useless.

> So somebody is able to spent a few thousand dollars, puts an antenna
> onto some tree, flips the switch, and a few hundred phones can (and
> do) log on.

> Now more and more of those low-cost networks grow up, and people
> want to connect them. Internet is available in some places, cheap to
> buy and install WiFi-links are established, the whole thing evolves,
> some simple structure grows.

This story makes sense to me.  The question seems to be how to
interwork the GSM radio call-control protocol with SIP, so that a set
of these base stations can operate as an integrated system.  You'd
want some sort of SIP registrar/proxy to operate as an ITSP, and all
of the base stations make SIP connections with it.

The next step is for someone to start designing this use of SIP.  No
doubt a lot of interesting questions will arise, and you may need to
design some SIP extensions.  But until you've got the design started
and can discuss the design decisions, you're not in a position to talk
about what SIP extensions are needed.

Dale