Internet Telephony merges with the GSM Network
by Jori Paananen
VTT Information Technology has played a significant role in the
development of the Nokia GSM Intranet Office product, which was
launched at the CeBIT’98 exhibition. This product is the first
in the world to combine Internet Protocol (IP) telephone systems
and the worldwide GSM standard using normal GSM phones as terminal
devices. By merging the corporate intranet and the GSM network,
the Nokia product makes internal company calls extremely cheap
or even totally free of charge.
The Nokia GSM Intranet Office product uses standard GSM phones
as terminal devices and GSM base stations connected to the corporate
intranet. The system utilises the corporate intranet to route
internal calls to other GSM phones or workstations (H.323 terminals)
equipped with software for IP telephony. Outside the office the
calls are routed normally through the public GSM network. The
integration of the corporate intranet and the GSM network represents
a quantum leap towards total mobility and reachability of company
employees at a reasonable cost. On the other hand, new cost-effective
services will enable telecom operators to improve customer loyalty
and increase the use of mobile phones.
The GSM Intranet Office prototype system demonstrated at CeBIT’98
was equipped with a Gatekeeper and an Intranet Location Register
(ILR) developed by VTT. For the GSM phones registered to the system,
the Gatekeeper is equivalent to a Mobile Switching Centre (MSC).
The other system network elements are connected to the Gatekeeper
over an IP-based intranet. The Gatekeeper checks the ILR to determine
whether the phones involved in the call are authorised to use
the system and whether they are located in the GSM Intranet Office
area. If they are, it routes the GSM signalling and traffic inside
the system. If either one is located outside the area, or is not
registered as a user, it routes the call through the A-interface
Gateway to the public GSM network.
The development of the GSM Intranet Office system towards the
final product has continued throughout 1998. VTT Information Technology
has participated in the development of various parts of the system.
Fore more information, see: http://www.nokia.com/networks/16/gio/index.html
Please contact:
Jori Paananen - VTT Information Technology
Tel: +358 9 456 5646
E-mail: jori.paananen@vtt.fi
