Filipe Leitão, Sérgio Freire, Solange Rito Lima*
PT INovação, S.A.Tel.: +351 253 604436
Fax.: +351 253 604471
E-mail: solange at di.uminho.pt
To increase the trust and acceptance of Next Generation Networks
(NGN) by new and existing subscribers, it is necessary to ensure that
the most popular services of legacy networks (GSM/GPRS) are still in
place. The Short Message Service (SMS) is a widespread data service
with high revenue for telecommunication operators, which allows the
exchange of short messages between fixed, mobile and, indirectly,
Internet subscribers. In this context, it is essential to extend this
service for the NGN and allow its interaction with the new messaging
services. With that in mind, a study was carried out to ensure the
coexistence between SMS and the Instant Messaging (IM) service present
in NGN. The present study identifies the relevant technical
specifications impacting on the functionality of the IP Multimedia
Subsystem (IMS) messaging services so that the interoperability with
SMS can be ensured. The results of this study, covered in this article,
aim to help the comprehension of the proposed interoperability
solution, and demonstrate that the exchange of messages between legacy
and NGN messaging services or equipment can be successfully
accomplished. In this context, both SMS and IMS messaging services are
detailed, along with the main protocols they involve. Finally, the
entity responsible for ensuring message interoperability - the IP Short
Message Gateway (IP-SM-GW) - is presented and tested in a commercial
delivery content testbed.