Emerging Tech: IMS: The Mobile IP

IP multimedia subsystem (IMS) is a standardized reference architecture
consisting of: session control, connection control, and an applications services
framework along with subscriber and services data. It is an international
recognized standard. It specifies interoperability and roaming; and it provides
bearer control, charging, and security. At its core, it is an IP multimedia and
telephony network. It is defined by 3GPP and 3GPP2 standards and organizations,
based on IETF Internet Protocols. It is access independent as it supports IP to
IP sessions over wireline IP, 802.11, 802.15, CDMA, and packet data along with
GSM/EDGE/UMTS and other packet data applications.

Need For Change

First, old equipment and technologies need to be replaced. Most of these
replacements would be IP-enabled replacements. Even if all other factors remain
the same, just the replacement market should create enough of feel good in the
global market. Among others, the vendors are glued to this hope and are
feverishly pitching their new wares.

Then, the business scenario is changing. If the telcos remain telcos, they
will be wiped out of the market. IP has changed the telecommunications business.
With the Internet hosting so many new services and applications for all types of
communications, network operators are feeling threatened. While the others offer
premium services over the telcos' networks, the telcos themselves are
constantly being squeezed with bandwidth price cuts.

How Is IMS Different?

Most of what IMS promises in terms of person-to-person communications, is
based on the 3GPP variant of SIP. So far, SIP has been the domain of Internet.

Though IMS can be called the telecom equivalent of the Internet, it differs
from the Internet in one major way. The Internet as a best-effort technology
promises anything. Besides, the Internet does not work very well when the
network is overloaded. With IMS you can deliver what you promise.

Looking ahead, the aim of IMS is not only to provide new services, but also
to provide all the services, current and future that Internet provides.
Moreover, as opposed to the next-generation network approach, which aims at just
carrying circuit services on top of the Internet protocol (IP), IMS offers
operators the opportunity to build an open IP-based service infrastructure that
will enable an easy deployment of new multimedia communication services, mixing
telecom and data services.

And because IMS is based on open standards, the operator retains the freedom
to create and provide the multimedia services with heterogeneous elements
without being bound to a particular equipment or technology vendor. Also, unlike
in a traditional architecture, the network operator is not required to host all
the services (and servers) at its premises. As long as the applications server
are IMS (or SIP) compliant, services can be offered from anywhere in the
network, without the need for physical presence of servers at the operator's
premises.

Everyone gains from it. The service providers today, aim to deliver all the
needs of the customers on one network. The customers want newer services
everyday, preferably delivered on a mobile terminal, and that too at a good
price. And they would want to use these services, the way they want. This is
certainly not the way their service provider finds it convenient. And IMS can
make us realize that future.

Alok Singh

aloksi@cybermedia.co.in