Today, carriers cannot enable
their customers to mix multimedia components text,
pictures, voice, video within a single call.
A two-party voice call cannot be extended to
a multi-party audio and video conference. IP
Multimedia Subsystem (IMS) overcomes these
limitations and makes the above scenario possible.
IMS is an IP multimedia and telephony core
network that supports IP to IP sessions over
both wireline and mobile networks. IMS includes
session control, connection control, and an
applications services framework along with
subscriber and services data. The Third Generation
Partnership Project (3GPP) has defined UMTS
support for IMS, with the same architecture
being re-used by 3GPP2 for CDMA.
As this technology continues to gain attention
and acceptance in the communications industry,
service providers including O 2 , TeliaSonera
and BT have initiated projects to deploy IMS
capabilities to enable converged services for
both fixed and mobile customers. Hardware manufacturers
are assembling comprehensive solutions that
are increasingly standards-based. Nortel, Lucent,
Alcatel, Nokia and other manufacturers have
announced new equipment with IMS capabilities.
Forward-thinking operators are already exploring
the value of IMS.
IMS enables a number of new and enhanced services,
including:
- Person-to-person real-time IP-based multimedia
communications including voice or videotelephony and
person-to-machine communications, like gaming
services
- Fully integrated real-time and non-real-time
multimedia communications, such as live streaming
and chat services
- Seamless interaction between different
services and applications, like the combined
use of presence and instant messaging
- User configuration of multiple services
in a single session, or multiple simultaneous
synchronized sessions
IMS enables service providers
to keep the intelligence and service control
in the network, rather than being relegated
to bit-pipe providers
of high speed access. Through service control,
carriers can retain a larger part of the value
chain and offer higher-margin services. At
the same time, service providers can use their
IMS infrastructure to provide network access
to third-party content.
While IMS presents a wealth
of new opportunities, it also presents challenges.
New IMS deployments will need to interwork
with an operator's existing circuit-switched
and packet-switched networks. Currently deployed
services such as Push-to-Talk and instant messaging
will need to be seamlessly migrated to the
new architecture. Operators will need to provide
flexible pricing for new services and the
rate of change in new services will likely
increase. In order to provide effective service
fulfillment and billing for IMS services, carriers
must utilize both the new IMS equipment as
well as their vast infrastructure of legacy
equipment and networks.
IMS also introduces increased
complexity because it is multi-service (Instant
Messaging, Push-to-Talk, VoIP, etc.), it affects
multiple levels in the network (Application
Servers, Session Control, Transport), and it
is multi-vendor even traditional
hardware vendors may position themselves as
system integrators. These factors make it even
more crucial to deploy comprehensive automation
through a fully featured Operations Support
System (OSS). An effective OSS makes it possible
to provide flexible provisioning and mediation
that enables the service provider to abstract
network element-specific information and provide
centralized service fulfillment.
In addition, an automated OSS helps carriers
realize the full benefit of their network investments,
by enabling new service offerings and reducing
the cost of operations and integration in a
multi-vendor network. These strategic goals
simply cannot be attained with single-vendor,
specialized applications, cobbling new systems
onto legacy applications, or installing single-domain
applications.
The OSS for the next evolution in communications
must be flexible enough to address both legacy
and next generation service fulfillment needs.
In deploying a robust OSS and achieving automated
flow-through provisioning, the following five
issues must be addressed:
- Network Convergence While
IMS focuses on IP to IP communications, interworking
is still required with existing circuit-switched
networks. In order to provision bundled services,
all layers of the converged network must
be addressed. This requires a complete OSS
solution that supports cross-domain functions
including data, voice, and video, as well
as both mobile and wireline.
- Core Product Functionality To
enable successful service provisioning for
IMS, the OSS must provide robust functionality
around multi-domain provisioning as well
as intelligent mediation.
Multi-Domain Service Provisioning In
order to support the expectant volumes and
importance of IMS services, the OSS must include
a proven, carrier-grade service provisioning
platform that supports flow-through provisioning
across multiple service and network domains
as well as across core, switching, messaging
and application domains. Support for multiple
types of potentially bundled services, together
with pre-built support specifically designed
for IMS services, is particularly important.
The service provisioning solution needs to
operate in both existing and new environments
and support modular, component deployments
for provisioning control, logical subscriber
and service inventory, and activation. Through
a data-driven architecture, it should also
facilitate rapid modeling and deployment of
services to meet the burgeoning rollout of
new SIP-based services in high volumes and
at low cost.
Given the distributed nature of the IMS architecture,
the provisioning solution will need to provide
both provisioning and activation control, to
enable the management of orders and constituent
tasks required to deliver services. A sophisticated
process and rules engine is needed to enable
operators to define and structure the order
fulfillment process, and synchronize both manual
and automated tasks in one system.
Intelligent Network Mediation IMS-based
services will require a mix of session, event
and subscription-based service pricing, including
revenue sharing with partners. Billing for
service and network usage means collecting
and processing usage information from a mix
of network elements at multiple layers in the
network.
For offline charging, 3GPP has defined the Charging Data Function and Charging
Gateway Function to collect usage data from IMS NEs using the Diameter protocol
and create ASN.1 encoded records. But numerous IMS NEs will not support Diameter,
even in the long term, driving the need for a flexible mediation system that
can simultaneously support different transport protocols and record formats.
Wireless and wireline carriers offering IMS services will also need convergent
mediation to simultaneously support softswitches and the packet core network.
Softswitches acting as Application Servers enable telephony, audio & video
conferencing and call features (Call Return (*69), 3-way call, etc.), all of
which can be priced based on usage. Usage on the packet core needs to be taken
into account when billing for IMS-based services, as subscribers will not accept
being charged for both services used and bytes transferred.
The introduction of new IMS network elements, plus the ongoing network and
services evolution over the next decade, make it imperative for service providers
to move away from legacy mediation systems and implement a convergent, flexible
mediation solution that simultaneously supports IMS, voice and packet networks
in a single solution.
- Relationship to other OSS Components Carriers
must achieve effective communication among
various legacy and next generation OSS components.
Many hardware vendors looking to supply IMS
capabilities are also teaming with various
software providers to enable a more complete
solution. All these factors further complicate
the process of fulfilling services via IMS.
How the service fulfillment OSS solution is
linked to other key business processes varies
from carrier to carrier. Some will need all
of the OSS elements integrated into a single
system, while others may choose one or more
components to combine with an existing system.
Ideally, one vendor could offer the choice
of unbundling these core service fulfillment
components, to provide only products best suited
to delivering services as they emerge reducing
the time and cost of implementation.
- Integration Capabilities Regardless
of the OSS components implemented, they must
be easily adapted into the operator's existing
infrastructure. Various standards initiatives,
including OSS through Java (OSS/J) and 3GPP,
promote integration and interchangeability
between OSS applications. Choosing products
that adhere to these standards helps minimize
systems integration work and reduces the
time and cost of deploying the OSS .
- Partner Experience Although
IMS is a new entrant in the communications
arena, there are OSS applications already
in production and proven effective for advanced
service fulfillment. Consider OSS partners
with a history of successful implementations
in voice and data, over multiple mobile and
wireline technologies. It also is important
to choose a partner that can provide a single
point of accountability across an extensive
solution set.
As IMS enables service providers to offer
rich multimedia features, and leverage these
high-margin services to increase revenues,
OSS solutions must evolve to meet the additional
challenges of service fulfillment across the
expanding variety of legacy and next-generation
services.
About the Author
David Sharpley is the Senior Vice President
of Marketing and Product Management for MetaSolv
Software and leads the company's strategic
product and marketing direction. David's extensive
experience in OSS/BSS software also includes
several years building the OSS product suite
at Nortel Networks and leading Clarify CRM
into the Service Provider market.
