Seamless mobility will be the new paradigm

IMS is taking center stage in the market in terms of acceptance from
vendors, network operators - wireless, wireline, broadband - and
application developers. Poonacha Machaiah outlines the importance of
IMS for the evolution of Next Generation Networks...

Poonacha Machaiah is the Senior Director of Seamless Mobility & Wireless Broadband at Motorola, Inc. Machaiah joined Motorola from Vibrant Solutions where he was responsible for strategic engagement and involved himself in the sales of revenue assurance applications and cost management solutions to service providers. He holds an MBA frm the College of William and Mary in Virginia and a Bachelor of Science in Computer Science and Engineering from the B.M.S. College of Engineering in India

The telecom industry is faced with huge revenue pressures. Mobile network operators are facing the challenge of offsetting the declining ARPUs (Average Revenue per User) with differentiated quadplay services (voice, data, video and mobility). Cable operators are considering to extend their services from Internet and TV services to offer Voice over
Broadband (VoBB) and Mobility. Hybrid operators, with assets in the fixed as well as the mobile space, are contemplating ways and means of consolidating networks at the core level to offer bundled services to
address both the segments. New ISP providers are extending their current services beyond PC-to-PC voice calls over the Internet, to offer VoIP services to mobile customers as well. With such profound changes, the division between the markets of fixedline and wireless operators is getting dismantled and the offering for quad-play services is taking the main stream.

These industry dynamics are also resulting in the need for the service providers to transform their networks from homogeneous technology - centric architected networks to a service-oriented architecture that
supports heterogeneous access and device environments. The focus is quickly shifting to place the consumer at the heart of the network and deliver services in a highly personalized and secure manner wherever,
whenever and whatever the users want. The end-user services are becoming more and more multi-media in nature and the user demands for quality of service are forevermore crucial, requiring broadband access in fixed and mobile environments. IP Multimedia Subsystem (IMS) is becoming the glue to connect services where once separate, delivery and management systems can now be consolidated across a single cohesive platform. In other words, IMS is being adopted as the universal standard to achieve fixed and mobile convergence and to deliver real-time multi-media synchronous end-user services.

Services across networks and devices - Seamless Mobility

With IMS, the IP network is extended all the way to the user equipment making the core network access agnostic. Devices will use Session Internet Protocol (SIP) to anchor and transfer sessions across access networks to seamlessly support the best user experience. So as a person moves from the home, to the car, to the public space, the call or multi-media session (or combination of the two) will automatically change from broadband access to cellular to public hot-spots to provide uninterrupted and always-on access to information, entertainment and communications when, where and how people want it. Known as seamless mobility, this envisions the delivery of continuous uninterrupted user experience across different devices and access networks.

IMS is designed to greatly extend the range of services available to operators enabling them to offer both real-time (e.g. voice and video streaming) services and non-real-time services like multimedia downloads. In addition, the services can go beyond user-to-user type services, to server-to-user and multi-user type applications; user-to-user type services include applications like rich voice, video call, Push-To-Talk, instant messaging, and chat; server-to-user products include applications like dynamic push services (Push-To-X), click-to-dial and video streaming; while multi-user services include conferencing and gaming. Each of the applications can be personalized to the end-user through key IMS features like location, presence, and group call management. This new flexibility delivers services that are more immediate, richer, and interactive than current applications. The technology provides a level of versatility that will affect everything from the design, integration, and deployment of applications, to the evolution of network infrastructure and the devices used to access those networks.

Evolution of IMS

Whether it's a carrier with a circuit-switched network, a mobile operator in a mature market considering a fast-paced evolution to an all-IP core, or a cable operator seeking to create a compelling 'quad-play' bundle by adding wireless mobility to the mix of telephony, digital video and high-speed data, IMS is the platform to deliver these new services. And because it provides a flexible, unifying protocol, it allows operators to rapidly deploy numerous services. IMS provides an environment where many new services can be launched quickly. These can then be scaled to meet demand or removed depending on subscriber interactions.

Mobile Operators - IMS will appeal to a broad range of mobile providers as it enables easier and lower cost provisioning of services. It presents the opportunity to market mobile services supporting cellular and VoIP (through broadband wireless) with guaranteed quality of service and with the inherent advantage that the IMS core allows users to enhance the voice session through interaction with a menu of services. For example, a user may access the 'presence' function via their buddy list to see if the person they wish to contact is available and once connected, switch to a video call or send an MMS to enrich a conversation. Coupled with accelerated transmission through HSDPA, CDMA-DO, Rev. A and WiMAX, IMS will optimize the entertainment and communication capabilities of mobile devices. From easily sharing music files to holding a video call or convening a voice chat with a group of friends, IMS provides the glue to connect services, and retain and attract customers. While IMS is often presumed to be the backbone of all 3G and 4G networks, it is in fact already having a significant revenue impact with early applications like VoIP and Push-To-Talk over Cellular (PoC).

Fixed-Line Operators - Many operators have applied SoftSwitch architecture to offer VoIP services and are assessing the opportunities for extending offerings beyond voice and fixed broadband to video/TV over DSL. With IMS, mobility also comes into the equation by integrating wireless technology into Next Generation Networks. They can offer mobility beyond subscribers' premises either in partnership with mobile operators, or by using wireless access technologies - like WiMAX and Wi-Fi. In this scenario, fixed-line carriers can compete for emerging high-speed data applications including gaming on the move and enhanced person-to-person services like video messaging and conferencing.

Enterprises - IMS can seamlessly connect VoIP telephony (through an IP-PBX or via carrier-hosted solution) with Wi-Fi to support in-building voice mobility which scan be extended beyond the office through integration with the cellular network to bridge enterprise and wireless access. With enhanced access speeds complemented by services connected on an IMS core, companies will be able to improve communications services to support employees. VPN access will enhance and work-group collaborative applications will provide richer interaction (such as the ability to push documents to colleagues and discuss these together) to improve overall business performance. New ways to monitor and control the physical world will also present opportunities for companies to overhaul supply chain, manufacturing or service delivery processes.

Cable Operators - IMS allows operators to complement TV, telephony and broadband services by providing a standard way to connect to cellular networks. This 'quad-play' services package extends the voice and data offering beyond the home and provides the scope for cable companies to compete for 'one number' unified communications. IMS also enables the design of new services and applications for both WLAN handsets and on the CPE, with its common standards allowing a wider community of developers to target application development at the cable market - enhancing service innovation.

IMS-Enabled Services and Billing As far as services are concerned, for consumers they could be voice/video call with presence and location, music, gaming, seamless mobility of end-user services across multiple devices; for enterprises, they will be more about the "creation" of the mobile office with multi-media sessions, global video conferencing facilities, extended office capabilities and seamless mobility services across enterprise and cellular networks. For all these scenarios to shape up quickly in terms of commercial adoption, devices also need to be more affordable.

With IMS rendering numerous possibilities, it's apparent that IMS-enabled services will have a significant impact on operator billing systems, the most critical for operators from a revenue perspective. IMS provides operators with immense opportunities for innovative subscriber services and user experiences, along with the flexibility to authorize access, capture usage data and charge appropriately for those services. But, the flexibility of IMS adds several layers of complexity to the charging, rating, billing and mediation functions of the system.

The billing system on an IMS network needs to charge appropriately for the value-added services, made possible by IMS while being able to handle basic circuit- switched telephony and non-telephony services. Essentially, it must cater to the requirements of all players in the IMS space - right from end- users, operators to third parties who provide content or hosted applications. End-user experience can be enhanced by a single authentication or sign-on to access all services. With convergence of services, users will naturally expect a converged bill and thus network operators should be able to charge in different ways for different services and service bundles - event-based, session-based, and contentbased - supporting both pre-paid and post-paid capabilities.

Owning the Services Layer

Most service providers find their network architectures presenting numerous barriers to fast, easy service creation, service delivery and management, to offer a portfolio of compelling end- user services. Now, however, there is a way for service providers to transform their network architectures into service-oriented architectures that can easily, rapidly and cost-effectively deliver the services that their customers demand. Service providers focusing on delivering quad-play services are realizing the importance of an efficient service enabling and managing an environment that cuts across multiple access networks and devices; hence the need for architecting the Service Layer that leverages the existing network assets while introducing new functionalities to deliver seamless and personalized end-user experiences.

The services layer is an architecture that enables the delivery of dynamic telephony, messaging, video and multi-media content to multiple devices, allowing them to be addressed as a single communication entity in any environment, where services can be personalized to suit the users' preferences. The service layer includes both legacy services such as SMS-based services and IMS-enabled end-user services beyond basic voice communications, such as picture messaging, Push-to-Talk over Cellular (PoC), and access to internet content. It includes reusable service components that can be used when building new applications. The layer also provides application-creation, delivery and management functions that can be extended across third party application and content developers. In addition, the service layer acts as the interface to functions in the underlying layers of the network, and to service provider business processes such as billing and management.

The service layer, then, provides an end-to-end view of the network and its services in a very controlled and secure manner. This horizontal service layer approach has the potential to transform network service providers' business strategies, by changing the way services are developed and rolled out.

Traditionally, each individual service has been built on its own specialized technology platform, often with its own unique management, billing and other functions. This design slowed development and meant that services were often tied to specific networks. In contrast, a horizontal service layer provides a means to build new services using ready-made building blocks from a variety of suppliers, integrated with existing business processes, and independent of network infrastructure. New services can be rolled out over different network infrastructures, as long as each network can support all the features of the service. Existing applications can enjoy a longer life, continuing to generate revenue as they are extended to new networks. The service layer approach makes it easier to incorporate new IMSenabled services and functions developed by the growing network of third parties. This, in turn, makes service development faster and less expensive.