Enhanced Service Delivery with IP Multimedia Subsystems and AdvancedTCA

Network operators are moving to reinvent themselves as service providers, and looking to new enhanced services to attract and retain customers in order to increase revenue. The IP Multimedia Subsystem (IMS) architecture, a modular standards-based service platform that uses Internet Protocol (IP) and Session Initiation Protocol (SIP), is poised to help transform network operators into service providers at a low cost and with minimal network disruption.

 

IMS is generating renewed interest amongst network operators because of its ability to provide modular, flexible service delivery and fast time-to-market. The dynamic architecture of IMS allows operators to offer promising new services more quickly, add resources for successful services as demand increases, and downplay or remove unsuccessful services easily.

 

Because IMS has standards-based interfaces and network elements, some network operators and carriers are deploying hybrid implementations using existing equipment or applications. With this approach they can leverage prior investments and migrate over time to a standard implementation.

 

The Need for New Services - and a New Network to Support Them

 

Because the acceptance of new services is unpredictable, and what succeeds in generating huge amounts of revenue in one market may fail in another, network operators and service providers are working to develop their own unique set of "must-have" services. Some examples of potential new services are:

 

Multimedia video on a mobile handset - The number of mobile TV users is expected to grow exponentially in the coming years and innovative services based on user-generated multimedia content are also rapidly growing in popularity.

 

Network-based gaming applications - Game enthusiasts are increasingly looking to the mobile handset as the "platform of choice" for interactive and collaborative network-based versions of popular games.

 

Triple-play services - Historically, separate providers have delivered residential telephone (voice), entertainment (video), and Internet (data) services over different infrastructures. Today, the ability to offer triple play services can allow network operators to differentiate themselves with the right mix of all three services, at a price point that will retain old customers and attract new ones. As the success of a particular service can not be predicted with certainty, a dynamic environment that can provide the capability to develop and deploy promising new services quickly, add resources to successful services on demand and reduce resources for unsuccessful services - or remove them entirely - is critical.

 

IMS: A Different Approach

 

Designed to work across wireless, wireline, and cable networks, IMS was developed by the Third Generation Partnership Project (3GPP) as an umbrella framework for providing enhanced IP-based services. Unlike other approaches, which are aimed at carrying circuit services on top of IP, the IMS framework allows operators to build an open IP-based service infrastructure that will enable easy deployment of rich multimedia communications services.

 

IMS addresses the following network and user requirements:

 

• The delivery of person-to-person, real-time, IPbased multimedia communications such as voice or video telephony, as well as person-to-machine communications such as gaming, video-on-demand, and web surfing;
• The full integration of real-time communications such as live streaming and chat, with non-real-time multimedia;
• The enablement of multiple services and applications to interact, e.g., video conferencing and gaming or real-time video and instant messaging combined with presence;
• The ability to escalate communications sessions easily, e.g., turning an instant messaging session into a voice session with "one click."

 

The Advantages of IMS

 

As today's network operators seek to converge traditional telecom services such as voice calls and Short Message Service with data services such as email, web browsing, and Instant Messaging, IMS has recently taken on increasing importance. Just as cable providers are exploring the possibility of delivering telecom services along with video services, network operators also would like the ability to provide video services to remain competitive. In addition, customers are expecting converged services, and network operators now have an opportunity to deliver them with IMS.

 

Although IMS has many advantages, the following four are particularly noteworthy to mention: mobility management, service quality, service control, and standard interfaces. Mobility Management. IMS is designed to find users and establish sessions between them regardless of geographical location within an IP infrastructure. One important component holds subscriber data and enables end users (or servers) to find and communicate with other end users. Another important component aids in the setup and management of sessions and forwards messages between IMS networks. Together, these two components provide very efficient mobility management.

 

Service Quality. Quality of Service (QoS) is often an issue for IP-based telecommunication systems. Impairment factors such as latency, jitter, packet loss and echo caused by inadequate bandwidth provisioning, among other factors, can result in unacceptable transmission quality. Voice over IP has been able to grow in popularity because QoS mechanisms have been developed to control impairment factors and guarantee a specific level of quality. Special mechanisms have been incorporated into IMS to control real-time mobile IP communication quality by interacting with and controlling the underlying packet network to ensure acceptable quality.

 

Service Control. Service provider networks are very complex, especially when implemented on both wire line and wireless networks, since providers must deploy a wide variety of services efficiently to a large number of customers on demand. The provider must also be able to manage, control, and bill for these services transparently.

 

To streamline service delivery, IMS focuses on provisioning services efficiently. When a customer accesses a provider's IMS network, a personalized profile is downloaded. Once the system is in possession of this profile, it knows what services the customer is entitled to use and can make decisions about the order in which services are executed, if necessary, and will know which application server(s) on the network are delivering these services. Such a relatively simple structure allows mobile operators to control and manage very complex service delivery in very large networks.

 

Standard Interfaces. Because IMS has a standardized architecture for deploying advanced IP services, a variety of services can be developed independently by third parties for IMS deployment. It also allows some components to be combined to allow operators to use existing equipment and/or simplify their deployment. This facilitates broader service integration, interoperability, and roaming, while also enabling a robust network of innovators to address service provider requirements.

 

Choosing the Right Platform for IMS

 

In the past, modular infrastructures have been prevalent in packet-based data networks where standardization and flexibility have proven their value. However, communications networks have a different set of criteria, and the challenge in the last few years has been to create an infrastructure that can provide the high availability, "five-nines" reliability, and the excellent performance expected of telecom equipment.

 

Because of the success of modular infrastructure in data networks, more than 100 communications industry leaders have been working with the standards organization.

 

PCI Industrial Computer Manufacturers Group (PICMG) to create the Advanced Telecom Computing Architecture (AdvancedTCA or ATCA), a modular platform architecture designed to address the requirements of the communications industry in its move to modularity. Due to the heavy technical demands placed on an IMS, AdvancedTCA is an excellent platform for IMS infrastructure deployment, meeting the differing needs of telecom equipment manufacturers and service providers alike.

 

Satisfying Technical Requirements for IMS

 

AdvancedTCA addresses the following specific requirements for IMS elements:

 

High Availability. AdvancedTCA has a sophisticated standards-based high-availability framework that allows redundancy, shelf management, and other techniques that maximize system uptime for stringent "five-nines" availability. Such availability is particularly critical in the IMS Call Session Control Function (CSCF) network element, which performs call routing; the Home Subscriber Service (HSS) network element, which holds subscriber data regarding service access rights; and the security gateway, which must be functional for users to gain access to services.

 

High Performance for SIP and Media Processing. AdvancedTCA provides 200 watts of power draw per slot, which allows high-performance processors to be used and cooled adequately. This enables a high compute density, which is important in minimizing delay in call setup times in a SIP environment such as IMS. The multimedia processing node in the IMS environment, also known as the Media Resource Function (MRF), can also be software based, allowing for more flexibility in the IMS environment. This allows a full software-based MRF platform to be utilized in conjunction with other software technologies to form a complete multimedia MRF.

 

Video Encoding and RTP Acceleration. Advanced Mezzanine Card (AdvancedMC or AMC) technology can provide the supplemental processing that may be required for rich media environments. For example, specialized DSPs can be used to obtain higher scalability than a pure software environment.

 

Signaling. AdvancedTCA processing boards can be customized via AMC daughterboards to provide connectivity to legacy networks when SS7 or other PSTN signaling is required.

 

Storage. CSCF and HSS elements may require bladed storage for fast access to subscriber data. AdvancedTCA supports a bladed storage architecture across either base or extended fabric interfaces.

 

In-Memory Database. Because an HSS typically needs to keep upwards of ten gigabytes of subscriber information in memory for fast access, it requires the large pool of memory available on today's high-performance processors. AdvancedTCA enables this type of access with linear addressing to 64 bits.

 

Control and User Data Separation. An IMS may require up to four separate networks, and AdvancedTCA can fulfill this requirement with its flexible GbE fabric interface architecture. GbE fabric architecture allows physical partitioning of control and use data, which is critical for security and high performance.

 

Privacy and Security - TLS, SSL. Security features in high-performance systems usually require network processors. Network processor blades can be integrated easily into AdvancedTCA systems either as AMC daughterboards or as standalone boards that integrate into the flexible packet-based backplane.

 

Moving Ahead

 

As service providers continue to work toward a truly converged network, key strategies to consider include: increasing ARPU with new, unique service deliveries; delivering compelling new services quickly to meet the demands of a more sophisticated, fast-paced, and highly mobile customer base; and expanding network services and creating greater customer service value.

 

Building stable, flexible infrastructures that can support the dynamic delivery of new services, including triple play voice, video, and data services, allows network operators and service providers to easily take advantage of new opportunities in the marketplace and stay competitive in today's rapidly evolving market, while reducing customer churn.

 

IMS is moving to the forefront as a top choice for meeting these challenges and is ready to enable the telecommunications industry to deliver enhanced services dynamically for sustained profitability.

 

By Chris Fullam is Director of Product Management, Media Service Provider Products, Dialogic Corporation (www.dialogic.com).