Can the IMS, along with Advanced TCA, enhance converged service delivery after all? Is that why it is generating renewed interest from operators?
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.
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: 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 cannot 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.
Different Approach
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, IP-based 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."
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 others. 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
Impairment factors such as latency, jitter, packet loss and echo caused by inadequate bandwidth provisioning, among other factors, can result in unacceptable transmission 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
When a customer accesses a provider's IMS network, a personalised 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.
Standard Interfaces
Because IMS has a standardised 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.
Choose the Right Platform
In the past, modular infrastructures have been prevalent in packet-based data networks where standardisation 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.
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. AdvancedTCA addresses the following specific requirements for IMS elements:
High Availability
AdvancedTCA has a framework that allows redundancy, shelf management, and other techniques that maximise system uptime for stringent "five-nines" availability – particularly critical in the IMS Call Session Control Function (CSCF) network element, and the Home Subscriber Service (HSS) network element.
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, important in minimising delay in call setup times in a SIP environment.
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, specialised DSPs can be used to obtain higher scalability than a pure software environment.
Signaling
AdvancedTCA processing boards can be customised 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.