To compete with Internet-based VoIP providers, the challenge for service providers today is to deliver a robust suite of multimedia services that converge the Internet with the mobile network cost effectively and profitably. Most service providers are looking towards Internet Protocol (IP) technology at the session layer to make end-to-end delivery of multimedia services cost-effective. For a true IP network to be realized, the most utilized application wireless voice must eventually be transitioned to become IP end-to-end. However, a number of issues prevent service providers from immediately migrating tens of millions of voice users to an all-IP service. Current bandwidth and latency constraints on cellular data access networks and a large investment in IP technology in the core network is required to replace the circuit-switched SS7 and Intelligent Network (IN) technology used by voice.
Instead of this overnight, wholesale conversion to IP, an evolutionary process is needed in both the core and access networks to achieve the all- IP goal. Today, a business case for service providers transitioning to an all-IP network for multimedia service transport remains uncertain. However, voice, as the initial multimedia service, offers a proven revenue and profit solution whose value is substantially enhanced by fixed-mobile convergence by seamless, single-number reach anywhere, anytime. The key is building the bridge with fixed broadband and unlicensed wireless VoIP to achieve rapid user adoption that accelerates the business case for an all-IP network deployment based on the current base of voice users.
Service providers can justify the investment in an all-IP network that conforms to the emerging IP Multimedia Subsystem (IMS) standard using voice as the killer application.
Is There Demand for IMS?
Mainstream adoption of multimedia services is underway. Today, consumers and enterprises are beginning to purchase voice, data, and video services that are delivered across a wide variety of end-user devices and over different networks, both mobile (CDMA/GSM) and fixed (DSL, Cable Broadband, WiFi). As a sign of the growing importance of multimedia over non-traditional platforms, the National Academy of Television Arts & Sciences plans to award a new Emmy category for original programming created specifically for computers, mobile phones, PDAs, and similar devices.
But as the number of separate services, devices, and networks increases, consumers also want a simple and consistent seamless experience with shared information across those networks. To meet this demand, many service providers are considering major investments to support fixed-mobile convergence (FMC) services. Pyramid Research has estimated that traffic moving over a converged fixed-mobile network will grow to over $80 billion in revenues by 2007.
The challenge for todays service providers is to deliver a robust suite of converged multimedia services, cost effectively and profitably. Most service providers are looking to IP technology at the session layer to make end-to-end delivery of multimedia services cost-effective. For a true IP network to be realized, the most utilized application wireless voice must eventually be transitioned to become end-to-end IP. However, there are issues! Current bandwidth and latency constraints on cellular data access networks (EVDO Rev A, 3G) would severely degrade voice service. In addition, in the core network, a large investment in IP technology is needed to replace the circuit-switched SS7 and Intelligent Networking (IN) technology used by voice.
Today, the business case for wireless service providers transitioning to an all- IP network for multimedia service transport remains uncertain. Despite the number of new multimedia service trials, it is too early to be able to clearly make the case for an all-IP migration based on what is currently known about the adoption rates and profitability of other multimedia services, such as Push-to-talk over Cellular (PoC), multiplayer gaming, and mobile TV.
However, voice is a service with a proven revenue and profit potential, whose value is substantially enhanced by FMC. The explosive growth of the Skype-Out voice service that converges IP technology with the PSTN demonstrates the strong market demand for converged voice services allowing Skype to monetize usage in addition to advertisement. At the time of writing, Skype claims five percent of its user base, or about three million subscribers, pay to use Skype-Out for Internet to circuit-switched voice calls. The key, therefore, is building the bridge applications that converge current circuitswitched voice services with fixed broadband/unlicensed wireless VoIP (WiFi) to the cellular network to achieve rapid, Skype-like, user adoption. As Skype has proven, this can accelerate the business case for an all-IP network deployment based on the current base of voice users.
IMS Requirements and Definition
When making the transition to an all-IP network, service providers must keep in mind subscriber demand for seamless functionality and consistency across multiple service provider networks and types. To achieve this, the mobile industry has developed a standard for all-IP operations called Internet Protocol Multimedia Subsystem (IMS). IMS is defined by the third Generation Partnership Project (3GPP) standards body. The IMS standard promises to allow service providers to manage a variety of services that can be delivered via IP over any network type including the mobile networks packet switched domain (GPRS, 1xRTT, EVDO, 3G). With IMS, service providers will use IP to transport both bearer traffic and Session Initiation Protocol (SIP) for signaling.
IMS is a framework for managing robust applications (services) and networks (access) providing multimedia services. IMS defines, among other things, an Application Server to be the network element that delivers services that subscribers use. IMS manages applications by defining control components that all Application Servers must use and share. These shared control components manage housekeeping matters, including subscriber profiles, IMS mobility, network access, authentication, service authorization, charging and billing, interoperator functions, and interoperation with the legacy phone network.
While multimedia services (applications) will operate more efficiently and seamlessly using IMS, many multimedia applications can operate today on a stand alone basis, but control and service systems are dedicated to each multimedia service (increasing operations cost, and limiting bundling flexibility). IMS generates efficiency by consolidating common functions that can be shared by many applications by enforcing common policies (e.g., Quality of Service) across a wide range of applications. The goal of IMS is to make new service introductions faster and less expensive by leveraging IP technology, while providing a consistent and controllable user experience.
Why Deploy IMS and How?
Service providers seem to have embraced a vision of delivering robust multimedia applications that will help differentiate their service from their competitors helping to reduce churn to the Skypes of the world. To achieve this vision, service providers desire to deploy end-to-end IP-based multimedia services via IMS. However, since many of the multimedia applications are new and unproven, it is difficult to prove the business case for a network-wide IMS deployment before these new revenue-generating services can be rolled out and assessed. As such, service providers are faced with the difficult choice: either invest in a new network architecture before demonstrating its rate of return, or do nothing and potentially lose ground to competitors.
However, there is an alternative. Instead of a network-wide IMS deployment and investment, service providers can initiate phased deployment. Service providers can lower their risk by deploying and launching FMC voice and messaging services to prove the business case for network-wide deployment of IMS.
The revenues and profits associated with a known service, like voice, will demonstrate the potential for further investment in the IMS architecture. Furthermore, the investment in FMC capabilities can be leveraged to launch many additional data and multimedia services. Subsequent FMC services benefit from the existing infrastructure and achieve profitability faster.
Key points of consideration for service providers exploring the pre-IMS to IMS evolutionary path include:
1) Network Convergence: Bridging legacy 2G and 2.5G networks with IP broadband networks and allowing user attachment to these networks to ensure delivery of a variety of voice and data applications (including SMS, MMS, Message Waiting, and more).
2) Single Number: Supporting single number identity across any SIP device (PC, mobile device, dual-mode device, etc.) that is best suited to an end users location, interface preference and circumstance.
3) Handover: Offering dual-mode handover between cellular and WiFi networks.
4) Enterprise Connectivity: Connectivity options to seamlessly expand an enterprise extension to the mobile network via SIP and Gateway MSC functionality to popular IP PBX and IP Centrex systems.
In summary, the 3GPP/3GPP2-based and IMS-evolvable approach allows new revenue generating voice and messaging fixed mobile convergence services to be easily and quickly created and tested in pre-IMS target markets before a service provider invests in a full IMS network deployment.
To reduce implementation cost and risk, and to accelerate time-to-market, service providers should seek infrastructure solutions that are future proof and fully IMS-compliant. Any solution needs to be designed to bridge existing 2G and 2.5G networks with the IMS maximizing new revenue generating opportunities, to allow mobile to WiFi handover to be quickly and cost effectively implemented, with a minimal number of new network-based IMS boxes maximizing network operational efficiencies. It also should integrate easily with existing and future SIP-based enterprise capabilities making it the platform of choice for deploying new enterprise-based services. IT
Sanjay Jhawar is senior vice president, marketing and business development at BridgePort Networks. For more information, please visit the company online at www.bridgeport-networks.com (news - alerts).
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