Fixed Mobile Convergence -
A Pre-IMS Solution
Fixed Mobile Convergence Migration for Cable Operators
Moving From Next Generation Network to IMS Environment
The growing market demand for service convergence is the driving force behind the development of IP Multimedia Subsystem (IMS) and Wi-Fi / cellular integration, commonly known as fixed-mobile convergence (FMC). FMC has become a recurring theme amongst service providers such as cable operators worldwide, many of whom are seeking to deliver combined fixed-mobile services to their customers as part of a ‘quadruple’ service bundle.
Whatever form these services take, they will require operator investment in network infrastructure, subscriber devices, and back office systems. But there are immediate, viable, standards-compliant FMC solutions on the market now that migrate forward into an IMS environment without stranding capital investments – and that provide for a graceful customer experience during the network evolution.
FMC as a Value
Creating
Opportunity for
Cable Operators
The IP Multimedia Subsystem (IMS) or PacketCable 2.0, which lies at the core of Next-Generation Networks (NGN), delivers user oriented broadband services over multiple types of access networks in a way that is transparent to the end user. An IMS-based NGN is the ultimate target. The key challenge is how to migrate existing networks to reach this target while still taking advantage of shorter-term revenue opportunities from, for example, fixed mobile convergence.
Fixed mobile convergence promises a superior user experience delivered cost-efficiently and with welcomed convenience. FMC enables a differentiated MSO ‘quadruple play’ bundle to attract and retain customers as well as gain momentum with MSO broadband services. But this isn’t just about voice.
More and more, video and multimedia are seen as the means to capture customers and differentiate from voice-only solutions like Skype and Vonage. And for MSOs there is unique opportunity to leverage their relationships with content providers to deliver content to mobile devices. The key to a successful FMC business is to compete not on price, but with value-added IMS-based services.
Today’s
Approaches for
FMC
Unlicensed Mobile Access (UMA)
UMA provides GSM services over a WLAN air link with built-in roaming and handover between WLAN and GSM. It offers operators value in two ways: it lowers cost by offloading traffic from the macro cellular network to low-cost IP networks, and it creates more revenue opportunity by allowing mobile operators to increase indoor voice minutes.
But while UMA may be appealing to GSM operators, there are several drawbacks with this approach:
It applies only to GSM operators and is not ideal for a cable operator that would
like to put traffic directly on its IP backbone;
It doesn’t provide any new end-user services: only connectivity to legacy voice
Fixed Mobile Convergence -
A Pre-IMS Solution
UMA is not based on SIP. This is a particularly strategic drawback because the
IMS architecture adopts SIP as the underlying protocol; and
It doesn’t accommodate SIP-compliant devices, which will be implemented on all
WLAN compatible devices in the long term.
SIP-Based pre-IMS and IMS for Voice Call Continuity (VCC)
The IMS framework is being developed within the Third Generation Partnership Project and is designed to provide operators with a common service delivery platform across wireless and IP networks. CableLabs has adopted the IMS framework as the basis for PacketCable 2.0. Voice call continuity, currently under development in 3GPP R7, extends an IMS network to cellular coverage and addresses handover. It provides seamless voice call continuity between the cellular domain and any IP-connectivity access networks that support VoIP.
IMS-VCC provides for the use of a single phone number (or SIP identity) as well as handover between WLAN and cellular. It also provides key advantages:
Enhanced IMS multimedia services, such as greater personalization and control Handover of voice calls between a circuit-switched domain and IMS
Integration with other VoIP networks; and Access to service from any IP device.
Lengthy IMS
Deployment
Horizon
Operators recognize the efficiencies associated with IMS, and major system manufacturers are rapidly winning IMS trials and contracts. Many operators will have an FMC component as part of these IMS initiatives. But despite the progress that is being made with mobility based on SIP in the IMS environment, many industry observers concede that SIP-based mobility solutions within the IMS framework are not ready for deployment.
Delayed IMS infrastructure
Many analysts forecast that full IMS switchover will occur in the 2009-12 timeframe for several reasons:
Depreciation of legacy non-NGN infrastructure requires a minimum of 3-5 years The need to operationalize SIP-based FMC solutions as part of the evolution to
longer term ‘All SIP’ service architectures (IMS Release 7 and 3GPP2 MMD)
A weak IMS business case: many IMS services are relatively unproven, eg,
push-to-talk, mobile VoIP, video sharing, and instant voice messaging; and
MSOs are also faced with DOCSIS migration that tends to slow their full IMS
adoption.
IMS phones for FMC – delayed availability
Fixed Mobile Convergence -
A Pre-IMS Solution
But in the meantime, 1.6 billion ‘naked’ SIP phones are predicted to ship between 2006 and 2011 that allow FMC to proceed in pre-IMS and full IMS environments. Third-party developers, Internet brands, enterprises and competing service providers constitute demand. In response, a large number of specialist firms are emerging to supply SIP, FMC and IMS software for mobile phones (PCTel, et al) to create immediate availability of SIP-based FMC dual-mode handsets and client software.
Solution: FMC
Migration Path
for MSOs
Even though end-to-end IMS networks and IMS phones will not be fully deployed for some time, MSOs are not precluded from deploying IMS-compliant FMC solutions ahead of a full IMS transformation.
Pre-IMS Migrating to PacketCable 2.0 IMS
Pre-PacketCable 2.0 or Pre-IP Multimedia Subsystem architectures are being developed to provide an evolution path to full PacketCable 2.0 or IMS as these architectures begin to deploy. As shown in Figure 1, Pre-PacketCable 2.0 architectures are designed to integrate with today’s softswitch architectures to enable FMC service offerings before full PacketCable 2.0 deployment.
The new element in this FMC architecture is referred to as a Mobility Application Server (AS). The application server has two main interfaces. On the IP side of the network it is a Session Initiation Protocol (SIP) proxy and registrar, or in some implementations, a SIP redirect proxy. SIP trunking between the Mobility AS and the softswitch is an option to the link shown in Figure 1. From the cellular network’s perspective this Mobility AS appears as another Gateway Mobile Switching Center. This allows subscribers to be located when attached to the cellular network. The Mobility AS also looks like a CAMEL or WIN SCP. This function is used to anchor calls in the IP network for the purpose of seamless handover. As a result, the solution architecture is very flexible and supports many different deployment paradigms and networks around the
FIGURE 1.PRE-PACKETCABLE 2.0; PRE-IMSFMCARCHITECTURE
Fixed Mobile Convergence -
A Pre-IMS Solution
world.
This architecture enables a single phone number that is independent of the user’s access technology. VoIP-based Pre-PacketCable 2.0 architectures enable the MSO to participate in the value chain by giving them the opportunity to provision subscribers and the services they receive. Another clear benefit of this architecture is its current availability along with its evolution path to PacketCable 2.0. In fact this solution will simultaneously support pre-IMS and IMS deployments allowing for a seamless transition from pre-IMS to full IMS.
The pre-IMS Mobility Application Server evolves into becoming the VCC function in the full PacketCable 2.0 architecture and interfaces with the CSCF (Figure 2.). Only software reconfiguration is required for the transition. The Telephony Application Server (TAS) is a new member of the full-IMS application layer and provides the telephony calling features such as caller ID, etc. For both the MAS and the TAS migration, no service-affecting outages need to occur.
For FMC dual-mode subscriber devices, the migration to a full IMS is straightforward as well. The dual-mode phones can be downloaded from a remote MSO facility with updated client software. And the access points for the WLAN can remain in place with no changes.
IMS Packet Cable 2.0
PacketCable 2.0 is an all IP, SIP based, layered architecture that enables service delivery in an access agnostic manner. The layers (Figure 2) of this architecture are Service, Control, and Transport. Applications reside in the service layer. Switching, QoS, subscriber data, and gateway functions reside in the control layer. The access layer can range from DOCSIS to WiMAX, but the goal is for the core to be access technology independent.
ARRIS Migration Scenario
With its FMC product portfolio, ARRIS’ equipment and software play a substantial role
FIGURE 2. FMC IN IMSENVIRONMENT
Fixed Mobile Convergence -
A Pre-IMS Solution
in the migration scenario for a specific cable operator:
ARRIS moves from being trunking partner with the MSO’s softswitch in a pre-IMS
network to becoming part of the IMS application layer
The ISUP trunk interconnect to the MSO’s softswitch shown in Figure 1. is
eliminated in the IMS environment
The ARRIS Mobility Application Server becomes part of the IMS application layer
as the VCC function in Figure 2.; and
ARRIS calling features migrate to a Telephony Application Server in IMS
environment via a simple software porting operation. Third party supplied equipment and software migration includes:
The media server and voice mail server would move to the IMS application layer –
presuming the suppliers have designed for IMS migration; and
The session border control function remains in IMS architecture - presuming the
suppliers have designed for IMS migration.
Depending on the specific MSO’s IMS adoption, the only stranded capital would the trunk interface to the MSO softswitch, a very minor capital expense.
OSS / BSS
Impacts
With the ARRIS FMC solution, the MSO’s integration for billing, user provisioning, and profile management is simplified. The FMC Mobility Application Server generates the CDR data for each call through the system. The CDR is temporarily stored in the CDR core portion of the MAS. The raw CDR is filtered, consolidated and processed for export to the existing MSO rating and billing system. The export is implemented through a FTP interface as a flat text file, BAF, or other customized format to meet the MSO system interface.
The user profile is created and managed via web-based application using an open API available for customized application. The approach allows for unique service package definitions for family plans, bundled service plans, etc. with minimal MSO capital expense.
To further simplify end-user provisioning, ARRIS provides an end user self profile management capability that is a Web-based application. It is implemented via an open API available for customized application for profile updates, service parameter updates, and call history. This capability keeps the MSO’s FMC general and administrative expense to a minimum.
Benefits of
Migration
Solution
Graceful Customer Experience
Adopting new features: As new user features are incorporated in the ARRIS
solution, they are made available to the consumer via over-the-air downloads to user devices. The customer is not required to purchase new dual-mode handsets or suffer the inconvenience of trips to service centers for feature updates.
Adopting new devices: The ARRIS solution incorporates new dual-mode devices
as they become available providing the consumer a broader choice of handsets.
Operational Integration
Minimal stranded capital investment: As cable operators gradually migrate from
Fixed Mobile Convergence -
A Pre-IMS Solution
pace, common network elements such as application servers, border controllers and media gateways are re-deployed in full IMS PacketCable networks.
Back office systems: Improved service levels from simplified and centralized
operations as well as standard OAMP interfaces minimize operating and capital expense.
Core network operations: Since the ARRIS management system includes built-in
monitoring, provisioning, and diagnostic tools, operators can reduce their operational expenditures through lower staffing requirements, increased productivity, and more efficient problem troubleshooting.
Scalability: ARRIS FMC solution uniquely and efficiently scales from thousands to
millions of MSO subscribers.
Flexibility in adding new services: The ARRIS solution allows cable operators to
use a “pay as you grow” model for an IMS-NGN migration by efficiently adding new application servers for video and multimedia.
Higher Subscriber Loyalty
Churn reduction is achieved by delivering new, bundled FMC services to provide
further improvement in customer retention. In addition, handsets provide for branding and customization for various target MSO market segments.
New Revenue Generation - Now
Pre-IMS FMC available now: The ARRIS approach facilitates immediate new
revenue generation – now – by incorporating FMC service as part of the MSO’s “quad play” offering of voice, video, data and wireless services.
Why ARRIS for
FMC
ARRIS’ FMC solution leverages the existing network infrastructure yet requires no additional changes beyond the appropriate interconnection to the IMS system — addressing all access network types, including GSM/UMTS, CDMA, wireline and cable. ARRIS’ FMC portfolio consists of the Mobility Application Server, certified handset client software, WiFi-enabled eMTAs, and the Telephony Application Server. The ARRIS FMC portfolio stands apart from other offers in three key areas:
Differentiated end-user offering
ARRIS is leveraging its longtime expertise in cable access networks, VoIP and SIP to deliver a customizable and rich user experience with the Mobility Application Server for FMC.
Open client and handset strategy
Pro-active interoperability and collaboration with six leading handset client vendors ensures a market-leading dual-mode client/device solution and coverage of various operating systems, devices, and geography. Our approach accelerates the availability of core FMC capabilities and performance in the devices.
PacketCable standards leadership
Fixed Mobile Convergence -
A Pre-IMS Solution
Conclusion
Perhaps the most common argument against SIP-based mobility solutions is that fullend-to-end IMS networks will not be fully deployed for several years. While this may be true, it does not preclude cable operators from deploying IMS-compliant FMC solutions ahead of completing their IMS infrastructure transformation.