Mobility

September 1, 2006
IMS: A Hook for VAS

Geetanjali Babbar

INTRO -- While in a taxi from the airport, you call your work colleague 'A' on his mobile number to discuss some issues on an important project. You activate the phone’s video mode so that you can show 'A' exactly what you are talking about. 'A' views the images on his mobile while you discuss how best to move forward. Suddently, there is a need to contact your colleagues back in the office. You select the names from your buddy list, and initiate a push-to-talk (PTT) group session. Your colleagues answer that they have a few ideas that they would like you to look at. You switch on your laptop, and invite 'A', 'B' and 'C' from your personal buddy list to join a videoconference. 'B' opens up a presentation and shares it with his colleagues. 'A' is still walking back to the office and participates on his mobile phone, but swaps to his PC when he arrives at his desk a few minutes later. This scenario shows us how simple rich communication can be when supported by IMS.

NEW DELHI -- IP Multimedia subsystem (IMS), which enables person-to-person and person-to-content communications in a variety of modes, including voice, text, pictures and video, or any combination of these in highly personalised and value-added ways. IMS is important as the world of telecom is quickly moving to an all-IP world, where applications, calls, subscribers and their data are all accessible and interoperable via IP-based applications and devices.

IMS can turn an "Intelligent Network" into an "Intuitive Network" that is device aware, application aware, and end-user aware. This means an explosion of personalised mobility services that can increase operator revenue, differentiate service offerings, and empower subscribers.

IMS is clearly the buzz word in the telecom industry and many vendors and service providers are anxious to demonstrate leadership in this area. As a result many recent contract in wireless and wireline markets have been touted as IMS-wins even though there were no IMS-compliant products in the deals. For example, some vendors positioned wireless push-to-talk over cellular (POC) contracts and wireline soft switch contracts as IMS wins.

IMS was originally defined by the 3rd Generation Partnership Project (3GPP) as part of their work for 3G mobile phone systems and for W-CDMA networks. It first appeared with the evolution from 2G to 3G networks for UMTS. SIP-based multimedia domain was then added and support for GSM, GPRS and WLAN was provided. Since then, another organisation, 3GPP2 based their CDMA2000 multimedia domain (MMD) on 3GPP IMS, adding support for their CDMA2000.

There are number of factors driving the industry to turn toward IMS, including that it reduces operational and capital expenses, it has the ability to implement and introduce new services faster, and it facilitates the convergence of different core and access networks, allowing the user the same services no matter the location. The telecom industry is encouraged by the potential of IMS-based platforms to deliver new applications that combine voice and data and facilitate continued fixed-mobile convergence (FMC), which allows for people to use one phone with one number, address book and voicemail, whether at home, in the office, or while traveling outside the coverage of their mobile or fixed network. IMS will make it easier to offer just about any IP-based service, including VoIP, POC, multi-party gaming, videoconferencing, IM, etc., no matter the location of access technology of users.

IMS not only provides new services but also all the services, current and future, that the Internet provides. Therefore IMS will give network operators and service providers the ability to control and charge for each service. Also, users have to be able to execute all their services when roaming as well as from their home networks. To achieve these goals, IMS uses open standard IP protocols, defined by the IETF. So, a multimedia session between two IMS users, between an IMS user and a user on the Internet, and between two users on the Internet is established using exactly the same protocol. Moreover, the interfaces for service developers are also based on IP protocols. This is why IMS truly merges the Internet with the cellular world; it uses cellular technologies to provide ubiquitous access and Internet technologies to provide appealing services.

The IMS reference architecture defines a set of network functional elements, their interfaces and protocols, and network procedures. The IMS reference architecture is agnostic to access technology and legacy technology allowing for its deployment across wireless and wireline networks. It is also designed to let service providers bring to market multimedia applications utilising the Internet paradigm of rapid deployment and cost efficiency.

The IMS reference architecture is the first multi-industry and multi-standard architecture that unifies next-generation services across the user device, access network, core network, and the applications. With the deployment of advanced real-time multimedia applications, IMS enables the service provider to control three important network layers - bearer media, session control, and application. The architecture is being defined and supported by all major wireless and wireline standards bodies including, IETF, 3GPP, 3GPP2, TISPAN, WiMAX Forum, and others.

Possible Applications Using IMS

According to industry experts, new applications will come from the combinational effect when re-using IMS elements from different core applications. For example, a video content store used by a SIP application server for a core offering like videomail could, using IMS, be easily repurposed to support a video blog, video share application or a "rich voice call," not necessarily created by the original vendor but more likely by a new third-party vendor using IMS's SCIM (service capability interaction manager) layer. This creates a new ecosystem that takes out the "vertically integrated" silos of the past and fundamentally changes the time-to-market for network-based applications.

IMS provides an environment where the application layer is somewhat independent from the core network layer, and IMS is enabling the approach for application of "develop once, deploy everywhere". IMS will enable end users to set up voice, video, instant messaging, m-commerce transactions, online gaming and more with a click of a button - in a single session. Applications will have the same look and feel, regardless of how they are connected to the network. As an example how many "contact lists" do subscribers have today? One on their Outlook business e-mail, another on a PDA, a third on their cell phone, a fourth on home wireline phone -- maybe yet another on home computer personal e-mail? With IMS, they could have a single integrated contact list for all types of communications.

Nortel's IMS open solution includes applications for GSM/UMTS, CDMA, wireline and cable service providers. The applications currently being offered include POC, IM, presence, converged mobility, interactive mutimedia gaming, and interactive video across wireless and broadband.

The vision as set by the 3GPP and 3GPP2 was to ensure that all the services, both current and future that the Internet provides, can also be accessed by cellular users. The idea arose to executive these services from both a mobile as well as a fixed environment, such as a home or office. Recognising that the transition to an IMS-based network will take years to complete, however, operators must look at how best to provide new revenue generating services to users while utilizing existing network infrastructures.

A number of FMC service clusters are available to operators now, which work both on IMS networks as well as existing 2G/3G networks. The first cluster is of PC applications, which can transform the PC into a mobile phone. Users can keep all the same services offered to them on their mobile phone, and with one phone number, identity and bill. The second cluster of services operators would provide a mobile line over broadband, working with any fixed device, and providing all mobile services, including voicemail, VPN, ring-back tone, prepaid billing, etc., all adding up to, once again, one bill. Operators can provide users with a dual mode handset, which enables users to have the same user experience using WiFi and GSM/CDMA access. Users would have one phone number and one device, but one that provides for a seamless handover between networks, when crossing over different coverage areas.

However, according to Rich Poole, director, business development, AudioCodes, voice will continue to be the primary application for the near term and beyond, as it produces the most revenue. However, FMC is an important application that IMS enables as it converges multiple access networks using a common IP core network to allow call delivery to the subscriber no matter which access network the subscriber is currently attached to. FMC allows the subscriber to be contacted or to initiate calls while connected to a cellular network, WiFi network or over cable access.

An important aspect of IMS is that it allows for the convergence of applications as well as converging the network. For instance, the subscriber will be able to have a common voice mail system, common prepaid system, and other application servers providing new applications to a subscriber no matter which network the subscriber is connecting from or which subscriber device the subscriber is using, be that a computer, a cell phone, etc.

The exciting aspect of the IMS core network is that service providers can take advantage of the common IP IMS core network to more cost effectively deploy services across multiple networks and multiple device types to increase revenues. One can look at the Internet and the new applications being developed on the Internet to get an idea of some of the applications that could potentially be delivered over IMS, including voice, video, data, etc. Being able to access these new applications using new and existing devices will provide a feature-rich experience for users globally. Users will want their applications on whatever device they are using wherever they are.

IMS: Crowded with vendor offerings?

Mike Katz, director, video products, NMS Communications, said: "IMS offerings to date have addressed primarily legacy voice applications and have not yet extended into new next-generation, lucrative application offerings. Such new applications will combine older services with new uses like video mail to support video sharing, blogging and YouTube.com-like content. While many are planning to enter this space, no one is dominant yet, and the field is not yet crowded."

The current main drivers for introducing the IMS technology is mainly based on reducing the Opex and Capex, which makes their business case clear and can be easily calculated. The current remaining main challenge is to create new IMS-based services that will bring value to the end user on one hand and will have a clear business case and ROI to the operator on the other.

Boaz Goldman, vice president, marketing and business development, Outsmart, supports Mike Katz's view on room for more vendors. "Currently, the IMS-based services offering is limited hence, there is still room for new and innovative vendors," he added.

The IMS space is getting a lot of attention currently, with existing telecom vendors trying to convert their equipment to be IMS-ready. In general, operators are looking for quick and flexible ways to respond to new business opportunities. Today, users are expanding their voice telephony behavior into multimedia services, and therefore operators are trying to deliver a seamless and consistent user experience wherever and however the services are accessed. "Crowded" sounds a bit excessive, but it is true, that few vendors try to position non-IMS (they often call it pre-IMS) solutions to enter the supposed IMS market and pave the way for future IMS positioning. But these solutions are often far away from IMS and can hardly be migrated. At the beginning, operators were receptive to such vertical solutions as long as they quickly could address specific needs (e.g. UMA for WLAN/DSL access) and were easy to introduce. But meanwhile there is a strong commitment to IMS and operators explicitly ask for IMS-based solutions.

Impact On The Telecom Industry

IMS will reshape the telecom market. The current telecom infrastructure was designed for delivering calls, not applications. IMS is designed from the ground up to go well beyond delivering just a call to deliver services and applications that bring new revenues and values to the market.

IMS allows for the physical convergence of gateways and other key network components onto a unified architecture, and thus no stranded investment in one-off solutions. But the true untapped potential of this technology lies in the revenue opportunities it presents, with the introduction of a common application environment that seamlessly delivers services to end users regardless of the device in front of them. IMS significantly reduces development time and allows you to bring new services from concept to market faster.

For service providers, IMS means convenient, converged communications - one-stop, finger-tip access to a plethora of multimedia services. There was a time when technology was allowed for a number of means of communication but there was no synergy between them. Different devices and providers were required for different services and no roaming was allowed. Networks have essentially been individual islands - voice, data, video, e-mail, IM, etc., and traveling from one to the next has meant signing in and authenticating with each other. For service providers, provisioning each new network has been expensive, inefficient and time-consuming.

"IMS allows personalised services to be delivered independent of the type of network and device being used. IMS offers a network framework with common session control, and thus the opportunity to deploy a seamless, simpler, richer set of multimedia services to your customers. A converged network makes efficient use of transport and access media and greatly simplifies the challenges of OSS integration by moving all management systems under a single, common network umbrella," added Malur Narayan, vice president, wireless solutions, Nortel India.

Today, IP or IMS is changing all that, emerging to meet demand. It is, after all, an "always-on" world in which we now live. Consumers want intelligent services that can be personalised across multiple devices and that can be easily accessed anywhere, anytime with a single password.

The impact of IMS is profound. Analysts believe that the IP telephony carrier market is poised to grow from US $1.6 billion in 2004, to about US $4.7 billion by 2010 due to the emergence of IMS. It is expected to bring more competition for services, greater mobility and more specialised services and content. As mobile devices and services evolve, operators and equipment vendors are standardising on the IMS architecture to tap into the high bandwidth of fixed and local-area wireless network resources. "Looking toward the future, we may also see that the whole concept of roaming, when a user travels between different coverage areas, disappear, because IMS will allow for a seamless handover of calls between different networks," said Boaz Goldman of Outsmart.

Dieter Schinagel, head, portfolio management, mobile core department, Siemens AG, said: "IMS is a key enabler of a converging telecom world with seamless service offerings. Today´s communications are separated by different networks and different terminals. In the future, technical progress will efface the borders of networks and terminals. We will communicate without borders, seamless and with any terminal."

Rich Poole of AudioCodes suspects that most networks in the future will migrate to an IMS or IMS-like core network that merges multiple access networks onto a common core network to provide a common user experience. The primary question that remains is when does it make sense to move to an IMS network. Existing operators may choose to deploy IMS over time and continue to use their current networks as well as continue to deliver existing applications over their current networks.

But, as new applications are developed, it may make sense to deploy these new applications on the IMS network to eventually move to the IMS network. Greenfield operators may choose to move immediately to an IMS core network to take advantage of the many benefits of a common core network. As operators begin to offer new applications that are developed and deployed to end subscribers over multiple access networks using IMS, this will force incumbent operators to move to IMS or potentially get left behind not able to effectively compete.

Technology for Service Providers

IMS can provide the operators with a standards-based, consistent, predictable environment allowing best-of-breed choices in infrastructure technology, while enabling delivery of new, creative and uniquely enhanced services. The world's top 20 operators have already committed to either deploy or have a roadmap to deploy IMS services over the next three years.

According to Malur Narayan of Nortel India, the ultimate end goal for service providers is to deliver all communication services over a single converged network. There is a strong motivation to deliver rich, high value services using IMS as well as to accelerate the time to market for new applications and reduce operational costs associated with it. By providing unified identity management capabilities as well as a unique control and application layer serving all the telecoms domains, IMS is enabling these benefits to converged carriers. It is now much easier to mix and match basic applications to built a richer combinational service for the end-user. With IMS you can have a single friends list with presence status whatever device and access network you use, you can activate a gaming session with third party and talk in parallel with your gaming partners benefiting from an enhanced end-user experience.

There are lots of deployments of NGNs and VoIP services. IMS is now on Nortel's agenda because operators securing solutions for NGN, VoIP or R4 core networks want to have a good sense of how these will migrate into IMS. This is why Nortel has one of the most flexible deployment capabilities in the industry leveraging existing operator investments as well as new industry capabilities such as ATCA second generation platform.

Many contracts or deployment claims from the industry on IMS are not real IMS, claims Mulur. Nortel has deployed real IMS testing solutions with the largest operators in each of the four key telecom domains (Wireline, Cable, GSM/UMTS and CDMA) in the US, Asia and Europe.

Nortel is engaged in a number of IMS activities, among which a trial with Verizon Communications, as part of their ongoing plans to evaluate IMS technologies. Nortel is Verizon Communications largest softswitch vendor, with multiple solutions deployed across the US. Nortel's Communication Server (CS) 2000 is part of the backbone of Verizon's nationwide packet network. These softswitches control more than 3.8 million packet trunk and line ports, with the capacity to deliver several million more. VoIP is being introduced into the local service network as well, potentially allowing Verizon Communications to provide customers with network-based services that dramatically increase functionality, mobility and productivity.

IMS deployment is still evolving and still in its early stages. Yet as IMS continues to penetrate the telecom industry, operators are challenged to provide users a smooth migration into a new IMS environment, providing cross network services that can work not only on IMS networks, but also on existing 2G/3G networks. Recognising that the transition to an IMS based network will take several years to complete, it is very important to provide for a clear and smooth roadmap from these pre-IMS services toward a full IMS environment. Operators are looking for investments that will produce revenues for them today in a pre-IMS environment, as well as in the future, in a full IMS implemented industry.

IMS has been adopted by wireline operators, whose networks face similar challenges in going to all-IP next-generation. Because of their wide deployment of broadband, fixed carriers are adopting IMS more aggressively than mobile. For fixed-line, IMS has another, more powerful proposition, which gives fixed-line a platform from which to fight back, namely broadband IP. "IP will ultimately deliver convergence of voice, data, fixed and mobile and this could help create a level playing field between the two halves of the telecom industry -- mobile and fixed line," emphasised Dieter from Siemens AG.

For Gennady H. Sirota, vice president, product management and marketing, Starent Networks, IMS offers an opportunity to offer differentiated multimedia services rapidly, thus providing competitive leverage and brand differentiation against service providers that do not implement IMS. Further more, IMS will provide a long-term advantage as new multimedia services can be quickly added for an incremental cost.

New operators are looking at IMS as a starting point for new networks. Even MVNO (Mobile Virtual Network Operators) and cable operators are looking at IMS as a means for revenue generation, market differentiating features, where they would operate the application servers and maintain call control for their users even thought the calls may be serviced by another operator's network(s). IMS provides a hook for them to insert their value-add. As with any new network architecture, it will take some time for IMS to be deployed as standards firm up and additional capabilities are introduced.

Another important component to the deployment status of IMS is the integration necessary to pull together a complete IMS system as well as add new application servers to the IMS network. This requires the IMS components to be widely interoperable with multiple controllers, application servers, etc.

Last chance to compete against Internet?

There's a classic battle between legacy telecom providers and the new virtual telecom providers like Yahoo, Google, etc., that provide service "over the top" of legacy telecom providers' infrastructure. If the legacy telecom providers don't implement IMS, they will be relegated to bit pipes. It's not good enough to just replace the voice services with IMS services, but they need to match the offerings of the virtual telecom operators, a la Skype.

The IMS true killer app is the ability to speedily create new multimedia services, mix them and deliver them to the end-users across multiple access types. Such services are accepted faster by subscribers than if they were delivered by one access type, e.g. mobile phone or PC or TV. The power of IMS is to unify the service portfolio available to the end-users, in other words, to deliver a particular service or a bundle of services to multiple access devices, e.g. bundling VoIP with 3G/Wi-Fi seamless mobility or IM/presence with IPTV, etc.

As an example, VoIP is one of many services available off the IMS solution. VoIP is very important because voice is the cornerstone telecom service and applications built on top of voice are successful. This is why rich voice services such as voice+picture, voice+video sharing, voice+content push are used as flagship services by IMS community. Obviously, VoIP requires similar voice quality as we know in today's PSTN. However, free VoIP has been available over the Internet but has significant short-comings such as no guarantee of QoS, or non free VoIP when a user calls outside of the VoIP community.

"The IMS and the 'Pre IMS' type of services can assist the classic operators to compete an Open Internet, but the IMS by itself is not enough. The classic operators must continue working hard in bringing higher value to the end user. The way to compete with the new open Internet player is to bring to the end user services and value that the open Internet can’t," added Boaz Goldman of Outsmart.

However, it's not about competing against an open Internet world (you cannot stop it), but integrating it à network and service convergence, means same look and feel over multiple access for seamless end-user experience and thus maximum end-user penetration. Large subscriber communities are key for future success in the context of quadruple play (voice, broadband, content, mobility) and with IMS classic network operators are good positioned in such a converging world.

Rich Poole of AudioCodes is of the view that the open Internet will continue to drive new innovation globally. IMS is not really competing with the open Internet, rather it is complimenting the open Internet, in that it provides a means for end users to access new features and applications, as well as Internet capabilities, not only from their PC connected to their home or hot spot, but via multiple different devices wherever they are whenever they want. This is more complimentary to the Internet. So, instead of being tethered to your PC, you are able to take the Internet with you wherever you go. This new capability will change the way people communicate, work, play, socialize and enjoy life. The world of the wired "black" phone is crumbling and IMS does provide a means to move into the future of telecommunications.

Srikant Shitole, business development manager, Cisco Systems, India & SAARC, added: "While SIP traffic will likely increase significantly over time, non-SIP/non-IMS applications and services dominate the vast majority of IP network bandwidth today and will likely remain present in many provider networks for some time to come. All of these non-SIP/non-IMS applications represent sizable revenue streams for service providers. So, it's important for providers to have networks that support both IMS and non-IMS traffic so that they can provide the most attractive, profitable service mix for their customers."

Business Challenges in Building Solutions

While IMS represents lots of opportunities for new applications, it also represents the opportunity to build bigger and broader silos inside legacy telecom providers that will not provide subscriber access across multiple operators' IMS implementations. Subscribers of a new service or application want to be able to roam and take the application with them on their phone when they're in the foot print of another IMS-based operator. There are no business justifications or business relationships that make sense to enable a subscriber to do this between two competing operators in the same footprint. Without resolution of this basic issue, IMS may be relegated to just voice call replacement.

One challenge which arises is how to migrate legacy users to the next-generation of mobility. While in its initial stages, operators need to test equipment and build confidence in IMS at the same time as retaining customer loyalty through existing services. This leads to a further dilemma for operators "What is the best approach to implement IMS so that operators can provide legacy services to IMS handsets without investing heavily in existing, legacy platforms?"

Operators are also challenged to provide IMS services under all coverage conditions, ensure IMS users seamless service continuity while roaming to 2G/3G coverage areas, and be able to introduce new IMS services to 2G/3G customers. What remains very important is that, recognising that the move to an IMS-based network will take years to complete, mobile operators must provide their customers a smooth transition into IMS, in which users will be able to continue to stick with their trusted and familiar services while switching to new IMS devices.

Another business challenge for service providers is that the initial cost of IMS is high, because it is a new technology requiring many new nodes to handle bearer media, session control and application layers. However, the incremental cost of adding new applications that are service differentiating is driving the business case for the initial investment. This requires service providers to model the ROI appropriately based on long-term benefits of an IMS deployment and evolution.

According to Srikant Shitole of Cisco, IMS is a complex and extensive architecture that will take years to implement fully in an operators network. He doesn't see IMS as an event that will occur in an operators network, but rather a journey that will happen at it's own pace.

Service Continuity is the Key!

The 'many advantages' of IMS have been well documented. However, before nationwide adoption of IMS is to take place, the key for operators is to be able provide service continuity with the transition to the new IMS network, as well as introducing new IMS services over their existing network. This allows users to continue using their trusted and familiar services when changing to new IMS devices, while enabling vendors and operators to get a "head-start" on launching IMS, extending the time in which new IMS services can be tested and proven mature enough for IMS users.

One such way operators can offer converged services to users, while IMS continues to evolve, is to provide for a seamless handoff of calls to those moving between cellular and Wi-Fi coverage areas, since it automatically switches an existing call from one network to the other when the wireless signal level drops in one domain. By doing such, the handoff guarantees continuous coverage without dropping the call and also provides coverage from the best network connectivity available.

For example, a user will be able to receive a mobile phone call at home with simultaneous ringing on all devices, as well as be able to pick up calls from a mobile to a fixed line, all with one voicemail and one prepaid account.

The key for the industry right now is to be able to provide service continuity with the transition to the new IMS network. Operators must provide their subscribers with an IMS service that facilitates the use of current IN services to IMS users, without any change to the IN service logic or platform. This will enable users to continue using their trusted and familiar services changing to new IMS devices, while enabling vendors and operators to get a 'head-start' on launching IMS.

Where Do We Stand?

As far as India is concerned, the present licensing regime is service-specific and does not allow an operator to take full advantage of the technology in an unrestricted manner. While there has been some migration to NGN technologies in the core network by operators, the access network is particularly poor and narrowband and could take many years to be fully transitioned to NGN. Many operators with end users connected to PSTN are migrating to IP-based transport, leaving the access part unchanged. The transition to NGN access will be critically dependent on a number of developments including success of alternate access technologies, Unbundling of Local Loop and market success of triple play services. Further, the awareness about NGN and innovative services it can provide is not yet wide spread nor are the access networks suitable to support these services.