While technologies, regulatory conditions, and service provider business models have changed dramatically since then, overall industry objectives have not. Confronted by continually increasing complexity in devices, signaling and transport protocols, and applications—and by the need to interwork across multiple network and technology boundaries—the telecommunications community has been working hard to develop an architecture that could bring these together in the simplest ways possible.
While both the fixed and mobile sectors each carried out their own work and focused on their specific problems, it was the mobile community that got there first, mainly as a result of the economic downturn that limited fixed-network investment at the start of this decade. 3GPP, the main global coordinating body for 3G network development, initiated work on a concept called IP multimedia subsystem (IMS) that would act as the standard for the converged core network of the future.
With many fixed-network operators now starting to confront issues similar to those anticipated by the mobile community a few years ago, IMS-based solutions are also becoming attractive to them as they face a future based on offering the "triple play" of integrated voice, data, and content services. In this context, IMS is expected to have a major role to play in driving the continued convergence of the fixed, mobile, and wireless sectors and greatly simplifying usability from the end user's perspective.
With first-stage deployments of IMS already being announced by service providers, interest in IMS is rapidly gathering pace with some systems planned to go live in late 2005. One of the significant drivers for IMS adoption is the technology's potential for rationalizing all the different network and service infrastructures that have been inherited by multinational mobile operators as a result of the industry consolidation of recent years.
Particularly acute is the issue of continued interworking with legacy public switched telephone network (PSTN) infrastructures. Hundreds of billions of dollars have been invested over the last century around the world in both access and switching equipment and it will be impossible to completely replace this for many decades, despite the efficiencies of the new IP-based systems. For this reason, interworking between the two domains will remain an important issue for the foreseeable future.
Additionally, if truly global brands are to be established, they must be backed by a consistency in the ways in which services are created, delivered, and managed. Additionally, the use of a single and coherent—yet highly distributed—architecture is essential if system integration and legacy support costs are not to become unmanageable.
This article is intended to explain the role that IMS is intended to have in both the fixed and mobile networks of the near future and, in particular, the impact that it will have on the ways in which our industry does business.
At the heart of the IMS is an all-packet core that fully supports the ever-growing diversity of access technologies including 2G, 3G, wireless fidelity (Wi-Fi), and worldwide interoperability for microwave access (WiMAX), as well as the still largely open concept of fourth generation (4G). Supporting this, a number of other standards bodies are also developing appropriate extensions to allow IMS to interwork with other access technologies such as digital subscriber line (DSL), PacketCable (data over cable service interface specifications [DOCSIS]), and fiber in the local loop.
The prime purpose behind IMS is to enable the seamless convergence of all the communications services that we currently use but are partitioned by the nature of the networks that they run on. While we have become used to using fixed Internet for some transactions, our mobiles for others, and so on, this silo concept is increasingly inefficient and expensive for both user and service provider.
With traditional voice revenues under constant erosion, it is essential that service providers of all types are able to move up the value chain, away from basic connectivity and toward more advanced communications services that include multimedia, messaging, and business and lifestyle applications. IMS has been specifically designed to allow this type of rich interaction between services, allowing users to set up voice or multimedia sessions on the fly, exchange content and messages in highly flexible ways, direct fixed-line voice mails to mobile inboxes, or use presence and availability information to direct calls to the most appropriate person in an enterprise.
IMS also supports the core next-generation network (NGN) objective of openness and transparency. On one hand, the presence of standards ensures that multivendor purchasing strategies can be pursued without an accompanying rise in integration overheads. On the other hand, commercial relationships with content and application owners and aggregators can be protected within a secure framework for financial transactions, supported as well by underlying techniques to guarantee quality of service (QoS) across multiple network and operational domains.
The changing role of industry standards in telecommunications is particularly important here. In direct contrast to the IT industry, standards in telecommunications have generally been established through consensus and through the workings of national and international industry bodies such as the ITU. As the world's networks shift toward becoming open platforms, new technologies must be integrated at an ever-faster rate to achieve continued competitive advantage, placing a strain on increasingly fragile and multisector standards processes.
By providing what is, in effect, a common and open applications platform for both service providers and third parties to use, IMS goes a long way toward helping the telecommunications industry take its first steps toward a truly retail-oriented future, and step away from its utility past.
IMS has a unique ability to simplify this process by opening up the value chain while allowing the network operator to retain control of certain essential functions. While some may argue that the increasing sophistication and power of edge devices eliminates the need for a centralized authority, service providers have a wide number of assets that they can deploy to protect their current positions. The longer-term benefits of IMS must be seen in this wider strategic context—that of turning a communications infrastructure and its associated IT systems into a business-ready platform capable of adding real worth across the whole of the value chain.
Pulling together all these disparate functions and technologies involves invoking a type of holistic thinking that was largely unnecessary in the past. With standardization work spread across a number of bodies—with third-generation partnership project (3GPP) and the OMA being the two main players—it is essential that the underlying framework of the IMS allows interactions in all directions to happen smoothly.
In this setting, IMS provides the network operator with a wide series of functions in the core network that can be used to help them retain their market position and share of revenues. Among these, significant elements include support for the following:
- Presence and availability information-With the network knowing whether users are available for calls and what device they are using at that particular moment, it becomes possible to offer premium services to both private and business customers that ensure that calls or transactions always get through to the appropriate person or device. Examples of such services are already appearing, using, for example, SIP to enable seamless roaming across cellular, Wi-Fi, and fixed-access networks with a single device.
- Location information—If the network knows where the user is, a broad portfolio of location-specific services and applications can be offered to the customer, extending to special promotions in shopping areas or traffic and weather alerts. While location-based services have been feasible for a number of years, they have never really taken off properly because of wider integration issues and problems with the performance of positioning technologies. Here, IMS can be combined with the now ready availability of global positioning system (GPS) and other positioning technologies to finally make location-based services a commercial reality.
- Security and risk management—Sensitivity to security vulnerabilities is finally becoming a serious issue for both business and private users, and the emergence onto the scene of viruses that target mobile devices or the impact of denial of service (DoS) attacks are hitting the headlines. Against this backdrop, customers will be increasingly reluctant to take the do-it-yourself route and will choose instead service providers able to provide a proper trusted services environment.
It is important to realize that customers are already recognizing that there are two aspects to data security. First, there is the security of the messages actually being sent over the network. A number of techniques already exist to protect this in an end-to-end fashion, with the service provider acting as guarantor of the overall network integrity, using appropriate tools to identify and block attempted hacks or spamming attacks, for example. The second important aspect concerns the integrity of the data that the service provider holds about the customer. Issues such as identity theft have a particular importance in the digital realm, where a single password may give hackers access to a range of personal profile and financial information. Service providers have the potential here to act as trusted and highly secure intermediaries. - Shared user data and profiles—While communications service providers have an initial major advantage in that they are already set up to handle customer billing, they can extend this still further by leveraging their control of the increasingly wide range of customer information that will be needed to support advanced services. With IMS able to handle and authorize interactions across a variety of access networks and devices, it becomes possible for them to offer a standardized log-on procedure, almost regardless of the originating device or network. For IMS, this is another important aspect of the mobility dimension-bringing a consistent and common interface to all transactions and billing procedures but being highly agnostic in terms of its functionality.
Profile and preference information can also be used more proactively, encouraging users to build on-line communities of friends, neighbors, and colleagues and making multimedia transactions between them that are easier to build and run. The rise of blogging is an early example of this, which could be easily extended to support communities based on shared interests or common locations. - Flexible charging—In traditional telecommunications, money usually flowed directly from the customer to the operator, with some also directed to interconnect partners. Bills in turn were generally calculated on the basis of call duration and distance covered, with only fairly simple data records needed to calculate the value of these transactions. By contrast, the highly diverse, multimedia nature of NGN services is about to revolutionize this "one size fits all" billing model, with service providers requiring almost infinite flexibility in how they package and price their services to meet smaller and smaller market niches and support far more complex relationships with third parties.
IMS provides a framework to simplify these procedures, making it easier to associate particular service quality parameters with specific customers to create gold and silver service grades, for example, or to rapidly create cross-charging and payment relationships with partners, such as TV programs for televoting or the original owners of brands and content such as film studios. - Service creation and management—Service creation was often a problematic area in the days of intelligent networks (INs). In many cases—although stipulated in the standards in the original Telcordia generic requirements—it was rudimentary or even absent, while service creation today often still demands specialized and expensive skills. One of the important complementary areas to IMS involves the current evolution of standardized service delivery platforms, capable of providing an abstraction layer between service creation and management activities and the underlying complexity of the different protocols and networks involved. New techniques are also being developed that could allow the drag-and-drop creation of new multinetwork and multiprotocol services and applications by nontechnical staff, driving the rapid low-cost prototyping and introduction of new services.
- Transparency of value—With IMS at the heart of both the network and the service environment, data can be readily gathered from a multitude of network elements, end devices, and third parties to produce clarity in billing and associated reconciliation procedures. This will become an increasingly important aspect of communications to fulfill regulatory requirements from an ever-widening range of interested agencies, such as those in the financial services sector.
- Monetizing every transaction—It is arguable that IMS could also be interpreted as the "IP Metering System," given its ability to track and charge for every conceivable transaction that takes place, irrespective of whether this is via a standard credit or prepaid payment systems, or through service-specific micropayments. This, however, will only be possible if service providers are able to exploit a full range of charging trigger functions in real time, and for this we must rely on suppliers providing the relevant interfaces. Once again, this helps communications service providers and network owners to retain their market dominance and opens up bandwidth for the flow of money, as well as data.
Even where the legacy equipment in the network has not been designed to provide the appropriate data, alternatives that use packet inspection techniques to create "charging proxies"—an approach recently implemented by Telcordia—offer an efficient solution. This method allows service providers to rate and bill for complex multitechnology and multisource services in truly dynamic yet cost effective ways without heavy integration overheads.
If much of the IMS flight path remains clouded in commercial confidentiality, it is becoming clear that there are two areas where it could have a major impact:
- Fixed-Mobile-Wireless Convergence. Already major operators such as BT are examining the role of IMS as a tool to offer truly "joined up" services to customers, allowing them to roam freely between fixed, WiFi, and cellular communications both at home and in public spaces. One important issue here lies in allowing customers to connect in the most appropriate way for the service required at the optimum cost - but through a single account and customer profile. For example, content could be ordered over a cellular phone, but delivered through a fixed broadband link to the customer's home.
- User Profiles. Adding to work done by the OMA, the part of IMS dedicated to supporting customer details and preferences might be accelerated to enhance data, messaging, and virtual operator services by providing a much richer, more personalized experience. This, in turn, can help drive take up of advanced services by on-line communities, increasing both revenues and brand loyalty.
- QoS. It will no longer be possible to take a simple, deterministic view of service quality based purely on a few connectivity-based, network-centric parameters. This prescriptive approach will have to be replaced by far more flexible and dynamic methods that can aggregate multiple sources of QoS data based far more on the customer's actual experience of a transaction.
- Service Assurance and Risk Management. These QoS issues are magnified by the fact that communications will increasingly take place across different commercial and technological domains, only a few of which may be actually owned by the primary service provider. Protecting both the integrity of the service and of the primary service provider without any direct control over the entire length of the value chain will present challenges for technologists, business development specialists, and lawyers. Valuable work has already been done in this area through the TeleManagement Forum's Service Management initiative, with key principles reaching the market through commercialized solutions such as the Telcordia® Service Director product.
- Security. The merging of the IP and PSTN worlds opens up the previously protected telecommunications space to the threat of attack from fraudsters and hackers alike. With VoIP calls, for example, needing the same addressing functions as World Wide Web pages require–in this case using ENUM look-ups–even ordinary voice calls can be hit by DoS attacks. Alternatively, both VoIP and messaging sessions could be affected by spoofing and spamming, and service providers need to ensure that both their networks and their customers are efficiently protected.
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