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Service innovation in Next Generation Networks

By Valérie Blavette, Eurescom

Next Generations Networks (NGN) have been fashionable in telecoms for some years. Their success will depend mainly on services. NGN services are the crucial factor for deciding on investments in NGN equipments.

NGN “switches” are as expensive as PSTN switches. The assumption that operational costs will be lower due to scales saving is not a sufficient incentive for Telecommunication operators for installing NGN networks to replace their legacy transit network equipment.

Another important factor is the lifespan of a PTSN/ISDN switch, which ranges from 20 to 30 years. If TDM switches are only replaced by NGN switches when they have become obsolete, it could take up to 20 years to have them all replaced.

Therefore, quick investment in NGN equipment is only justified, if this creates additional profits, and it will only happen, if new revenue-generating services are introduced.

Characteristics of Next Generation Networks
A main feature of NGN networks is the separation between the transport layer and the service layer. This has the advantage that services are defined independently from the underlying technology.

The NGN concept was born, when engineers tried to combine the best of two different worlds: the adaptability of the Internet networks and the Quality of Service of the fixed networks (PSTN and ISDN).

The core NGN is a packet IP-based network, which supports data and real-time services such as telephony. Moving to an NGN architecture means moving to a multi-service core network replacing a number of separate core networks largely dedicated to one service type (e.g. telephony for the PSTN network, data services for the internet).

In an NGN architecture, however, diverse access networks will coexist. The NGN service layer should be independent from the underlying networks including the access networks. As a consequence, users should experience a continuity of services when they roam from one access network to the other. In practice this is realised through the NGN service architecture and user profile.

While separation of the network and service layers is the first characteristic of NGN, their second important characteristic is the openness to third-party service providers.

There will be a lot of new players providing services, and this will facilitate and accelerate the introduction of new services. It will even be possible for users to develop their own services.

NGN service challenges
Customers generally do not attach much importance to the network technology. They are rather concerned with the usefulness of the service and the Quality of Service (QoS).

To be convincing and successful, NGNs must provide the traditional telecom services with similar or better Quality of Service as well as new attractive services. These are two different challenges, which need to be addressed.

Traditional service QoS
The first challenge concerning the provision of traditional telecom services with similar or better Quality of Service and enhanced functionalities is not exactly as easy as it may seem.

Besides the capacities of the NGN core network itself, the different access networks have different constraints on QoS. Some access technologies like ADSL already allow advanced and interactive services. Later VDSL will bring further possibilities but this is not expected to happen in the next two years since the required investment in fiber is heavy.

Telephony and access to the Internet (web browsing, e-mail, file transfer, e-commerce, chat, news groups) will be part of the minimal package offered by telecom operators to the customer. NGN architecture allows an enhanced provision of already existing services like other data services (SMS, MMS), video on demand, videotelephony, videoconferencing, digital TV channel distribution and other multimedia services (telelearning, telemedicine, online gaming…).

For high-speed Internet the user will be able to dynamically choose between different service levels. The Quality of Service level will be part of his user profile.

NGN will allow enhanced videotelephony with included presence management (buddy list, black list and more). Besides interoperating with PSTN, the videotelephony service will also interoperate with the 3G mobile network videotelephony and could be supported in WLAN and Bluetooth access networks. Before videotelpehony the immediate difficulty however is to offer the same quality of service in NGN telephony services compared to PSTN or ISDN.

Concerning video on demand, this service has already been available via cable and satellite TV and could be enhanced if offered in an NGN architecture. In order to provide true video on demand, a dedicated video channel must be reserved between the video server and the user equipment. It has to be noted that high quality video needs high transmission bandwidth and storage capacity and as a consequence a high cost for providing the service through NGN.

Concerning digital TV channel distribution, customers have already been used to digital broadcast satellite and DVD quality. The contents will have to be adapted to this new distribution technique The use of ADSL is promising in terms of interactivity and bandwidth (up to 8 Mbit/s for ADSL+). Possible innovative features are search functions, reminders or tape recorder functions, as analysed by Eurescom project ANFINA [1].

Most of those services will in the longer term provide nomadic functionalities making use of the NGN service architecture and user profile. Thus, NGNs provide a real value-added service.

Creating innovative services
As a second challenge, telcos will have to use their imagination to go out of the frame of their traditional communication services to use the full power of the NGN architecture.

Innovative services will be introduced gradually in the medium-long term and meet the foreseen interest of customers for, among others, a wide range of multimedia services.

To understand the variety of services that can be offered on top of NGN, let us first have a look at the NGN architecture (see figure 1).

An NGN architecture includes a service creation environment, and a service execution server, usually called ’application server‘ as well as the following network service components:

  • Framework: providing functions for the secure and controlled access by external applications to the Network services, AAA functions and support of upgrading of network functionalities.
  • Communication server: providing communication control function for both synchronous and asynchronous communications.
  • Directory server: providing static data about the service and the user profile.
  • Context server: providing dynamic information about the users and devices such as location status, availability, on-going session related information.
  • Media server: enabling the interactions between users and applications through different devices. As an example it may answer a call and play an announcement, use speech synthesis to read an e-mail, use voice recognition to send input to an application according to some voice command and more.
  • Media gateway: providing the media translation between the access network media format and the NGN packet network media format.

Many services are possible in the context of this architecture. A recent Eurescom study on NGN service concepts [2] has identified promising service scenarios in an NGN context. Researchers from six countries have explored the needs of prospective customers and developed some ideas for future service concepts. To check the pertinence of these service concepts, the next step is to validate them against daily-life user scenarios.

The technical feasibility is then to be evaluated. The Eurescom study team examined technologies like SIP (Session Initiated Protocol), OSA/Parlay API, Web Services and Mobile Agents to evaluate their suitability for the implementation of the network services components described above and to detect technological gaps.

Finally the study team investigated whether the service concepts could be implemented on top of the network service components, as well as their business feasibility.

Below are two service examples that can be implemented within an NGN architecture without too many technological obstacles:

“Let’s meet” service
The “Let’s meet” service is based on the intuitive concept of helping people who should benefit from meeting each other (similar interests, help needed,…). A matchmaking service would be a particular example of the “Let’s meet” service. Another example could be, for instance, helping some colleagues to meet in an airport without having to know each other’s mobile phone number.

Community communication services
Some community services, such as community portals, have already been developed. However, community services are still in their infancy, and we can expect to get interest for more advanced services allowing users to work, debate, exchange information, do business, play, teach, learn, and more. Community services could be enjoyed by e.g. the parents of the children in the same class at school.

The strength of Next Generation Networks is to build a single architecture, which will allow the provisioning of existing services as well as paving the way for completely new services.

It is important that similar or better Quality of Service is provided for the already existing services.

Regarding new services, the business opportunities are high but require that business is shared with third parties by opening the NGN service platforms in a secure and billable way.

[1] Eurescom project P1303 “ANFINA: Access Networks control Functions and Interfaces in NGN Architectures”, http://www.eurescom.de/public/projects/P1300-series/P1303/

[2] Eurescom study P1341“NGN service concepts”, http://www.eurescom.de/public/projects/P1300-series/p1341/

Valérie Blavette
Since March 2000 she has been supervising research projects at Eurescom in the areas of: NGN, Service platforms, Internet networks and services, e-commerce, Fraud and Security, and wireless technologies (12 projects, among them: P1341”NGN Service Concepts” and P1303 ANFINA:

“Access Networks control Functions and Interfaces in NGN Architectures”.

She started as R&D engineer in France Telecom Research Center FTR&D (formerly known as CNET), in the field of Broadband networks and services in Lannion in 1994, after a training period at NTT Commutation and Switching Laboratories, Musashino (Tokyo).

She had been contributing to a number of standardisation activities: first ETSI NA1 (work group “broadband user interfaces, services and charging”) and then ITU SG11 in the area of IN evolution in 1998-2000. In parallel she had been taking part to a number of International projects, among them EURESCOM P506 and P607 projects on ATM networks, and the TINA-IN initiative in the area of the service platforms. In particular she had been leading the task “Architecture for IN evolution and IN-Internet integration” of Eurescom P909 project using PARLAY specifications.

Educated in France and Poland, she graduated from “Institut National des Telecommunications” (INT) a French “Grande Ecole” in 1993.

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