( ETSI Ad Hoc Group on Fixed/Mobile Convergence - Final Report - 11 March 1998) (1) Telecom Italia, V. di Valcannuta 250, Rome (Italy)

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1 (1) Telecom Italia, V. di Valcannuta 250, Rome (Italy) (2) Telecom Italia, V. di Valcannuta 250, Rome (Italy (3) CSELT, V. R. Romoli, 274 Turin (Italy) The term convergence is more and more associated to the fixed and mobile network relation. It is assigned different and somehow controversial meanings, depending on the viewpoint used to look at the process. Convergence can be realised through various approaches, having different impact on involved networks infrastructure; for example the telecommunications operators can decide to provide: Single bill: the subscriber will receive a unique bill for the fixed and mobile traffic Single customer care: a single point of contact for the customers Seamless fixed and mobile services: same user interfaces and procedures in the fixed and mobile environments One service supplier: a single provider for all the offered services Furthermore, in such complex world we can detect several elements that anticipate convergence issues, like for example: the deregulation process that can lead to the opportunity of offering convergent services in both fixed and mobile networks the availability of new enhanced service platforms suitable for both fixed and mobile networks the development of technical standards compatible between the two environment the increasing competition for which customers care is essential in facing the user needs for personalised services the numbering issues including Local number portability that may require optimised routing capabilities Within the standard world, ETSI has provided a definition for FMC, reported in the following: ( ETSI Ad Hoc Group on Fixed/Mobile Convergence - Final Report - 11 March 1998)

2 The above definition does not indicate a specific path for the convergence or a standardisation process to be followed. In fact each network operator or service provider can consider different views and approaches to FMC based on the availability of capabilities that could facilitate the convergence. In this context IN can guarantee a wide range of integration scenarios, from service and management integration up to network integration. Very promising IN applications are related to personal mobility in a competitive environment, with the possibility for the users to migrate to/from different networks, or use different terminals while keeping the same service profile. Based on the growing adoption of IN in mobile network, the dialogue between different IN can guarantee seamless services to the customers. The adoption of shared IN Application Protocols (INAP) and Mobile Application Part (MAP) protocols in the dialogue between the intelligent layer and the PSTN and an unified IN platform serving both networks may be subsequent steps. This service is a basic application of the fixed-mobile convergence and it is typically offered to residential or SoHo customers. It allocates a unique account and number to the subscriber who can be reached under pre-defined fixed and mobile destinations via that number dialed by any calling party. Furthermore, the One Number subscriber will receive a single bill including costs associated with his fixed and mobile terminations activity. The One Number service can include other features to personalize the handling of terminating calls, such as: incoming call screening; fax store and forward; dynamic call redirect; caller name playback; priority caller indication. The advantage for the service provider is twofold: the potential for a high degree of customer retention and the increased revenue margins due to service support to the traffic over other networks and, optionally, towards the voic . The commercial configuration for this service is heavily dependent on the associated numbering and pricing options; for example: use of existing fixed line number: this case requires an agreement with the mobile operator in order to offer discounts on fixed-mobile calls. Regulatory solutions should be envisaged because the routing towards the mobile termination implies an "upgrade" of the fixed line service that has to be made explicit through a different charging scheme (mobility premium); use of existing mobile number: this type of configuration is more a fixed-mobile substitution rather than a convergence approach; adoption of a Personal Number and possibly new tariff schemes to cater for the case of calls directed towards a potentially mobile user. This service may possibly imply a relaxation of existing regulatory constrains. Fixed, mobile and third party service providers can offer this kind of service. From the user perspective, multi-mode terminals represent another kind of convergence enabling the access to different service features (on different networks) through a single physical terminal. The customer may roam in domestic, office, public environments with appropriate service prices, matched to the relevant mobility level and traffic volumes. As an example, outgoing calls placed within a "domestic" range are normally charged according to PSTN (public switched telephone network) costs. An example of service based on the use of GSM/DECT dual-mode terminals is the OnePhone service Using a multi-mode terminal in different networks does not necessarily require that inter-working functions should be made available between the involved networks. In fact, multiple, separate subscriptions can be associated with the same multi-mode terminal. Nevertheless, solutions like the One Number service when

3 combined with OnePhone capability, seem to be very promising from a market viewpoint. Presumably both mobile and fixed operators would be interested in addressing this kind of convergence scheme. In fact customers can use extended mobility services having, at the same time, access to local services with in-door quality while operators realize an integration of market segments and may increase the efficiency of radio resources use in high population density zones. Different service and network scenarios can be envisaged, on the basis of the target customer segment (residential, small business, corporate). Business applications adopt WPABX solutions for the indoor coverage and the GSM network for the external coverage. Additional functions have to be added to the WPABX in order to route incoming calls to the context where the user is roaming. Implementing specific entities that are integrated with the WPABX can solve the problem. The configuration is particularly suited for small, single premise enterprises. Conversely, IN-based solutions are to be pursued for the domestic and corporate (multi-premises) segments. In these cases in fact, centralizing the user location functions (private or public context) and the related (re)- routing mechanisms allows for the adoption of optimal routing schemes. At present, on the GSM/DECT front, dual-mode terminals are still in a pre-commercial phase: this solution integrates indoor and outdoor mobility by offering the possibility of being reached in international, national, local and indoor contexts through a single terminal. A further convergence configuration relies on Unified Messaging features. Accordingly, the subscriber is able to access a single or unified mailbox from heterogeneous networks (fixed/mobile/internet) using different terminals to send and receive various types of messages (voice, fax, ). The subscriber is notified of new messages and can access them through the current termination. In a convergence perspective, two configurations can be envisaged: the multi-number unified box with which all the user s numbers are associated (cellular phone number, one or more domestic or business numbers, fax numbers). The Unified Messaging subscriber can interrogate all his messages by accessing the unified box either by means of a fixed or mobile telephone, or a PC; the single number unified box; in this case, all the incoming messages to the subscription number are routed to the single box where they can be accessed by the Unified Messaging user via the current (fixed or mobile) termination. The implementation of Unified Messaging services does not necessarily imply an integration of the preexisting messaging platforms, but it requires inter-working solutions realizing the appropriate alignment of the involved platforms. For incumbent operators, the Unified Messaging configuration, (particularly if associated with a discount mechanism) could represent a further element leveraging the customer acquisition objectives. The companies mobility requirements together with the growing decentralization of work locations and the use of mobile work-force, drive company management to optimize communications costs. Virtual Private Network (VPN) configurations can fulfill these requirements by integrating fixed and mobile users on a single service platform. This may represent a key opportunity for operators and service providers addressing the business market segment. The VPN service offered by means of an IN solution provides the interconnection of corporate locations (regional, national and international) through the public network. From the customer perspective, typical VPN features include: on-net and off-net calls; private numbering plan; personal call; closed user group;

4 outgoing and incoming call screening; help desk. VPN services are currently provided by mobile and fixed operators in their network, mostly based on IN solutions. The provision of a common service has to take into account the legacy of existing implementations. Therefore, in order to guarantee a smooth migration towards integrated VPN service, the first step is to identify a common subset of features available in both mobile and fixed environments. Then the service offer can be improved by allowing IN interoperability between the two platforms (e.g., in order to adopt a common Private Numbering Plan). All the features provided within an integrated VPN imply to provide a seamless service capability, namely: the VPN subscriber requires that the same service features are available from fixed and mobile terminations (for example, it should be possible to associate both fixed and mobile users with the same Closed User Group, CUG); the VPN user requires that the same user interface be provided on mobile and fixed phones; the VPN user using the same mobile terminal in the public and private environments (the latter served by a wireless PBX, private branch exchange) requires a network independent access procedure. The IN platform is key to enabling the integration of fixed and mobile services. In that respect, the current IN standardisation process in ETSI is aiming at the definition of a capability set based on Core INAP CS3 which should apply for both fixed and mobile networks and lead to an IN integrated architecture. This solution would enable convergent services through a single service provisioning and management chain. Mobility management features for mobile users will be in any case independent of the IN-based service control and will rely again on MAP or MAP-enhanced protocols. The target IN convergent architecture can therefore be based on a single IN platform able to control both fixed and mobile switches and offering a single point of service provisioning and management to the operator [Figure 1]. )0&Ã,1Ã VHUYLFHÃGRPDLQ )L[HGÃ,1Ã VHUYLFHÃGRPDLQ )0&Ã6HUYLFHÃ SURYLVLRQLQJ 6&3 )0&Ã6HUYLFHÃ 0DQDJHPHQW 0RELOHÃ,1Ã VHUYLFHÃGRPDLQ 6&3 6&3 +O5 LE/SSP MSC/SSP Mobility management features for mobile users are independent and managed via MAP protocol This scenario, in most cases where two separate IN platform are already available, requires the identification of a master IN network operator for service delivery and a FMC service provider for customer management and service provisioning. The identification of such roles can have a relevant impact on the existing process for service and network provisioning as well as on the IN platform. However, the above scenario cannot be realised in the short/medium term, at least for the reason that, in most cases, two separate IN platforms are already working in the two reference networks. In this case the target convergent IN architecture can anyway be reached according to a phased approach by

5 adopting, as an intermediate step, the concept of Virtual Home Environment (VHE). A Virtual Home Environment feature offers the user the capability of maintaining his service profile and his terminal usage mode through different networks and can also include the capability of offering the same service to fixed and mobile users. The major problem to be faced with VHE is network interoperability, namely the requirement of giving access to the subscriber profile from a remote access (visited) network while ensuring privacy and security for the data exchanged between the home and the visited network. Furthermore, whenever user data are exchanged between the two networks, a real-time alignment of network databases is needed in order to maintain user data consistency. Concerning the information exchange, two types of functional interfaces should be considered: the control interface, where service and mobility procedures interact. These procedures are activated both in-call and in-between calls, therefore call related and non-call related state models developed for the two networks should be compatible (or, better, the same models should be applicable in the two environments); the data interface, where user data profiles can be accessed and operated on in both networks. Obviously, this type of interaction is eased if the two networks share the same data model. SDP SCP h 3 SDP SCP SCP SCP h 2 SCP 1 SSP SSP SSP Figure 2 (v and h suffixes stand for visited and home respectively). SDP SCP h 3 SDP SCP SCP SCP h 2 SCP 1 SSP SSP SSP In option 1 a direct SSPv-SCPh (Service Switching Point - Service Control Point) dialogue is used between the two networks. With this option, the main advantage is that only one service logic, installed in the home network, is used for call handling and no distribution of the subscriber profile data in the visited network is needed. On the other hand, this scenario requires that user related data be dynamically configured at the SSP level for the local activation of the triggering criteria towards the home IN node. In option 2, SCPv should be able to re-route the IN query to the home SCP, in this case SCPv acts as a

6 mediation node in the SSPv-SCPh dialogue. With this option there is no impact at the SSP network level since the same triggering criteria used for resident users in network v can be adopted for the roaming users as well. A critical point in this scenario relates to the use of an SCP-SCP interface for which a standardized protocol is not yet available. In option 3, an SCPv-SDPh (Service Control Point - Service Data Point) dialogue is used. Here, a single subscriber profile is accessed by the service logic that is duplicated in the visited and home SCP. The impact on the SSP and SCP is low, but the solution requires an alignment between the service offered in the two networks and this is a limiting factor in view of the potential service differentiation perspectives. This article has addressed the role of IN for the FMC framework from a technical point of view, identifying the most important service and architectural aspects together with their impact on the existing telecommunication infrastructure. Of course, from a commercial point of view the acceptance level of the convergent services depends mostly on the attractiveness of the related commercial offerings and on service usability. Operators generally perceive service integration as an opportunity to reduce the customer churn and increase marginal gains. Convergence policies have to be tailored to the market segment they are addressing, i.e., residential, SoHo and corporate. Residential users are mostly interested in convergent service offerings available at home and in main locations, low tariff (similar to fixed), single terminal and single number. For the SoHo market segment convergent services must implies good service quality, a single terminal for business and private usage with independent numbers, one-stop-shopping, simple pricing and charging documentation, value added services. The accessibility to a wide variety of services offered through a single commercial interface, seems to be the key point for the corporate segment. Other expectations are: volume discounts, one-terminal solutions and a common private numbering plan (fixed and mobile). M. C. Ciancetta, G. Colombo, R. Lavagnolo, and D. Grillo, " Convergence Trends for Fixed and Mobile Services, IEEE Personal Communications, Vol. 6, No. 2, April 1999