RAINBOW investigates, through a laboratory implementation, the architectural and integration issues relevant to expected transport and mobility control functions of UMTS. The implementation is based on the conceptual designs developed within the project.
The radio access part of UMTS is implemented mainly to study a "generic" UMTS access infrastructure capable of coping with different innovative radio access techniques and, at the same time, guaranteeing a soft migration from the second to third generation mobile systems.
All local transport and control functions associated with terminal mobility (e.g. handover) are studied by implementing a platform emulating the radio behaviour of the adopted radio access techniques.
The infrastructure is integrated with the B-ISDN network to realise the IN based service functions needed to control the upper layer mobility procedures.
The above diagram shows the relationship between the main objectives of RAINBOW and the basic entities of the demonstrator architecture.
The test-bed implements the UMTS access infrastructure with the relevant transport and control functions. The integration and interworking with IBC are achieved by using National Host facilities to provide B-ISDN Call Control capabilities and ATM transport in the Core/Access Network. The test-bed works in real time to experiment with voice and data traffic.
The integrated test bed will be built on an emulated platform modelling the radio, traffic and user mobility encountered in real environment.
Architectural solutions will be implemented by carrying-out specific laboratory demonstrations adopting second generation systems (GSM and DECT) on the UMTS access infrastructure.
Specific results of RACE II projects relevant to the UMTS network functions and the emulated radio environments are extensively used as specifications for the experiments.
The radio segment of the demonstrator is defined so that innovative radio access techniques, developed by other projects within the ACTS framework, can be managed by the generic mobility control functions. In particular, it is planned to replace the RAINBOW radio path emulator with the FRAMES base stations that will be controlled by the RAINBOW network infrastructure.
A Study will extend the system concepts developed in RAINBOW to analyse the support of the Internet by the UMTS system, and investigate the applicability of the software radio concept and assess the possibility of achieving multi-media/multi bearers calls and inter LE handover.
Summary of Trial
The trials will verify the real time performance of the high-level UMTS protocols implementing registration, location/registration updating, call handling, and handover procedures for both data and speech calls. The trials will validate the detailed specification of those protocols, the implementation of UMTS access network entities, and its interworking with B-ISDN networks. The demonstrator will use two terminals of second generation (GSM and DECT) to prove the migration towards the UMTS, and a third generation terminal to test the UMTS network configuration. The fixed terminal provided by the National Host will not be implemented in the demonstrator. Mobile-to-mobile (both between terminals of the same generation and combined between second and third generation), mobile-to-fixed and fixed-to-mobile calls will be tested. Several handover types will be demonstrated depending with different network configurations. With project FRAMES, joint trials will demonstrate speech and data calls (www browser) with handover.
Demonstrating the feasibility and evaluating the complexity of an UMTS access infrastructure able to cope with different UMTS innovative radio access techniques representing, at the same time, a solution for the migration from the second generation mobile systems (GSM, DCS1800 and DECT) to UMTS.
Contributing to the standardisation process of the UMTS system, within ETSI SMG, ETSI RES03, ETSI NA, ITU-R TG8/1, UMTS Forum, and GSM MoU 3GIG.
Studying possible solutions for the integration of the UMTS Radio Access System in the B-ISDN and IN for both transport (ATM based) and control procedures.
Evaluating the impact of multimedia services and variable bit rate techniques on the transport and control procedures of the UMTS Radio Access System.
Evaluating Internet support.
RAINBOW reflects some of the ACTS Programme strategies in the area of mobile communication for implementing the "UMTS Systems Demonstrators" and developing conceptual studies of the UMTS access network. In line with these strategies, the project proposes a reference configuration for the UMTS system with a single generic functional interface between the UMTS access part and the core network, and the separation of the radio technology dependent parts from the radio technology independent parts. These two new concepts have been presented and promoted in ETSI SMG and ITU-R TG8/1 to obtain a unified view on the evolution of the standards towards UMTS.
The main achievements RAINBOW are:
the design of the real-time emulator with an innovative radio access part;
the description of the trials and the identification of the innovative features that the UMTS will provide;
and the complete specification of the demonstrator architecture in term of hardware/software platforms and interfaces between the various entities of the test bed.
The implementation and integration of the mobility applications with all the procedures relevant to establish, control and manage a call, including the achievement of the emulation of the radio access part are underway.
Operators will benefit from the precise knowledge of the possible UMTS network configurations and their relevant flexibility in terms of service/environment application. Service issues related to the migration from the second to third generation systems will be identified and investigated.
During the third year of work, the demonstrator implementation has progressed.
Manufacturers can verify the basic characteristics of the developed UMTS entities. RAINBOW aims to verify the feasibility and complexity of the Radio Access segment of UMTS. It also addresses the question of the network performance requirements and the relevant impact on the control structure of the implemented entities.
New issues will be identified that are of interest to Universities and Research centres: modelling of innovative radio access techniques; traffic studies and modelling of new telecommunication processes; definition and performance evaluation of UMTS architectures.