Telecommunications convergence towards services evolution
Simultaneous use of several services through different systems with a single terminal is an important issue for wireless communications, as high demands on data transfer rates are anticipated. The foreseen convergence of services intends to provide the broad interoperability needed for users to seamlessly switch among different systems based on whichever is the best connection at the time. Within the European project FLOWS, research and development in emerging wireless communication technologies was based on this 'Always best connected' concept for ensuring continuity of services. More specifically, to enable the mapping between different services and multiple digital standards, a convergence manager was developed at the Technischen Universität Hamburg-Harburg in Germany. The term 'standard' was used in the framework of the FLOWS project to designate a single or a collection of specifications, which apply to standardised radio communication systems. Standards such as the Global System for Mobile Communications (GSM), the Universal Mobile Telecommunications System (UMTS) and High Performance Radio Local Area Network (HIPERLAN), each defined a specific radio access scheme. For mapping services to standards, different criteria needed to be evaluated in order to ensure that it will benefit all involved actors, including end users, network operators and service providers. The final decision would be made on the basis of the different Quality of Service (QoS) requirements, the network capacity and channel status, as well as the mapping policy among others. However, the benefits from mapping services to different standards depend on the location and the complexity of the convergence manager's functionality. As possible hosting entities, the terminal and components of the access, core and backbone network components were proposed. Moreover, extensive simulations were carried out to evaluate the advantages of the possible locations of the convergence manager along with the constraints imposed. It was found that it is imperative for the mobile terminal to have a convergence manager module, although an additional module in the core network would provide the most flexible arrangement. At a technical level, it will enhance the Quality of Service (QoS) in telecommunications transmission facilities optimised for particular data applications, such as speech telephony and asynchronous data transfer.
