Multimedia Services

... convergence of services and growing development of applica-tions based on a combination of ... the issue of simplifying the regulatory framework to adapt to this new situation [3 ... 737, “Review of Spectrum and Regulatory Requirements to Facilitate World-wide Harmonization of ...

Powerful computers and affordable digital media appliances result in a rapid growth of possibilities in the field of multimedia applications. There has been a significant increase in creation and use of multimedia content. Nowadays everybody can be treated as a potential creator and user of multimedia content. In order to deliver multimedia services to end-users, many parties are integrated and a series of Web services is accessed. A Web service in the composition can become unreachable by a number of circumstances, which requires run-time actions to replace it by another compatible Web service. A Web service can also perform less well than guaranteed, which also requires action in order to fulfill QoS requirements. To answer these requirements, we designed a broker middleware offering dynamic selection and composition of Multimedia Content Delivery services and automatic load balancing of these services over the available application servers. Since users want fast and reliable conn...

Abstract—The paper reports on recent developments and challenges focused on multimedia distribution over IP. These are subject for research within the research project” Routing in Overlay Networks (ROVER)”, recently granted by the EuroNGI Network of Excellence (NoE). Participants in the project are Blekinge Institute of Technology (BTH) in Karlskrona, Sweden, University of Bradford in UK, University of Catalunia in Barcelona, Spain and University of Pisa in Italy. The foundation of multimedia distribution is provided by several components, ...

The possibility to provide multimedia services over a wide area using small mobile terminals represents a challenging task. This task is even more challenging especially if high frequency bands are used and high service availability is required, considering that the atmospheric conditions are very severe and geographically variable within a wide area. The use of high frequencies is necessary to provide wideband services at high data rate for a large number of users and the link availability has to be comparable with that provided by other systems working at lower bands. In the frame of the Advanced Communications Technologies and Services program of the European Union a team of thirteen partners is working since September 1995 on the design of a satellite system named SECOMS (Satellite EHF COmmunications Multimedia Services) (Losquadro and Vatalaro, 1995; Losquadro, 1996). The system aims at providing multimedia services by means of GEO satellites utilising set‐top or palm‐top terminals working respectively at Ka‐band (20/30 GHz) and at EHF‐band (40/45 GHz). Within the SECOMS project the problems mentioned above have been studied in depth and the main system parameters have been finalised. This paper aims at a description of the main system characteristics of the SECOMS project and suggesting a design approach for satellite systems providing multimedia services to mobile users. The proposed approach consists in providing an adjustment (static or dynamic) of the satellite EIRP among the spot beams to get the same link availability within the coverage area using the same terminal, considering that the distribution of rain fade statistics depends on the location. To this aim several technical solutions can be adopted.

The convergence of telecommunications, computing, and content industries has been one of the major trends during recent years. The convergence has led to the creation of a wide range of multimedia services that are available in digital form through the Internet. There is a need for user and terminal mobility supporting both personal communication and multimedia services on top of the Internet. To help meet this need, this paper presents ongoing research on the Fourth Generation (4G) roaming and mobility model. The 4G model is compatible with existing IP standards. The basic elements of the model are described and the model is compared to the GSM (2G) model.

In this paper we are concerned with broadband wireless access via high altitude platform system, providing the Internet access and broadband multimedia services to passengers equipped with WLAN terminals connecting through a collective terminal mounted on the train. The main challenge in such scenario is the development of efficient and reliable radio interface for the broadband communication link in the mobile wireless access segment. We are focusing on performance analysis of the adaptive coding and modulation scheme in the communication link between a high altitude platform and a collective terminal on-board moving train. In order to increase the reliability of the communication system in a fading environment we also exploit space and platform diversity. The proposed approach significantly increases the throughput of the wireless access system, while bit error rate remains below the target value regardless of the considered propagation environment.