Journal of Electrical & Electronic Systems

Solar energy is the source of the most promising energy and the powerful one among renewable energies. Photovoltaic electricity (statement) is obtained by direct transformation of the sunlight into electricity, by means of cells statement. Greenius is a powerful simulation environment for the calculation and analysis of renewable power projects such as solar thermal trough power plants, photovoltaic systems, wind parks or Dish/Stirling systems. This program offers a unique combination of detailed technical and economical calculations as they are needed for planning and installation of renewable power projects. Greenius is the first simulation environment with comfortable user interface for the analysis of solar thermal power plants, photovoltaic systems and wind parks. In fact, any heat energy source can be used with the Stirling engine. The solar radiation can be focused onto the displacer hot-end of the Stirling engine, thereby creating a solar-powered prime mover. The direct conversion of solar power into mechanical power reduces both the cost and complexity of the prime mover. In theory, the principal advantages of Stirling engines are their use of an external heat source and their high efficiency. Stirling engines are able to use solar energy that is a cheap source of energy. Since during two-thirds of the day, solar energy is not available, solar/fuel hybrids are needed [1]. Two versions of Greenius exist: the standard and the expert version. The expert version has extended input and calculation options for solar thermal trough power plants. In all other points both versions are identical. Greenius distinguishes itself by numerous export possibilities for intermediate and final results. Almost all contents of tables and graphics can be copied to other windows applications or can be saved in other formats. The calculation results are detailed and the extended simulations perform very fast. Greenius was developed at the German Aerospace Centre (DLR). Dr. Rainer Kistner, Winfried Ortmanns, Dr. Volker Quaschning and Dr. Jürgen Dersch belonged to the development team. Marketing, distribution and service are made under licence of DLR [2].

The user demand for high speed multi-media application has been increasing many folds in the recent years. New smart phones are launching in the market. The wireless communication is looking forward for a new generation technology that will match the application demand and resources. This is where the fourth generation (4G) wireless communication is required. 4G wireless communication is expected to provide better speed, high capacity, low cost IP based services. The main objective of the 4G wireless communication is to supersede the current core technology with a single unified technology. More and more advanced interactive multimedia applications are emerging as 4G networks resulting in a rapid development of video coding and communication techniques. This paper deals with the current scenario and the future prospects of the 4G system in addition with the challenges it is going to witness.