A high capacity mobile communications satellite system for the firstgeneration MSS

1986 ◽  
Author(s):  
R. WIEDEMAN

The world’s only satellite organization providing mobile communications on a commercial basis is the International Maritime Satellite Organization (Inmarsat). This paper reviews the origins of the organization and the needs of the shipping and offshore industry that led to its formation. The current system and its operations are described. The success achieved so far by Inmarsat in providing the satellite capacity for telephone, telex, facsimile and data communications to the maritime community makes it apparent that the system could also be used to provide capacity to the aeronautical community. Also, studies are now being made on future configurations of the system in which it may be possible to integrate a polar-orbiting satellite system, such as Sarsat-Cospas. Inmarsat is proceeding with the procurement of a new series of satellites that would come into operation from 1988. This paper reviews the enhanced capabilities that these new satellites will provide in the context of the requirements for mobile communications via satellite in the next decade.


Author(s):  
Hala Adnan Fadel, Yasser Emleh, Ali Diab

The applications of the fifth generation in 5G communications depend on the Internet Of Things (IOT), meaning that every person and everything will be connected to the Internet, so any tool or device in the house or in the street or any work place will be connected to the internet, and this leads us to the term Smart cities, i.e. data is formed everywhere by any person or any machine and is analyzed in a short time to obtain useful information in a timely manner such as monitoring the health status of patients and the elderly, and monitoring devices and tools at home and determining whether there is a malfunction or a lack of a substance, As well as analyzing the traffic situation in the streets and assisting and warning drivers Non-visual risks, which pave the way towards self-driving cars. Here, machine-to-machine (M2M) mobile communications play a pivotal role in enabling the effective and safe transfer of this information from machine to machine without human intervention at full speed and with minimal delay. This poses more challenges for the future network that must accommodate mobile data and the huge number of devices and sensors deployed everywhere in order to be a large-scale network with high capacity and efficiency [16, RODRIGUEZ.J]. In this article, several scenarios have been tested to evaluate the performance of M2M technology within 4Generation LTE / LTE-A networks by adding an external simulated network load. The results showed that the amount of data sent by the MMS sensors is fully received by the remote host, so we get 100% productivity. As for other applications, the productivity is around 99% and the average delay is relatively small as long as the network operates within the available transfer rates. In addition, the process of exchanging packages takes place almost completely (a small amount of losses).


Author(s):  
Dimitrios Bilios ◽  
Christos Bouras ◽  
Georgios Diles ◽  
Vasileios Kokkinos ◽  
Andreas Papazois ◽  
...  

Long Term Evolution Advanced (LTE-A) technology is considered as the most possible candidate for next generation mobile communications. LTE-A networks offer high capacity and are specified and designed to accommodate small, high performance, power-efficient end-user devices. Similarly to its predecessor LTE, LTE-A incorporates inter-cell interference mitigation methods in order to mitigate interference and to enhance efficiency in bandwidth usage. These methods include power and frequency allocation schemes that allow neighbouring cells and femtocells in heterogeneous networks to co-ordinately share and reuse available spectral resources, in order to avoid performance degradation for interference suffering cell-edge users. In this paper, the authors study the LTE-A multi-cell systems' performance using a simulation framework, which integrates several frequency reuse techniques and provides a user-friendly graphical presentation of the evaluation results. The optimal Fractional Frequency Reuse (FFR) configuration for the user-defined network instance is also determined, based on overall performance and fairness index metrics. Finally, the authors examine FFR techniques in two-tier femtocell/macrocell environments and evaluate them based on the optimization of different metrics, depending on the network operator's needs.


Author(s):  
Ioannis Chochliouros ◽  
Anastasia S. Spiliopoulou ◽  
George K. Lalopoulos ◽  
Stergios P. Chochliouros

The world economy is currently moving in transition from the industrial age to a new set of rules, that of the so-called “Information Society,” which is rapidly taking shape in different multiple aspects of the everyday life. In fact, the exponential growth of the Internet, the penetration of mobile communications, the rapid emergence of electronic commerce, the restructuring of various forms of businesses in all sectors of the economic activity, the contribution of digital industries to growth and employment, and so forth, are among the current features of the new global reality, and they are all considered significant dynamic factors for further evolution and development (Commission of the European Communities, 2005). Changes are usually underpinned by technological progress and globalization, while the combination of worldwide competition and digital technologies is having a crucial sweeping effect. Digital technologies facilitate transmission and storing of information, while they offer multiple access facilities, in most cases without implying subsequent extra costs. As digital information may be easily transformed into economic and social value, this can offer huge opportunities for the development of new products-offerings, services, or applications. Thus, information becomes the “keyresource” and the prime “engine” of the new e-economy (Crandall, Jackson, & Singer, 2003). Companies in different sectors have already started to adapt to the new economic situation in order to become e-businesses (Commission of the European Communities, 2001c). In addition, the full competitiveness of the state in the current high-tech digitally converging environment is strongly related to the existence of modern digital infrastructures of high capacity and of high performance, rationally deployed and properly priced, capable of providing easy, cost-effective, secure, and uninterrupted access to the international “digital web” of knowledge and commerce without imposing any artificial barriers and/or restrictions (Wallsten, 2005). Broadband development is nowadays an essential strategic priority (Chochliouros & Spiliopoulou, 2005), not only for the European Union (EU) but for the global environment. More specifically, broadband can be considered an “absolutely necessary prerequisite” in order to materialize all potential benefits from information society facilities and so to improve living standards (Commission of the European Communities, 2001b). The availability, access, and ultimate use of broadband in both business and residential settings are critical issues. Both businesses and consumers can derive increased benefits from the availability of broadband connection to the Internet, as the technology speeds up some applications and creates entirely new possibilities (Hu & Prieger, 2007).


Author(s):  
Hsin-Yuan Chen ◽  
◽  
Chen-Hung Liu

Global Positioning System (GPS) is based on a satellite system. Much work has been carried out on a non-satellite positioning systems using the existing Global System of Mobile Communications (GSM) infrastructure. This leads to a hybrid GPS/GSM positioning systems in the paper. We purpose to adopt GSM for positioning via an integrated switch design with fuzzy logic, if GPS lose efficacy. This induces four main research features in this paper. (1) Designs with optimal-based Fourier analyzer to achieve error of GPS decrease is presented. (2) New applications of fuzzy set theory are presented to solve the problem of GPS accuracy. (3) An integrated switch of fuzzy logic is designed for selecting GPS or GSM positioning systems. (4) Discussions on various GSM positioning methods are adopted with different error and location parameters of environment.


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