When a robot arm(s) conducts some tasks on a satellite, the satellite attitude stability is necessary against the robot arm's motion to maintain the communication link and to generate electrical power from the solar panel(s). However the reaction from the robot arm is much stronger than the natural environmental disturbance torque that the traditional satellite attitude control system cares. Na...

In satellite communication, Spatial Division Multiple Access (SDMA) has become one of the most promising techniques that can accommodate continuing increase in the number of users and traffic demands. The technology is based on radio resource sharing that separates communication channels in space. It relies on adaptive and dynamic beam-forming technology and well-designed algorithms for resourc...

In recent years, free space optical (FSO) communication has gained significant importance owing to its unique features: large bandwidth, license free spectrum, high data rate, easy and quick deployability, less power and low mass requirement. FSO communication uses optical carrier in the near infrared (IR) and visible band to establish either terrestrial links within the Earth’s atmosphere or i...

Wireless communication systems are considered a favourable information infrastructure for many developing countries, because they are easier and cheaper to introduce and to maintain, especially in remote and less developed areas. In this paper we present the application analysis of a distributed health care information system in Tanzania, and study which wireless communication technologies are ...

According to structure feature of satellite network management, the global policy servers and the local policy servers have been established. Function modules of satellite networks were designed on the base of system architecture, such as policy management tools, policy library, policy decision point and policy execution point, etc. The policy description method based on XML has been implemente...

this paper focuses upon the development of an efficient method for conceptual design optimization of a satellite. there are many option for a satellite subsystems that could be choice, as acceptable solution to implement of a space system mission. every option should be assessment based on the different criteria such as cost, mass, reliability and technology contraint (complexity). in this rese...

LEOS communication systems are rapidly moving from dream to reality. When operational, the LEOS systems can offer mobile and fixed-site communications between any two points on the globe. Yet, many LEOS system design issues remain unresolved. Some of the planned systems, such as Iridium and Teledesic, rely on intersatellite communication to provide space based routing from origin to destination...