Satellite Personal Communication Networks Research Articles

Interference Mitigation in Satellite Personal Communication Networks Using Adaptive Antenna Arrays and Filtering Technique

We address the problem of interference as related to Satellite Personal Communication Networks (S-PCNs). Basic low Earth orbit (LEO) constellation is considered. The paper uses combined adaptive antenna arrays and adaptive filtering technique. This hybrid linear adaptive technique provides improved performance eliminating interference, particularly uncorrelated signals residing in the antenna sidelobes.

Iteration-based identification of faulty links in LEO/MEO satellite communication networks

Satellite systems are going to be an important part of the future personal communication infrastructure. The first-generation candidates for satellite personal communication networks (S-PCN) will rely on low earth orbiting (LEO) and medium earth orbiting (MEO) constellations. For LEO satellite systems employing intersatellite links (ISLs), we present a iteration-based algorithm to identify faulty links, which applies to a satellite network assuming a connection-oriented network structure, e.g., ATM or ATM-type switches on-board satellites. In the algorithm a management satellite can autonomously and real-time identify a ranked list of the most probable failed network links through building discrete-time dynamic virtual topology graph (DT-DVTG), then testing can be used to quickly pinpoint the actual faulty links. The performance of the algorithm is evaluated through simulations.

Payload nonlinearity impact on the Globalstar forward link multiplex. I. Physical layer analysis

Forthcoming satellite personal communication networks (S-PCNs) like Globalstar are going to use bent-pipe transponders and an active phased-array antenna in conjunction with code-division multiple access (CDMA). Efficient payload operations require operating the on-board power amplifiers (PAs) close to their saturated power whereby distortion effects cannot be neglected. This paper analyzes the impact of solid-state amplifiers on the Globalstar forward link multiplex when a single PA per beam is used and for the more practical case of an active phased-array satellite antenna. It is shown that the conventional noise power ratio (NPR) intermodulation figure fails to accurately predict the end-to-end system performance. Multibeam active-phased array is shown to provide superior performance compared to a system employing a single amplifier per antenna beam.

Satellite systems for personal communication networks

The paper addresses some issues related to Satellite Personal Communication Networks (S-PCNs). The role of satellite communications in that scenario is discussed, and some characteristics of S-PCNs are identified. In addition, the problem of the integration of S-PCNs with the Universal Mobile Telecommunication System (UMTS) is considered. In this respect an original methodology for accomplishing such integration is proposed; such methodology aims at avoiding complex protocol conversions at the interfaces between the terrestrial and the satellite segment. The paper is partly based upon the work performed by the authors in the framework of the European Community INSURED Project “INtegrated Satellite UMTS Real Environment Demonstrator”.

Satellite systems for personal communication networks

The paper addresses some issues related to Satellite Personal Communication Networks (S-PCNs). The role of satellite communications in that scenario is discussed, and some characteristics of S-PCNs are identified. In addition, the problem of the integration of S-PCNs with the Universal Mobile Telecommunication System (UMTS) is considered. In this respect an original methodology for accomplishing such integration is proposed; such methodology aims at avoiding complex protocol conversions at the interfaces between the terrestrial and the satellite segment. The paper is partly based upon the work performed by the authors in the framework of the European Community INSURED Project “INtegrated Satellite UMTS Real Environment Demonstrator”.

A dynamic routing concept for ATM-based satellite personal communication networks

Satellite systems are going to build a part of the future personal communications infrastructure. The first-generation candidates for satellite personal communication networks (S-PCN) will rely on low Earth orbit (LEO) and medium Earth orbit (MEO) constellations. A noticeable trend in this field is toward broadband services and the use of ATM. For LEO satellite systems employing intersatellite links (ISLs), this paper proposes an overall networking concept that introduces the strengths of ATM to their operation. The core of the paper is the design of a new routing scheme for the periodically time-variant ISL subnetwork, discrete-time dynamic virtual topology routing (DT-DVTR), and its ATM implementation. DT-DVTR works completely off line, i.e., prior to the operational phase of the system. In a first step, a virtual topology is set up for all successive time intervals of the system period, providing instantaneous sets of alternative paths between all source-destination node pairs. In the second step, path sequences over a series of time interval are chosen from that according to certain optimization procedures. An ATM-based implementation of DT-DVTR in LEO satellite ISL networks is presented with some emphasis on the optimization alternatives, and the performance in terms of delay jitter is evaluated for an example ISL topology.