TRENDS AND CONCEPTS OF DEVELOPMENT OF COMMUNICATION NETWORKS USING NON-GEOSTATIONARY SATELLITE CONSTELLATIONS

2020 ◽  
Author(s):  
Г.В. Чечин
Keyword(s):  
Communication Networks ◽  
Performance Indicators ◽  
Information Exchange ◽  
Multiple Access ◽  
Communication Channels ◽  
Satellite Communications ◽  
Geostationary Satellite ◽  
Exchange System ◽  
Satellite Constellations ◽  
Communications Networks

Рассматриваются тенденции и концепции построения спутниковых сетей связи на базе негеостационарных орбитальных группировок. Анализ существующих и перспективных сетей основан на большом количестве показателей эффективности, таких как параметры орбитальных группировок, типы антенн, построение системы информационного обмена (протоколы многостанционного доступа и разделения каналов связи, протоколы маршрутизации и передачи информации по каналам связи), а также стоимость. The trends and concepts of satellite communications networks based on non-geostationary orbital constellations are considered. Analysis of existing and prospective networks is based on a large number of performance indicators, such as parameters of orbital constellations, type of antennas, construction of an information exchange system (protocols for multiple access and separation of communication channels, protocols for routing and transmitting information over communication channels), and cost.

Modifi cation of the CGR-Algorithm on Data Routing in a Communication Network of Satellite Constellation

2020 ◽  
Vol 21 (2) ◽  
pp. 75-85 ◽  
Author(s):  
O. V. Karsaev
Keyword(s):  
Communication Networks ◽  
Data Storage ◽  
Communication Channels ◽  
Adaptive Method ◽  
Satellite Constellations ◽  
Network Nodes ◽  
Contact Graph ◽  
Data Routing ◽  
Promising Solution ◽  
Contact Graphs

Communication networks in space systems involving the use of satellite constellations are DTN networks (Delay and Disruption Tolerant Networks). The establishment of communication channels in space communication networks has certain specifics: communication channels can be planned. In this regard, the CGR approach (Contact Graph Routing) is considered as the most promising solution to the problem of data routing. At the basis of this approach, taking into account this specificity, the calculation of the contact plan is considered. On the basis of this plan in the network nodes contact graphs are calculated, which are used to search the shortest data transmission routes. The paper proposes two interrelated solutions as a modification of this approach: the route search based on the contact plan, i.e. without calculation and use of the contact graph, and an adaptive method of finding the set of shortest routes required for routing. The essence of the first solution is as follows. In the standard CGR approach, the graph vertices correspond to the planned contacts between the network nodes, and the edges correspond to the data storage processes in the network nodes. In contrast, in the proposed approach, the vertices of the graph correspond to the nodes of the network, and the edges of the graph and their weight are determined dynamically, in the process of finding the shortest routes. The second solution is based on the concept of the planning front, which means a list of the closest contacts in time. The required routes are divided into a certain number of pools. Each pool combines the routes that use the specified contact from the planning front. The planning front is updated in two cases. If the network topology changes, the completed or not established contacts are replaced by subsequent ones with the same network nodes that are closest in time. If message traffic grows, a certain extension of the planning front and the use of additional route pools are performed. The article concludes with a description and justification of the expected advantages of the proposed approach.

scholarly journals Worldwide Coverage Mobile Systems for Supra-Smart Cities Communications: Featured Antennas and Design

Smart Cities ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 556-584
Author(s):  
César Benavente-Peces ◽  
Iván Herrero-Sebastián
Keyword(s):  
Mobile Communications ◽  
Smart Cities ◽  
Low Cost ◽  
Satellite Communications ◽  
Mobile Systems ◽  
Size Factor ◽  
Polar Regions ◽  
Satellite Constellations ◽  
Design Constraints ◽  
Communications Networks

Current terrestrial mobile communications networks can’t provide worldwide coverage. Satellite communications are expensive, and terminals are large and heavy. Worldwide mobile coverage requires the use of satellites providing an appropriate QoS, including polar regions. The analysis of the potential satellite constellations demonstrates that LEO one is the best solution. A new generation of low cost, small size, lightweight and global mobile coverage LEO satellites is emerging. The main limitation of the terminals is the antenna size factor, and innovative antennas must be developed to meet this goal. This paper investigates the technologies and techniques for designing and developing antennas aimed at LEO satellite communications in Smart Cities and beyond, which are especially beneficial for mobile communications in areas without 4G/5G coverage. The paper focuses on the terrestrial segment and future mobile devices, remarking the design constraints. In this scenario, the paper reviews the most relevant technologies and techniques used to design suitable antennas. The investigation analyses the state-of-the-art and most recent advances in the design of antennas operating in the Ku-band. The main contribution of the authors is a novel antenna design approach based on SIW technology. The antenna features are compared with other approaches, highlighting the benefits, advantages and drawbacks. As a conclusion, the proposed antenna demonstrates to be a good solution to meet the design constraints for such an application: light, low cost, small size factor.

scholarly journals Subscriber and inter-satellite paths in LEO communications networks

2019 ◽  
Vol 29 (3) ◽  
pp. 48-54
Author(s):  
S. B. Pichugin
Keyword(s):  
Communication Networks ◽  
Communication Systems ◽  
Satellite Communications ◽  
Communications Networks ◽  
Advantages And Disadvantages ◽  
Commercial Use ◽  
Radio Band ◽  
Technical Solutions ◽  
The Relationship ◽  
Current Stage

The purpose of the study is to propose and substantiate technical solutions for inter-satellite and subscriber paths of loworbit communication networks. There is a prospect of commercial use of such networks; therefore, the current stage of low-orbit satellite communications development is characterized by an increase in efforts to put the projects into practice. As part of the study, solutions for inter-satellite paths (ISP) in low-orbit communication systems and solutions that increase the capacity of their subscriber paths are considered. It is noted that ISPs can be built on the basis of radio and optical bands equipment. In this regard, the advantages and disadvantages of each case are considered. The expediency of constructing subscriber paths based on radio band equipment and the preference of constructing ISP based on optical band equipment are substantiated. The relationship between the feasibility of increasing the capacity of subscriber paths and the capabilities of ISP in terms of reliability and bandwidth is established.

Nanonetworks in Biomedical Applications

2019 ◽  
Vol 20 (8) ◽  
pp. 800-807 ◽  
Author(s):  
Jose Luis Marzo ◽  
Josep Miquel Jornet ◽  
Massimiliano Pierobon
Keyword(s):  
Communication Networks ◽  
Information Exchange ◽  
Biomedical Applications ◽  
Chemical Compounds ◽  
The Internet ◽  
Molecular Communication ◽  
Common Goal ◽  
Communication Paradigm ◽  
Communication Needs ◽  
Electromagnetic Signals

By interconnecting nanomachines and forming nanonetworks, the capacities of single nanomachines are expected to be enhanced, as the ensuing information exchange will allow them to cooperate towards a common goal. Nowadays, systems normally use electromagnetic signals to encode, send and receive information, however, in a novel communication paradigm, molecular transceivers, channel models or protocols use molecules. This article presents the current developments in nanomachines along with their future architecture to better understand nanonetwork scenarios in biomedical applications. Furthermore, to highlight the communication needs between nanomachines, two applications for nanonetworks are also presented: i) a new networking paradigm, called the Internet of NanoThings, that allows nanoscale devices to interconnect with existing communication networks, and ii) Molecular Communication, where the propagation of chemical compounds like drug particles, carry out the information exchange.

A collision feedback based multiple access control protocol for very high frequency data exchange system in E-navigation

2021 ◽  
pp. 1-16
Author(s):  
Xu Hu ◽  
Bin Lin ◽  
Ping Wang ◽  
Hongguang Lyu ◽  
Tie-Shan Li
Keyword(s):  
Access Control ◽  
High Frequency ◽  
Multiple Access ◽  
Data Exchange ◽  
High Frequency Data ◽  
Frequency Data ◽  
Exchange System ◽  
Very High Frequency ◽  
Time Division ◽  
Very High

Abstract The very high frequency data exchange system (VDES) is promising in promoting electronic navigation (E-navigation) and improving navigation safety. The multiple access control (MAC) protocol is crucial to the transmission performance of VDES. The self-organising time division multiple access (SOTDMA) protocol, as the only access mode given by current recommendations, leads to a high rate of transmission collisions in the traditional automatic identification system (AIS), especially with heavy traffic loads. This paper proposes a novel feedback based time division multiple access (FBTDMA) protocol to address the problems caused by SOTDMA, such that collision of transmissions can be avoided in information transmission among vessels. Simulation results demonstrate that the proposed FBTDMA outperforms the traditional SOTDMA in terms of channel utilisation and throughput, and significantly reduces the transmission collision rate. The study is expected to provide insights into VDES standardisation and E-navigation modernisation.

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