7 research outputs found

    An emergency communication system based on software-defined radio

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    Wireless telecommunications represent an important asset for Public Protection and Disaster Relief (PPDR) organizations as they improve the coordination and the distribution of information among first responders in the field. In large international disaster scenarios, many different PPDR organizations may participate to the response phase of disaster management. In this context, PPDR organizations may use different wireless communication technologies; such diversity may create interoperability barriers and degrade the coordination among first time responders. In this paper, we present the design, system integration and testing of a demonstration system based on Software Defined Radio (SDR) technology and Software Communication Architecture (SCA) to support PPDR operations with special focus on the provision of satellite communications. This paper describes the main components of the demonstration system, the integration activities as well as the testing scenarios, which were used to evaluate the technical feasibility. The paper also describes the main technical challenges in the implementation and integration of the demonstration system. Finally future developments for this technology and potential deployment challenges are presented.JRC.G.6-Digital Citizen Securit

    Exploitation of wireless control link in the software-defined LEO satellite network

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    software-defined satellite network, control link, cross layer optimization, power-efficient control link algorithmThe low earth orbit (LEO) satellite network can benefit from software-defined networking (SDN) by lightening forwarding devices and improving service diversity. In order to apply SDN into the network, however, reliable SDN control links should be associated from satellite gateways to satellites, with the wireless and mobile properties of the network taken into account. Since these characteristics affect both control link association and gateway power allocation, we define this new cross layer problem as an SDN control link problem. The problem is discussed from the viewpoint of multilayers such as automatic repeat request (ARQ) and gateway power allocation at the Link layer, and split transmit control protocol (TCP) and link scheduling at the Transport layer. A centralized SDN control framework constrained by maximum total power is introduced to enhance gateway power efficiency for control link setup. Based on the power control analysis of the problem, a power-efficient control link algorithm is developed, which establishes low latency control links with reduced power consumption. Along with the sensitivity analysis of the proposed control link algorithm, numerical results demonstrate low latency and high reliability of control links established by the algorithm, ultimately suggesting the feasibility, both technical and economical, of the software-defined LEO satellite network.open1. INTRODUCTION 1 1.1 Software-Defined Satellite Network 1 1.2 Wireless SDN Control Link Problem Statement 4 1.3 Contributions and Overview of Theses 5 1.4 Related Works 6 2. MODELING AND FORMULATION 8 2.1 Control Link Association 8 2.1.1 Graph Model 8 2.1.2 ARQ and Split TCP 9 2.1.3 Link Association Variable 10 2.2 Control Link Reliability and Expected Latency Formulation 12 2.2.1 Control Link Reliability and Gateway Power 12 2.2.2 Expected Latency Formulation 13 2.3 SDN Control Link Problem 16 2.3.1 Expected Latency Minimization Problem 16 2.3.2 Power-Efficient SDN Control Link Problem 17 3. SDN CONTROL LINK ALGORITHM 22 4. NUMERICAL RESULTS AND ANALYSIS 25 4.1 Latency Analysis and Feasibility of the Software-Defined Satellite Network 27 4.2 Sensitivity Analysis and Selection of the Maximum Total Power 33 5. CONCLUSION 37 APPENDIX 38 REFERENCES 40์ €๊ถค๋„(LEO) ์œ„์„ฑ ๋„คํŠธ์›Œํฌ๋Š” ๋ฐ์ดํ„ฐ ์ „๋‹ฌ ์žฅ์น˜๋ฅผ ๊ฐ„์†Œํ™”ํ•˜๊ณ  ์„œ๋น„์Šค ๋‹ค์–‘์„ฑ์„ ํ–ฅ์ƒ์‹œํ‚ค๋Š” ๋“ฑ, ์†Œํ”„ํŠธ์›จ์–ด ์ •์˜ ๋„คํŠธ์›Œํ‚น(SDN)๋กœ๋ถ€ํ„ฐ ๋‹ค์–‘ํ•œ ์ด์ ์„ ์–ป์„ ์ˆ˜ ์žˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ SDN์„ ์œ„์„ฑ ๋„คํŠธ์›Œํฌ์— ์ ์šฉํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š”, ์‹ ๋ขฐ์„ฑ ์žˆ๋Š” SDN ์ œ์–ด ๋งํฌ๊ฐ€ ์œ„์„ฑ ๊ฒŒ์ดํŠธ์›จ์ด๋กœ๋ถ€ํ„ฐ ์œ„์„ฑ๊นŒ์ง€ ์—ฐ๊ฒฐ๋˜์–ด์•ผ ํ•˜๋ฉฐ, ์œ„์„ฑ ๋„คํŠธ์›Œํฌ์˜ ๋ฌด์„  ํŠน์„ฑ๊ณผ ์ด๋™์„ฑ์ด ๋™์‹œ์— ๊ณ ๋ ค๋˜์–ด์•ผ ํ•œ๋‹ค. ์ด๋Ÿฌํ•œ ํŠน์„ฑ๋“ค์€ ์ œ์–ด ๋งํฌ ์—ฐ๊ฒฐ๊ณผ ๊ฒŒ์ดํŠธ์›จ์ด ์ „๋ ฅ ํ• ๋‹น ๋ชจ๋‘์— ์˜ํ–ฅ์„ ๋ฏธ์น˜๊ธฐ ๋•Œ๋ฌธ์—, ์šฐ๋ฆฌ๋Š” ์ด๋Ÿฌํ•œ ๊ต์ฐจ ๊ณ„์ธต ๋ฌธ์ œ๋ฅผ SDN ์ œ์–ด ๋งํฌ ๋ฌธ์ œ๋กœ ์ƒˆ๋กญ๊ฒŒ ์ •์˜ํ•œ๋‹ค. ์ด ๋ฌธ์ œ๋Š” ์ „์†ก ๊ณ„์ธต์˜ ์ž๋™ ์žฌ์ „์†ก ์š”๊ตฌ(ARQ) ๋ฐ ์ „์†ก ์ œ์–ด ํ”„๋กœํ† ์ฝœ(TCP), ๋„คํŠธ์›Œํฌ ๊ณ„์ธต์˜ ๋ผ์šฐํŒ…, ๋ฌผ๋ฆฌ ๊ณ„์ธต์˜ ์ „๋ ฅ ํ• ๋‹น๊ณผ ๊ฐ™์€ ๋‹ค์ค‘ ๊ณ„์ธต์˜ ๊ด€์ ์—์„œ ๋…ผ์˜๋œ๋‹ค. ๋ณธ ๋…ผ๋ฌธ์—์„œ๋Š” ์ œ์–ด ๋งํฌ ์„ค์ •์— ํ•„์š”ํ•œ ๊ฒŒ์ดํŠธ์›จ์ด ์ „๋ ฅ ํšจ์œจ์„ ๋†’์ด๊ธฐ ์œ„ํ•ด ์ตœ๋Œ€ ์ด ์ „๋ ฅ์„ ์ œํ•œํ•˜๋Š” ์ค‘์•™์ง‘๊ถŒํ™” SDN ์ œ์–ด ํ”„๋ ˆ์ž„์›Œํฌ๋ฅผ ๋„์ž…ํ•œ๋‹ค. ์ œ์•ˆ๋œ ๋ฌธ์ œ์— ๋Œ€ํ•œ ์ „๋ ฅ ํ• ๋‹น ๋ถ„์„์„ ๊ธฐ๋ฐ˜์œผ๋กœ, ์ „๋ ฅ ์†Œ๋น„๊ฐ€ ์ ์œผ๋ฉด์„œ๋„ ์ง€์—ฐ์ด ์ ์€ ์ œ์–ด ๋งํฌ๋ฅผ ์—ฐ๊ฒฐํ•˜๋Š” ์ „๋ ฅ ํšจ์œจ์ ์ธ ์ œ์–ด ๋งํฌ ์•Œ๊ณ ๋ฆฌ์ฆ˜์ด ์ œ์•ˆ๋œ๋‹ค. ์ œ์•ˆ๋œ ์ œ์–ด ๋งํฌ ์•Œ๊ณ ๋ฆฌ์ฆ˜์˜ ๋ฏผ๊ฐ๋„ ๋ถ„์„๊ณผ ํ•จ๊ป˜, ์‹œ๋ฎฌ๋ ˆ์ด์…˜ ๊ฒฐ๊ณผ๋Š” ์•Œ๊ณ ๋ฆฌ์ฆ˜์— ์˜ํ•ด ์„ค์ •๋˜๋Š” ์ œ์–ด ๋งํฌ์˜ ๋‚ฎ์€ ์ง€์—ฐ๊ณผ ๋†’์€ ์‹ ๋ขฐ์„ฑ์„ ๋ณด์—ฌ์ฃผ๋ฉฐ, ๊ถ๊ทน์ ์œผ๋กœ ์†Œํ”„ํŠธ์›จ์–ด ์ •์˜ LEO ์œ„์„ฑ ๋„คํŠธ์›Œํฌ์˜ ๊ธฐ์ˆ ์  ๋ฐ ๊ฒฝ์ œ์  ํƒ€๋‹น์„ฑ์„ ์ œ์‹œํ•œ๋‹ค.MasterdCollectio

    A Survey on Rapidly Deployable Solutions for Post-disaster Networks

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    International audienceIn post-disaster scenarios, for example, after earthquakes or floods, the traditional communication infrastructure may be unavailable or seriously disrupted and overloaded. Therefore, rapidly deployable network solutions are needed to restore connectivity and provide assistance to users and first responders in the incident area. This work surveys the solutions proposed to address the deployment of a network without any a priori knowledge about the communication environment for critical communications. The design of such a network should also allow for quick, flexible, scalable, and resilient deployment with minimal human intervention

    Modeling the Use of an Airborne Platform for Cellular Communications Following Disruptions

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    In the wake of a disaster, infrastructure can be severely damaged, hampering telecommunications. An Airborne Communications Network (ACN) allows for rapid and accurate information exchange that is essential for the disaster response period. Access to information for survivors is the start of returning to self-sufficiency, regaining dignity, and maintaining hope. Real-world testing has proven that such a system can be built, leading to possible future expansion of features and functionality of an emergency communications system. Currently, there are no airborne civilian communications systems designed to meet the demands of the public following a natural disaster. A system allowing even a limited amount of communications post-disaster is a great improvement on the current situation, where telecommunications are frequently not available. It is technically feasible to use an airborne, wireless, cellular system quickly deployable to disaster areas and configured to restore some of the functions of damaged terrestrial telecommunications networks. The system requirements were presented, leading to the next stage of the planned research, where a range of possible solutions were examined. The best solution was selected based on the earlier, predefined criteria. The system was modeled, and a test ii system built. The system was tested and redesigned when necessary, to meet the requirements. The research has shown how the combination of technology, especially the recent miniaturizations and move to open source software for cellular network components can allow sophisticated cellular networks to be implemented. The ACN system proposed could enable connectivity and reduce the communications problems that were experienced following Hurricane Sandy and Katrina. Experience with both natural and man-made disasters highlights the fact that communications are useful only to the extent that they are accessible and useable by the population

    Aerial Base Station Deployment for Post-Disaster Public Safety Applications

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    Earthquakes and floods are constant threats to most of the countries in the world. After such catastrophes, a rapid response is needed, which includes communications not only for first responders but also for local civilians. Even though there are technologies and specialized personnel for rapid deployment, it is common that external factors will hinder the arrival of help while communication requirements are urgently required. Such communication technologies would aid tasks regarding organization and information dissemination from authorities to the civilians and vice-versa. This necessity is due to protocols and applications to allocate the number of emergency resources per location and to locate missing people. In this thesis, we investigate the deployment problem of Mobile Aerial Base Stations (MABS). Our main objective is to ensure periodic wireless communication for geographically spread User Equipment (UE) based on LTE technology. First, we establish a precedent of emergency situations where MABS would be useful. We also provide an introduction to the study and work conducted in this thesis. Second, we provide a literature review of existing solutions was made to determine the advantages and disadvantages of certain technologies regarding the described necessity. Third, we determine how MABS, such as gliders or light tactical balloons that are assumed to be moving at an average speed of 50 km/h, will be deployed. These MABS would visit different cluster centroids determined by an Affinity Propagation Clustering algorithm. Additionally, a combination of graph theory and Genetic Algorithm (GA) is implemented through mutators and fitness functions to obtain best flyable paths through an evolution pool of 100. Additionally, Poisson, Normal, and Uniform distributions are utilized to determine the amount of Base Stations and UEs. Then, for every distribution combination, a set of simulations is conducted to obtain the best flyable paths. Serviced UE performance indicators of algorithm efficiency are analyzed to determine whether the applied algorithm is effective in providing a solution to the presented problem. Finally, in Chapter 5, we conclude our work by supporting that the proposed model would suffice the needs of mobile users given the proposed emergency scenario. Adviser: Yi Qia

    Aerospace Communications for Emergency Applications

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    In this paper, the current trends and the most recent advancements in the utilization of aerospace communications for emergency rescue applications will be discussed, with a special focus on the integration of the aerospace segment with terrestrial backbones and ad hoc terrestrial networks for both data connections and assisted localization (information about position is essential in emergency relief
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