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Communication satellite payload has redundancy networks with multi port switches connecting input units to output units. In case of a probable failure at an output unit, connected input unit must be re-routed to a redundant output unit via changing the positions of switches. This paper proposes a mathematical model to represent the redundancy netwo...
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... payload redundancy network is composed of input and output units connected through multiport switches. Switches provide redundancy by changing path of the signal from input to output. Inputs and outputs can be different type of units for different section of satellite payload. An example receiver redundancy network of a satellite is shown in fig. 3. Input units are signal received from horizontal and vertical polarization ports of two different antennas (A1 and A2) and third antenna (A3) with vertical polarization only. Output units are receivers amplifying signals coming from different antenna ...
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Citations
... On the academic side, a bread-first-search was proposed to optimally connect channels but this approach is unsuitable for large payloads [19,6]. In [8], the authors proposed a recursive algorithm to generate all paths connecting inputs to outputs. This algorithm should minimize the interruption of connected channels and explore redundant paths in case of failures. ...
... States are deduced after optimization using exclusively flows and not the other way round. The new set of flow conservation constraints (8) is only composed of 4 constraints (one per port). For an instance of 4 channels to connect, this set would be replicated 4 times (one for each layer). ...
... The same sketch of proof can be applied on the remaining constraints of set (8) leading to the equivalent set (12). One can notice that P eq1 is the projection (see 13) of this new set P eq2 on P 1 = 0, P 2 = 0, P 3 = 0, P 4 = 0, P 5 = 0, P 6 = 0. To obtain P eq2 ⊆ P eq1 , it suffices to have at least P i > 0, i ∈ {1, 2, 3, 4, 6}. ...
Communication satellites have the crucial role to forward signals to customers. They filter and amplify uplink signals coming from Earth stations to improve the signal quality before reaching customers. These operations are performed by the payload component of the satellite that embeds reconfigurable components (e.g., switches). These components route signals to appropriate signal processing components (e.g., amplifiers, filters) and lead amplified signals to the output antenna. In order to route the channels that compose signals, satellite engineers can remotely modify switch states. These are typically updated when one or more new channels must be connected or when failures occur. However, satellites embed always more switches to answer customer demands, which makes their reconfiguration time consuming and error prone without appropriate decision aid tools. Power transmission is a crucial objective to ensure a maximum quality of service at reasonable cost. This is why satellite operators aim at minimizing incoming power signals while guaranteeing a maximum factor of amplification at the output antenna. This problem is referred to as the “satellite payload power problem.” Previous works have outlined the difficulty to solve exactly large instances of this problem. This work proposes to improve the existing mathematical formulation of the switch network. We show that it can be modeled as a static network and switch states can be deduced after optimization, thus limiting the combinatorial explosion. Computational experiments on different sizes of realistic instances using the adaptive ε-constraint method demonstrate the computational time gain with this new model and the possibility to solve larger instances.
... From the academic point of view, only few works have tackled the considered problem. In Gulgonul et al. (2012), a recursive algorithm was proposed to perform a breadthfirst-search (BFS) in order to find all feasible paths that connect channels to amplifiers. Experiments showed the efficiency of the proposed method on a small switch network (i.e 7 switches and 9 amplifiers). ...
The satellite communications market is competitive and rapidly evolving. The payload, which is in charge of applying frequency conversion and amplification to the signals received from Earth before their retransmission, is made of various components. These include reconfigurable switches that permit the re-routing of signals based on market demand or because of some hardware failure. In order to meet modern requirements, the size and the complexity of current communication payloads are increasing significantly. Consequently, the optimal payload configuration, which was previously done manually by the engineers with the use of computerized schematics, is now becoming a difficult and time consuming task. Efficient optimization techniques are therefore required to find the optimal set(s) of switch positions to optimize some operational objective(s). In order to tackle this challenging problem for the satellite industry, this work proposes two Integer Linear Programming (ILP) models. The first one is single-objective and focuses on the minimization of the length of the longest channel path, while the second one is bi-objective and additionally aims at minimizing the number of switch changes in the payload switch matrix. Experiments are conducted on a large set of instances of realistic payload sizes using the CPLEX® solver and two well-known exact multi-objective algorithms. Numerical results demonstrate the efficiency and limitations of the ILP approach on this real-world problem.
... Besides, their solver offer no transparency which lead to a lack of flexibility. Similarly to these two commercial tools, Gulgonul et al. [3] have also performed payload optimization by using a recursive path search algorithm. Finally, Simone et al. [4] use pathfinding algorithms as well in order to obtain paths crossing a minimal number of switches and to minimize the use of some critical paths according to the physical architecture of the payload. ...
... On the academic side, few works have been proposed that deal with the considered problem. In [7] a recursive algorithm was proposed to perform a breadth-first-search (BFS) in order to find all feasible paths that connect channels to amplifiers. Experiments showed the efficiency of the proposed method on a small switch network. ...
The increasing complexity of current telecommunication satellite payloads has made their manual management a difficult and error prone task. As a consequence, efficient optimisation techniques are re- quired to help engineers to configure the payload. Recent works focusing on exact approaches faced scalability issues while metaheuristics provided unsatisfactory solution quality. This work therefore proposes three hybridisation schemes that combine both metaheuristics and an exact method. We focus on the initial configuration problem case and we consider as objective to minimise the length of the longest channel path. Experimental results on realistic payload sizes demonstrate the advantage of those approaches in terms of efficiency within a strict operational time constraint of ten minutes on a single CPU core.
... Haberleşme uydularında faydalı yük sistemi, yer istasyonlarından gönderilen sinyalleri alıp frekanslarını değiştirerek güçlendirdikten sonra, tekrar yeryüzüne gönderilmesini sağlar [1]. Faydalı yük sistemi, Şekil 1'de gösterildiği gibi antenler, alıcılar, frekans düşürücüler, giriş çoklayıcıları, güçlendiriciler ve çıkış çoklayıcılarından oluşan karmaşık bir sistemdir [2]. Yeryüzünden uyduya gönderilen sinyaller, alış antenleri ile alınmaktadır. ...
... Akıllı Yedekleme Algoritmasının (AYA) tek giriş cihazı için uygulanması, makalenin yazarları tarafından bir bildiride sunulmuştur [2]. Bu yeni çalışmada, geliştirilen algoritmaya çoklu giriş cihazları için yedek yolların bulunması ile üzerinden geçilen anahtar sayısı ve kesinti sayısı kriterleri eklenmiştir. ...
Haberlesme uydusu faydali yuk sisteminde, cihazlar birbirine cok uclu anahtarlar ile baglanmaktadir. Ariza olusmasi durumunda, anahtarlarin pozisyonlari degistirilerek yedek cihazlara baglanti saglanir. Uydu isletmeciliginde, uygun anahtar pozisyonlarinin hesaplanmasini gerektiren bu zor problemin cozumu icin ticari yazilimlar kullanilmaktadir. Bu tez kapsaminda gelistirilen Akilli Yedekleme Algoritmasi (AYA), faydali yuk sisteminin iki matris ile modellendigi, yedek cihazlara giden yollarin ozyinelemeli olarak bulundugu yeni bir algoritmadir. AYA’nin acik mimarisi ile her turlu faydali yuk sebekesi tanimlanabilmekte ve karsilasilabilecek yedekleme problemleri cozulebilmektedir. AYA’nin uygulama sonuclari ve etkinligi, TURKSAT-3A uydusunun isletmesinde kullanilan ICAREF ticari yazilimi ile dogrulanmistir. AYA, yuksek maliyetli ticari yazilimlara bir alternatif sunmaktadir. AYA, yedek cihazlara giden yollari bulurken diger baglantilarda olusacak kesinti sayisi ve sinyalin uzerinden gecebilecegi anahtar sayisi kriterlerini de dikkate alarak kisa surelerde uygun cozumleri uretebilmektedir.
... Haberleşme uydularında faydalı yük sistemi, yer istasyonlarından gönderilen sinyalleri alıp frekanslarını değiştirerek güçlendirdikten sonra, tekrar yeryüzüne gönderilmesini sağlar [1]. Faydalı yük sistemi, Şekil 1'de gösterildiği gibi antenler, alıcılar, frekans düşürücüler, giriş çoklayıcıları, güçlendiriciler ve çıkış çoklayıcılarından oluşan karmaşık bir sistemdir [2]. Yeryüzünden uyduya gönderilen sinyaller, alış antenleri ile alınmaktadır. ...
... Akıllı Yedekleme Algoritmasının (AYA) tek giriş cihazı için uygulanması, makalenin yazarları tarafından bir bildiride sunulmuştur [2]. Bu yeni çalışmada, geliştirilen algoritmaya çoklu giriş cihazları için yedek yolların bulunması ile üzerinden geçilen anahtar sayısı ve kesinti sayısı kriterleri eklenmiştir. ...
Redundancy is provided by using multiport switches which are connecting equipment in communication satellite payload systems. In case of a failure, signal path is re-routed by changing suitable switch positions. SmartRedundancy Reconfiguration Algorithm (SRRA) is a novel algorithm, able to model any payload system and to find paths recursively to redundant equipment. Results of the SRRA are verified by means of comparing them to those of the ICAREF commercial software which is currently being used in TURKSAT-3A satellite operations.SRRA can find all paths connecting given input(s) to any output(s) by taking number of interruptions and number of switches crossed constraints into account.
... On the academic side, few works have been proposed for the considered problem. In [7] a recursive algorithm was proposed to perform a breadth-first-search (BFS) in order to find all feasible paths that connect channels to amplifiers. Experiments showed the efficiency of the proposed method on a small switch network. ...
The size and complexity of communication satellite payloads have been increasing very quickly over the last years and their configuration / reconfiguration have become very difficult problems. In this work, we propose to compare the efficiency of three well-known metaheuristic methods to solve an initial configuration problem, which objective is to minimise the length of the longest channel path. Experiments are conducted on real-world problem instances with realistic operational constraints (e.g., a maximum computation time of 10 minutes) and Wilcoxon test is used to determine with statistical confidence what technique is more suitable and what are its limitations. The results of this work will serve as an initial step in our research to design hybrid approaches to push even further the solving capabilities, i.e., tackling bigger payloads and more channels to activate.
The design of Canister Satellite (CanSat) chassis plays a crucial role in ensuring the structural integrity, stability, and functionality of the payload during its mission. This research paper proposes a novel approach to CanSat chassis design by drawing inspiration from the biomechanical characteristics of the human skeleton. By mimicking the efficient load distribution, flexibility, and durability observed in the human skeletal system, this bio-inspired design aims to enhance the performance and survivability of CanSats. The paper presents a detailed analysis of the human skeletal system, discusses the fundamental principles of bio mimicry, and outlines the application of these principles to CanSat chassis design. Finite Element Analysis (FEA) and prototyping are utilized to validate the effectiveness of the proposed bio-inspired chassis design. The results demonstrate the potential benefits of integrating bio mimicry into aerospace engineering, fostering innovation in satellite technologies.
The redundancy networks are widely used in the design of communication satellite payloads. Currently, the design of the redundancy switch matrix mainly relies on rebuilding existing matrix based on experience. As the scale of the redundancy network continues to increase, it is difficult for the existing design methods to meet the requirements and ensure the optimal design, which requires both minimum number of switches and compliance of the redundant switching functions. In this paper, the mathematical model of the redundancy network is abstracted based on the graph theory, and the key elements in the model including vertices, edges and connectivity are introduced. A new method of designing the switch matrix is proposed through the Harary graph theorem in conjunction with the method of graphic construction.
