Two-terminal reliability analysis for multi-phase communication networks

Ji-Min Lu, Fares Innal, Xiao-Yue Wu, Yiliu Liu, Mary Ann Lundteigen
2016 Eksploatacja i Niezawodnosc  
Network has become a common and effective description for many engineering systems such as transportation, communications, and gas-pipeline systems. In graph theory, the network is usually denoted as G= (V,E), where V is the vertex set representing terminals (bus stop, switchboard, etc.), and E is the edge set representing links (road, cable, etc.). Graph theory further classifies edges into directed and undirected edges. Communication networks, as well as transportation systems, are typical
more » ... mples of undirected networks. In literature, networks structures normally remain unchanged during the entire mission. However, changing network structures and varying stress on components have become increasingly common in many engineering applications. This kind of systems can be termed as the multi-phase network systems (MPNS) in comparison to traditional single-phase network systems (SPNS). A typical example of MPNS is the satellite telemetry, tracking and control (TT&C) system which is responsible for the data transmission between satellites and ground facilities. In satellite TT&C systems, communications between a certain ground station and a target satellite usually rely on many relay satellites. As different relay satellites fly over the ground station, the communication networks changes its link structures and constitutes a MPNS. Two-terminal reliability (or terminal-pair reliability) is one of key concern in the design and maintenance of network systems. Take communication systems for instance. The two-terminal reliability can be considered as the probability of successfully transmitting data from one source to one receiver. Researches on two-terminal reliability of single-phase networks have been extensively conducted since 1970s. Early methods are mainly based on the enumeration of minimal paths/ cuts, or based on the factoring theory. In minimal paths/cuts methods [2, 9, 16, 23, 25, 28] , the reliability is evaluated by enumerating all minimal paths/cuts and summing the probabilities of their disjoint forms. A path is a set of network components (edges/vertices) such that if these components are operational, the system is up. A path is minimal if it has no proper subpaths. Conversely a cut can be considered as a set of network components such that if these components fail, the system is down. Literature [1, 22] shows that the number of cuts is usually much smaller than the number of paths for many practical systems, meaning that cut-based methods (i.e. to calculate the unreliability) have better performance. However, both paths and cuts based method have difficulties in applying to large networks since the number of paths/cuts may grow exponentially with the network size. In contrast to paths/cuts based approaches, factoring methods (or decomposition/ topology methods) may exhibit better performance, especially combined with some reduction techniques [27, 30, 31, 38] . In factoring methods, a certain component of the network is chosen and then the network is decomposed into two subnetworks. One subnetwork assumes the component is up and the other subnetwork assumes the component is down. Another version of this method does not choose a single component, but replaces some special substructures by smaller ones [8, 12] . Some experiments [32, 43] show that LU J-M, INNAL F, WU X-y, LIU y, LUNdteIgeN MA. two-terminal reliability analysis for multi-phase communication networks. eksploatacja i Niezawodnosc -Maintenance and Reliability 2016; 18 (3): 418-427, http://dx.Two-Terminal reliabiliTy analysis for mulTi-phase communicaTion neTworks analiza niezawodności par Terminali w wielofazowych sieciach komunikacyjnych Most researches of network reliability generally assume that the system structures do not change with time. This paper presents the concept of multi-phase network systems (MPNS) to consider dynamic characteristics of networks, and analyze the reliability of MPNS. MPNS reliability is evaluated through a cross-phase binary decision diagram (BDD ). The BDD-based algorithm can act as a platform to consider various components behaviors such as repair and growing pressure. Case study shows that the proposed MPNS concept is an effective description of some practical communication networks, and the cross-phase BDD model is efficient in analyzing MPNS reliability. Keywords: Binary decision diagram, component-behavior model, multi-phase network systems, system reliability. Większość badań niezawodności sieci ogólnie przyjąć, że struktury systemu nie zmieniają się w czasie. W artykule przedstawiono koncepcję systemów sieciowych wielofazowych (MPNS) rozpatrywanie dynamicznych właściwości sieci i analizy niezawodności MPNS. MPNS niezawodność jest oceniany przez cross-fazowego schematu decyzyjnego binarny (BDD). Algorytm z siedzibą w BDD może działać jako platforma do rozważenia różnych komponentów zachowań, takich jak naprawy i rosnącej presji. Studium przypadku pokazuje, że proponowana koncepcja MPNS jest skutecznym opis niektórych praktycznych sieci komunikacyjnych, a cross-fazowego modelu BDD jest skuteczny w analizie MPNS niezawodność. Słowa kluczowe: Binarny schemat decyzji, model zachowania komponentów, systemów sieciowych wielofazowe, niezawodność systemu.
doi:10.17531/ein.2016.3.14 fatcat:ok64rnqtsvartbbvinkab4dmsa