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We present a solution to evaluate the performance of transport protocols as a function of link layer reliability schemes (i.e. ARQ, FEC and Hybrid ARQ) applied to satellite physical layer traces. As modelling such traces is complex and may require approximations, the use of real traces will minimise the potential for erroneous performance evaluations resulting from imperfect models. Our Trace Manager...
Reliability and availability have always been important characteristics of systems but become even more critical and complex issues on networks. Due to the high complexity of accurate calculation methods, simulation methods for network reliability and availability evaluation have been a popular area of research, and received significant attention. In this paper the network topology model, the failure...
In the deep sub-micron ICs, growing amounts of on-die memory and scaling effects make embedded memories increasingly vulnerable to reliability and yield problems. Spare columns are often included in memories to repair defective cells or bit lines during production test. In many cases, the repair process will not use all spare columns. Schemes have been proposed to exploit these unused spare columns...
Breadcrumb systems (BCS) aid first responders by communicating their physiological parameters to remotely located base stations. However, state-of-the-art research only focuses on deploying breadcrumb systems on the assumption of uncoordinated users, which is inefficient. In this paper, we present the first design, implementation, and evaluation of reliable multiuser breadcrumb systems (MUBCS) which...
Failure Mode and Effect Analysis (FMEA) has already been used as a qualitative measure for identifying failure modes and causes, in order to mitigate the effects of failure in different sectors of power systems. This paper presents a quantitative approach called Risk-Based-FMEA, based on the failure probabilities and incurred failure costs instead of rating scales. As a case study, this approach has...
This paper introduces a robust point-to-point transmission scheme: Tetrys, that relies on a novel on-the-fly erasure coding concept which reduces the delay for recovering lost data at the receiver side. In current erasure coding schemes, the packets that are not rebuilt at the receiver side are either lost or delayed by at least one RTT before transmission to the application. The present contribution...
The discrete-time one-unit repairable system was studied, whose lifetime, repair delay time, corrective maintenance time and preventive maintenance time are all assumed to be random variables with general discrete distributions. We investigated the relationship of system states including operational state, waiting state for repair, state for preventive maintenance, and state for corrective maintenance...
Coordination studies utilize time current curves to determine the extent to which upstream overcurrent protective device pick-up and time delays must be increased to provide selectivity with downstream devices. These increases in device time delays result in increased let through energy and greater arc flash hazards. Advanced breaker trip unit technologies, including zone selective interlock, maintenance...
This paper proposes a new multiuser scheduling scheme for MIMO system that can simultaneously support various QoS requirements of different user groups while satisfying fairness among the same user group in a RRS (Round Robin Scheme) manner. To guarantee high transmission reliability, a cross-layer scheme is adopted by combing spatial diversity in the physical layer and systematic Raptor code in the...
According to the MSG-3 analysis, because the degradation of SSI has the characteristics of a delay-time, the threshold and repeated intervals should be considered together. So the variables to be optimized are the inspection level, threshold and repeated intervals, and an optimal inspection model for aircraft structure is developed to minimize the maintenance cost rate subject to a required reliability...
Accurate modeling of a system's operational availability is vital to determine its sparing needs. Two different families of sparing tools are available to model operational availability. The first was designed for use by the logistics community and the second was designed by the reliability community. Both of these families of tools were analyzed to obtain an understanding on their differences for...
The railway has been accepted as one of the most environmentally friendly modes of transport for goods and passengers. However, the railway sector is striving to increase its capacity to meet the growing demand for the transport of goods and passengers with a high level of punctuality in its services. Higher availability requires the effective operation and maintenance of infrastructure, often necessitating...
There was a lot of interest in multicast communications within this decade as it is an essential part of many network applications, e.g. video-on-demand, etc. In this paper, we model flow rate allocation for application overlay as a utility based optimization problem constrained by capacity limitations of physical links and overlay constraints. The optimization flow control presented here addresses...
In this paper, an integrated methodology is developed for optimizing inspection and maintenance of a component where delayed repair is considered to be one of feasible options. The models of failures, risk and life cycle cost are developed using probability, stochastic process and the delay time concept. The model is intended to optimise the inspection intervals and the delay of repair simultaneously...
Present and future semiconductor technologies are characterized by increasing parameters variations as well as an increasing susceptibility to external disturbances. Transient errors during system operation are no longer restricted to memories but also affect random logic, and a robust design becomes mandatory to ensure a reliable system operation. Self-checking circuits rely on redundancy to detect...
Networks on chips (NoCs) provide a mechanism for handling complex communications in the next generation of integrated circuits. At the same time, lower yield in nano-technology, makes self repair communication channels a necessity in design of digital systems. This paper proposes a reliable NoC architecture based on specific application mapped onto an NoC. This architecture is capable of recovering...
In this paper, we present a new technique to improve the reliability of H-tree SRAM memories. This technique deals with the SRAM power-bus monitoring by using built-in current sensor (BICS) circuits that detect abnormal current dissipation in the memory power-bus. This abnormal current is the result of a single-event upset (SEU) in the memory and it is generated during the inversion of the state of...
The minimum operating voltage (Vmin) of nano-scale LSIs is investigated, focusing on logic gates, SRAM cells, and DRAM sense amplifiers in LSIs. The Vmin that is governed by SRAM cells rapidly increases as devices are miniaturized due to the ever-larger variation of the threshold voltage (VT) of MOSFETs. The Vmin, however, is reduced to the sub-one-volt region by using repair techniques and new MOSFETs...
With an increased focus on national security and public safety communications, the US Congress revisited its plan to reclaim television broadcaster frequencies to be reallocated and auctioned by the FCC and it specifically allocated a portion of that spectrum for use by public safety. The FCC was charged with the duty of auctioning this spectrum and licensing it to create a public safety network....
Wireless sensor networks are increasingly being used in applications where QoS and low cost are the overriding considerations. Conventional schemes of using sensor nodes and incorporating these three phenomena (reliability, availability and serviceability) to attain QoS can effectively improve not only the reliability of the overall WSNs but security as well. We discuss the reverse look of QoS and...
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