GORA: Goodput Optimal Rate Adaptation for 802.11 using Medium Status Estimation,”

Abstract-Rate Adaptation for 802.11 has been deeply investigated in the past, but the problem of achieving optimal Rate Adaptation with respect not only to channel-related errors but also to contention-related issues (i.e., collisions and variations in medium access times) is still unsolved. In this paper we address this issue by proposing 1) a practical definition of the Medium Status in a multi-user 802.11 scenario in terms of channel errors, MAC collisions and packet service times, and a method for its estimation based on measurements; 2) an analytical model of the goodput performance as a function of the Medium Status; 3) a rate adaptation algorithm, called Goodput Optimal Rate Adaptation (GORA), which is based on this model. Unlike other Rate Adaptation schemes proposed in literature, which require either modifications to the IEEE 802.11 standard or cooperation among nodes, GORA is totally stand-alone and standard compliant. In fact, the Medium Status Estimation used by GORA is obtained by using standard MAC counters that are commonly collected by commercial MAC drivers, and no explicit interactions with the other devices in the network is required. Therefore, GORA offers the advantage of being readily deployable on real devices. The performance of GORA is evaluated through NS2 simulations which reveal that, as expected, GORA outperforms other wellknown Rate Adaptation algorithms in several scenarios and can be used as a new reference benchmark

Современное состояние электрификации России

В статье показано, что современное развитие электрификации РФ в сопоставлении с государствами, входящими в G8, очевидно недостающее. При этом есть большой потенциал электросбережения в секторах экономики. Потребление электроэнергии населением существенно находится в зависимости от значения их денежных доходов и темпов роста тарифов на электричество

Method and system for controlling operation of a network, such as a WLAN, related network and computer program product therefor

A system controls operation of a network, such as a WLAN, where at least one information stream is delivered to at least one user via a link that is exposed to variable operating conditions. The system includes a controller module for monitoring the operating conditions of the link, and at least one transcoder for selectively transcoding the information stream by selectively varying one or more transcoding parameters as a function of the monitored operating conditions

An exploration methodology for a customizable OpenCL stereo-matching application targeted to an industrial multi-cluster architecture

Open Computing Language (OpenCL) is emerging as a standard for parallel programming of heterogeneous hardware accelerators. With respect to device specific languages, OpenCL enables application portability but does not guarantee performance portability, eventually requiring additional tuning of the implementation to a specific platform or to unpredictable dynamic workloads. In this paper, we present a methodology to analyze the customization space of an OpenCL application in order to improve performance portability and to support dynamic adaptation. We formulate our case study by implementing an OpenCL image stereo-matching application (which computes the relative depth of objects from a pair of stereo images) customized to the STMicroelectronics Platform 2012 many-core computing fabric. In particular, we use design space exploration techniques to generate a set of operating points that represent specific configurations of the parameters allowing different trade-offs between performance and accuracy of the algorithm itself. These points give detailed knowledge about the interaction between the application parameters, the underlying architecture and the performance of the system; they could also be used by a run-time manager software layer to meet dynamic Quality-of-Service (QoS) constraints. To analyze the customization space, we use cycle-accurate simulations for the target architecture. Since the profiling phase of each configuration takes a long simulation time, we designed our methodology to reduce the overall number of simulations by exploiting some important features of the application parameters; our analysis also enables the identification of the parameters that could be explored on a high-level simulation model to reduce the simulation time. The resulting methodology is one order of magnitude more efficient than an exhaustive exploration and, given its randomized nature, it increases the probability to avoid sub-optimal trade-offs

New Sensor Nodes, Cloud, and Data Analytics: Case Studies on Large Scale SHM Systems

The progress in the world of new sensors is running fast, offering good performances, and reliable solutions with initial costs orders of magnitude lower than those faced only a few years ago. The spread of new electronic devices, like microcontrollers, the increasing power of the networks for data transmission and management and in the end the availability of the new data-driven approaches have created a revolution in SHM approaches, not yet fully mastered. The way to design a SHM system is going to be deeply revised in an industrial perspective, within a complex framework in which everything has to be planned into details since the beginning, including the development of a metrological culture, the personnel education, the need of spare parts, re-calibration, …. This also means a revolution in data management: huge data flows not only create hardware problems related to their transfer; the software too requires a great deal of effort to compress data, also due to the actual cost of cloud resources. All these facts, accounting for the real metrological performances of the best MEMS sensors available at present, also require simplified data analyses, as software complexity is now mainly transferred to the network management. A trade-off must be looked for between the big redundancy offered by the actual networks and the need of a simple and prompt information, granting the structure safety: That is why as the data rates increase, the algorithms to be adopted must be simple, reliable, eventually adapted to edge computing at the sensor level, where hardware power is now present though at a reduced scale. The chapter shows such an approach in a real case from the system design, its birth, and its proper use for damage detection, up to the detection of a structural failure

PRO3D, Programming for Future 3D Manycore Architectures: Project Interim Status

International audiencePRO3D tackles two important 3D technologies, that are ThroughSilicon Via (TSV) and liquid cooling, and investigates their consequenceson stacked architectures and entire software development. Inparticular, memory hierarchies are being revisited and the thermal impactof software on the 3D stack is explored. As a key result, a software design flow based on the rigorous assembly of software components andmonitoring of the thermal integrity of the 3D stack has been developed.After 30 months of research, PRO3D proposes a complete tool-chain for3D manycore, that integrates state-of-the-art tools ranging from system-levelformal specification and 3D exploration, to actual programming andruntime control on the 3D system. Current efforts are directed towardsextensive experiments on an industrial embedded manycore platform

PRO3D, Programming for Future 3D Manycore Architectures: Project\u2019s Interim StatusFormal Methods for Components and Objects

PRO3D tackles two important 3D technologies, that are Through Silicon Via (TSV) and liquid cooling, and investigates their consequences on stacked architectures and entire software development. In particular, memory hierarchies are being revisited and the thermal impact of software on the 3D stack is explored. As a key result, a software design flow based on the rigorous assembly of software components and monitoring of the thermal integrity of the 3D stack has been developed. After 30 months of research, PRO3D proposes a complete tool-chain for 3D manycore, that integrates state-of-the-art tools ranging from system-level formal specification and 3D exploration, to actual programming and runtime control on the 3D system. Current efforts are directed towards extensive experiments on an industrial embedded manycore platfor