Search results for "Telecommunication"

On ARQ feedback intensity of the IEEE 802.16 ARQ mechanism

2008

The IEEE 802.16 standard defines the ARQ mechanism as a part of the MAC layer. The functioning of the ARQ mechanism depends on a number of parameters. The IEEE 802.16 specification defines them but it does not provide concrete values and solutions. We ran simulation scenarios to study how the ARQ feedback intensity impacts the performance of application protocols. The simulation results reveal that a low ARQ feedback intensity results only in a marginal improvement. Though it is possible to optimize the ARQ feedback intensity, it is reasonable to rely upon more frequent ARQ feedback messages as they do not result in a performance degradation. At the same time, ARQ connections, which work on…

Gray code for permutations with a fixed number of cycles

2007

AbstractWe give the first Gray code for the set of n-length permutations with a given number of cycles. In this code, each permutation is transformed into its successor by a product with a cycle of length three, which is optimal. If we represent each permutation by its transposition array then the obtained list still remains a Gray code and this allows us to construct a constant amortized time (CAT) algorithm for generating these codes. Also, Gray code and generating algorithm for n-length permutations with fixed number of left-to-right minima are discussed.

Digital Platforms for Restructuring the Public Sector

2018

Many technological innovations have led to the emergence of the platform economy in recent years. This development is changing the entire landscape of business in the era of digitalisation. However, the impacts of the platform economy on public services and government are not well known. In this article we study the potential for the digital platform economy to help restructure the public sector. Firstly, central features of the new platform technology are explored, pointing to an algorithmic revolution, big data and cloud computing. Platforms are used in coordinating market transactions in an extremely efficient way. In order to apply the platform concept to the public sector, an experimen…

A Graph Database Approach to Wireless IIoT Workcell Performance Evaluation

2020

The workcell is considered a main building block of various industrial settings. Hence, it is examined as a primary testing environment for studying wireless communication techniques in factory automation processes. A new testbed was recently designed and developed to facilitate such studies in workcells by replicating various data flows in an emulated production environment. In this paper, an approach to storing and analyzing network performance data from a manufacturing factory workcell is introduced. A robotic testbed was constructed using two collaborative grade robot arms, machine emulators, and wireless communication devices. A graph database approach was implemented to capture networ…

Kernel-Based Inference of Functions Over Graphs

2018

Abstract The study of networks has witnessed an explosive growth over the past decades with several ground-breaking methods introduced. A particularly interesting—and prevalent in several fields of study—problem is that of inferring a function defined over the nodes of a network. This work presents a versatile kernel-based framework for tackling this inference problem that naturally subsumes and generalizes the reconstruction approaches put forth recently for the signal processing by the community studying graphs. Both the static and the dynamic settings are considered along with effective modeling approaches for addressing real-world problems. The analytical discussion herein is complement…

Robust Graph Topology Learning and Application in Stock Market Inference

2019

In many applications, there are multiple interacting entities, generating time series of data over the space. To describe the relation within the set of data, the underlying topology may be used. In many real applications, not only the signal/data of interest is measured in noise, but it is also contaminated with outliers. The proposed method, called RGTL, infers the graph topology from noisy measurements and removes these outliers simultaneously. Here, it is assumed that we have no information about the space graph topology, while we know that graph signal are sampled consecutively in time and thus the graph in time domain is given. The simulation results show that the proposed algorithm h…

Fully pipelined real time hardware solution for High Efficiency Video Coding (HEVC) intra prediction

2016

International audience; A fully pipelined hardware accelerator for the High Efficiency Video Coding (HEVC) intra prediction is presented in this paper in order to reduce the computation complexity coming with this module and to accelerate the concerned calculations. Two reconfigurable structures are developed in this paper, the first one concerns angular modes and is identified as Processing Element for Angular (PEA) modes, the other is made in order to handle with the Planar mode and is identified as Processing Element for the Planar (PEP) mode. Each structure is repeated in five paths, that our architecture composed of, working in parallel way. This architecture supports all intra predict…

Handover and Uplink Power Control Performance in the 3.84 Mcps TDD mode of UTRA Network

2003

In this article we consider the performance of the 3.84 Mcps time-division duplex (TDD) mode of UTRA (Universal Terrestrial Radio Access) network. We emphasize two of the radio resource management algorithms, handover and uplink power control, whose role in the overall system performance is studied extensively. First, a handover algorithm used in WCDMA (Wideband Code Division Multiple Access) standard is considered in a TDD-mode operation. This gives rise to a careful setting of different handover parameters, and the evaluation of the effects to the system performance. Secondly, the specified uplink power control algorithm is considered. Since it is based on several user-made measurements w…

Editorial

2002

FADaC

2019

Solid state drives (SSDs) implement a log-structured write pattern, where obsolete data remains stored on flash pages until the flash translation layer (FTL) erases them. erase() operations, however, cannot erase a single page, but target entire flash blocks. Since these victim blocks typically store a mix of valid and obsolete pages, FTLs have to copy the valid data to a new block before issuing an erase() operation. This process therefore increases the latencies of concurrent I/Os and reduces the lifetime of flash memory. Data classification schemes identify data pages with similar update frequencies and group them together. FTLs can use this grouping to design garbage collection strategi…