Performance of message-passing systems using a zero-copy communication protocol

From virtual reality and telepresence, to augmented reality, holoportation, and remotely controlled robotics, these future network applications promise an unprecedented development for society, economics and culture by revolutionizing the way we live, learn, work and play. In order to deploy such futuristic applications and to cater to their performance requirements, recent trends stressed the need for the Tactile Internet, an Internet that, according to the International Telecommunication Union, combines ultra low latency with extremely high availability, reliability and security. Unfortunately, today's Internet falls short when it comes to providing such stringent requirements due to several fundamental limitations in the design of the current network architecture and communication protocols. This brings the need to rethink the network architecture and protocols, and efficiently harness recent technological advances in terms of virtualization and network softwarization to design the Tactile Internet of the future. In this paper, we start by analyzing the characteristics and requirements of future networking applications. We then highlight the limitations of the traditional network architecture and protocols and their inability to cater to these requirements. Afterward, we put forward a novel network architecture adapted to the Tactile Internet called FlexNGIA, a Flexible Next-Generation Internet Architecture. We then describe some use-cases where we discuss the potential mechanisms and control loops that could be offered by FlexNGIA in order to ensure the required performance and reliability guarantees for future applications. Finally, we identify the key research challenges to further develop FlexNGIA towards a full-fledged architecture for the future Tactile Internet.

Routing protocols in Delay Tolerant Networks are designed for the unstable network with frequent disconnections and long propagation delay, which are different from the traditional network protocols. This chapter will introduce some basic routing protocols which show the significant feature of the mobile node in Delay Tolerant Networks which serves as a communication node to build the network, storing, carrying, and forwarding information from the source node to the destination. Since this kind of network does not depend on infrastructure and is easy to deploy on vehicles and other devices, some improved protocol in vehicular and aerial aspects and their practical applications in Smart City will be focused on. This chapter also discusses some possible future research directions which may lead to further development in Delay Tolerant Networks.

Based on the analysis of the wireless sensor networks in the application of the public utilities, a new approach which can change channel dynamically in buildings using wireless sensor networks was designed and implemented. In this paper, the WSN platform supported for AES encryption. And on the basis of the TDMA protocol, using linear regression and BBS generator, a new WSN protocol which has the ability to change communication channel dynamically was designed. Compared with traditional network protocols, the proposed method can decrease the degree of network congestion, energy consumption, program complexity and easy to achieve.

Reliable and secure content distribution in a disruptive environment is a critical challenge due to high mobile and lossy channels. Traditional IP networking and wireless protocols tend to perform poorly. In this paper, we propose Content Centric Networking (CCN) for emergency wireless ad hoc environments. CCN is a novel communication architecture capable to access and retrieve content by name. This new approach achieves scalability, security, and efficient network resource management in large scale disaster recovery and battlefield networks. Existing Internet CCN schemes cannot be directly applied to wireless mobile ad hoc networks due to different environments and specific limitations. Thus, we must extend the CCN architecture by introducing features and requirements especially designed for disruptive networks. We prove feasibility and performance gain of the new design via implementation and experimentation.

<div class="section abstract"><div class="htmlview paragraph">Technological advances in automotive industry have resulted in an increased number of Electronic Control Units (ECU)s. These ECUs are used for sensing and controlling actuators in the modern vehicles. Various network protocols have been proposed to achieve scalable and reliable communication amonglarge number ECUs in modern vehicles.Various network protocols have been proposed for invehicle communication,such as Controlled Area Network (CAN), Local Interconnected Network (LIN), Media Oriented System Transport (MOST), and FlexRay. This study compares latency and reliability of CAN-Bus and FlexRay communication protocols. The HSC12 microcontroller is used to implement these protocols, and for secure communication data is encrypted.Our experimental results indicate that the CAN-Bus communication protocol is a better option for <i>hard real-time systems</i> and FlexRay protocol is appropriate for deterministic data transmission, e.g., priority-less message communication.</div></div>

The North American Freight Railroad industry has been exploring ways in which on-board real time or near real-time monitoring of important railcar components and cargo can be accomplished. This approach alleviates the danger from fast occurring catastrophic events like bearing failure, which is not always possible using the traditional wayside monitoring techniques. The use of Wireless Sensor Networks is a viable candidate technology that is being explored for this application. However, popular communication protocols based on IEEE 802.15.4 have been evaluated by the railroad industry and our lab, and were found to perform unacceptably for this application domain, among other reasons, as a consequence of the long linear chain-like network topology of a sensor network deployment on a train. Hybrid Technology Networking (HTN) protocol has been designed to address these issues. HTN structures the network as a communication hierarchy using multiple different network technologies. It allows small clusters to communicate internally using IEEE 802.15.4 and utilizes IEEE 802.11 as the inter-cluster transport method for data delivery over multiple hops to the locomotive. It aims to maximize the benefits afforded by each technology. Energy is a scarce resource in such networks and hence modeling it for energy analysis and optimization is vital. A model that accurately predicts the energy consumption of a particular network deployment is therefore of utmost necessity. However, most modelling efforts concentrate on network deployments utilizing only a single type of communication protocol and the structure of such deployments are often mesh-like. Also the existing modelling approaches tend to model the entire network as a single phenomenon, which is often not the case in network deployments such as those in the freight railroad scenario. It is also expensive to commission large network deployments to evaluate energy consumption profiles. The problem is compounded when this process has to be repeated for several different communication protocols and channel conditions. The task will be made economically viable and massively scalable with the use of a modular energy model. The philosophy behind our approach is to model the important and contributing constituents of the protocol within each node and also external to the node and then utilize inter-dependencies to connect the individual models. This work is the first step towards a modular energy model for the Hybrid Technology Network, and is also applicable to many other networking approaches. In this work we propose a model design that is capable of predicting the network behavior of nodes in a linear chain-like topology utilizing the ContikiMAC duty cycling protocol for multi-hop communication with the sink node. We have used channel emulation to test hardware nodes in a chain-like topology to validate the model predictions, and present our findings in this paper.

Performance of I/O intensive applications on a multiprocessor system depends mostly on the variety of disk access delays encountered in the I/O system. Over the years, the improvement in disk performance has taken place more slowly than the corresponding increase in processor speeds. It is therefore necessary to model I/O delays and evaluate performance benefits of moving an application to a better multiprocessor system. We perform such an analysis by measuring I/O delays for a synthesized application that uses a parallel distributed file system. The aim of this study is to evaluate the performance benefits of better disks in a multiprocessor system. We report on how the I/O performance would be affected if an application were to run on a system which would have better disks and communication links. In this study, we show a substantial improvement in the performance of an I/O system with better disks and communication links with respect to the existing system.

WLAN devices based on CSMA/CA access schemes have become a fundamental component of network deployments. In such wireless scenarios, traditional networking applications, tools, and protocols, with their built-in measurement techniques, are usually run unchanged. However, their actual interaction with the dynamics of underlying wireless systems is not yet fully understood. A relevant example of such built-in techniques is bandwidth measurement. When considering WLAN environments, various preliminary studies have shown that the application of results obtained in wired setups is not straightforward. Indeed, the contention for medium sharing among multiple users inherent to CSMA/CA access schemes has remarkable consequences on the behavior of and results obtained by bandwidth measurement techniques. In this paper, we focus on evaluating the effect of CSMA/CA-based contention on active bandwidth measurement techniques. As a result, it presents the rate response curve in steady state of a system with both FIFO and CSMA/CA-based contending cross-traffic. We also find out that the distribution of access delay shows a transient regime before reaching a stationary state. The duration of such transient regime is characterized and bounded. We also show how dispersion-based measurements that use a short number of probing packets are biased measurements of the achievable throughput, the origin of this bias lying on the transient detected in the access delay of probing packets. Overall, the results presented in this paper have several consequences that are expected to influence the design of bandwidth measurement tools as well as to better understand the results obtained with them in CSMA/CA links.

Chapter 25 - Optimizing and Uprating of Existing Systems

Motivated by recent advances in TFT array technology for display, this study develops a theoretical treatment of dual granular scintillating screens sandwiched around a light detector and applies this to investigate possible improvements in imaging performance of indirect active-matrix flat-panel imagers (AMFPI’s) for x-ray applications, when dual intensifying screen configurations are used. Theoretical methods, based on previous studies of granular intensifying screens, are developed and applied to calculate modulation transfer function (MTF), normalized noise power spectrum (NNPS), Swank factor (As), Lubberts function L(f), and spatial frequency-dependent detective quantum efficiency (DQE(f)) for a variety of detector configurations in which a pair of screens are sandwiched around a light sensing array. Single-screen front illuminated (FI) and back illuminated (BI) configurations are also included in the analysis. DQE(f) is used as a performance metric to optimize and compare the performance of the various configurations. Large improvements in performance in MTF and DQE(f) are found possible, when the substrate layer between the light sensing array and the intensifying screen is optically thin. The ratio of the thicknesses of the two screens which optimizes DQE performance is generally asymmetric with the thinner screen facing the incident flux, and the ratio depends on the x-ray attenuation length in the phosphor material.

Many real-time systems require end-to-end delay guarantee. After coronavirus (Covid 19) infection spread throughout the world, adoption of telemedicine service has become extremely important. Effective telemedicine may involve providing services having different delay and bandwidth requirements. The traditional network protocols are not suitable for providing Quality of Service (QoS) as the Internet operates in best-effort mode. We explore a solution based on Software Defined Networking (SDN) to offer services varying in end-to-end delay and bandwidth requirements. We leverage programmability and centralized view of SDN network and propose a strategy where different telemedicine services may follow routes based on the available bandwidth on links and total delay along a path from the source to destination. Our simulation results show that the strategy is able to scale to a large number of requests and a large percentage of flows is able to meet the delay requirements.

The diffusion of RFID technology continues using the Electronic Product Code (EPC) as unique identifier for physical objects. The EPC Network enables companies to share information about read events by defining EPC Information Services (EPCIS). The communication protocols in the EPC Network are defined to be XML and SOAP. We claim that a binary encoded communication protocol is more appropriate given the fact that billions of read events will occur. We extend the Fosstrak EPCIS repository by binary encoded Google's Protocol Buffers. Our experimental evaluation shows that this switch in the protocol from textual encoding to binary encoding reduces the message size by about 75%, the processing time by at least 11% for XML and at least 59% for SOAP communication. With regards to the Internet of Things, our contribution shows the importance of the appropriate choice of communication protocols. We encourage that the EPC Network should be extended by a binary encoded communication protocol.

The Underwater Internet of Things (UW-IoT) is a novel class of Internet of Things (IoT) that enables extend the terrestrial internet to the marine environment. However, as the underwater acoustic channel poses extremely challenging difficulties for underwater IoT communication and networking, the performance of the underwater IoT networks lags far behind the terrestrial internet. Due to the expense of conducting experiments in real underwater systems many researches have been endowed with only simulation model and analysis. This paper presents the design and implementation of an underwater IoT network test platform in order to evaluate and analyze the performance of underwater communication and network protocol in physical shallow water environment. The design of this IoT network platform considers the application background of environment parameter acquisition in marine environment stereoscopic monitoring. The software and hardware implementation of the IoT platform are introduced. Sea test result shows that the platform is effective in evaluating the performance of underwater IoT network.

This paper analyzes the characteristics and key technologies of Zigbee wireless sensor network. It adopts modularization to realize Zigbee protocol stack, and designs Zigbee wireless sensor network platform. It also designs and realizes the overall framework, hardware circuit and software design module framework of this platform. The platform uses newly emerging communication protocol to be the communication protocol of sensor network, so that this wireless sensor network platform can make up multi-hop sensor network in high fault tolerance, low energy consumption and low cost. The teaching practice proves that our platform has advantages such as low cost, stable performance and easy extension of access.

Using node and socket information to implement MPI Cartesian topologies