Ring Protocol Research Articles

The impact of escape mapping for roof line completion during BOX isolation for atrial fibrillation

Abstract Background and Aim The creation of complete roof line (RL) is often challenging due to the presence of epicardial myocardial bundle or fat interposition. The disconnecting the septopulmonary bundle from the Buchmann bundle arrays requires for RL completion. Therefore, the conduction time to the left atrial appendage (LAA) and the high right atrium (HRA) potentials under left superior pulmonary vein pacing (LSPVp), so-called •escape mapping•, should be significantly prolonged after the creation of the transmural RL. This study investigates whether the changes conduction times from LSPVp to LAA and HRA (∆LSPVp-LAA and ∆LSPVp-HRA) between before and after the creation of the line as the assessment of bi-directional RL block. Methods 76 de-novo non-paroxysmal atrial fibrillation (nPAF) patients underwent BOXI strategy ablation. We initially intended single ring protocol BOXI for all patients. The activation times were measured at LAA and HRA under LSPV pacing at baseline and after application for the RL. Then we compared the change of activation time at LAA (∆LSPVp-LAA) and at HRA (∆LSPVp-HRA) between 2 groups; the group that completed BOXI with the first-pass roof line (fp-RL group) and the other group (Nfp-RL group). Results In 47 patients, the first-pass roof line was successfully obtained and in patients was done with additional application for gap(s) on the roof line to complete BOXI. There was a stepwise increase in mean ∆LSPVp-HRA not ∆LSPVp-LAA. Increased LA diameter, lower LVEF, and thinner LA wall were associated with the first-pass roof line. ∆LSPVp-HRA ≥33ms predict roof line block with high specificity and sensitivity. Conclusions Our findings suggest that the changes conduction times between LSPV and HRA during LSPV pacing help in the assessment of RL block.

A Versatile Resilience Packet Ring Protocol Model for Homogeneous Networks

Optimizing routes and paths improves network performance. Due to the encapsulation and tunneling of the packets, mobile IP-based communication contributes to packet drops or significant delays between the sender and receiver. Packet loss during handoff reduces TCP throughput as well. One solution is to use the IEEE 802.11 Medium Access Control (MAC) protocol and TCP or UDP models to increase routing protocol performance. In the linkage of homogeneous networks, it is challenging to determine route failure. In addition, the 802.11 MAC also uses a link connection. As a result, re-covering the entire route path takes a longer time. Thus, improving wired and wireless mobile node communication and handover is both challenging and critical. To overcome this challenge, we propose to use the Versatile Resilience Packet Ring protocol (VRPR)-based model. In this paper, we propose a novel VRPR-based network model that allows uninterrupted communication in both wired and wireless media. VRPR is used in the network layer to avoid buffer overflow and client mobility. Our new model also identifies the cause of the route failure, whether it is due to client mobility (handover), due to link breakage (channel degradation), or due to buffer overflow. We evaluate our network model based on three performance factors, namely, the delay, packet, and packet loss, and compared it between wired and wireless media. Our Enhanced-VRPR-based network model outperforms the current VRPR wired and wireless network models. We validate our model through OMNet++ simulations.

Retinal layer segmentation in a cohort of healthy children via optical coherence tomography.

High-resolution optical coherence tomography (OCT) allows the detection of macular pathology and involvement of the optic nerve in a wide spectrum of diseases. For the differentiation of diseased and healthy status, normal values of retinal layer segmentation are critical. Yet, normative values mostly cover adult populations with only sparse data for paediatric cohorts. We present data of retinal layer characteristics via OCT in a healthy paediatric cohort. This prospective cross-sectional study screened 75 healthy children (male = 42, female = 33, range 4-17 years) without visual problems. OCT was performed with a peripapillary ring and macula scan protocol to determine paediatric normative values for routine parameters (peripapillary retinal nerve fibre layer thickness (pRNFL), total macular volume (TMV), macular retinal thickness (RT)). The macula scan (6mm grid) was segmented using the device-inherent automated segmentation software (Heidelberg Eye Explorer) for retinal layers: RNFL, ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL) in 9 segments each and mean of the 9 segments. We obtained OCT data of 72 children with mean age 12.49 years (standard deviation, SD, 2.18; minimum 3.93). Mean global pRNFL was 102.20 μm (SD 8.24), mean TMV 8.81 mm3 (0.30) and mean RT (all segments) 318.22 μm (10.19). Segmented macular retinal layer thicknesses (mean of all segments) were: RNFL 27.67 μm (2.14), GCL 41.94 μm (2.50), IPL 34.97 μm (2.10), INL 35.18 μm (2.15), OPL 29.06 μm (2.24), ONL 68.35 μm (6.20). The OCT is a useful non-invasive imaging technique for the examination of the retina in children with short duration, high imaging resolution and no known adverse effects. Normative values may serve as a comparator for different neuropaediatric disorders and are first presented with this study using an up-to-date and standardized OCT imaging technique.

A 7-nm Four-Core Mixed-Precision AI Chip With 26.2-TFLOPS Hybrid-FP8 Training, 104.9-TOPS INT4 Inference, and Workload-Aware Throttling

Reduced precision computation is a key enabling factor for energy-efficient acceleration of deep learning (DL) applications. This article presents a 7-nm four-core mixed-precision artificial intelligence (AI) chip that supports four compute precisions—FP16, Hybrid-FP8 (HFP8), INT4, and INT2—to support diverse application demands for training and inference. The chip leverages cutting-edge algorithmic advances to demonstrate leading-edge power efficiency for 8-bit floating-point (FP8) training and INT4 inference without model accuracy degradation. A new HFP8 format combined with separation of the floating- and fixed-point pipelines and aggressive circuit/architecture optimization enables performance improvements while maintaining high compute utilization. A high-bandwidth ring protocol enables efficient data communication, while power management using workload-aware clock throttling maximizes performance within a given power budget. The AI chip demonstrates 3.58-TFLOPS/W peak energy efficiency and 26.2-TFLOPS peak performance for HFP8 iso-accuracy training, and 16.9-TOPS/W peak energy efficiency and 104.9-TOPS peak performance for INT4 iso-accuracy inference.

System Performance of Wireless Sensor Network Using LoRa–Zigbee Hybrid Communication

Wireless sensor network (WSN) is considered as the fastest growing technology pattern in recent years because of its applicability in varied domains. Many sensor nodes with different sensing functionalities are deployed in the monitoring area to collect suitable data and transmit it to the gateway. Ensuring communications in heterogeneous WSNs, is a critical issue that needs to be studied. In this research paper, we study the system performance of a heterogeneous WSN using LoRa–Zigbee hybrid communication. Specifically, two Zigbee sensor clusters and two LoRa sensor clusters are used and combined with two Zigbee-to-LoRa converters to communicate in a network managed by a LoRa gateway. The overall system integrates many different sensors in terms of types, communication protocols, and accuracy, which can be used in many applications in realistic environments such as on land, under water, or in the air. In addition to this, a synchronous management software on ThingSpeak Web server and Blynk app is designed. In the proposed system, the token ring protocol in Zigbee network and polling mechanism in LoRa network is used. The system can operate with a packet loss rate of less than 0.5% when the communication range of the Zigbee network is 630 m, and the communication range of the LoRa network is 3.7 km. On the basis of the digital results collected on the management software, this study proves tremendous improvements in the system performance.

Full Information Estimation for Time-Varying Systems Subject to Round-Robin Scheduling: A Recursive Filter Approach

The full information estimation (FIE) problem is addressed for discrete time-varying systems (TVSs) subject to the effects of a round-Robin (RR) protocol. A shared communication network is adopted for data transmissions between sensor nodes and the state estimator. In order to avoid data collisions in signal transmission, only one sensor node could have access to the network and communicate with the state estimator per time instant. The so-called RR protocol, which is also known as the token ring protocol, is employed to orchestrate the access sequence of sensor nodes, under which the chosen sensor node communicating with the state estimator could be modeled by a periodic function. A novel recursive FIE scheme is developed by defining a modified cost function and using a so-called “backward-propagation-constraints.” The modified cost function represents a special global estimation performance. The solution of the proposed FIE scheme is achieved by solving a minimization problem. Then, the recursive manner of such a solution is studied for the purpose of online applications. For the purpose of ensuring the estimation performance, sufficient conditions are obtained to derive the upper bound of the norm of the state estimation error (SEE). Finally, two illustrative examples are proposed to demonstrate the effectiveness of the developed estimation algorithm.

A Novel Multipath Routing Ring Protocol Adapted for WMSN

<p>In this paper an enhanced protocol of multipath routing ring that is suitable for transferring images by making many upgrades. First, instead of using propagation between the layers, we use certain parameters such distance and delay to pick the next node of the lower layer. Then, we used an heterogeneous network, including sensors (capture and send images) and connectors (serve as a bridge to the sink). Finally, we used the pyramid decomposition technique. To avoid congestion, we adjust the number of levels based on the state of the network. To verify our protocol, we used Castalia simulator to simulate the real transmission conditions. Then, we compared it with GPSR protocol and the original Multipath routing ring protocol. Our proposed protocol proves its efficiency by transferring more images with better quality (PSNR) and consuming less energy compared to other protocols.</p>

A Combinatorial Approach for Developing Ring Communication Graphs for Vehicle Formations

In this paper, we study vehicle formations employing ring-structured communication strategies and propose a combinatorial approach for developing ring graphs for vehicle formations. In vehicle platoons, a ring graph is formed when each vehicle receives information from its predecessor, and the lead vehicle receives information from the last vehicle, thus forming a ring in its basic form. In such basic form, the communication distance between the first and the last vehicle increases with the platoon size, which creates implementation issues due to sensing range limitations. If one were to employ a communication protocol such as the token ring protocol, the delay in updating information and communication arises from the need for the token to travel across the entire graph. To overcome this limitation, alternative ring graphs which are formed by smaller communication distances between vehicles are proposed in this paper. For a given formation and a constraint on the maximum communication distance between any two vehicles, an algorithm to generate a ring graph is obtained by formulating the problem as an instance of the traveling salesman problem (TSP). In contrast to the vehicle platoons, generation of a ring communication graph is not straightforward for two- and three-dimensional formations; the TSP formulation allows this for both two- and three-dimensional formations with specific constraints. In addition, with ring communication structure, it is possible to devise simple ways to reconfigure the graph when vehicles are added/removed to/from the formation, which is discussed in the paper. Further, the experimental results using mobile robots for platooning and two-dimensional formations using ring graphs are shown and discussed.

Performance Analysis and Comparison of Multi Hop Token Ring and Token Bus LAN Technologies

Token ring and token bus networks are two of the most commonly used type of local-area network (LAN). Token ring is designed in such a way that it can provide high throughput under heavy loads. Token bus is implemented using the token ring protocol over a virtual ring on a coaxial cable. The names, token ring and token bus, are applied to LANs which support a multiple access system using a token passing scheme. It is possible to define the maximum access delay experienced by a packet and thus to define the end-to-end delay across the network. In this paper after simulating the token ring and token bus technologies we have focused on the performance issues like throughput, mean delay, normalized throughput and response time of both the techniques. Lastly using some graphs and the data deduced from our simulation we have compared and concluded that token ring performs better than token bus for multi hop network design.

A Hybrid Quorum Protocol for Improved Availability, Capacity, Load and Reduced Overhead

Data replication is playing a vital role in the design of distributed information systems. This paper presents a novel and efficient distributed algorithm for managing replicated data and for better performance and availability. This paper presents an extension to existing wheel protocol for improved performance. Wheel protocol imposes a logical wheel structure on the set of copies of an object and gives smallest read quorum. In addition to small read quorum size for read intensive applications, it is necessary to have good write availability as well. This paper proposes two hybrid wheel protocols, which superimpose logarithmic and ring protocols on top of the wheel protocol. It shows that, both protocols help in improving write availability, read capacity, load and message overhead and also compare their performances with wheel and other protocols. Hybrid protocols expand usage of wheel protocol to different type of applications.

Modelling, analysis and validation of wireless controller area network

The controller area network (CAN) is the pioneer in standardising vehicle and automation bus standards. For the wired CAN to meet the emergent pervasive wireless technology, wireless controller area network (WCAN) is introduced. WCAN is based on wireless token ring protocol (WTRP); a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message-based communication. CAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and better packet delivery ratio. WCAN is tested by simulation using QualNet and compared with IEEE 802.11 and is found to outperform it in ring network. The test results are validated using SAE benchmark.

An Enhanced Service Ring Protocol for Service Discovery in MANET

Semantic service trading is a powerful mechanism to allow devices to share the resources and services in highly dynamic environment. Mobile devices are able to spontaneously form highly dynamic Ad-hoc networks allowing the communication even when no infrastructure exists. These types of networks enable the participating devices to share resources and services and thus overcome the often severe limitations of the individual device capabilities. The devices cooperate with each other by providing different types of services. These services must be discovered before they can be used. Locating a network service or a device on demand is a challenging task for enabling mobile and pervasive computing. There exists a variety of network protocols and architectures that enable an application to discover a network service with little manual configuration. In this paper our studies is focused on Service Rings Protocol and suggests caching to improve its performance. The modification increases the performance and efficiency of Service Ring protocol for service discovery in MANET by reducing the flooding and exchange of service discovery messages. General Terms Service Discovery , Service Ring , Caching, MANET et al.

REAL TIME ANALYSIS OF WIRELESS CONTROLLER AREA NETWORK

It is widely known that Control Area Networks (CAN) are used in real-time, distributed and parallel processing which cover manufacture plants, humanoid robots, networking fields, etc., In applications where wireless conditions are encountered it is convenient to continue the exchange of CAN frames within the Wireless CAN (WCAN). The WCAN considered in this research is based on wireless token ring protocol (WTRP); a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message based communication. WCAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and good packet delivery ratio. The most important factor to consider when evaluating a control network is the end-to-end time delay between sensors, controllers, and actuators. The correct operation of a control system depends on the timeliness of the data coming over the network, and thus, a control network should be able to guarantee message delivery within a bounded transmission time. The proposed WCAN is modeled and simulated using QualNet, and its average end to end delay and packet delivery ratio (PDR) are calculated. The parameters boundaries of WCAN are evaluated to guarantee a maximum throughput and a minimum latency time, in the case of wireless communications, precisely WCAN.

Multi-Gb/s Fiberoptic Physical Layer for Spacecraft Interconnects

We report on the development of a fiberoptic physical layer bus with RapidIO-protocol for spacecraft avionics interconnects. To emulate spacecraft instrument data transmission, dynamic routing of real-time live camera data packets is demonstrated through a switch-based network. For real-time instrument data input/output, an interface bridge between Ethernet protocol and RapidIO protocol is developed. RapidIO-based fiberoptic avionic system is compared with 1393 ring protocol based interconnect in terms of performance, flexibility, mass/power/size, and suitability for different mission applications. Fault tolerant architectures for RapidIO and 1393 ring-protocol-based spacecraft buses are also presented.

Performance Evaluation of Wireless Controller Area Network (WCAN) Using Token Frame Scheme

In this paper, a proposed new wireless protocol so-called wireless controller area network is introduced. WCAN is an adaptation of its wired cousin, controller area network protocol. The proposed WCAN uses token frame scheme in providing channel access to nodes in the system. This token frame method follows the example used in wireless token ring protocol which is a wireless network protocol that reduces the number of retransmissions as a result of collisions. This scheme based on CAN protocol allows nodes to share a common broadcast channel by taking turns in transmitting upon receiving the token frame that circulates around the network for a specified amount of time. The token frame allows nodes to access the network one at a time, giving `fair' chance to all nodes instead of competing against one another. This method provides high throughput in a bounded latency environment. The proposed WCAN protocol has been developed and simulated by means of QualNet simulator. The performances of this proposed protocol are evaluated from the perspective of throughput, end-to-end delay and packet delivery ratio, and are compared against the IEEE 802.11 protocol. Simulation results show that the proposed WCAN outperforms IEEE 802.11 based protocol by 62.5 % in terms of throughput with increasing network size. Also, it shows an improvement of 6 % compared to IEEE 802.11 standard at a higher data interval rate.

Verification of telecommunication systems specified using communicating finite-state automata using colored Petri nets

Uniform systems of communicating extended finite-state automata are considered. These systems can be used for the initial specification of telecommunication systems such as ring protocols and telephone networks. This paper aims to present an automata systems verifier tool (ASV) designed for the analysis and verification of automata specifications. It is based on an algorithm for the translation of automata systems into colored Petri nets (CPN) presented and justified in [4]. The ASV tool uses CPN Tools [10] for analysis and simulation of CPN, also it uses Petri Net Verifier [12] to verify CPN properties by applying the model checking method to CPN reachability graph with respect to the properties expressed in μ-calculus. The application of the ASV tool is described for the ring RE-protocol verification and the study of the feature interaction in telephone networks.

Protection Technique for Complex Distribution Smart Grid Using Wireless Token Ring Protocol

Distributed generation is expected to increase sharply as more and more renewable are integrated to power system with the realization of smart grid, consequently complex distribution smart grid is given. The traditional protection devices cannot be able to protect complex power system configuration due to many fault current loops will feed the fault point. Relays based on standalone decisions cannot provide reliable and correct action when used on a complex distribution system. This paper proposes new protection philosophy using wireless technology. Data sharing among relays to obtain reliable and accurate decision are introduced. Wireless Token Ring Protocol (WTRP) as a wireless local area network (LAN) protocol inspired by the IEEE 802.4 Token Bus Protocol is used for data sharing. WTRP is selected to improve efficiency by reducing the number of retransmissions due to collisions. WTRP architecture and protocol are described to verify operation. MATLAB simulation program is used to simulate the data exchange protocol between relays in a ring for a specified amount of time.

Throughput analysis of network coding enabled wireless backhauls

This study derives upper bounds on the throughput of the wireless backhaul link within a cluster of inter-connected three base stations (BSs) or a cluster of a controlling BS and three fixed relay stations. The authors propose and analyse the Ring protocol for the former and the Star protocol for the latter using network coding concept. These protocols can be used individually or in an overlaid fashion in a coordinated multi-cell system or in a cellular-distributed-antenna system to exchange information in the backhaul. To avoid the weakest link acting as a bottleneck and determining the backhaul throughput, as a result, the authors derive throughput optimising time sharing factors to compensate for the resulting bit imbalances in the backhaul.

Review of Researches in Controller Area Networks Evolution and Applications

Initially designed as a new mean in providing communication network between control units in automotive industries, the controller area network (CAN) has shown a great surge of interest due to its vast advantages. Since then it is widely used in various automation industries including military, aviation, electronics, factories and many others. CAN was designed to allow microcontrollers and devices to communicate with each other without the presence of a host computer and avoiding extensive load to the main controller. It is a high performance and high reliable advanced serial communication protocol which effectively supports distributed realtime control. Ideally, CAN is suitable in application requiring a large number of short messages with high reliability in rugged environment. These characteristics along with many others, allows wide opportunity in development of intelligent ubiquitous sensor network and controller system. This paper presents a brief introduction on CAN operating principles, its architecture and protocols. Also, various applications of CAN are introduced and surveyed with more attention given on smart home. Due to its reliability, efficiency and robustness, an extension of CAN applicants in home automation is proposed that uses sign language smart controller. Finally, this paper concludes with a proposed improvement by converting CAN into wireless CAN (WCAN) by using wireless token ring (WTRP) protocol. WCAN gives a solution when industrial mobile stations under certain constraints should continue to use CAN protocol as frame exchange protocol.

An input traffic allocation strategy and an efficient transmission technique for collisions-free WDM ring MANs

This paper presents a wavelength division multiplexing multi-ring architecture with a separate control wavelength for metropolitan area networks. We study the critical problem of low fiber bandwidth utilization that many access ring protocols introduce, especially at high load conditions. In our study this problem is effectively faced by: (1) applying an efficient slotted access algorithm to avoid both data wavelengths and receiver collisions, (2) introducing a number of buffers at each node to effectively allocate the incoming traffic into them, and (3) applying an efficient algorithm for buffer selection for transmission that combines the priority criteria of packet age and receiver collisions avoidance. In this way, we obtain maximum fiber bandwidth utilization. Especially, our aim is to achieve not only significant throughput enhancement, but also essential dropping probability and total delay reduction. Also, the number of transmission buffers per node is investigated in order to manage maximum throughput improvement, while considering the financial cost. Finally, a discrete-event simulation model based on Poisson statistics is developed for the performance measures evaluation.