Distributed Communication Protocol Research Articles

Variable Layer Heights in Wire Arc Additive Manufacturing and WAAM Information Models

In Wire Arc Additive Manufacturing (WAAM), variable layer heights enable the non-parallel or non-planar slicing of parts. In researching variable layer heights, this paper documents printing strategies for a reference geometry whose key features are non-orthogonal growth and unsupported overhangs. The complexity of 3D printing with welding requires parameter optimization to control the deposition of molten material. Thus, 3D printing with welding requires the precise deposition of molten material. Currently, there is no standard solution for the customization of process parameters and intelligent collection of data from sensors. To address this gap in technology, this research develops an Internet of Things (IoT)-enabled, distributed communication protocol to control process parameters, synchronize commands, and integrate device data. To intelligently collect sensor information, this research creates a query-able database during pre-planning and production. This contributes to fundamental research in WAAM by documenting strategies for printing variable layer heights, the customization of control parameters, and the collection of data through a WAAM Information Model (WIM).

Importance-based distributed persistent coverage strategy over environmental hotspots using quadrotors: Algorithm and experiments

This paper proposes a novel importance-based persistent coverage for environments with hotspots. Multiple quadrotors are utilized to maintain coverage while acquiring high-quality information over prioritized regions by lowering the altitude. To achieve this, the approach utilizes distributed communication protocols and cost functions to address the tradeoff between wider coverage and better quality information. The cost functions determine three-dimensional waypoints based on coverage levels, sensor resolution, and Euclidean distance. Voronoi tessellations are used locally for efficient computation and collision avoidance. Trajectories of the quadrotors are generated based on quadrotor dynamics using error functions that take into account state information and desired waypoints. The proposed approach is validated through simulations, comparisons, and experiments for multi-agent systems under quadrotor dynamics. Further, metrics of performance analysis are formulated that show consistent coverage levels and differences to assess the novel importance-based approach. The simulations and experiments demonstrate the feasibility and effectiveness of the approach, with prioritized regions receiving higher sensor resolution while maintaining persistent coverage of the environment.

Distributed Persistent Coverage Control over Importance-based Environments with Quadrotors⋆

This paper proposes a distributed persistent coverage strategy for environments with important regions. The strategy involves using quadrotors at varying altitudes to acquire high-resolution information from these regions. The information is then transmitted through distributed communication protocols that use local coverage maps to retain periodic and high-quality data. To resolve the trade-off between high-resolution data from low altitudes and wider coverage from high altitudes, cost functions based on distance, coverage, and sensor resolution are used to determine three-dimensional waypoints. Further, Voronoi tessellations are used to aid in collision avoidance and efficient computation. To generate feasible trajectories, the quadrotor's dynamics are considered, along with error functions that use state information and desired waypoints. Simulation results demonstrate the efficacy of the proposed approach for multi-agent systems under quadrotor dynamics.

Development and validation of distributed communication protocol from finite-state machines

This work documents the use of communication finite state machines for the representation of interactions in a network of devices. Likewise, a hierarchical structure between elements is adopted, under an organization of master-slave nodes; from which, the implemented communication protocol assumes the particular functions of each device, while ensuring the exchange of information between them. In order to validate the adequate constitution of the proposed protocol, through its respective programming, Arduino and Raspberry free hardware and software are used, as well as a basic interface created from the Thonny development environment, for data entry by the user and the feedback of information to this. The results obtained demonstrate the functionality of the developed protocol, which was implemented from the serial communication standard, supported by the hardware used. However, it is essential to clarify that it is possible to implement this type of application from the use of other standards, as available.

Distributed Communication Protocol in Wireless Sensor Network Based on Internet of Things Technology

Distributed Communication Protocol in Wireless Sensor Network Based on Internet of Things Technology

Distributed Byzantine-Resilient Multiple-Message Dissemination in Wireless Networks

The byzantine model is widely used to depict a variety of node faults in networks. Previous studies on byzantine-resilient protocols in wireless networks assume reliable communications and do not consider the jamming behavior of byzantine nodes. Such jamming, however, is a very critical and realistic behavior to be considered in modern wireless networks. In this paper, for the first time, we integrate the jamming behavior of byzantine nodes into the network setting. We show that, in this much more comprehensive and harsh model, efficient distributed communication protocols can be still devised with elaborate protocol design. In particular, we developed an algorithm that can accomplish the basic multiple-message dissemination task close to the optimal solution in terms of running time. Empirical results validate the byzantine-resilience and efficiency of our algorithm.

Iota Tangle: A cryptocurrency to communicate Internet-of-Things data

The emergence of distributed ledger technologies (DLT) and design limitations of Blockchain systems for some types of applications led to the development of cryptocurrency alternatives for various purposes. Iota is a cryptocurrency with a new architecture called Tangle, which promises high scalability, no fees, and near-instant transfers, focused on the Internet-of-Things (IoT) solutions. This paper aims to present a systematic community’s visions of this new technology and to provide minimum background to understand the Iota Tangle and ecosystem generated by this distributed Ledger. The first parts of this article describe the ecosystem behind Iota, theoretical mathematical foundation, and its challenges and solutions for implementation. In the second part, we presented systematic research about Iota Tangle in academic databases: IEEE, ScienceDirect, Scopus, and Research Gate. We select the articles those of high impact which can be filtered with the H5-index indicator. This criterion aims to guarantee that the papers analyzed underwent a careful selection process, evaluated by peers. The methodology used helped have a global vision of Iota, including that this innovation is not only understood as a cryptocurrency but can be considered as a “distributed communication protocol”, absence of fees, low latency, and low computational cost for sending transactions. However, there exist several challenges in the vanguard of development of this ledger. It could also be identified that this technology enables many possibilities, however, it is fundamental to understand the potentials and limitations of this ecosystem to generate the best use cases.

Globally optimal distributed time-varying weight information filter of mobile sensor network

The networked state estimation for a linear dynamic system is studied in this paper. Firstly, a time-varying distributed communication protocol governed by the network topology is introduced for delivering information among the neighboring sensors. Secondly, based on this protocol, a two stage distributed state estimation algorithm is presented to achieve the global optimal results in a least square sense. In the first stage of the proposed algorithm, distributed computation on the sum of global information vector contributions is conducted, and the second stage is to derive the state estimations via utilizing the interaction results offered by the first stage. Thirdly, it is shown that the proposed algorithm only demands finite neighbor interaction times to obtain global optimal estimations. The optimality and stability properties of the proposed algorithm are also proved by using the Riccati equation. Finally, through numerical simulations, it is further illustrated that the proposed algorithm could outperform the previous distributed estimators.

Blockchain for Mobile Health Applications Acceleration with GPU Computing.

Blockchain is a linearly linked, distributed, and very robust data structure. Originally proposed as part of the Bitcoin distributed stack, it can be applied in a number of fields, most notably in smart contracts, social media, secure IoT, and cryptocurrency mining. It ensures data integrity by distributing strongly encrypted data in widely redundant segments. Each new insertion requires verification and approval by the majority of the users of the blockchain. Both encryption and verification are computationally intensive tasks which cannot be solved with ordinary off-the-shelf CPUs. This has resulted in a renewed scientific interest in secure distributed communication and coordination protocols. Mobile health applications are growing progressively popular and have the enormous advantage of timely diagnosis of certain conditions. However, privacy concerns have been raised as mobile health applications by default have access to highly sensitive personal data. This chapter presents concisely how blockchain can be applied to mobile health applications in order to enhance privacy.

A Fast and Collision Avoidance Distributed TDMA Schedule Based on the Multi-Arms Bandit

In this paper, we propose a novel distributed TDMA protocol based on the Multi-Arms Bandit model for the dynamic UAVs environment. Because of the frequent topology changes of UAVs, we consider a distributed communication protocol, which do not require the maintenance of accurate network topology information. Through the adaptive interaction between nodes, perceiving the surrounding topology environment and learning from historical experience, each node in the network can transmit information in a fast collision-free way. Also, the MAB model is utilized in our protocol, so that the time slot can obtain sufficient multiplexing rate through multiple rounds of node selection. Experiments show that the protocol can achieve better throughput and fast enough convergence speed, even in the case of high network density, and scales well with the size of the network.

Distributed Medium Access Control Protocol for Successive Interference Cancellation-Based Wireless Ad Hoc Networks

Successive interference cancellation (SIC) enables the successful reception of multiple concurrent transmissions and elimination of interference through successive decoding. However, previously proposed distributed medium access control protocols have not exploited SIC. They mostly focused on either interference avoidance, based on the assumption that a receiver can only decode one transmission at a time, or self-interference cancellation, where a node can be a receiver and a transmitter at the same time. In this letter, we propose the first distributed communication protocol for SIC-based wireless networks, based on a novel message exchange and decision mechanism, to enable the simultaneous transmission of multiple neighboring nodes around the transmitter and receiver. The message exchange allows a random subset of neighboring nodes to test the feasibility of their simultaneous transmission. The decision mechanism evaluates the successive decoding capability of SIC receivers with the additional activation of neighboring nodes. We demonstrate the throughput improvement of the proposed algorithm via extensive simulations.

GPS Based Distributed Communication Protocol for Static Sensor Network (GDCP)

Overall energy of network is a major issue in current sensor network. This paper proposes (GDCP) GPS (Global Positioning System) based reactive communication protocol for Static WSN (Wireless Sensor Network) to extend the life time of entire network. In GDCP, energy efficient routing is achieved using local communication among sensor nodes. While routing, packets are routed via reliable shortest path from source node to sink node. The shortest path is determined with the help of a Neighbouring Table (NT) of a node. This table stores information such as location, distance to neighbour node and distance to a sink node. If the neighbouring node has sufficient energy and its distance to a sink node is less than other neighbours then it becomes the receiver and packet forwards to neighbour node. After receiving the packet, receiver becomes sender node and it checks its neighbouring table for minimum sink node's distance and sufficient energy. This process continues till the packet reaches the sink node. Sink node is assumed to move from one location to another as its neighbour node's energy becomes less than threshold energy. Energy consumption is analysed on 100 static sensor nodes and one sink node. A simulated result shows that overall energy of network is improved.

Distributed Containment Control for Nonlinear Multi‐Agent Systems with Time‐Delayed Protocol

AbstractIn this paper, the containment control problem is considered for nonlinear multi‐agent systems with directed communication topology. Under the guidance of designed distributed communication protocols with/without previous state information, the followers are expected to converge to a dynamic convex hull spanned by multiple leaders. Two multi‐step algorithms are proposed to construct the corresponding protocols, the state feedback protocol and the delay‐coupled protocol, under which the containment control can be achieved asymptotically. Furthermore, it is found that the delay‐coupled protocol is rather sensitive to time delays. That is, real‐time tracking will become impossible by only using long‐dated previous state information. Finally, a numerical example is given to demonstrate the applicability and efficiency of the proposed schemes.

EXTENDED DISTRIBUTED UML-BASED PROTOCOL SYNTHESIS METHOD

Synthesizing specifications for real time applications that involve distributed communication protocol entities from a service specification, which is modeled in the UML state machine with composite states, is a time-consuming and labor-intensive task. Existing synthesis techniques for UML-based service specifications do not account for timing constrains and, therefore, cannot be used in real time applications for which the timing constraints are crucial and must be considered. In this paper, we address the problem of time assignment to the events defined in the service specification modeled in UML state machine. In addition, we show how to extend a technique that automatically synthesizes UML-based protocol specifications from a service specification to consider the timing constraints given in the service specification. The resulting synthesized protocol is guaranteed to conform to the timing constraints given in the service specification.

Extended Distributed UML-Based Protocol Synthesis Method

Synthesizing specifications for real time applications that involve distributed communication protocol entities from a service specification, which is modeled in the UML state machine with composite states, is a time-consuming and labor-intensive task. Existing synthesis techniques for UML-based service specifications do not account for timing constrains and, therefore, cannot be used in real time applications for which the timing constraints are crucial and must be considered. In this paper, we address the problem of time assignment to the events defined in the service specification modeled in UML state machine. In addition, we show how to extend a technique that automatically synthesizes UML-based protocol specifications from a service specification to consider the timing constraints given in the service specification. The resulting synthesized protocol is guaranteed to conform to the timing constraints given in the service specification.

Self-Healing Networks: Redundancy and Structure

We introduce the concept of self-healing in the field of complex networks modelling; in particular, self-healing capabilities are implemented through distributed communication protocols that exploit redundant links to recover the connectivity of the system. We then analyze the effect of the level of redundancy on the resilience to multiple failures; in particular, we measure the fraction of nodes still served for increasing levels of network damages. Finally, we study the effects of redundancy under different connectivity patterns—from planar grids, to small-world, up to scale-free networks—on healing performances. Small-world topologies show that introducing some long-range connections in planar grids greatly enhances the resilience to multiple failures with performances comparable to the case of the most resilient (and least realistic) scale-free structures. Obvious applications of self-healing are in the important field of infrastructural networks like gas, power, water, oil distribution systems.

Phoenix: Storage Using an Autonomous Mobile Infrastructure

We propose a system that makes opportunistic use of mobile computing devices and ad hoc networking to provide a transient storage service to clients in a localized geographical region. The main challenge is to offset the potential data loss caused by node mobility with internode communication. We first argue on the basis of simulation and theory that such a service is feasible, given a sufficiently high density of mobile devices. A distributed communication and storage protocol is then presented for situations where all mobile devices are within communication range of each other, and it is shown through testbed experiments and simulation that the protocol operates correctly and makes efficient use of storage space and communication bandwidth, while maximizing the longevity of stored data.

Gossiping for resource discovering: An analysis based on complex network theory

This paper analyzes the adoption of unstructured P2P overlay networks to build resource discovery services. We consider a simple distributed communication protocol, which is based on gossip and on the local knowledge each node has about resources hold by its neighbors. In particular, upon reception (or generation) of a novel query, a node relays the message to those neighbors that have resources whose profile matches the query. Moreover, the node gossips the query to other remaining neighbors, so that the query can be disseminated through the overlay. A mathematical analysis is provided to estimate the number of nodes receiving the query (and consequently, the portion of query hits), based on the network topology, resource availability and gossip probability. Results show that the use of unstructured networks, coupled with simple dissemination protocols, represent a viable approach to build P2P resource discovery systems.

Safe and Distributed Kinodynamic Replanning for Vehicular Networks

This work deals with the problem of planning collision-free motions for multiple communicating vehicles that operate in the same, partially-observable environment in real-time. A challenging aspect of this problem is how to utilize communication so that vehicles do not reach states from which collisions cannot be avoided due to second-order motion constraints. This paper initially shows how it is possible to provide theoretical safety guarantees with a priority-based coordination scheme. Safety means avoiding collisions with obstacles and between vehicles. This notion is also extended to include the retainment of a communication network when the vehicles operate as a networked team. The paper then progresses to extend this safety framework into a fully distributed communication protocol for real-time planning. The proposed algorithm integrates sampling-based motion planners with message-passing protocols for distributed constraint optimization. Each vehicle uses the motion planner to generate candidate feasible trajectories and the message-passing protocol for selecting a safe and compatible trajectory. The existence of such trajectories is guaranteed by the overall approach. The theoretical results have also been experimentally confirmed with a distributed simulator built on a cluster of processors and using applications such as coordinated exploration. Furthermore, experiments show that the distributed protocol has better scalability properties when compared against the priority-based scheme.

UNISIM: An Open Simulation Environment and Library for Complex Architecture Design and Collaborative Development

Simulator development is already a huge burden for many academic and industry research groups; future complex or heterogeneous multi-cores, as well as the multiplicity of performance metrics and required functionality, will make matters worse. We present a new simulation environment, called UNISIM, which is designed to rationalize simulator development by making it possible and efficient to distribute the overall effort over multiple research groups, even without direct cooperation. UNISIM achieves this goal with a combination of modular software development, distributed communication protocols, multilevel abstract modeling, interoperability capabilities, a set of simulator services APIs, and an open library/repository for providing a consistent set of simulator modules.