Batteryless Internet of Things (IoT) networks enabled by Ambient Backscatter Communication (AmBC) represent a promising approach for large-scale and energy-sustainable deployments. Yet, dense and time-varying environments introduce major challenges, such as unpredictable fluctuations in incident RF power, strong interference, and unstable link quality. These non-stationary conditions make traditional fixed or reactive reflection-level control methods suboptimal. This work introduces DDPG-AmBC, a deep reinforcement learning (DRL) framework designed to perform continuous and adaptive reflection control for batteryless AmBC devices. The method employs the Deep Deterministic Policy Gradient (DDPG) algorithm to dynamically adjust the reflection coefficient ( Γ ) based on real-time observations of the wireless environment. This mechanism enables joint optimization of communication throughput and energy efficiency while preserving passive operation. The paper presents a complete system formulation, an expanded discussion of related studies, and comparative evaluations against fixed-reflection and competitive DRL-based baselines. The results show that DDPG-AmBC significantly improves throughput stability under varying interference conditions and supports enhanced energy-sustainable operation. Experiments conducted using OMNeT++ for network emulation and Google Colab for DRL training confirm the effectiveness of the proposed framework and its suitability for next-generation IoT scenarios.

Quality of service is one of the major concerns in cloud computing. Virtual machines (VMs) balancing techniques can help reduce service degradation in cloud computing environments. Several works have presented cloud computing balance techniques, however, only a few used the similarity between VMs and physical hosts to map VMs migrations. In addition, most proposals do not consider the size, dynamism, and heterogeneity of the cloud when developing a management technique. We present a cloud computing VMs balancing algorithm that uses the similarity between VMs and physical hosts to create the map of migrations. Furthermore, the proposal takes into account the size, dynamism, and heterogeneity of the cloud when mapping VMs migrations, thus the proposal is developed in a distributed fashion, enabling the processing of each cluster at a time. To evaluate the proposal, we used the Google cluster data set. Experiments demonstrate that the proposed technique can improve the balance of allocated resources, thus helping reduce service degradation. Moreover, the runtime of the algorithm indicates that it is feasible to be used in a real cloud computing environment with hundreds of physical servers and virtual machines.

This paper presents the implementation and tests of a flexible and extensible framework, named Order@Cloud, that improves the Virtual Machine placements of a Cloud. It receives new VMs on the Cloud and organises them by relocating their placements based on the Multiple-Objectives of the environment. These Objectives are represented by Rules, Qualifiers and Costs, which can be easily added, extended and prioritised. Based on Evolutionary and Greedy Searches, Order@Cloud theoretically guarantees the adoption of a better set of Placements. More specifically, it seeks the non-dominated solutions (Pareto Set) and compares them considering the implementation cost of the scenario and its benefits. In contrast to existing solutions, that address specific objectives, our framework was devised to be objective-agnostic and easily extensible, which enables the implementation of new and generic prioritised elements. To understand the applicability and performance of our solution we conducted experiments using a real Cloud environment and discuss its performance, flexibility and optimality.

Due to constant workload growth, the infrastructure used to support cloud computing (CC) environments increases in size and complexity. As a consequence of that, human administrators are not able to monitor, analyze, plan and execute actions upon the environment, seeking goals such as the environment optimization and service level agreements fulfillment. This proposal provides an autonomic framework to create virtual machines migrations and heuristics to select hosts to be activated or deactivated when needed. Moreover, the framework proposed in this paper works in a distributed way using multi-agent systems concepts. We provide an architecture to deal with the size, heterogeneity and dynamism of CC environments. Further, our proposal was added to the CloudStack platform as a plug-in for validation and experimentation.

Cloud computing is a distributed computing model that still faces problems. New ideas emerge to take advantage of its features and among the research challenges found in the cloud, we can highlight Identity and Access Management. The main problems of the application of access control in the cloud are the necessary flexibility and scalability to support a large number of users and resources in a dynamic and heterogeneous environment, with collaboration and information sharing needs. This paper proposes the use of risk-based dynamic access control for cloud computing. The proposal is presented as an access control model based on an extension of the XACML standard with three new components: the Risk Engine, the Risk Quantification Web Services and the Risk Policies. The risk policies present a method to describe risk metrics and their quantification, using local or remote functions. The risk policies allow users and cloud service providers to define how to handle risk-based access control for their resources, using different quantification and aggregation methods. The model reaches the access decision based on a combination of XACML decisions and risk analysis. A prototype of the model is implemented, showing it has enough expressivity to describe the models of related work. In the experimental results, the prototype takes between 2 and 6 milliseconds to reach access decisions using a risk policy. A discussion on the security aspects of the model is also presented.

The essential characteristics of Cloud computing are scalability, elasticity, and heterogeneous resource pooling. However, managing these systems is challenging due to their complexity and dynamism. Using Autonomic Computing to achieve self-management is a prominent approach to respond these challenges. The fundamental basis for the decision making process of such systems is the updated status of the system and its operational context. In this paper, we propose a monitoring architecture devised for private Cloud that focuses on providing data analytics capabilities to the monitoring system and that considers the knowledge requirements of autonomic systems. We implemented this architecture as a framework named Panoptes and integrated it to a simple self-protection framework of private Clouds as proof-of-concept. Additionally, we complemented the validation with analytical analyses of the monitoring framework.

Purpose – This paper aims at presenting a cyclical evaluation model of information security (IS) maturity. The lack of a security evaluation method might expose organizations to several risky situations. Design/methodology/approach – This model was developed through the definition of a set of steps to be followed to obtain periodical evaluation of maturity and continuous improvement of controls. Findings – This model, based on controls present in ISO/IEC 27002, provides a means to measure the current situation of IS management through the use of a maturity model and provides a subsidy to take appropriate and feasible improvement actions, based on risks. A case study is performed, and the results indicate that the method is efficient for evaluating the current state of IS, to support IS management, risks identification and business and internal control processes. Research limitations/implications – It is possible that modifications to the process may be needed where there is less understanding of security requirements, such as in a less mature organization. Originality/value – This paper presents a generic model applicable to all kinds of organizations. The main contribution of this paper is the use of a maturity scale allied to the cyclical process of evaluation, providing the generation of immediate indicators for the management of IS.

The SOA architecture primarily based on Web services is experiencing a steady adoption, although its growth was lower than expected when it was launched, mainly because of security related concerns. Web services inherited many well-known security problems of Web applications and brought new ones. Major data breaches today are consequences of bad input validation at the application level. This paper presents a way to implement an input validation model for Web services which can be used to prevent cross-site scripting and SQL injection through the use of predefined models which specify valid inputs. The proposed WSIVM (Web Services Input Validation Model) consists of an XML schema, an XML specification, and a module for performing input validation according to the schema. A case study showing the effectiveness and performance of this mechanism is also presented.

Wireless sensor networks are a limited set of devices in low battery power, processing, communication, and also low memory bandwidth. For these limitations, most security methodologies applied in wired networks cannot be exploited in this environment. Due to this reality is that we present a hybrid protocol that handles the regime group of key management system and for the interconnection of the transparent cluster. Do not treat the problem of tampering with node-key control group. The feasibility of this protocol was verified by simulation and proved that the increase of network nodes does not affect the performance of the interconnection between two clusters.

Intrusion detection systems (IDSs) have been substantially improved in recent past. However, network attacks have become more sophisticated and increasingly complex: many of current attacks are coordinated and originated in multiple networks. To detect these attacks, IDSs need to obtain information on network events from multiple networks or administrative domains. This work demonstrates that a Distributed IDS (DIDS) can be composed of existing IDSs, improving the detection of misuses in a multiple network environment. We use a grid middleware for creating a service-based intrusion detection grid. We demonstrate through experimental results that the proposed DIDS allows the integration of heterogeneous existing IDSs and improves the detection of attacks by exploring the synergy between existing IDSs.

In this article, we describe a grid of sensors to collect patients' vital data and to allow real time monitoring of patients in heath-care centres. We analyse the problem scenario and identify the components involved towards the construction of an integrated and homogeneous management system. Finally, we present a case study to demonstrate the applicability of our approach

The standards for composition, communication and discovery for Web Services constitute a framework with the goal of achieve interoperability. Even else, some problems, like QoS provisioment were not solved. This article presents an architecture for Web Services discovery with QoS support. This architecture relies in a broker as an intermediate component between the client, the server and the UDDI, what it facilitates the discovery for QoS-support Web Services. This work presents the architecture proposed as main contribution, and a XML schema documents defining the way as the QoS parameters must be specified, allowing to each client to specify distinct QoS parameters to each kind of service.

In this paper we present a proposal of a middleware to integrate mobile computing with grid computing. We describe the support to be provided by the combination of the two technologies, propose a middleware to support the development and management of mobile grids, and discuss how this scenario contributes to the development of a new age of mobile service applications

Current intrusion detection technology is limited in providing protection against the intrusions that may violate the security of computational grids. We present the problem of grid intrusions, analyze the requirements of a system to detect them, propose a system architecture, and show how it overcomes the limitations by integrating the detection of the typical host computer and network attacks with the detection of grid-specific attacks and user behavior anomalies

This paper presents a data model designed to format answers in intrusion detection systems. The featured model aims at allowing interoperability between different systems. An architecture proposal for the intrusion detection systems that makes response treatment feasible is also introduced. Both architecture and data model are compatible with interoperability among IDSs related works already carried out by the IDWG group. Also, the development and testing of the proposed model and the architecture components are presented.

An Ad Hoc nework is formed by mobile computer (nodes) with wireless interfaces that communicate amongst themselves without the help of any infrastructure. Due to their characteristics, the Ad Hoc networks are prone to the presence of malicious nodes that can degrade your performance. This fact motivated the appearance of security protocols that implement mechanisms to avoid attacks like DoS. In this article is accomplished a verification the impact caused in the performance of the Ad Hoc networks with the use of security protocols (SEAD and Ariadne) in relation to the use of protocols that don't have security mechanisms (DSDV and DSR). Firstly an Ad Hoc network is simulated using these routing protocols and soon afterwards a comparative study is accomplished through graphs of the values obtained for each basic QoS metrics.

Abstract The centralized system approach for computer and telecommunication network management has been presenting scalability problems along with the growth in the amount and diversity of managed equipment. Moreover, the increase in complexity of the services being offered through the networks also contributes to adding extra workload to the management station. The amount of data that must be handled and processed by only one administration point could lead to a situation where there is not enough processing and storage power to carry out an efficient job. In this work we present an alternative approach by creating a highly distributed computing environment through the use of Grids of autonomous agents to analyze large amounts of data, which reduce the processing costs by optimizing the load distribution and resource utilization. Copyright © 2004 John Wiley & Sons, Ltd.

The TINA (Telecommunications Information Networking Architecture) concepts and principles are introduced with the objective to remedy problems of centralized service control and service data model existing in the IN (intelligent network). Now, it is becoming clear that future sophisticated services breaking away from the simple telephony call model, e.g., multimedia, multi-party conferencing, etc., will need to be rapidly and efficiently introduced, deployed, shared, operated and managed. In this context, TINA developed a comprehensive architecture for multi-service networks that shall enable multimedia communications and give access to information for business and private consumers. On the other hand, the provisioning of all management context instrumentation for TINA services (i.e. FCAPS service management functions) is still an open research question. In this paper, we discuss accounting features and requirements, security of accounting management, and issues for their integration in a TINA-based service environment. A prototype has been implemented to validate the concept and the results are also presented. The reader is assumed to be familiar with the TINA business model and to have at least a high-level overview of the TINA service and network resource architecture concepts.

TINA has been designed with the goal to offer an universal vision of telecommunications services, it answers to the increasing needs of fast developments of news services (e.g., multimedia, multi-party conference, etc.) in heterogeneous networks environments (e.g., fixed, mobile and multimedia) with interaction of several actors. However the management context functionality (FCAPS management functions) is still in an initial state of research and development. We discuss the requirements and security services for the TINA management context, particularly for TINA accounting management architecture. We propose and implement a model of the security management middleware architecture, based on secure objects, cryptography and ticket distribution. To provide security services, secure objects, which have security functionality like authentication and access control, have been defined in the security domain. Secure objects in our model are CORBA objects. The security domain, also called SBS, provides security services and has a security management information base (SMIB) that contains security policies, cryptographic algorithms and other relevant information.

Concepts and principles of TINA (Telecommunications Information Networking Architecture) are introduced with the objective of correcting problems of centralized service control and service data model existent in INs (intelligent networks). Now, it is becoming clear that future sophisticated services breaking away from the simple telephony call model, e.g., multimedia, multi-party conferencing, etc., will need to be rapidly and efficiently introduced, deployed, operated and managed. In this context, TINA developed a comprehensive architecture for multi-service networks that will support multimedia services. On the other hand, the provisioning of all the service management functionality for TINA services (i.e. FCAPS) is still an open research question. In this paper, we discuss accounting features and requirements, security of accounting management, and issues for their integration in a TINA-based service environment. A prototype has been implemented to validate the concepts and results are also presented.

This work presents the development of a distributed security management system for telecommunication networks. The system consists in reducing the use of cloned mobile telephones (same both number and series of a genuine phone a perfect copy) using three main techniques. (1) An ISO Formal Technique (LOTOS) is used to specify and validate the system through the Eucalyptus software employment. The validation process includes exhaustive and interactive simulations, testing and verifications in order to guarantee the correctness of the system. (2) A pattern recognition technique is used to classify the telephone users into classes. From this classification it is easier to identify if a call does not correspond to the patterns of a specific user, and thus identify whether a nongenuine caller made the call. MatLab software was employed to implement the classification algorithms. (3) A distributed object technique is used for the implementation of this distributed system (i.e., manager and agents), with CORBA support, considering TMN and ATM technologies, by VisiBroker and JDK software employment.

This article describes the effort to join two different approaches for the development of the proactive network management. The first approach was developed in the Laboratory of Network and Management, at Federal University of Santa Catarina, which uses remote monitoring and simulation tools. The second one, was developed in the National Supercomputing Center, which handles the problem with artificial intelligence and SunNet Manager's agents usage. The new concept of proactive network management aims at identifying the existing troubles in advance of any performance degradation, as well as providing support for future decision-making actions. The goal of this work is to adapt a complete proactive environment which will be used to explore the remote monitors and simulation tools to identify the symptoms of proactive management problems; and specially to recognize the problem using artificial intelligence techniques and to take proactive actions to solve it, configuring a proactive management application for the prevention of problems in computer networks.

This article presents a formal design of a generic platform for heterogeneous network management. A platform is defined to support management applications with the objective of solving problems associated with the distribution of processes and supplying the telecommunication carriers' necessities related to the efficient development of management applications. Specifying this platform formally significantly contributes in the sense of providing a rigorous approach to the description and validation process, thus collaborating toward its exactness, mainly in the studies that aim at attesting the conformity between the product obtained and the description of the requirement which were considered.