Springer Science and Business Media LLC

Internet of Vehicles is in demand with the technological expansion, where smart vehicles can communicate with other vehicles, infrastructure, and humans. Traffic management has become more complex with increased traffic density on the road. To avoid severe road accidents, emergency message dissemination in a timely manner is a significant challenge. In this paper, we proposed an emergency message dissemination technique for vehicular networks with the integration of Software defined networks and fog computing. The aim is to offer V2I and V2V communication with minimal latency, reduced congestion, and a high packet delivery rate while achieving maximum information coverage. Three distinct communication modes are defined, each with its own set of algorithms. In the event of a failure in any of these mechanisms, an alternative method is available to deliver a message without the need for an extended wait for link recovery. An optimum forwarder node is selected to rebroadcast a message to the destination. The proposed architecture is analyzed and compared with an existing protocol by conducting a set of simulations. The results section demonstrates the efficiency of our proposed architecture.

The conventional protocol architectures based on rigid and inflexible layering principles are not suitable to meet the key challenges posed by ad-hoc networks. To overcome the performance limitations caused by lack of coordination between layers, the communication protocols crossing different layers need to be optimized jointly. In this paper, we explore a novel cross-layer framework for joint optimization of congestion control, routing, contention control, and power control in multi-flow ad-hoc networks. Accordingly, a generalized mathematical model is developed for cross-layer optimization formulation that can seamlessly address these issues with the aid of network utility maximization. Convexity is essential to attain a global optimum solution for the optimization problem in its feasible region. Therefore, the original non-convex optimization problem is convexified through suitable logarithmic transformations. Then, we employ a two-level dual decomposition technique for relaxing the interlayer coupling constraints in the network. In the first level, the problem is vertically decomposed into four disjoint subproblems that are solved independently across transport, network, MAC and physical layers. In the second level, a horizontal decomposition is applied within the physical layer. Each of the four subproblems is jointly correlated through the set of Lagrangian dual variables that control the interlayer coupling. Subsequently, the subgradient projection procedure is used to solve the associated dual problem. For this, a distributed iterative algorithm is proposed to implement the cross-layer approach with static channels and multiple source–destination pairs. Simulation results and analyses depict the global convergence of the convex optimization problem to a unique optimal solution. We also present the convergence process of the dual variables that act as bridges connecting and coordinating the four subproblems. Finally, we compare our proposed cross-layer algorithm with two previous algorithms employing cross-layer deign of two and three layers. Numerical results show that our algorithm offers considerable performance enhancement over the previous work in terms of throughput, persistence probability, and power consumption.

Ubiquitous computing which enabled by the availability of mobile, heterogeneous devices that supply context information, is currently not matured by the lack of programming support for the design and development of context-aware applications. Especially, ubiquitous computing environment is not static which can be compensable dynamically according to need of environment. Mobile agent is a very efficient framework applications can cooperative in heterogeneous environment. Therefore, we have developed a mobile agent based framework that significantly eases the development of mobile, context-aware applications. The framework allows developers to fuse data from disparate sensors, represent application context, and reason efficiently about context, without the need to write complex code. An event based communication paradigm designed specifically for ad-hoc wireless environments is incorporated, which supports loose coupling between sensors, actuators and application components.

The information-communication in an energy efficient and scalable manner in a wireless sensor network is a basic need. In this work, we use the multi-agent approach in order to build an Information Importance Based Communication (IIBC) for large scale wireless sensor network data processing. A multi-agent cooperation can be used to greatly reduce the communication cost, especially over low bandwidth links, by treating data cooperatively in sensor nodes rather than bringing this data to a central processor. The principal goal of our proposition is to maximize the wireless sensor network life time and simultaneously to insure a sufficient level of performance in term of latency, packet loss and reliability. Through successive simulations, IIBC proved its ability to reduce the power consumption of the sensor node to maximize “the mean time to first network partition” in several network densities and scales.

In this paper, we present the intelligent multimedia data hiding techniques and their possible applications. An introduction on intelligent multimedia data hiding is described which covers backgrounds, recent advances, methodologies, and implementations. The recently developed research branch called reversible data hiding is also depicted. Two major classes for the implementation of reversible data hiding, namely, the difference expansion method, and the histogram-based scheme, are discussed. With its ease of implementation, the histogram-based reversible data hiding technique is then illustrated with simulation results and actual implementations. Possible extension for our work is also depicted in the concluding remarks.

Recent trends in enterprise networks are radically changing the composition of these systems. Instead of having diverse data networks, each of which is dedicated to a single class of applications, corporations are moving to a unified IP (Internet Protocol) Intranet. Traffic demands on these Intranets include delay-sensitive traffic that requires better than the standard “best effort” service provided by IP networks. As a result, various new technologies and strategies to provide “end-to-end” Quality of Service (QoS) within IP enterprise networks are being developed and implemented. However, current IP network design methodologies are limited in that they can only design networks providing “best effort” service or else, a single delay constraint for all traffic. In this paper, we discuss a new design methodology for IP enterprise networks that takes into account the new technologies and techniques that can provide QoS. In particular, we identify and discuss the most crucial design issues that must be addressed when specialized queuing-based QoS strategies are used in the network. We describe the new constraints introduced by the underlying technologies and discuss how these factors affect the formulation of the IP Enterprise Network Design Problem. We then describe some specific features and methodologies that have been incorporated into a network design-planning tool for IP enterprise networks with QoS.

OVSF codes are used as channelization codes in WCDMA. Due to code blocking property of OVSF codes, the bandwidth available in the system is severely limited. Code reassignments mitigate the impact of the blocking property at the expense of causing delays and decreasing the throughput of the system. Nonblocking OVSF (NOVSF) codes have been proposed to alleviate the adverse effect of code reassignments. This paper presents a code assignment algorithm for NOVSF codes, which does not require any code reassignments. Simulation results show that NOVSF codes achieve better throughput than OVSF codes, even though code reassignments are allowed in the assignments of OVSF codes.

For connectionless cell multiplexing, we propose and analyze a burst admission control scheme based on prediction of cell losses. It guarantees zero cell loss in an ATM network. Compared to other methods, the proposed scheme can accept more sources in cell multiplexing and does not need to have a threshold.

In this letter, we propose a SH (Service History) and SINR (Signal to Interference plus Noise Ratio) based PROMETHEE (SHS-PROMETHEE) vertical handoff (VHO) decision algorithm. An attribute matrix is constructed considering the SH information and the SINR in the source network and the equivalent SINR in the target network and so on. Handoff decision meeting multi-attribute QoS requirement is made according to the traffic features. The weight relation of decision elements is determined with LS method. Finally decision is made using PROMETHEE algorithm based on the attribute matrix and weight vector. The simulation results have shown that the SHS-PROMETHEE algorithm can reduce unnecessary handoffs and provide satisfactory vertical handoff performance.