Luis Javier García Villalba

Routing Protocols in Wireless Sensor Networks

The applications of wireless sensor networks comprise a wide variety of scenarios. In most of them, the network is composed of a significant number of nodes deployed in an extensive area in which not all nodes are directly connected. Then, the data exchange is supported by multihop communications. Routing protocols are in charge of discovering and maintaining the routes in the network. However, the appropriateness of a particular routing protocol mainly depends on the capabilities of the nodes and on the application requirements. This paper presents a review of the main routing protocols proposed for wireless sensor networks. Additionally, the paper includes the efforts carried out by Spanish universities on developing optimization techniques in the area of routing protocols for wireless sensor networks.

SDN: Evolution and Opportunities in the Development IoT Applications

The exponential growth of devices connected to the network has resulted in the development of new IoT applications and on-line services. However, these advances are limited by the rigidity of the current network infrastructure, in which the administrator has to implement high-level network policies adapting and configuring protocols manually and usually through a command line interface (CLI). At this point, Software-Defined Networking (SDN) appears as a viable alternative network architecture that allows for programming the network and opening the possibility of creating new services andmore efficient applications to cover the actual requirements. In this paper, we describe this new technology and analyze its opportunities in the development of IoT applications. Similarly, we present the first applications and projects based on this technology. Finally, we discuss the issues and challenges in its implementation.The exponential growth of devices connected to the network has resulted in the development of new IoT applications and on-line services. However, these advances are limited by the rigidity of the current network infrastructure, in which the administrator has to implement high-level network policies adapting and configuring protocols manually and usually through a command line interface (CLI). At this point, Software-Defined Networking (SDN) appears as a viable alternative network architecture that allows for programming the network and opening the possibility of creating new services and more efficient applications to cover the actual requirements. In this paper, we describe this new technology and analyze its opportunities in the development of IoT applications. Similarly, we present the first applications and projects based on this technology. Finally, we discuss the issues and challenges in its implementation.

Auto-Configuration Protocols in Mobile Ad Hoc Networks

The TCP/IP protocol allows the different nodes in a network to communicate by associating a different IP address to each node. In wired or wireless networks with infrastructure, we have a server or node acting as such which correctly assigns IP addresses, but in mobile ad hoc networks there is no such centralized entity capable of carrying out this function. Therefore, a protocol is needed to perform the network configuration automatically and in a dynamic way, which will use all nodes in the network (or part thereof) as if they were servers that manage IP addresses. This article reviews the major proposed auto-configuration protocols for mobile ad hoc networks, with particular emphasis on one of the most recent: D2HCP. This work also includes a comparison of auto-configuration protocols for mobile ad hoc networks by specifying the most relevant metrics, such as a guarantee of uniqueness, overhead, latency, dependency on the routing protocol and uniformity.

Hierarchical Neighbor Discovery Scheme for Handover Optimization

In the future mobile Internet, one of the most challenging aspects is to discover the available neighbor access networks and its characteristics as the user moves. Using the IEEE 802.21 Media Independent Handover (MIH) standard, this letter proposes a new neighbor network discovery mechanism, considering a hierarchical view of the network information. Through a NS-2 based simulation, it is shown that the proposed model can significantly improve the mobility user experience.

Evolution and Challenges of Software Defined Networking

Software Defined Networking (SDN) proposes the separation of the control plane from the data plane in network nodes. Furthermore, Openflow architecture through a centralized control of the packet forwarding engines enables the network administrators to literally program the network behavior. The research and results of experiments show clear advantages over traditional network architectures. However, there are open questions to be solved in order to integrate SDN infrastructure and applications in production networks. This paper presents an analysis of the evolution of SDN in recent years. Additionally, this piece of work also describes some interesting SDN/Openflow research initiatives and applications. Finally, there is a disscussion on the main challenges of this new technology.

Distributed Dynamic Host Configuration Protocol (D2HCP)

Mobile Ad Hoc Networks (MANETs) are multihop wireless networks of mobile nodes without any fixed or preexisting infrastructure. The topology of these networks can change randomly due to the unpredictable mobility of nodes and their propagation characteristics. In most networks, including MANETs, each node needs a unique identifier to communicate. This work presents a distributed protocol for dynamic node IP address assignment in MANETs. Nodes of a MANET synchronize from time to time to maintain a record of IP address assignments in the entire network and detect any IP address leaks. The proposed stateful autoconfiguration scheme uses the OLSR proactive routing protocol for synchronization and guarantees unique IP addresses under a variety of network conditions, including message losses and network partitioning. Simulation results show that the protocol incurs low latency and communication overhead for IP address assignment.

Trends on virtualisation with software defined networking and network function virtualisation

Software defined networking (SDN) and network function virtualisation (NFV) have become hot topics in recent years. On one hand, SDN decouples the control plane from the data plane allowing the rapid innovation and the introduction of new services in an easy way. On the other hand, currently proprietary appliances such as load balancers and firewalls are implemented in hardware, NFV aims to change these network functions to an open software environment using virtualisation and cloud technologies. This means a reduction of spends in the provisioning and management of telecom services. SDN and NFV are two different concepts but these can coexist and help each other. In this study, the authors present a survey of SDN and NFV focusing in virtualisation projects and the use cases where a synergy between these technologies is possible. This study includes the basic concepts of network virtualisation, NFV and SDN, current research and the relation between both technologies.

Key Technologies in the Context of Future Networks: Operational and Management Requirements

The concept of Future Networks is based on the premise that current infrastructures require enhanced control, service customization, self-organization and self-management capabilities to meet the new needs in a connected society, especially of mobile users. In order to provide a high-performance mobile system, three main fields must be improved: radio, network, and operation and management. In particular, operation and management capabilities are intended to enable business agility and operational sustainability, where the addition of new services does not imply an excessive increase in capital or operational expenditures. In this context, a set of key-enabled technologies have emerged in order to aid in this field. Concepts such as Software Defined Network (SDN), Network Function Virtualization (NFV) and Self-Organized Networks (SON) are pushing traditional systems towards the next 5G network generation.This paper presents an overview of the current status of these promising technologies and ongoing works to fulfill the operational and management requirements of mobile infrastructures. This work also details the use cases and the challenges, taking into account not only SDN, NFV, cloud computing and SON but also other paradigms.

Smartphone image clustering

Every day the use of images from mobile devices as evidence in legal proceedings is more usual and common.Image source acquisition identification is a branch of digital forensic analysis.We use a combination of hierarchical and flat clustering and the use of Sensor Pattern Noise for source identification.We make a series of experiments which emulate similar situations to those that may occur in reality. Every day the use of images from mobile devices as evidence in legal proceedings is more usual and common. Therefore, forensic analysis of mobile device images takes on special importance. This paper explores the branch of forensic analysis which is based on the identification of the source, specifically on the grouping or clustering of images according to their source acquisition. In contrast with other state of the art techniques for source identification, hierarchical clustering does not involve a priori knowledge of the number of images or devices to be identified or training data for a future classification stage. That is, a grouping by classes with all the input images is performed. The proposal is based on the combination of hierarchical and flat clustering and the use of Sensor Pattern Noise (SPN). There has been a series of experiments which emulate similar situations to those that may occur in reality to test the robustness and reliability of the results of the technique. The results are satisfactory in all the experiments, obtaining high rates of success.

Malware detection system by payload analysis of network traffic (poster abstract)

This paper presents a system for detecting intrusions when analyzing the network traffic payload looking for malware evidences. The system implements the detection algorithm as a Snort preprocessor component. Since they work together, a highly effective system against known attacks has been achieved (based on Snort rules) and a highly effective system against unknown threats (which was the main aim of the designed system). As the majority of such systems, the proposal consists of two phases: a training phase and a detection phase. During the training phase a statistical model of the legitimate network usage is created through Bloom Filters and N-grams techniques. Subsequently, the results obtained by analyzing a dataset of attacks are compared with such model. This will allow a set of rules to be developed which will be able to determine whether the packets payloads contain malware. In the detection phase, the traffic to analyze is compared with the model created in the training phase and the results obtained when applying rules. The performed experiments showed really satisfactory results, with 100% malware detection and just 0.15% false positives.