Evangelos A. Kosmatos

Integrating RFIDs and Smart Objects into a UnifiedInternet of Things Architecture

The term Internet of Things refers to the networked interconnection of objects of diverse nature, such as electronic devices, sensors, but also physical objects and beings as well as virtual data and environments. Although the basic concept of the Internet of Things sounds simple, its application is difficult and, so far, the respective existing architectural models are rather monolithic and are dominated by several limitations. The paper introduces a generic Internet of Things architecture trying to resolve the existing restrictions of current architectural models by integrating both RFID and smart object-based infrastructures, while also exploring a third parameter, i.e. the social potentialities of the Internet of Things building blocks towards shaping the “Social Internet of Things”. The proposed architecture is based on a layered lightweight and open middle-ware solution following the paradigm of Service Oriented Architecture and the Semantic Model Driven Ap-proach, which is realized at both design-time and deployment–time covering the whole service lifecycle for the corresponding services and applications provided.

Exploiting PONs for mobile backhaul

The growing popularity of mobile data services necessitates a rapid rise in network capacity not only on the air interface to the end user, but also in the backhaul network. The latter is quite important for the mobile operator business model, affecting capital investment, operational expenses, service deployment, and customer experience. Fiber infrastructure is inevitably the only long-term solution, and the deployment of passive optical networks presents an opportunity for a cost-effective, scalable, and future-proof solution. In this article we investigate the use of PONs for mobile backhaul and propose a resource allocation framework building on the efficiency of PONs to share resources, dynamically allocate bandwidth in real time, and enhance efficiency by improved statistical multiplexing. The main objective of this work is to exploit existing standardized technologies, and provide design and deployment guidelines regarding PON MAC operation, enabling a gradual and future-safe infrastructure upgrade of mobile backhaul systems.

Next generation optical nodes: The vision of the European research project IDEALIST

As traffic demands become more uncertain and newer services continuously arise, novel network elements are needed to provide more flexibility, scalability, resilience and adaptability to todays optical networks. Considering these requirements, within the European project IDEALIST the investigation of elastic optical networks is undertaken with special focus on next generation optical node architectures. As an evolution of existent ROADMs and OXCs, these optical nodes will establish a new paradigm in which the network requirements will be efficiently addressed considering various emerging dimensions. In this article, we describe the drivers, architectures, and technologies that will enable these novel optical nodes. In addition, multivendor traffic interoperability, optical defragmentation, and node cascadability are also described as considerations in the node design.

Future Internet Infrastructure Based on the Transparent Integration of Access and Core Optical Transport Networks

It is increasingly recognized that the Internet is transforming into a platform providing services beyond todaypsilas expectations. To successfully realize this transformation, the structural limitations of current networking architectures must be raised so that information transport infrastructure gracefully evolves to address transparent core-access integration, optical flow/packet transport, and end-to-end service delivery capability, overcoming the limitations of segmentation between access, metro, and core networks and domains. We propose and evaluate an integrated control plane for optical access and core networks, which addresses the above consideration. The proposed control plane can lead to a unified transport infrastructure integrating state-of-the-art components and technologies including wavelength division multiplexing, passive optical networking, and optical packet routers with inherent traffic grooming capabilities. The performance of the proposed architecture is assessed by means of simulation in terms of cost, resource utilization, and delay.

Performance evaluation of handoff algorithms applied in vehicular 60GHz radio-over-fiber networks

We present the handoff techniques required to support mobile end-users in 60GHz Radio-over-Fiber (RoF) networks. We analyze the dominant handoff algorithms proposed for 60GHz RoF networks in outdoor environments, by emphasizing to the corresponding handoff algorithms that can be applied in high speed vehicular communications, i.e. Moving Cell (MC), Moving Extended Cell (MEC) and Virtual Cellular Zone (VCZ), respectively. We finally present the results of the corresponding simulation scenarios we performed, in order to demonstrate and evaluate the performance of the handoff algorithms and confirm that, at least some of them could be safely applied in high-speed vehicular RoF architectures, even for challenging services such as High-Definition TV and Ultra High-Definition TV.

An Integrated Architecture for Remote Healthcare Monitoring

Remote healthcare monitoring has attracted the interest of many research projects during last years. The need to address the issue of ageing population has lead to the exploitation of modern communication and software technologies in this domain too. This is instigated by related technological evolutions such as the evolutions in sensor networks which can now support self organization. This paper presents the INCASA architecture that provides advances towards mainly two directions. To start with, by using the appropriate middleware, it manages to transform the network of devices to a network of services following a Service Oriented Architecture. In this way, it turns the implementation of applications (e.g. clinical applications) on top of the middleware to be easy and efficient. Furthermore, INCASA architecture provides an integrated solution for profiling user habits. This is particularly important in case of elderly people who tend to follow daily activities in a repeating manner. In the proposed architecture, the procedure of modeling user habits is the necessary step in order to generate alert actions in case of divergence.

Efficient resource allocation with service guarantees in passive optical networks

Feature Issue on Passive Optical Network Architectures and TechnologiesWe propose and evaluate a resource allocation scheme for time-division multiplexing passive optical networks (PONs), which supports multiple service classes; dynamic bandwidth allocation for services with varying (in time) capacity demand; and bounded quality of service parameters for services with real-time requirements. Although several algorithms have been proposed in the literature considering several of the above objectives in isolation, our work focuses on the fundamental problem of trading-off between PON upstream channel utilization and strict delay and jitter bounds when supporting a dynamically changing mix of services with different requirements.

Handoff algorithms in vehicular Radio-over-Fiber networks: Packet loss mathematical analysis and performance evaluation study

The paper focuses on the dominant handoff algorithms in vehicular Radio-over-Fiber (RoF) networks at 60 GHz. We present in short the afore-mentioned handoff algorithms, i.e., the Traditional Handoff (THO), the Virtual Cellular Zone (VCZ), the Moving Extended Cell (MEC) and the Moving Extended N-Cells (MENC), respectively. Furthermore, we analyze the corresponding mathematical models regarding packet loss for each one of the above handoff algorithms and we finally realize a simulation study in order to verify the theoretical results and strengthen the performance evaluation study.

Hybrid resource reservation scheme for transparent integration of access and core optical transport networks

In this paper, we present a novel traffic control and distributed multiplexing scheme based on a hybrid long-reach fiber access network architecture. The proposed network architecture exploits very low cost end-user ONUs and achieves energy efficiency, reduced complexity and high-level scalability. The scheme allows a group of users to share an ultra-wide band long reach WDM-PON, in a fiber to the cabinet configuration, leading to core node consolidation and access-core integration. We show that this architecture can be exploited as a large scale distributed multiplexer that can be used to funnel traffic directly from access networks over a core optical network and describe a control plane architecture compatible with the concept of Software Defined Networking for simplifying the aggregation process and improving performance at the same time.

The Moving Extended N-Cells handover algorithm in vehicular radio-over-fiber networks at 60GHz

The paper presents a candidate handover algorithm, i.e., the “Moving Extended N-Cells” (MENC algorithm), that supports high end-user mobility in vehicular Radio-over-Fiber Networks at 60 GHz and minimizes packet losses. The mathematical analysis regarding packet loss is presented against the corresponding “traditional” handover algorithm and it is then verified by the corresponding simulation study. The paper concludes by presenting the respective results.