Edmundo Monteiro

Security for the Internet of Things: A Survey of Existing Protocols and Open Research Issues

The Internet of Things (IoT) introduces a vision of a future Internet where users, computing systems, and everyday objects possessing sensing and actuating capabilities cooperate with unprecedented convenience and economical benefits. As with the current Internet architecture, IP-based communication protocols will play a key role in enabling the ubiquitous connectivity of devices in the context of IoT applications. Such communication technologies are being developed in line with the constraints of the sensing platforms likely to be employed by IoT applications, forming a communications stack able to provide the required power-efficiency, reliability, and Internet connectivity. As security will be a fundamental enabling factor of most IoT applications, mechanisms must also be designed to protect communications enabled by such technologies. This survey analyzes existing protocols and mechanisms to secure communications in the IoT, as well as open research issues. We analyze how existing approaches ensure fundamental security requirements and protect communications on the IoT, together with the open challenges and strategies for future research work in the area. This is, as far as our knowledge goes, the first survey with such goals.

Cognitive radio: survey on communication protocols, spectrum decision issues, and future research directions

Currently, the radio spectrum is statically allocated and divided between licensed and unlicensed frequencies. Due to this inflexible policy, some frequency bands are growing in scarcity, while large portions of the entire radio spectrum remain unused independently of time and location. Cognitive Radio is a recent network paradigm that aims a more flexible and efficient usage of the radio spectrum. Basically, it allows wireless devices to opportunistically access portions of the entire radio spectrum without causing any harmful interference to licensed users. The present document surveys the literature on Cognitive Radio. It aims to provide a comprehensive and self-contained description of this research topic area, mainly focusing on communication protocols, spectrum decision issues, and future research directions. It is a tutorial in nature and consequently does not require any previous knowledge about Cognitive Radio. Readers are only required to have some general background on wireless data networks. Emphasis is put on Cognitive Radio genesis, issues that must be addressed, related technologies, standardization efforts, the state of the art, and future research directions according to the vision of the authors.

Research challenges in QoS routing

Quality of Service Routing is at present an active and remarkable research area, since most emerging network services require specialized Quality of Service (QoS) functionalities that cannot be provided by the current QoS-unaware routing protocols. The provisioning of QoS based network services is in general terms an extremely complex problem, and a significant part of this complexity lies in the routing layer. Indeed, the problem of QoS Routing with multiple additive constraints is known to be NP-hard. Thus, a successful and wide deployment of the most novel network services demands that we thoroughly understand the essence of QoS Routing dynamics, and also that the proposed solutions to this complex problem should be indeed feasible and affordable. This article surveys the most important open issues in terms of QoS Routing, and also briefly presents some of the most compelling proposals and ongoing research efforts done both inside and outside the E-Next Community to address some of those issues.

An overview of quality of experience measurement challenges for video applications in IP networks

The increase in multimedia content on the Internet has created a renewed interest in quality assessment. There is however a main difference from the traditional quality assessment approaches, as now, the focus relies on the user perceived quality, opposed to the network centered approach classically proposed. In this paper we overview the most relevant challenges to perform Quality of Experience (QoE) assessment in IP networks and highlight the particular considerations necessary when compared to alternative mechanisms, already deployed, such as Quality of Service (QoS). To assist on the handling of such challenges we first discuss the different approaches to Quality of Experience assessment along with the most relevant QoE metrics, and then we discuss how they are used to provide objective results about user satisfaction.

EuQoS: End-to-End Quality of Service over Heterogeneous Networks

The EuQoS (End-to-End QoS over Heterogeneous Networks) IST Integrated European Project aimed to define a Next Generation Network architecture that builds, uses and manages end-to-end QoS across different administrative domains and heterogeneous networks (UMTS, xDSL, Ethernet, WiFi, Satellite and IP/ MPLS). The EuQoS architecture preserves the openness and the decentralized decision model of the actual Internet, runs on off-the-shelf hardware and network equipment, and allows end users to request various services without changing the Application Signaling protocol, while meeting regulators’ and users’ Net Neutrality requirements. This paper presents the key elements of the EuQoS architecture and describes the main results obtained in field trials performed on a fully-functional EuQoS system prototype developed over a pan-European testbed. Furthermore, the paper discusses the main strengths of the system and the issues related to its actually deployment on a large scale, from both technical and market points

Quality of Service Routing

Constraint-based routing is an invaluable part of a full- fledged Quality of Service architecture. Unfortunately, QoS routing with multiple additive constraints is known to be a NP-complete problem. Hence, accurate constraint-based routing algorithms with a fast running time are scarce, perhaps even non-existent. The need for such algorithms has resulted in the proposal of numerous heuristics and a few exact solutions.

Cross-layer routing metrics for mesh networks: Current status and research directions

Despite efforts to improve the current IEEE 802.11 standard to fully optimize the physical layer, the performance of wireless mesh networks still depends on the routing process for a correct selection of routes. With regard to this question, several cross-layer routing metrics have been developed to improve wireless multi-hop mesh routing. This paper sets out a new taxonomy that can be used to help understand, classify and compare the state-of-the-art situation with regard to cross-layer routing metrics for wireless mesh networks. A simulation study has been carried out to evaluate the capability of the most recent and promising cross-layer routing metrics to support multimedia applications, such as Voice over IP. The evaluation of the routing metrics has been undertaken from three main perspectives: user perception, network performance, and routing stability. The simulation results show that the impact of routing metrics is more noticeable on the network and routing stability evaluation parameters than on the user-perception parameters. Furthermore, the results show that the routing metrics, the level of stability attained, and the application performance are interdependent. Finally, there is a discussion of the direction that future research might take with regard to some open issues in the design of routing metrics for wireless mesh networks.

Routing Metric for Interference and Channel Diversity in Multi-Radio Wireless Mesh Networks

More than providing a wireless structure for Internet access, Wireless Mesh Networks are being challenged to support diverse kinds of multimedia applications such as Voice over IP and video streaming in publish-subscriber and peer-to-peer service models. In this context, several routing metrics have been proposed to improve the routing performance as well as the network capability to satisfy the requirements of multimedia applications. However, most routing metrics lack the consistent integration of efficient monitoring mechanisms for interference and traffic load characterization in order to support the adequate decisions by the routing algorithms. In this sense, a new routing metric is proposed in this paper, called Metric for INterference and channel Diversity (MIND), that measures network interference and load, based on a passive monitoring mechanism in order to avoid the overhead of active network state information gathering. An evaluation of MIND and relevant existing routing metrics was performed using NS2. The results showed that when path selection is based on MIND, traffic performance is significantly better than with the other metrics.

Why is IPSec a viable option for wireless sensor networks

Many issues still remain to be addressed in order to achieve acceptable security in wireless sensor networks (WSNs). This necessity, together with the adoption of IPv6 on WSNs being defined at the 6lowpan working group of the IETF, motivates our investigation on the feasibility of the application of IPSec on sensor nodes. IPSec is already part of IPv6, which makes it a natural candidate to be directly employed or adapted for WSNs. We discuss results obtained from practical experiments on the usage of cryptographic algorithms typically employed within IPSec in real sensor nodes. We analyze the security and performance tradeoffs involved when employing cryptography measures in WSNs, also in the context of their usage side-by-side with IPv6. The results obtained show that the adoption of a security architecture such as IPSec is viable, and also point towards the successful design and deployment of a security architecture for WSNs.

Security in the integration of low-power Wireless Sensor Networks with the Internet

The integration of low-power wireless sensing and actuating devices with the Internet will provide an important contribution to the formation of a global communications architecture encompassing Wireless Sensor Networks (WSN), and to enable applications using such devices designed to bring unprecedented convenience and economical benefits to our life. Such applications also take place in the context of our current vision on an Internet of Things (IoT), which promises to encompass heterogeneous devices and communication technologies, including WSN. Due to the characteristics of the devices in WSN and to the requirements of applications, low-power wireless communications are employed and the functionalities supported must be carefully balanced against the limited resources at the disposal of applications. Low-power communication technologies are also currently being designed with the purpose of supporting the integration of WSN with the Internet and, as in isolated WSN environments, security will be a fundamental enabling factor of future applications using Internet-integrated WSN. Although various surveys currently exist addressing security mechanisms for WSN environments, our goal is to analyze how security may be addressed as an enabling factor of the integration of low-power WSN with the Internet, in the context of its contribution to the IoT. We analyze the current research and industry proposals supporting this integration, together with the security solutions and mechanisms designed in its context. Our discussion is supported by an analysis on the attack and threat model against Internet-integrated WSN, and on the security requirements to consider in this context. We believe that a survey with such goals may provide an important contribution to readers interested in embracing this important area of research and ours is, as far as our knowledge goes, the first article with such goals.