The term “Internet-of-Things” is used as an umbrella keyword for covering various aspects related to the extension of the Internet and the Web into the physical realm, by means of the widespread deployment of spatially distributed devices with embedded identification, sensing and/or actuation capabilities. Internet-of-Things envisions a future in which digital and physical entities can be linked, by means of appropriate information and communication technologies, to enable a whole new class of applications and services. In this article, we present a survey of technologies, applications and research challenges for Internet-of-Things.
One of the most important design problems for multi-UAV (Unmanned Air Vehicle) systems is the communication which is crucial for cooperation and collaboration between the UAVs. If all UAVs are directly connected to an infrastructure, such as a ground base or a satellite, the communication between UAVs can be realized through the in-frastructure. However, this infrastructure based communication architecture restricts the capabilities of the multi-UAV systems. Ad-hoc networking between UAVs can solve the problems arising from a fully infrastructure based UAV networks. In this paper, Flying Ad-Hoc Networks (FANETs) are surveyed which is an ad hoc network connecting the UAVs. The differences between FANETs, MANETs (Mobile Ad-hoc Networks) and VANETs (Vehicle Ad-Hoc Networks) are clarified first, and then the main FANET design challenges are introduced. Along with the existing FANET protocols, open research issues are also discussed.
The idea of the Internet of Things (IOT) notion is that everything within the global network is accessible and interconnected. As such Wireless Sensor Networks (WSN) play a vital role in such an environment, since they cover a wide application field. Such interconnection can be seen from the aspect of a remote user who can access a single desired sensor node from the WSN without the necessity of firstly connecting with a gateway node (GWN). This paper focuses on such an environment and proposes a novel user authentication and key agreement scheme for heterogeneous ad hoc wireless sensor networks. The proposed scheme enables a remote user to securely negotiate a session key with a general sensor node, using a lightweight key agreement protocol. The proposed scheme ensures mutual authentication between the user, sensor node, and the gateway node (GWN), although the GWN is never contacted by the user. The proposed scheme has been adapted to the resource-constrained architecture of the WSN, thus it uses only simple hash and XOR computations. Our proposed scheme tackles these risks and the challenges posed by the IOT, by ensuring high security and performance features.
In the Internet of Things (IoT), resource-constrained things are connected to the unreliable and untrusted Internet via IPv6 and 6LoWPAN networks. Even when they are secured with encryption and authentication, these things are exposed both to wireless attacks from inside the 6LoWPAN network and from the Internet. Since these attacks may succeed, Intrusion Detection Systems (IDS) are necessary. Currently, there are no IDSs that meet the requirements of the IPv6-connected IoT since the available approaches are either customized for Wireless Sensor Networks (WSN) or for the conventional Internet. In this paper we design, implement, and evaluate a novel intrusion detection system for the IoT that we call SVELTE. In our implementation and evaluation we primarily target routing attacks such as spoofed or altered information, sinkhole, and selective-forwarding. However, our approach can be extended to detect other attacks. We implement SVELTE in the Contiki OS and thoroughly evaluate it. Our evaluation shows that in the simulated scenarios, SVELTE detects all malicious nodes that launch our implemented sinkhole and/or selective forwarding attacks. However, the true positive rate is not 100%, i.e., we have some false alarms during the detection of malicious nodes. Also, SVELTE’s overhead is small enough to deploy it on constrained nodes with limited energy and memory capacity.
In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to reasonable times. In this paper we first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, we present a systematic and comprehensive taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data acquisition. Finally we conclude the paper with insights for research directions about energy conservation in WSNs.
VANETs have emerged as an exciting research and application area. Increasingly vehicles are being equipped with embedded sensors, processing and wireless communication capabilities. This has opened a myriad of possibilities for powerful and potential life-changing applications on safety, efficiency, comfort, public collaboration and participation, while they are on the road. Although, considered as a special case of a Mobile Ad Hoc Network, the high but constrained mobility of vehicles bring new challenges to data communication and application design in VANETs. This is due to their highly dynamic and intermittent connected topology and different application’s QoS requirements. In this work, we survey VANETs focusing on their communication and application challenges. In particular, we discuss the protocol stack of this type of network, and provide a qualitative comparison between most common protocols in the literature. We then present a detailed discussion of different categories of VANET applications. Finally, we discuss open research problems to encourage the design of new VANET solutions.
Cognitive radio (CR) technology is envisaged to solve the problems in wireless networks resulting from the limited available spectrum and the inefficiency in the spectrum usage by exploiting the existing wireless spectrum opportunistically. CR networks, equipped with the intrinsic capabilities of the cognitive radio, will provide an ultimate communication paradigm in wireless communications. CR networks, however, impose unique challenges due to the high fluctuation in the available spectrum as well as diverse quality-of-service (QoS) requirements. Specifically, in cognitive radio ad hoc networks (CRAHNs), the distributed multi-hop architecture, the dynamic network topology, and the time and location varying spectrum availability are some of the key distinguishing factors. In this paper, intrinsic properties and current research challenges of the CRAHNs are presented. First, novel spectrum management functionalities such as spectrum sensing, spectrum sharing, and spectrum decision, and spectrum mobility are introduced from the viewpoint of a network requiring distributed coordination. A particular emphasis is given to distributed coordination between CR users through the establishment of a common control channel. Moreover, the influence of these functions on the performance of the upper layer protocols, such as the network layer, and transport layer protocols are investigated and open research issues in these areas are also outlined. Finally, a new direction called the commons model is explained, where CRAHN users may independently regulate their own operation based on pre-decided spectrum etiquette.
The concept of Internet of Things (IOT), which is already at our front doors, is that every object in the Internet infrastructure (II) is interconnected into a global dynamic expanding network. Sensors and smart objects are beside classical computing devices key parties of the IOT. We can already exploit the benefits of the IOT by using various weareables or smart phones which are full of diverse sensors and actuators and are connected to the II via GPRS or Wi-Fi. Since sensors are a key part of IOT, thus are wireless sensor networks (WSN). Researchers are already working on new techniques and efficient approaches on how to integrate WSN better into the IOT environment. One aspect of it is the security aspect of the integration. Recently, Turkanović et al.’s proposed a highly efficient and novel user authentication and key agreement scheme (UAKAS) for heterogeneous WSN (HWSN) which was adapted to the IOT notion. Their scheme presented a novel approach where a user from the IOT can authenticate with a specific sensor node from the HWSN without having to communicate with a gateway node. Moreover their scheme is highly efficient since it is based on a simple symmetric cryptosystem. Unfortunately we have found that Turkanović et al.’s scheme has some security shortcomings and is susceptible to some cryptographic attacks. This paper focuses on overcoming the security weaknesses of Turkanović et al.’s scheme, by proposing a new and improved UAKAS. The proposed scheme enables the same functionality but improves the security level and enables the HWSN to dynamically grow without influencing any party involved in the UAKAS. The results of security analysis by BAN-logic and AVISPA tools confirm the security properties of the proposed scheme.
The Internet of Things or “IoT” defines a highly interconnected network of heterogeneous devices where all kinds of communications seem to be possible, even unauthorized ones. As a result, the security requirement for such network becomes critical whilst common standard Internet security protocols are recognized as unusable in this type of networks, particularly due to some classes of IoT devices with constrained resources. The document discusses the applicability and limitations of existing IP-based Internet security protocols and other security protocols used in wireless sensor networks, which are potentially suitable in the context of IoT. The analysis of these protocols is discussed based on a taxonomy focusing on the key distribution mechanism.
Wireless sensor networks can be deployed in any attended or unattended environments like environmental monitoring, agriculture, military, health care etc., where the sensor nodes forward the sensing data to the gateway node. As the sensor node has very limited battery power and cannot be recharged after deployment, it is very important to design a secure, effective and light weight user authentication and key agreement protocol for accessing the sensed data through the gateway node over insecure networks. Most recently, Turkanovic et al. proposed a light weight user authentication and key agreement protocol for accessing the services of the environment and claimed that the same protocol is efficient in terms of security and complexities than related existing protocols. In this paper, we have demonstrated several security weaknesses of the Turkanovic et al. protocol. Additionally, we have also illustrated that the authentication phase of the Turkanovic et al. is not efficient in terms of security parameters. In order to fix the above mentioned security pitfalls, we have primarily designed a novel architecture for the environment and basing upon which a proposed scheme has been presented for user authentication and key agreement scheme. The security validation of the proposed protocol has done by using logic, which ensures that the protocol achieves mutual authentication and session key agreement property securely between the entities involved. Moreover, the proposed scheme has simulated using well popular security tool, whose simulation results show that the protocol is under and models. Besides, several security issues informally confirm that the proposed protocol is well protected in terms of relevant security attacks including the above mentioned security pitfalls. The proposed protocol not only resists the above mentioned security weaknesses, but also achieves complete security requirements including specially energy efficiency, user anonymity, mutual authentication and user-friendly password change phase. Performance comparison section ensures that the protocol is relatively efficient in terms of complexities. The security and performance analysis makes the system so efficient that the proposed protocol can be implemented in real-life application.
In this paper, we introduce the first fully implemented two-way authentication security scheme for the Internet of Things (IoT) based on existing Internet standards, specifically the Datagram Transport Layer Security (DTLS) protocol. By relying on an established standard, existing implementations, engineering techniques and security infrastructure can be reused, which enables easy security uptake. Our proposed security scheme is therefore based on RSA, the most widely used public key cryptography algorithm. It is designed to work over standard communication stacks that offer UDP/IPv6 networking for Low power Wireless Personal Area Networks (6LoWPANs). Our implementation of DTLS is presented in the context of a system architecture and the scheme’s feasibility (low overheads and high interoperability) is further demonstrated through extensive evaluation on a hardware platform suitable for the Internet of Things.
To account for stochastic properties when modeling connectivity in wireless mobile systems such as cellular, ad hoc and sensor networks, spatial point processes are used. Since connectivity can be expressed as a function of the distance between nodes, distance distributions between points in spatial processes are of special importance. In this paper, we survey those results available for distance distributions between points in two mostly used spatial point models, namely, the homogeneous Poisson process in and independently uniformly distributed points in a certain region of . These two models are known for decades and various distance-related results have been obtained. Unfortunately, due to a wide application area of spatial point processes they are scattered among multiple field-specific journals and researchers are still wasting their time rediscovering them time after time. We attempt to unify these results providing an ultimate reference. We will also briefly discuss some of their applications.
The major challenge in designing wireless sensor networks (WSNs) is the support of the functional, such as data latency, and the non-functional, such as data integrity, requirements while coping with the computation, energy and communication constraints. Careful node placement can be a very effective optimization means for achieving the desired design goals. In this paper, we report on the current state of the research on optimized node placement in WSNs. We highlight the issues, identify the various objectives and enumerate the different models and formulations. We categorize the placement strategies into static and dynamic depending on whether the optimization is performed at the time of deployment or while the network is operational, respectively. We further classify the published techniques based on the role that the node plays in the network and the primary performance objective considered. The paper also highlights open problems in this area of research.
The high penetration rate of new technologies in all the activities of everyday life is fostering the belief that for any new societal challenge there is always an ICT solution able to successfully deal with it. Recently, the solution that is proposed almost anytime is the “ ” (IoT). This apparent of the ICT world takes different aspects on and, actually, is identified with different (often different) technological solutions. As a result, many think that IoT is just RFIDs, others think that it is sensor networks, and yet others that it is machine-to-machine communications. In the meanwhile, industrial players are taking advantage of the popularity of IoT to use it as a very trendy brand for technology solutions oriented to the consumer market. The scientific literature sometimes does not help much in clarifying, as it is rich in definitions of IoT often discordant between them. Objective of this paper is to present the evolutionary stages, i.e., , that have characterized the development of IoT, along with the motivations of their triggering. Besides, it analyzes the role that IoT can play in addressing the main societal challenges and the set of features expected from the relevant solutions. The final objective is to give a modern definition of the phenomenon, which shows a strong pervasive nature, and, if not well understood in its theories, technologies, methodologies, and real potentials, then runs the risk of being regarded with suspicion and, thus, rejected by users.
Cognitive radio networks (CRNs) are composed of cognitive, spectrum-agile devices capable of changing their configurations on the fly based on the spectral environment. This capability opens up the possibility of designing flexible and dynamic spectrum access strategies with the purpose of opportunistically reusing portions of the spectrum temporarily vacated by licensed primary users. On the other hand, the flexibility in the spectrum access phase comes with an increased complexity in the design of communication protocols at different layers. This work focuses on the problem of designing effective routing solutions for multi-hop CRNs, which is a focal issue to fully unleash the potentials of the cognitive networking paradigm. We provide an extensive overview of the research in the field of routing for CRNs, clearly differentiating two main categories: approaches based on a full spectrum knowledge, and approaches that consider only local spectrum knowledge obtained via distributed procedures and protocols. In each category we describe and comment on proposed design methodologies, routing metrics and practical implementation issues. Finally, possible future research directions are also proposed.
In cognitive radio (CR) networks, identifying the available spectrum resource through spectrum sensing, deciding on the optimal sensing and transmission times, and coordinating with the other users for spectrum access are the important functions of the medium access control (MAC) protocols. In this survey, the characteristic features, advantages, and the limiting factors of the existing CR MAC protocols are thoroughly investigated for both infrastructure-based and ad hoc networks. First, an overview of the spectrum sensing is given, as it ensures that the channel access does not result in interference to the licensed users of the spectrum. Next, a detailed classification of the MAC protocols is presented while considering the infrastructure support, integration of spectrum sensing functionalities, the need for time synchronization, and the number of radio transceivers. The main challenges and future research directions are presented, while highlighting the close coupling of the MAC protocol design with the other layers of the protocol stack.
As the future Internet architecture, information centric networking(ICN) can also offer superior architectural support for mobile ad hoc networking. Therefore, information-centric mobile ad hoc networks (ICMANET), a new cross-cutting research area, is gradually forming. In the paper, we firstly introduce the current advances in ICN and analyze its development trends, and then interpret the formation of ICMANET and sketch an overview of it. Subsequently, we define a concept model for content routing and categorize the content routing into proactive, reactive and opportunistic types, and then detail the representative schemes. Finally, the existing issues are summarized. The goal of the work is to provide the references and guidelines for readers approaching study on the new area.
Machine-to-machine (M2M) communications emerge to autonomously operate to link interactions between Internet cyber world and physical systems. We present the technological scenario of M2M communications consisting of wireless infrastructure to cloud, and machine swarm of tremendous devices. Related technologies toward practical realization are explored to complete fundamental understanding and engineering knowledge of this new communication and networking technology front.
Internet of Things (IoT) systems cannot successfully realize the notion of ubiquitous connectivity of everything if they are not capable to truly include ‘multimedia things’. However, the current research and development activities in the field do not mandate the features of multimedia objects, thus leaving a gap to benefit from multimedia content based services and applications. In this paper, we analyze this issue by contemplating the concept of IoT and drawing an inspiration towards the perspective vision of ‘Internet of Multimedia Things’ (IoMT). Therein, we introduce IoMT as a novel paradigm in which smart heterogeneous multimedia things can interact and cooperate with one another and with other things connected to the Internet to facilitate multimedia based services and applications that are globally available to the users. Some applications and use-cases for IoMT are presented to reflect the possibilities enabled by this new paradigm. An IoMT architecture is then presented which is segregated into four distinct stages; (i) multimedia sensing, (ii) reporting and addressability, (iii) multimedia-aware cloud, and (iv) multi-agent systems. Instead of proposing specific technical solutions for each individual stage of the presented architecture, we survey the already existing technologies, providing a synthesis for the realization of the vision of IoMT. Subsequently, various requirements and challenges as well as the feasibility of existing solutions for each stage of proposed IoMT architecture are comprehensively discussed.