https://cs.uwaterloo.ca/~brecht/courses/854-Emerging-2014/readings/iot/iot-survey.pdf

The Internet of Things: A survey

The increasing use of wireless networks and the constant miniaturization of electrical devices has empowered the development of Wireless Body Area Networks (WBANs). In these networks various sensors are attached on clothing or on the body or even implanted under the skin. The wireless nature of the network and the wide variety of sensors offer numerous new, practical and innovative applications to improve health care and the Quality of Life. The sensors of a WBAN measure for example the heartbeat, the body temperature or record a prolonged electrocardiogram. Using a WBAN, the patient experiences a greater physical mobility and is no longer compelled to stay in the hospital. This paper offers a survey of the concept of Wireless Body Area Networks. First, we focus on some applications with special interest in patient monitoring. Then the communication in a WBAN and its positioning between the different technologies is discussed. An overview of the current research on the physical layer, existing MAC and network protocols is given. Further, cross layer and quality of service is discussed. As WBANs are placed on the human body and often transport private data, security is also considered. An overview of current and past projects is given. Finally, the open research issues and challenges are pointed out.

/pdf/a-survey-on-wireless-body-area-networks-f3nx5ii4yv.pdf

A survey on wireless body area networks

The distributed nature and dynamic topology of Wireless Sensor Networks (WSNs) introduces very special requirements in routing protocols that should be met. The most important feature of a routing protocol, in order to be efficient for WSNs, is the energy consumption and the extension of the network's lifetime. During the recent years, many energy efficient routing protocols have been proposed for WSNs. In this paper, energy efficient routing protocols are classified into four main schemes: Network Structure, Communication Model, Topology Based and Reliable Routing. The routing protocols belonging to the first category can be further classified as flat or hierarchical. The routing protocols belonging to the second category can be further classified as Query-based or Coherent and non-coherent-based or Negotiation-based. The routing protocols belonging to the third category can be further classified as Location-based or Mobile Agent-based. The routing protocols belonging to the fourth category can be further classified as QoS-based or Multipath-based. Then, an analytical survey on energy efficient routing protocols for WSNs is provided. In this paper, the classification initially proposed by Al-Karaki, is expanded, in order to enhance all the proposed papers since 2004 and to better describe which issues/operations in each protocol illustrate/enhance the energy-efficiency issues.

Energy-Efficient Routing Protocols in Wireless Sensor Networks: A Survey

Network lifetime has become the key characteristic for evaluating sensor networks in an application-specific way. Especially the availability of nodes, the sensor coverage, and the connectivity have been included in discussions on network lifetime. Even quality of service measures can be reduced to lifetime considerations. A great number of algorithms and methods were proposed to increase the lifetime of a sensor network—while their evaluations were always based on a particular definition of network lifetime. Motivated by the great differences in existing definitions of sensor network lifetime that are used in relevant publications, we reviewed the state of the art in lifetime definitions, their differences, advantages, and limitations. This survey was the starting point for our work towards a generic definition of sensor network lifetime for use in analytic evaluations as well as in simulation models—focusing on a formal and concise definition of accumulated network lifetime and total network lifetime. Our definition incorporates the components of existing lifetime definitions, and introduces some additional measures. One new concept is the ability to express the service disruption tolerance of a network. Another new concept is the notion of time-integration: in many cases, it is sufficient if a requirement is fulfilled over a certain period of time, instead of at every point in time. In addition, we combine coverage and connectivity to form a single requirement called connected coverage. We show that connected coverage is different from requiring noncombined coverage and connectivity. Finally, our definition also supports the concept of graceful degradation by providing means of estimating the degree of compliance with the application requirements. We demonstrate the applicability of our definition based on the surveyed lifetime definitions as well as using some example scenarios to explain the various aspects influencing sensor network lifetime.

/pdf/on-the-lifetime-of-wireless-sensor-networks-59hdyqoqi3.pdf

On the lifetime of wireless sensor networks

Wireless sensor networks (WSNs) pose novel challenges compared with traditional networks. To answer such challenges a new communication paradigm, data-centric communication, is emerging. One form of data-centric communication is the publish/subscribe messaging system. Compared with other data-centric variants, publish/subscribe systems are common and wide-spread in distributed computing. Thus, extending publish/subscribe systems intoWSNs will simplify the integration of sensor applications with other distributed applications. This paper describes MQTT-S [1], an extension of the open publish/subscribe protocol message queuing telemetry transport (MQTT) [2] to WSNs. MQTT-S is designed in such a way that it can be run on low-end and battery-operated sensor/actuator devices and operate over bandwidth-constraint WSNs such as ZigBee-based networks. Various protocol design points are discussed and compared. MQTT-S has been implemented and is currently being tested on the IBM wireless sensor networking testbed [3]. Implementation aspects, open challenges and future work are also presented.

MQTT-S — A publish/subscribe protocol for Wireless Sensor Networks

In this paper, we assess the state of the art of Quality of Services (QoS) support in wireless sensor networks (WSNs). Unlike traditional end-to-end multimedia applications, many non-end-to-end mission-critical applications envisioned for WSNs have brought forward new QoS requirements on the network. Further, unique characteristics of WSNs, such as extremely resource-constrained sensors, large-scale random deployment, and novel data-centric communication protocols, pose unprecedented challenges in the area of QoS support in WSNs. Thus, we first review the techniques for QoS support in traditional networks, analyze new QoS requirements in WSNs from a wide variety of applications classified by data delivery models, and propose some non-end-to-end collective QoS parameters. Next, the challenges of QoS support in this new paradigm are presented. Finally, we comment on current research efforts and identify many exciting open issues in order to stimulate more research interest in this largely unexplored area. Keywords— Wireless networks, wireless sensor networks, QoS, collective QoS

QoS support in wireless sensor networks: A survey

Communications voids, where geographic greedy forwarding fails to move a packet further towards its destination, are an important issue for geographic routing in wireless networks. This article presents an overview of the void problem and surveys the currently available void-handling techniques (as of July 2006) for geographic routing. In the survey, we classify these void-handling techniques into six categories, each designed with a different approach, that is, planar-graph-based, geometric, flooding-based, costbased, heuristic, and hybrid. For each category, we present its basic principle and illustrate some classic techniques as well as the latest advances. We also provide a qualitative comparison of these techniques and discuss some possible directions of future research.

A survey of void handling techniques for geographic routing in wireless networks

In the IEEE 802.11 MAC protocol [1], virtual carrier-sense and physical carrier-sense functions are used to determine the availability of the shared medium. The medium is considered idle only when both of these two functions indicate that the medium is idle. While the physical carrier-sense function uses the physical layer to sense the carrier, the virtual carrier-sense function is based on the Network Allocation Vector (NAV). Most IEEE 802.11 frames carry a duration field, which is used to reserve the medium for a fixed time period. The NAV is a timer that indicates the amount of time for which the medium has been reserved. Transmitting nodes set the NAV to the time for which they expect to use the medium, including the transmission time of all the frames in a sequence. Other nodes set up a process to count down the NAV. When the NAV is greater than zero, the virtual carrier-sense function indicates that the medium is busy. When the NAV reaches zero, the medium is reported to be idle. This mechanism, combined with the RTS/CTS exchange, is designed to reduce frame collisions and prevent the hidden terminal problem. However, when nodes set up the NAV values, they do not know whether the expected frame exchange will actually take place. Furthermore, they do not verify if the NAV value has reserved a time that is indeed necessary for the current operation. These are vulnerabilities that a misbehaving node may exploit to block neighboring nodes from accessing the shared medium for an extended period of time. In this work, we investigate these vulnerabilities and potential virtual jamming attacks made possible by them. We also propose a backwardcompatible solution to overcome these vulnerabilities.

/pdf/protecting-wireless-networks-against-a-denial-of-service-500tspa6bx.pdf

Protecting Wireless Networks against a Denial of Service Attack Based on Virtual Jamming

Contention-based geographic forwarding (CGF) is a state-free forwarding technique. In this paper, we develop a general analytical framework to evaluate the performance of CGF with different forwarding areas in wireless multi-hop networks. In particular, we compare the performance of CGF for three typical forwarding areas, analytically and by extensive simulations. We further investigate the impact of several important assumptions on our analytical results. Our study provides guidelines regarding the selection of a specific forwarding area during the design phase of a CGF protocol. It also serves as a general performance evaluation framework for CGF protocols as well as traditional geographic forwarding protocols.

/pdf/selection-of-a-forwarding-area-for-contention-based-15mik34av5.pdf

Dazhi Chen

Papers

QoS support in wireless sensor networks: A survey

A survey of void handling techniques for geographic routing in wireless networks

Protecting Wireless Networks against a Denial of Service Attack Based on Virtual Jamming

Selection of a Forwarding Area for Contention-Based Geographic Forwarding in Wireless Multi-Hop Networks

On-demand Geographic Forwarding for data delivery in wireless sensor networks