Internet of Things (IoT) is one of the evolutionary directions of the Internet. This paper focuses on the low earth orbit (LEO) satellite constellation-based IoT services for their irreplaceable functions. In many cases, IoT devices are distributed in remote areas (e.g., desert, ocean, and forest) in some special applications, they are placed in some extreme topography, where are unable to have direct terrestrial network accesses and can only be covered by satellite. Comparing with the traditional geostationary earth orbit (GEO) systems, LEO satellite constellation has the advantages of low propagation delay, small propagation loss and global coverage. Furthermore, revision of existing IoT protocol are necessary to enhance the compatibility of the LEO satellite constellation-based IoT with terrestrial IoT systems. In this paper, we provide an overview of the architecture of the LEO satellite constellation-based IoT including the following topics: LEO satellite constellation structure, efficient spectrum allocation, heterogeneous networks compatibility, and access and routing protocols.

LEO Satellite Constellation for Internet of Things

Wireless sensor networks (WSNs) are becoming increasingly popular with the advent of the Internet of things (IoT). Various real-world applications of WSNs such as in smart grids, smart farming and smart health would require a potential deployment of thousands or maybe hundreds of thousands of sensor nodes/actuators. To ensure proper working order and network efficiency of such a network of sensor nodes, an effective WSN management system has to be integrated. However, the inherent challenges of WSNs such as sensor/actuator heterogeneity, application dependency and resource constraints have led to challenges in implementing effective traditional WSN management. This difficulty in management increases as the WSN becomes larger. Software Defined Networking (SDN) provides a promising solution in flexible management WSNs by allowing the separation of the control logic from the sensor nodes/actuators. The advantage with this SDN-based management in WSNs is that it enables centralized control of the entire WSN making it simpler to deploy network-wide management protocols and applications on demand. This paper highlights some of the recent work on traditional WSN management in brief and reviews SDN-based management techniques for WSNs in greater detail while drawing attention to the advantages that SDN brings to traditional WSN management. This paper also investigates open research challenges in coming up with mechanisms for flexible and easier SDN-based WSN configuration and management.

Software Defined Networking for Improved Wireless Sensor Network Management: A Survey

A range of applications, from predicting the spread of human and electronic viruses to city planning and resource management in mobile communications, depend on our ability to foresee the whereabouts and mobility of individuals, raising a fundamental question: To what degree is human behavior predictable? Here we explore the limits of predictability in human dynamics by studying the mobility patterns of anonymized mobile phone users. By measuring the entropy of each individual's trajectory, we find a 93% potential predictability in user mobility across the whole user base. Despite the significant differences in the travel patterns, we find a remarkable lack of variability in predictability, which is largely independent of the distance users cover on a regular basis.

http://absimage.aps.org/image/MAR10/MWS_MAR10-2009-007155.pdf

Limits of predictability in human mobility

Vehicular Ad-hoc NETworks (VANETs) are an emerging important type of wireless ad-hoc network. Unlike many other types of MANETs, VANET applications such as traffic data dissemination are inherently broadcast oriented and require communication protocols to be anonymous and scalable. Simple broadcast flooding satisfies these requirements, but its performance is highly dependent on network density and may lead to the broadcast storm problem.

This work is the first we are aware of to propose stochastic broadcast as a solution for VANET. Stochastic broadcast instructs nodes to rebroadcast messages according to a retransmit probability. Such a scheme is private since node identification is unnecessary, however it has an undesirable dependency on vehicle density in the same manner as simple flooding. To solve this problem, we demonstrate the link between the mathematical science of continuum percolation and stochastic broadcast. Specifically, that the critical percolation threshold in continuum percolation (≈ 4.5 expected neighbors) translates to the wireless broadcast context. Then we show that nodes can tune the performance of the broadcast system to efficient levels by adjusting the retransmit probability so the apparent density of the network approaches the critical threshold.

Stochastic Broadcast for VANET

The space segment has been evolved from monolithic to distributed satellite systems. One of these distributed systems is called the federated satellite system (FSS) which aims at establishing a win–win collaboration between satellites to improve their mission performance by using the unused on-board resources. The FSS concept requires sporadic and direct communications between satellites, using inter satellite links. However, this point-to-point communication is temporal and thus it can break existent federations. Therefore, the conception of a multi-hop scenario needs to be addressed. This is the goal of the Internet of satellites (IoSat) paradigm which, as opposed to a common backbone, proposes the creation of a network using a peer-to-peer architecture. In particular, the same satellites take part of the network by establishing intermediate collaborations to deploy a FSS. This paradigm supposes a major challenge in terms of network definition and routing protocol. Therefore, this paper not only details the IoSat paradigm, but it also analyses the different satellite network models. Furthermore, it evaluates the routing protocol candidates that could be used to implement the IoSat paradigm.

Internet of Satellites (IoSat): Analysis of Network Models and Routing Protocol Requirements

While software defined network (SDN) brings more innovation to the development of future networks, it also faces a more severe threat from DDoS attacks. In order to deal with the single point of failure on SDN controller caused by DDoS attacks, we propose a framework for detection and defense of DDoS attacks in the SDN environment. Firstly, we deploy a trigger mechanism of DDoS attack detection on data plane to screen for abnormal flows in the network. Then, we use a combined machine learning algorithm based on K-Means and KNN to exploit the rate characteristics and asymmetry characteristics of the flows and to detect the suspicious flows determined by the detection trigger mechanism. Finally, the controller will take corresponding actions to defense against the attacks. In this paper, we propose a new framework of cooperative detection methods of control plane and data plane, which effectively improve the detection accuracy and efficiency, and prevent DDoS attacks on SDN.

A New Framework for DDoS Attack Detection and Defense in SDN Environment

As a promising platform for implementing various applications, a wireless sensor and actor network (WSAN) consists of many sensor and actor nodes that can cooperatively handle complex tasks. However, many issues, including nodes’ mobility, the heterogeneity of capacity, topology, and energy consumption, may bring severe challenges to efficient WSAN operation. Currently, the software defined network (SDN) appears as a novel approach that is effective to manage and optimize networks in a programmable and centralized pattern. This paper studies the application framework and relevant methods for applying the SDN approach in a WSAN, with the objective of improving network’s efficiency and scalability. The details of the framework include a three-layer structure, the relevant system entities, the enhanced protocol stack, and the programmable message types for cooperative communication and task execution among WSAN nodes. Based on this framework, this paper explores the relevant challenges and mechanisms for effective system management from many aspects, including mobility, energy saving, reliability maintenance, and topology construction. This paper also proposes an optimization method for scheduling decomposed tasks to relevant nodes, with an example implemented by the genetic algorithm. Next, this paper demonstrates the typical application scenarios, including military, industry, transportation, and environmental disaster monitoring. Moreover, an indoor application scenario and an outdoor application scenario are presented to demonstrate the application of the SDN-assisted communication handoff. Finally, the future trends and technical challenges for SDN in WSAN are discussed.

SDN-Based Application Framework for Wireless Sensor and Actor Networks

Although traditional spatial-temporal features, such as gyration, probability, and the intervals between consecutive records, have contributed to model human dynamics, the importance of these basic...

https://journals.sagepub.com/doi/pdf/10.1177/1550147716671256

TCB: A feature transformation method based central behavior for user interest prediction on mobile big data:

With the rapid development of wireless sensor networks, satellite sensor networks (SSNs) and high-resolution SSNs (HRSSNs) have been proposed and demonstrated to have significant advantages over general networks. SSNs and HRSSNs have been applied in many fields, including national defense, military, national security, environmental monitoring, and traffic management. In addition, high-resolution satellites provide new technological means to improve the accuracy of environmental monitoring. However, huge amounts of data will cause problems in quality of service, such as the large and unbalanced load pressure of satellites, considerable packet loss rate, and network congestion. Hence, solving such problems and optimizing network performance are necessary. The snapshot integration routing (SIR) method is proposed in this study to redesign network topology and create a new static graph in HRSSNs, which are actually a type of delay-tolerant networks (DTNs). Our proposed SIR method, when used with a classical algorithm, can plan optimized routes and significantly improve the performance of HRSSNs in terms of successful data delivery rate, satellite storage, and network overhead compared with PRoPHET and contact graph routing(CGR). In periodic and predictable DTN-based HRSSNs, the proposed method can effectively avoid network congestion and maintain load balance.

Snapshot integration routing for high-resolution satellite sensor networks based on delay-tolerent network

Probabilistic forwarding is one of the routing methods that neighbors are selected as the next hop according to probability. The probability calculation method is different for different forwarding methods. Our work is based on selective forwarding and the selective forwarding probability based on the node degree and link loss is presented to increase the reliability of selective forwarding. The effect of parameters on performance is reflected in the simulation results and the qualitative analysis is done based on regular square network. Through the qualitative analysis, the calculation of forwarding probability is improved further

Jianguo Zhou

Papers

A New Framework for DDoS Attack Detection and Defense in SDN Environment

SDN-Based Application Framework for Wireless Sensor and Actor Networks

TCB: A feature transformation method based central behavior for user interest prediction on mobile big data:

Snapshot integration routing for high-resolution satellite sensor networks based on delay-tolerent network

A New Reliable Routing Method Based on Probabilistic Forwarding in Wireless Sensor Network