Showing papers on "Wireless mesh network published in 2016"

Survey of Important Issues in UAV Communication Networks

Abstract: Unmanned aerial vehicles (UAVs) have enormous potential in the public and civil domains. These are particularly useful in applications, where human lives would otherwise be endangered. Multi-UAV systems can collaboratively complete missions more efficiently and economically as compared to single UAV systems. However, there are many issues to be resolved before effective use of UAVs can be made to provide stable and reliable context-specific networks. Much of the work carried out in the areas of mobile ad hoc networks (MANETs), and vehicular ad hoc networks (VANETs) does not address the unique characteristics of the UAV networks. UAV networks may vary from slow dynamic to dynamic and have intermittent links and fluid topology. While it is believed that ad hoc mesh network would be most suitable for UAV networks yet the architecture of multi-UAV networks has been an understudied area. Software defined networking (SDN) could facilitate flexible deployment and management of new services and help reduce cost, increase security and availability in networks. Routing demands of UAV networks go beyond the needs of MANETS and VANETS. Protocols are required that would adapt to high mobility, dynamic topology, intermittent links, power constraints, and changing link quality. UAVs may fail and the network may get partitioned making delay and disruption tolerance an important design consideration. Limited life of the node and dynamicity of the network lead to the requirement of seamless handovers, where researchers are looking at the work done in the areas of MANETs and VANETs, but the jury is still out. As energy supply on UAVs is limited, protocols in various layers should contribute toward greening of the network. This paper surveys the work done toward all of these outstanding issues, relating to this new class of networks, so as to spur further research in these areas.

Placement Optimization of Energy and Information Access Points in Wireless Powered Communication Networks

Abstract: The applications of wireless power transfer technology to wireless communications can help build a wireless powered communication network (WPCN) with more reliable and sustainable power supply compared to the conventional battery-powered network. However, due to the fundamental differences in wireless information and power transmissions, many important aspects of conventional battery-powered wireless communication networks need to be redesigned for efficient operations of WPCNs. In this paper, we study the placement optimization of energy and information access points in WPCNs, where the wireless devices (WDs) harvest the radio frequency energy transferred by dedicated energy nodes (ENs) in the downlink, and use the harvested energy to transmit data to information access points (APs) in the uplink. In particular, we are interested in minimizing the network deployment cost with minimum number of ENs and APs by optimizing their locations, while satisfying the energy harvesting and communication performance requirements of the WDs. Specifically, we first study the minimum-cost placement problem when the ENs and APs are separately located, where an alternating optimization method is proposed to jointly optimize the locations of ENs and APs. Then, we study the placement optimization when each pair of EN and AP is colocated and integrated as a hybrid access point, and propose an efficient algorithm to solve this problem. Simulation results show that the proposed methods can effectively reduce the network deployment cost and yet guarantee the given performance requirements, which is a key consideration in future applications of WPCNs.

Channel Assignment Techniques for Multi-Radio Wireless Mesh Networks: A Survey

Abstract: With the advent of multiple radio interfaces on a single device, wireless mesh networks start to achieve significant improvement in network capacity, latency, and fault tolerance. The improvement is achieved through concurrent transmissions over different channels utilizing the multiple radio interfaces. However, the introduction of different channels over multiple radios on single mesh node compels to retrospect different issues such as interference, channel diversity, and channel switching from novel perspectives. Due to these novel perspectives, conventional channel assignment techniques proposed for single-radio wireless mesh networks are not generally applicable to the multi-radio cases. Consequently, we have to reconsider the different issues while making a tradeoff among all the available channel assignment options to extract the best performance from a multi-radio wireless mesh network. There are a number of research studies that propose various channel assignment techniques to extract the best performance. In this paper, we present a comprehensive survey on these studies. First, we point out various design issues pertinent to the techniques presented in the studies, and adopt the issues as the basis of our further discussion. Second, we briefly describe several important already-proposed channel assignment techniques. Third, we present a number of channel assignment metrics that are exploited by the already-proposed techniques. Then, depending on the considerations in these techniques, we categorize the techniques and present an exhaustive comparison among them. Nevertheless, we point out a number of real deployments and applications of these techniques in real scenarios. Finally, we identify several open issues for future research with their current status in the literature.

Implementation of a New Replacement Method in WMN-PSO Simulation System and Its Performance Evaluation

Abstract: With the fast development of wireless technologies, Wireless Mesh Networks (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented the Linearly Decreasing Vmax Method (LDVM) for our WMN-PSO simulation system. In this paper, we implement a new replacement method for mesh routers called Rational Decrement of Vmax Method (RDVM). We use Size of Giant Component (SGC) and Number of Covered Mesh Clients (NCMC) as metrics for optimization. From the simulation results, we found that RDVM converges faster to best solution than LDVM.

Secure Data Obfuscation Scheme to Enable Privacy-Preserving State Estimation in Smart Grid AMI Networks

Abstract: While the newly envisioned smart(er) grid (SG) will result in a more efficient and reliable power grid, its collection and use of fine-grained meter data has widely raised concerns on consumer privacy. While a number of approaches are available for preserving consumer privacy, these approaches are mostly not very practical to be used due to two reasons. 1) Since the data is hidden, this reduces the ability of the utility company to use the data for distribution state estimation. 2) The approaches were not tested under realistic wireless infrastructures that are currently in use. In this paper, we propose to implement a meter data obfuscation approach to preserve consumer privacy that has the ability to perform distribution state estimation. We then assess its performance on a large-scale advanced metering infrastructure (AMI) network built upon the new IEEE 802.11s wireless mesh standard. For the data obfuscation approach, we propose two secure obfuscation value distribution mechanisms on this 802.11s-based wireless mesh network (WMN). Using obfuscation values provided via this approach, the meter readings are obfuscated to protect consumer privacy from eavesdroppers and the utility companies while preserving the utility companies’ ability to use the data for state estimation. We assessed the impact of this approach on data goodput, delay, and packet delivery ratio (PDR) under a variety of conditions. Simulation results have shown that the proposed approach can provide very similar performance to that of nonprivacy approach with negligible overheads on the meters and network.

Implementation and evaluation of a simulation system based on particle swarm optimisation for node placement problem in wireless mesh networks

Abstract: With the fast development of wireless technologies, wireless mesh networks WMNs are becoming an important networking infrastructure due to their low cost and increased high speed wireless internet connectivity. This paper implements a simulation system based on particle swarm optimisation PSO in order to solve the problem of mesh router placement in WMNs. Four replacement methods of mesh routers are considered: constriction method CM, random inertia weight method RIWM, linearly decreasing Vmax method LDVM and linearly decreasing inertia weight method LDIWM. Simulation results are provided, showing that the CM converges very fast, but has the worst performance among the methods. The considered performance metrics are the size of giant component SGC and the number of covered mesh clients NCMC. The RIWM converges fast and the performance is good. The LDIWM is a combination of RIWM and LDVM. The LDVM converges after 170 number of phases but has a good performance.

A genetic algorithm-based system for wireless mesh networks: analysis of system data considering different routing protocols and architectures

Abstract: Wireless mesh networks (WMNs) are attracting a lot of attention from wireless network researchers. Node placement problems have been investigated for a long time in the optimization field due to numerous applications in location science. In our previous work, we evaluated WMN-GA system which is based on genetic algorithms (GAs) to find an optimal location assignment for mesh routers. In this paper, we evaluate the performance of four different distributions of mesh clients for two WMN architectures considering throughput, delay and energy metrics. For simulations, we used ns-3, optimized link state routing (OLSR) and hybrid wireless mesh protocols (HWMP). We compare the performance for Normal, Uniform, Exponential and Weibull distributions of mesh clients by sending multiple constant bit rate flows in the network. The simulation results show that for HWM protocol the throughput of Uniform distribution is higher than other distributions. However, for OLSR protocol, the throughput of Exponential distribution is better than other distributions. For both protocols, the delay and remaining energy are better for Weibull distribution.

A Bluetooth Low Energy real-time protocol for Industrial Wireless mesh Networks

Abstract: Low energy consumption and low cost are some of the primary issues that have to be addressed in Industrial Wireless Sensor Networks (IWSN). Such networks are being increasingly used to acquire sensory data that need to be processed in real-time. The Bluetooth Low Energy (BLE) protocol is an attractive solution for implementing low-cost IWSN with reduced energy consumption and high flexibility. However, the current BLE standard does not provide real-time support for data packets and is limited to a star topology. This paper presents a real-time protocol for industrial wireless mesh networks that is developed on top of the BLE and overcomes these limitations. The paper describes the protocol and provides analysis and experimental results.

Efficient Cache Placement Strategy in Two-Tier Wireless Content Delivery Network

Abstract: Internet content caching for multimedia services has received much attention mainly in the field of large-scale wired networking as a primary solution to save network resources and improve quality of service (QoS). Rapidly increasing consumption of multimedia content in mobile networks brings a challenge of how to efficiently deliver content in local wireless access networks. Cache embedment in wireless mesh environment is an intriguing attempt to enhance the QoS and service capacity, leading to the question of how to design an efficient content delivery network considering the inherent characteristics of the wireless environment. We propose and investigate an efficient cache placement strategy in novel two-tier wireless content delivery networks, which utilize separate channels for content dissemination and content service. Such a two-tier network system model helps to achieve much better content delivery performance with a greatly reduced system design complexity compared to single-tier network system models. Further, we incorporate a delay cost due to contention, which is mainly responsible for performance in shared-medium wireless networks, as a key metric for cache placement under the system model. After formally formulating the cache placement problem, we propose a cross-layer heuristic algorithm and demonstrate its performance compared with an optimal solution by integer linear programming. Simulation results show significant performance improvements by our strategy compared to the performance of existing representative strategies in terms of service delay, packet delivery ratio, and the amount of delivered packets within a given delay deadline.

Interference mitigation in wireless mesh networks through radio co-location aware conflict graphs

Abstract: Wireless Mesh Networks (WMNs) have evolved into a wireless communication technology of immense interest. But technological advancements in WMNs have inadvertently spawned a plethora of network performance bottlenecks, caused primarily by the rise in prevalent interference. Conflict Graphs are indispensable tools used to theoretically represent and estimate the interference in wireless networks. We propose a generic algorithm to generate conflict graphs which is independent of the underlying interference model. Further, we propose the notion of radio co-location interference, which is caused and experienced by spatially co-located radios in multi-radio multi-channel WMNs. We experimentally validate the concept, and propose a new all-encompassing algorithm to create a radio co-location aware conflict graph. Our novel conflict graph generation algorithm is demonstrated to be significantly superior and more efficient than the conventional approach, through theoretical interference estimates and comprehensive experiments. The results of an extensive set of ns-3 simulations run on the IEEE 802.11g platform strongly indicate that the radio co-location aware conflict graphs are a marked improvement over their conventional counterparts. We also question the use of total interference degree as a reliable metric to predict the performance of a Channel Assignment scheme in a given WMN deployment.

An Integrated Simulation System Considering WMN-PSO Simulation System and Network Simulator 3

Abstract: With the fast development of wireless technologies, Wireless Mesh Net-works (WMNs) are becoming an important networking infrastructure due to their low cost and increased high speed wireless Internet connectivity. In our previous work, we implemented a simulation system based on Particle Swam Optimization for solving node placement problem in wireless mesh networks, called WMN-PSO. In this paper, we implement an integrated system considering WMN-PSO and net-work simulator 3 (ns-3). For simulation, we consider two WMN architectures. From simulation results, we found that the total received throughput of I/BWMNis higher than Hybrid WMN and the delay of I/B WMN is lower than Hybrid WMN.

Routing Protocol for Heterogeneous Wireless Mesh Networks

Abstract: The introduction of heterogeneous wireless mesh technologies provides an opportunity for higher network capacity, wider coverage, and higher quality of service (QoS). Each wireless device utilizes different standards, data formats, protocols, and access technologies. However, the diversity and complexity of such technologies create challenges for traditional control and management systems. This paper proposes a heterogeneous metropolitan area network architecture that combines an IEEE 802.11 wireless mesh network (WMN) with a long-term evolution (LTE) network. In addition, a new heterogeneous routing protocol and a routing algorithm based on reinforcement learning called cognitive heterogeneous routing are proposed to select the appropriate transmission technology based on parameters from each network. The proposed heterogeneous network overcomes the problems of sending packets over long paths, island nodes, and interference in WMNs and increases the overall capacity of the combined network by utilizing unlicensed frequency bands instead of buying more license frequency bands for LTE. The work is validated through extensive simulations that indicate that the proposed heterogeneous WMN outperforms the LTE and Wi-Fi networks when used individually. The simulation results show that the proposed network achieves an increase of up to 200% in throughput compared with Wi-Fi-only networks or LTE-only networks.

PEACH: Predicting Frost Events in Peach Orchards Using IoT Technology

Abstract: In 2013, 85% of the peach production in the Mendoza region (Argentina) was lost because of frost. In a couple of hours, farmers can lose everything. Handling a frost event is possible, but it is hard to predict when it is going to happen. The goal of the PEACH project is to predict frost events by analyzing measurements from sensors deployed around an orchard. This article provides an in-depth description of a complete solution we designed and deployed: the low-power wireless network and the back-end system. The low-power wireless network is composed entirely of commercial off-the-shelf devices. We develop a methodology for deploying the network and present the open-source tools to assist with the deployment and to monitor the network. The deployed low-power wireless mesh network is 100% reliable, with end-to-end latency below 2 s, and over 3 years of battery lifetime. This article discusses how the technology used is the right one for precision agriculture applications.

Evaluation of BLE Mesh capabilities: A case study based on CSRMesh

Abstract: This work examines the applicability of the relatively young radio standard Bluetooth Low Energy (Bluetooth Smart) for mesh-enabled applications. To achieve this, a demonstrator application is used in multiple measurements to analyze the packet delivery ratio of different setups. Since no official mesh implementation for Bluetooth Low Energy (BLE) has been released to this date, the proprietary, BLE-based CSRmesh protocol is used in this study. Besides the measurement campaign, several simulations were performed in order to study the suitability of Bluetooth Mesh in large-scale networks. Our results show that Bluetooth Mesh is a promising technology for mesh applications but additional effort is required during the ongoing standardization process to exploit its full potential.

Intelligent multi-beam medium access control in ku-band for mission-oriented mobile mesh networks

Abstract: A MAC design for Ku-band mobile wireless mesh network with multi-beam smart antennas is disclosed. This MAC includes an overlay control that separates the collision domain. It also has lower layer CSMA-like scheme. The disclosed design includes an enhanced PCF and an enhanced DCF for two purposes: (1) exploiting multi-beam concurrent communication capability (2) supporting QoS and mission-based communications. An efficient time synchronization scheme is also disclosed to ensure all beams can concurrently send data to the star node. Finally, ARMA or HMM based prediction schemes are disclosed to predict future traffic profile in each beam. This helps the star node to better prepare the queue content and schedule information.

Effect of Social Groups on the Capacity of Wireless Networks

Abstract: In this paper, we study the effects of social interactions among nodes on the capacity of wireless networks. We consider three scenarios. In the first scenario, the size of the social group for all nodes is fixed while the frequency of communication within members of a social group follows power law distribution. In the second scenario, scale-free networks are studied where the size of the social group differs from node to node, and the destination in each group is selected uniformly among the members of that group. Further investigation in the second scenario reveals that traditional transport capacity definition provides misleading conclusions for such network models. We show that nodes with different social status impact the capacity differently. By separating nodes with different social status and allocating separate bandwidth to them, it is shown that majority of nodes scale in this network. In the third scenario, both the size of the social groups and the destination in each group are selected according to power law distributions. Our simulation results corroborate the analytical results. Further, we observe consistently that social interaction improves the capacity of wireless networks, which implies that the Gupta–Kumar results were pessimistic for practical networks.

Router Node Placement With Service Priority in Wireless Mesh Networks Using Simulated Annealing With Momentum Terms

Abstract: In wireless mesh networks (WMNs), mesh clients communicate with each other via the gateway and bridging functions of mesh routers. The performance of a WMN is generally affected by its network connectivity and client coverage, both of which are determined by its router node placement (RNP) in the deployment area. For simplicity, previous works considered only the RNP where each mesh client is served as an equal. In practice, however, mesh clients should be served with different priorities owing to factors such as their importance and their different payments for the service access. To fulfil this requirement, by assuming that each mesh client is also associated with a service priority, this paper investigates an RNP problem with a service priority constraint in which the mesh clients with service priorities higher than a threshold must be served. Given that this problem inherited from the complexity of the original RNP problem is computationally intractable in general, this paper also develops a novel simulated annealing (SA) approach that takes into account momentum terms to improve the efficiency and accuracy of annealing schedules and prevent fluctuations in values of the acceptance probability function. Additionally, the time complexity of the proposed SA algorithm is analyzed. Furthermore, evaluation of different-size instances under various parameters and annealing schedules demonstrates the superiority of the proposed approach.

Mininet-WiFi: A Platform for Hybrid Physical-Virtual Software-Defined Wireless Networking Research

Abstract: Software-Defined Wireless Networking (SDWN) is being considered an appealing paradigm to design and operate wireless networks through higher-level abstractions and programmatic interfaces such as the OpenFlow protocol. Identified benefits include cost savings, service velocity and customization, resource optimization through novel approaches to user mobility, traffic offloading, multi-layer and multi-path routing, and so on. This demonstration features Mininet-WiFi as a SDWN emulator with the ability to run realistic experiments in hybrid physical-virtual environments, where users attending the conference are able to experience first hand by connecting their devices and interacting with virtual WiFi stations in a wireless mesh network or reach the Internet through the emulated SDWN infrastructure. OpenFlow 1.3 metering and IP header re-writing actions will showcase HTTP flow redirection and rate limitation of real users' wireless traffic.

Integration of scheduling and network coding in multi-rate wireless mesh networks

Abstract: In order to fully utilize spectrum resource in wireless mesh networks (WMNs), we propose a combination of some popular communication techniques, including link scheduling, spatial reuse, power and rate adaptation and network coding (NC), to activate as many transmission links as possible during one scheduling period, so that the total scheduling length can be minimized and network throughput can be maximized. Different from previous studies, we consider the interplay among these techniques and present an optimal NC-aware link scheduling mechanism in multi-rate WMNs, which relies on the enumeration of all possible schedules. Due to the high computational complexity of our proposed model, we utilize a column generation (CG)-based method to resolve the optimization problem and decompose it into a master problem (MP) and a pricing problem (PP). Furthermore, we present a distributed power control algorithm for PP, by which the computational complexity of the CG-based scheme can be largely reduced. Simulation results demonstrate the superiority of our method under various network situations.

On the Capacity Gain from Full Duplex Communications in a Large Scale Wireless Network

Abstract: Compared to half duplex communications, full duplex communications can significantly improve link capacity. However, in a large scale wireless network such as a wireless mesh network, the capacity gain from full duplex communications has not been fully investigated. To this end, a metric of network capacity called transmission capacity is studied in this paper for a full duplex wireless network. It captures the maximum transmission throughput in a unit area, subject to a certain outage probability. The key challenge of deriving transmission capacity is to characterize the aggregate interference of the typical link in a full duplex wireless network, which is completely different from that in a half duplex wireless network. In this paper, stochastic geometry is employed to model the network topology as a Thomas cluster point process and then the aggregate interference is characterized as a shot-noise process. Based on these models, the transmission capacity is derived. Analytical results show that under the same network density the distribution of aggregate interference in a full duplex wireless network is more dispersed than that in a half duplex wireless network. Comparisons of transmission capacity between a full duplex network and a half duplex network reveal that the capacity gain from full duplex communications is limited due to severe aggregate interference. This result implies that self-interference cancellation alone cannot ensure scalable full duplex wireless networking.

Evaluation and analysis of an enhanced hybrid wireless mesh protocol for vehicular ad hoc network

Abstract: This paper presents a new clustering mechanism for the multi-hop relay in vehicular communication. In the proposed mechanism, the cluster-head selection is implemented using the enhanced hybrid wireless mesh protocol (E-HWMP) protocol, which is based on the IEEE802.11p and IEEE802.11s standards. Then, multi-hop routing is designed for VANET in Wireless Mesh Networks (WMNs). Therefore, the main aim of this study is to enhance the integration of VANET with a cellular network (i.e., LTE). As a result, the coverage can be extended. The proposed E-HWMP mechanism is evaluated by the NS2 simulator, and the VanetMobiSim is used as a mobility generator. The proposed E-HWMP mechanism is compared to the existing mechanism based on the packet’s delivery ratio, packet loss, throughput, overhead, and average end-to-end delay. The results demonstrate that the proposed E-HWMP mechanism outperforms the existing clustering mechanism.

A multi-objective evolutionary algorithm based QoS routing in wireless mesh networks

Abstract: Graphical abstractDisplay Omitted HighlightsThe present work proposes a Modified Non-dominated Sorting Genetic Algorithm-II which is applied to the routing problem in WMN.Dynamic crowding distance strategy aims to improve the diversity of the non-dominated solution.Analytic hierarchy process is used to find the best compromise solution.Compared to NSGA-II, the proposed algorithm can improve the throughput and minimizes the transmission delay. The huge demand for real time services in wireless mesh networks (WMN) creates many challenging issues for providing quality of service (QoS). Designing of QoS routing protocols, which optimize the multiple objectives is computationally intractable. This paper proposes a new model for routing in WMN by using Modified Non-dominated Sorting Genetic Algorithm-II (MNSGA-II). The objectives which are considered here are the minimization of expected transmission count and the transmission delay. In order to retain the diversity in the non-dominated solutions, dynamic crowding distance (DCD) procedure is implemented in NSGA-II. The simulation is carried out in Network Simulator 2 (NS-2) and comparison is made using the metrics, expected transmission count and transmission delay by varying node mobility and by increasing number of nodes. It is observed that MNSGA-II improves the throughput and minimizes the transmission delay for varying number of nodes and higher mobility scenarios. The simulation clearly shows that MNSGA-II algorithm is certainly more suitable for solving multiobjective routing problem. A decision-making procedure based on analytic hierarchy process (AHP) has been adopted to find the best compromise solution from the set of Pareto-solutions obtained through MNSGA-II. The performance of MNSGA-II is compared with reference point based NSGA-II (R-NSGA-II) in terms of spread.

Social-aware dynamic router node placement in wireless mesh networks

Abstract: The problem of dynamic router node placement (dynRNP) in wireless mesh networks (WMNs) is concerned with determining a dynamic geographical placement of mesh routers to serve mobile mesh clients at different times, so that both network connectivity (i.e., the greatest topology subgraph component size) and client coverage (i.e., the number of the served mesh clients) are maximized. Mesh clients are wireless devises associated with users, and in real world, the users with same interests or some social relationship have higher chance to gather and move together geographically, i.e., they form a community, and the WMN with multiple communities can be regarded as a social network. Therefore, this paper investigates the so-called social-aware WMN-dynRNP problem assuming that mesh routers should be aware of the social community structure of mesh clients to dynamically adjust their placement to improve network performance. To cope with this problem, this paper proposes a social-based particle swarm optimization approach, which additionally includes a social-supporting vector to direct low-loading mesh routers to support the heavy-loading mesh routers in the same topology subgraph component (community), so as to dynamically adopt to the social community behavior of mesh clients. As compared with the previous approach, our experimental results show that the proposed approach is capable of effectively reducing number of the unserved mesh clients and increasing network connectivity in dynamic social scenarios.

Wireless mesh network: A survey

Abstract: For next generation wireless networks, wireless mesh networks have become the basic technology. WMNs consist of mesh router and mesh client. WMNs provide broadband internet access, wireless local area network coverage and network connectivity for both mobile and stationary nodes. Routing are used in mesh networks in order deliver packets from source to destination efficiently. Mainly 3 types of routing protocols are used in WMNs. Proactive, reactive and hybrid protocol. In which hybrid protocol are the best protocols when compared to others. This paper presents a survey of wireless mesh networks.

A Channel Assignment and Routing Algorithm for Energy Harvesting Multiradio Wireless Mesh Networks

Abstract: Wireless mesh networks are being deployed all around the world both to provide ubiquitous connection to the Internet and to carry data generated by several services (video surveillance, smart grids, earthquake early warning systems, etc.). In those cases where fixed power connections are not available, mesh nodes operate by harvesting ambient energy (e.g., solar or wind power) and hence they can count on a limited and time-varying amount of power to accomplish their functions. Since we consider mesh nodes equipped with multiple radios, power savings and network performance can be maximized by properly routing flows, assigning channels to radios and identifying nodes/radios that can be turned off . Thus, the problem we address is a joint channel assignment and routing problem with additional constraints on the node power consumption, which is NP-complete. In this paper, we propose a heuristic, named minimum power channel assignment and routing algorithm (MP-CARA), which is guaranteed to return a local optimum for this problem. Based on a theoretical analysis that we present in the paper, which gives an upper bound on the outage probability as a function of the constraint on power consumption, we can guarantee that the probability that a node runs out of power with MP-CARA falls below a desired threshold. The performance of MP-CARA is assessed by means of an extensive simulation study aiming to compare the solutions returned by MP-CARA to those found by other heuristics proposed in the literature.

Outdoor wireless communication system based on LoRa ad-hoc network

Abstract: The invention provides an outdoor wireless communication system based on a LoRa ad-hoc network, which is used for solving technical problems of poor mobile network signals in severe environment, short transmission distance and absence of an interactive interface for information sharing of the existing outdoor wireless communication system. The outdoor wireless communication system based on the LoRa ad-hoc network comprises a central processing unit, a positioning module, a Bluetooth module, a peripheral interface, a power supply module, a LoRa communication module and a mobile phone APP terminal; the central processing unit is respectively connected with the positioning module, the Bluetooth module, the peripheral interface, the power supply module and the LoRa communication module; the LoRa communication module constructs a wireless Mesh network with the LoRa communication modules of other systems, and performs reliable data communication through a CSMA/CA protocol and an AODV routing algorithm; and the mobile phone APP terminal and the Bluetooth module perform data exchange through the Bluetooth. The outdoor wireless communication system based on the LoRa ad-hoc network performs communication without the mobile network, has long transmission distance, has the interactive interface for information sharing, and can be applied to the fields, such as the Internet of Vehicles and the Internet of Things.

Self-organizing network concepts for small cells backhauling

Abstract: A mesh network includes domain(s) of multiple nodes interconnected through links and in which there are gateway(s) connecting a domain to another network. The domain(s), their multiple nodes, and their links are part of a topology. A set of primary and backup routing paths, each including an ST that includes the selected gateway and route to that selected gateway for nodes in the domain, for a selected one of the gateway(s) is accessed or determined. Schedule(s) to be used by node(s) in the mesh network over one or more scheduling cycles are accessed or determined. Based on status of link(s) between nodes and on the schedule(s), switching is performed to a selected one of the primary or backup routing paths for the selected gateway. Routing in the mesh network is caused to be modified based on the selected routing path. Information is sent to nodes for the paths and schedules.

Auto-configuration and automation of a building management system

Abstract: A building management system is disclosed that is automatically configured using a wireless mesh network data and sensor data to create a virtual floor plan The building management system comprising a control processor, a plurality of lighting devices, and a plurality of control devices comprising lighting control devices, each directly controlling one or more of the lighting devices The control devices intercommunicate with each other over a wireless network, and each control device comprises a light sensor detecting light intensity The control processor creates the mesh graph of relative positioning of the control devices to each other using received wireless signal strengths of the control devices relative to each other The control processor determines relative positioning of the lighting devices to the control devices using the mesh graph and received light intensity readings obtained by the light sensors of the control devices when each lighting device was turned on and off The virtual floor plan comprises the relative positioning of the control devices to each other, the relative positioning of the control devices to the lighting devices, and room-by-room groupings of the plurality of control devices and the lighting devices

Modeling and performance evaluation of security attacks on opportunistic routing protocols for multihop wireless networks

Abstract: In wireless networks, opportunistic routing (OR) protocols are designed to route data packets towards their destination with greater reliability than traditional routing schemes. In addition to reliability, nodes' trustworthiness and willingness to cooperate can also play a significant role in the delivery of packets to their final destinations. More specifically, nodes in the network may be compromised, experience software or hardware failures, or behave maliciously for various reasons. Therefore, it would be beneficial to model the behavior of malicious or uncooperative nodes and study their effects in a wireless network that employs OR for communications. In this paper, the behavior of malicious nodes in a wireless mesh network that utilizes unicast opportunistic routing protocols is modeled using Discrete Time Markov Chain (DTMC). Afterwards, using the proposed model, we introduce a novel approach for the calculation of packet drop ratio, through which the negative effects of uncooperative nodes can be calculated. Furthermore, a customized version of a black-hole attack is introduced as an example of malicious behavior in OR protocols; we apply this routing attack to several well-known OR protocols, with the additional use of network simulation as well as through the proposed analytical technique. Finally, a comprehensive set of performance evaluation scenarios is designed and applied, with the purpose of investigating the effects of different parameters on a wireless mesh network that uses OR as a routing approach in the presence of malicious nodes. Evaluation results indicate that the proposed black-hole attack can significantly downgrade communication performance, and the proposed model can properly model the effects of malicious nodes on OR protocols.