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Showing papers on "Wireless mesh network published in 2017"


Journal ArticleDOI
TL;DR: This paper describes in detail about the Edge Mesh computing paradigm, including the proposed software framework, research challenges, and benefits of Edge Mesh, which distributes the decision-making tasks among edge devices within the network instead of sending all the data to a centralized server.
Abstract: In recent years, there has been a paradigm shift in Internet of Things (IoT) from centralized cloud computing to edge computing (or fog computing). Developments in ICT have resulted in the significant increment of communication and computation capabilities of embedded devices and this will continue to increase in coming years. However, existing paradigms do not utilize low-level devices for any decision-making process. In fact, gateway devices are also utilized mostly for communication interoperability and some low-level processing. In this paper, we have proposed a new computing paradigm, named Edge Mesh, which distributes the decision-making tasks among edge devices within the network instead of sending all the data to a centralized server. All the computation tasks and data are shared using a mesh network of edge devices and routers. Edge Mesh provides many benefits, including distributed processing, low latency, fault tolerance, better scalability, better security, and privacy. These benefits are useful for critical applications, which require higher reliability, real-time processing, mobility support, and context awareness. We first give an overview of existing computing paradigms to establish the motivation behind Edge Mesh. Then, we describe in detail about the Edge Mesh computing paradigm, including the proposed software framework, research challenges, and benefits of Edge Mesh. We have also described the task management framework and done a preliminary study on task allocation problem in Edge Mesh. Different application scenarios, including smart home, intelligent transportation system, and healthcare, are presented to illustrate the significance of Edge Mesh computing paradigm.

168 citations


Journal ArticleDOI
22 Jun 2017-Sensors
TL;DR: This paper comprehensively surveys state of the art BLE mesh networking, describing the variety of approaches that leverage existing BLE functionality to enable BLE Mesh Networks and identifying crucial aspects of BLEMesh network solutions.
Abstract: Bluetooth Low Energy (BLE) has gained significant momentum. However, the original design of BLE focused on star topology networking, which limits network coverage range and precludes end-to-end path diversity. In contrast, other competing technologies overcome such constraints by supporting the mesh network topology. For these reasons, academia, industry, and standards development organizations have been designing solutions to enable BLE mesh networks. Nevertheless, the literature lacks a consolidated view on this emerging area. This paper comprehensively surveys state of the art BLE mesh networking. We first provide a taxonomy of BLE mesh network solutions. We then review the solutions, describing the variety of approaches that leverage existing BLE functionality to enable BLE mesh networks. We identify crucial aspects of BLE mesh network solutions and discuss their advantages and drawbacks. Finally, we highlight currently open issues.

145 citations


Proceedings ArticleDOI
19 Mar 2017
TL;DR: A network traffic prediction method based on a deep belief network and a Gaussian model that outperforms three existing methods for wireless mesh backbone network prediction.
Abstract: Wireless mesh network is prevalent for providing a decentralized access for users. For a wireless mesh backbone network, it has obtained extensive attention because of its large capacity and low cost. Network traffic prediction is important for network planning and routing configurations that are implemented to improve the quality of service for users. This paper proposes a network traffic prediction method based on a deep belief network and a Gaussian model. The proposed method first adopts discrete wavelet transform to extract the low-pass component of network traffic that describes the long-range dependence of itself. Then a prediction model is built by learning a deep belief network from the extracted low-pass component. Otherwise, for the rest high-pass component that expresses the gusty and irregular fluctuations of network traffic, a Gaussian model is used to model it. We estimate the parameters of the Gaussian model by the maximum likelihood method. Then we predict the high-pass component by the built model. Based on the predictors of two components, we can obtain a predictor of network traffic. From the simulation, the proposed prediction method outperforms three existing methods.

89 citations


Proceedings ArticleDOI
21 May 2017
TL;DR: This paper presents a practical implementation of an SDN MANET, describes in detail the software components that are adopted, and provides a repository for all the new components that were developed and the performance of the proposed network implemented in real devices, as compared to a distributed ad hoc network.
Abstract: A promising approach for dealing with the increasing demand of data traffic is the use of device-to-device (D2D) technologies, in particular when the destination can be reached directly, or though few retransmissions by peer devices. Thus, the cellular network can offload local traffic that is transmitted by an ad hoc network, e.g., a mobile ad hoc network (MANET), or a vehicular ad hoc network (VANET). The cellular base station can help coordinate all the devices in the ad hoc network by reusing the software tools developed for software-defined networks (SDNs), which divide the control and the data messages, transmitted in two separate interfaces. In this paper, we present a practical implementation of an SDN MANET, describe in detail the software components that we adopted, and provide a repository for all the new components that we developed. This work can be a starting point for the wireless networking community to design new testbeds with SDN capabilities that can have the advantages of D2D data transmissions and the flexibility of a centralized network management. In order to prove the feasibility of such a network, we also showcase the performance of the proposed network implemented in real devices, as compared to a distributed ad hoc network.

68 citations


Journal ArticleDOI
TL;DR: This work proposes two certificate revocation schemes that can identify and nullify the false positives and proposes two schemes that are much more scalable than the conventional CRL and the mathematical and simulation results are almost identical.
Abstract: Given the scalability of the advanced metering infrastructure (AMI) networks, maintenance and access of certificate revocation lists (CRLs) pose new challenges. It is inefficient to create one large CRL for all the smart meters (SMs) or create a customized CRL for each SM since too many CRLs will be required. In order to tackle the scalability of the AMI network, we divide the network into clusters of SMs, but there is a tradeoff between the overhead at the certificate authority (CA) and the overhead at the clusters. We use Bloom filters to reduce the size of the CRLs in order to alleviate this tradeoff by increasing the clusters’ size with acceptable overhead. However, since Bloom filters suffer from false positives, there is a need to handle this problem so that SMs will not discard important messages due to falsely identifying the certificate of a sender as invalid. To this end, we propose two certificate revocation schemes that can identify and nullify the false positives. While the first scheme requires contacting the gateway to resolve them, the second scheme requires the CA additionally distribute the list of certificates that trigger false positives. Using mathematical models, we have demonstrated that the probability of contacting the gateway in the first scheme and the overhead of the second scheme can be very low by properly designing the Bloom filters. In order to assess the scalability and validate the mathematical formulas, we have implemented the proposed schemes using Visual C. The results indicate that our schemes are much more scalable than the conventional CRL and the mathematical and simulation results are almost identical. Moreover, we simulated the distribution of the CRLs in a wireless mesh-based AMI network using ns-3 network simulator and assessed its distribution overhead.

66 citations


Journal ArticleDOI
14 Feb 2017-Sensors
TL;DR: A new packet format and a new BLE mesh topology, with two different configurations: Individual Mesh and Collaborative Mesh are proposed and the results show how this topology improves the scalability, sustainability, coverage and performance.
Abstract: Current sensor networks need to be improved and updated to satisfy new essential requirements of the Internet of Things, where cutting-edge applications will appear. These requirements are: total coverage, zero fails (high performance), scalability and sustainability (hardware and software). We are going to evaluate Bluetooth Low Energy as wireless transmission technology and as the ideal candidate for these improvements, due to its low power consumption, its low cost radio chips and its ability to communicate with users directly, using their smartphones or smartbands. However, this technology is relatively recent, and standard network topologies are not able to fulfil its new requirements. To address these shortcomings, the implementation of other more flexible topologies (as the mesh topology) will be very interesting. After studying it in depth, we have identified certain weaknesses, for example, specific devices are needed to provide network scalability, and the need to choose between high performance or sustainability. In this paper, after presenting the studies carried out on these new technologies, we propose a new packet format and a new BLE mesh topology, with two different configurations: Individual Mesh and Collaborative Mesh. Our results show how this topology improves the scalability, sustainability, coverage and performance.

65 citations


Proceedings ArticleDOI
Yu Liu1, Kin-Fai Tong1, Xiangdong Qiu, Ying Liu, Xuyang Ding 
07 Jul 2017
TL;DR: How wireless mesh networks has the possibility to come together and how to integrate the mesh network into existing IoT networks to potentially make a difference in the new era is introduced.
Abstract: Internet of Things is one of the hottest topics in both industry and academia of the communication engineering world. On the other hand, wireless mesh networks, a network topology that has been discuss for decades that haven't been put into use in large scale, can make a difference when it comes to the network in the IoT world today. This paper is a brief introduction of how these technologies has the possibility to come together and how to integrate the mesh network into existing IoT networks to potentially make a difference in the new era.

51 citations


Journal ArticleDOI
TL;DR: Experimental results show that CLOC indeed ensures control application stability and fulfills communication constraints while maximizing the worst case redundancy gain of the system performance.
Abstract: When multiple control processes share a common wireless network, the communication protocol must provide reliable performance in order to yield stability of the overall system. In this paper, the novel cross-layer optimized control (CLOC) protocol is proposed for minimizing the worst case performance loss of multiple industrial control systems. CLOC is designed for a general wireless sensor and actuator network where both sensor to controller and controller to actuator connections are over a multihop mesh network. The design approach relies on a constrained max-min optimization problem, where the objective is to maximize the minimum resource redundancy of the network and the constraints are the stability of the closed-loop control systems and the schedulability of the communication resources. The optimal operation point of the protocol is automatically set in terms of the sampling rate, scheduling, and routing, and is achieved by solving a linear programming problem, which adapts to system requirements and link conditions. The protocol has been experimentally implemented and evaluated on a testbed with off-the-shelf wireless sensor nodes, and it has been compared with a traditional network design and a fixed-schedule approach. Experimental results show that CLOC indeed ensures control application stability and fulfills communication constraints while maximizing the worst case redundancy gain of the system performance.

50 citations


Journal ArticleDOI
TL;DR: Three novel data collection mechanisms to set the periodic reporting time of each SM to improve TCP performance in IEEE 802.11s-based wireless mesh AMI networks are proposed and simulation results indicate that the packet delay can be improved significantly without any negative impact on the other performance metrics.
Abstract: Designing efficient and reliable wireless mesh-based advanced metering infrastructure (AMI) networks is challenging. In AMI networks, fine-grained regular data collections from smart meters (SMs) create a lot of traffic and interference. The location of the gateway that collects data from SMs may also add to this interference by impacting the length of routes. Furthermore, TCP-like protocols that are employed for reliability may bring additional overhead. Therefore, it is critical to pick the suitable data collection strategy and gateway location to meet some smart grid performance requirements. In this paper, we proposed three novel data collection mechanisms to set the periodic reporting time of each SM to improve TCP performance in IEEE 802.11s-based wireless mesh AMI networks. The first idea was based on the nature of IEEE 802.11s routing protocol. Each SM is assigned a reporting time based on its location in the spanning tree network. The second idea was inspired by the time division multiple access methods where each meter is given a separate slot. The third idea was based on both previous ideas and clustering to increase the number of meters that can send at the same slot. For the gateway location, we also proposed a novel mechanism based on ${p}$ -center facility problem to minimize data delivery delay. The simulation results indicate that the packet delay can be improved significantly without any negative impact on the other performance metrics.

50 citations


Journal ArticleDOI
TL;DR: A mathematical model of the 802.11 wireless access network is developed and solved to optimality by means of integer linear programming, showing how much can be saved both in terms of energy and traffic, also considering various tradeoff points among the two contrasting objectives.
Abstract: SUMMARY In this paper, we study a wireless access network based on the Institute of Electrical and Electronics Engineers 802.11 standard and enriched with features such as caching and mesh networking. This system is analysed in terms of energy efficiency and traffic offloading, two objectives that are somewhat in contrast but both relevant to network and service providers as they directly impact the operational cost. In addition, QoS is also accounted for in the form of guaranteed bandwidth and bounded delay. To this aim, we developed a mathematical model of the system and solved it to optimality by means of integer linear programming. We can thus show how much can be saved both in terms of energy and traffic, also considering various tradeoff points among the two contrasting objectives. As a last step, we provide an investigation on the benefits of adding traffic aggregation features to the mathematical model. Copyright © 2014 John Wiley & Sons, Ltd.

49 citations


Book ChapterDOI
10 Jul 2017
TL;DR: Two hybrid simulation systems for solving node placement problem in WMNs are evaluated: WMN-PSOHC and WMn-PSOSA, and a comparison is compared by conducting computer simulations.
Abstract: Wireless Mesh Networks (WMNs) have many advantages such as low cost and increased high speed wireless Internet connectivity, therefore WMNs are becoming an important networking infrastructure. In our previous work, we implemented a Particle Swarm Optimization (PSO) based simulation system for node placement in WMNs, called WMN-PSO. Also, we implemented two intelligent hybrid systems for solving node placement problem in WMNs: PSO and Hill Climbing (HC) based system, called WMN-PSOHC, and PSO and Simulated Annealing (SA) based system, called WMN-PSOSA. In this paper, we evaluate two hybrid simulation systems WMN-PSOHC and WMN-PSOSA. We compare WMN-PSOHC with WMN-PSOSA by conducting computer simulations.


Journal ArticleDOI
TL;DR: The papers in this special section focus on the topic of smart grids, as they combine wide-area control, computation, and communications, and the ongoing discussion of future 5G systems is driven by the requirements of Smart Grids as one major use case.
Abstract: The papers in this special section focus on the topic of smart grids. Smart Grids are an essential component of future energy systems, which are characterized by distributed, volatile energy production (solar, wind) and entirely new components (electric vehicles) and operation concepts (virtual power plants). Smart Grids are also a prominent example of Cyber Physical Systems, as they combine wide-area control, computation, and communications. While traditional automation of the power grid makes use of wireline communications (copper, fiber), Smart Grids require wide-area coverage with flexible, cost-efficient, but also very reliable communications networks. Therefore, wireless communication technologies will play an increasingly important role in future deployment scenarios. The investigated options range from cellular networks over satellite systems to wireless mesh networks. Also, the ongoing discussion of future 5G systems is driven by the requirements of Smart Grids as one major use case. Particular challenges for wireless communication options include availability, real-time capabilities for incident mitigation, and resilience. The performance evaluation of Smart Grids calls for new methods, such as the interdisciplinary hybrid simulation of energy and communication networks.

Journal ArticleDOI
Adnan Aijaz1, Usman Raza1
TL;DR: DeAMON is introduced, which is decentralized adaptive multi-hop scheduling protocol for 6TiSCH wireless networks that outperforms state-of-the-art distributed scheduling protocols in terms of reliability, latency, and resource utilization.
Abstract: The IEEE 802.15.4-2015 standard provides a link-layer mechanism, based on time synchronized channel hopping (TSCH), to enable deterministic low-power wireless mesh networking. The emerging IPv6 over IEEE 802.15.4e TSCH (6TiSCH) working group aims at harmonizing an IP-enabled protocol stack with the IEEE 802.15.4e link layer. In 802.15.4-TSCH medium access control, nodes follow a communication schedule; however, the standard does not specify any scheduling policy. Therefore, a number of recent studies have investigated scheduling mechanisms for 6TiSCH wireless networks. This paper introduces DeAMON , which is decentralized adaptive multi-hop scheduling protocol for 6TiSCH wireless networks. The key features of DeAMON include traffic-awareness, sequential scheduling, parallel transmissions, robust over-provisioning, and adaptability to topology changes. Moreover, DeAMON incurs minimal signaling overhead. Performance evaluation demonstrates that DeAMON outperforms state-of-the-art distributed scheduling protocols in terms of reliability, latency, and resource utilization.

Journal ArticleDOI
TL;DR: How the 6TiSCH stack can be incorporated into existing and new curricula to teach the next generation of electrical engineering and computer science professionals about designing and deploying such networks is discussed.
Abstract: The IETF 6TiSCH stack encompasses IEEE802.15.4 TSCH, IETF 6LoWPAN, RPL, and CoAP. It is one of the key standards-based technologies to enable industrial process monitoring and control, and unleash the Industrial Internet of Things (IIoT). The 6TiSCH stack is also a valuable asset for educational purposes, as it integrates an Internet-enabled IPv6-based upper stack with stateof- the-art low-power wireless mesh communication technologies. Teaching with 6TiSCH empowers students with a valuable set of competencies, including topics related to computer networking (medium access control operation, IPv6 networking), embedded systems (process scheduling, concurrency), and wireless communications (multipath propagation, interference effects), as well as application requirements for the IIoT. This article discusses how the 6TiSCH stack can be incorporated into existing and new curricula to teach the next generation of electrical engineering and computer science professionals about designing and deploying such networks. It also gives a comprehensive overview of the 6TiSCH stack and the tools that exist to support a course based on it.

Journal ArticleDOI
TL;DR: Based on the constructed DFT or network graph model, reliability of the mesh SAN is evaluated using a binary decision diagram-based method and can provide insights into the behavior of general mesh SAN systems, providing guidelines in the reliable design and operation of SANs.
Abstract: With advances in Internet of Things (IoT), intelligent data sensors are being added to more and more devices that interact with human’s daily life in areas, such as medical services, smart grids, and financial services. IoT has made big contributions to data growth, requiring highly reliable data storage solutions. Storage area networks (SANs) are one of such solutions. To meet high reliability and availability requirements, SANs have to provide fault tolerance through redundancy to minimize or eliminate system downtime, thus preventing business discontinuity due to catastrophic events. Mesh is one of the common SAN topologies that have been applied to implement a fault tolerant SAN in practice. In this paper, failure behavior of a mesh SAN is modeled using a dynamic fault tree (DFT) in the case of perfect links, or a network graph in the case of imperfect links. Based on the constructed DFT or network graph model, reliability of the mesh SAN is evaluated using a binary decision diagram-based method. Results obtained from the case study can provide insights into the behavior of general mesh SAN systems, providing guidelines in the reliable design and operation of SANs.

Book ChapterDOI
10 Jun 2017
TL;DR: A hybrid simulation system based on PSO and Hill Climbing for solving node placement problem in WMNs, called WMN-PSOHC is implemented and simulation results show that the WMn-PS OHC has better performance than WMN -PSO.
Abstract: Wireless Mesh Networks (WMNs) have many advantages such as low cost and increased high speed wireless Internet connectivity, therefore WMNs are becoming an important networking infrastructure. In our previous work, we implemented a Particle Swarm Optimization (PSO) based simulation system for node placement in WMNs, called WMN-PSO. Also, we implemented a simulation system based on Hill Climbing (HC) for solving node placement problem in WMNs, called WMN-HC. In this paper, we implement a hybrid simulation system based on PSO and HC, called WMN-PSOHC. We compare WMN-PSO with WMN-PSOHC by conducting computer simulations. The simulation results show that the WMN-PSOHC has better performance than WMN-PSO.

Journal ArticleDOI
TL;DR: A social-aware framework for optimizing SPANs by exploiting two layers: users’ relationships in the online social network layer and Users’ offline connections and interactions in the physical wireless network layer is presented.
Abstract: In wireless ad hoc networks, each node participates in routing by forwarding data to other nodes without a pre-existing infrastructure. Particularly, with the wide adoption of smart devices, the concept of smartphone ad hoc networks (SPANs) has evolved to enable alternate means for information sharing. Using unlicensed frequency spectrum and short-range wireless technologies, a SPAN enables a new paradigm of applications and thus is seen as an attractive component in future wireless networks. In a SPAN, smartphones form local peer-to-peer networks to cooperate and share information efficiently. Recent studies have shown that if the users’ social relations are considered while designing cooperation schemes and protocols in SPANs, the cooperation initialization and content dissemination can be notably improved to increase the overall network efficiency and communications reliability. In this article, we present a social-aware framework for optimizing SPANs by exploiting two layers: users’ relationships in the online social network layer and users’ offline connections and interactions in the physical wireless network layer. The online content popularity distribution is also studied as a result of the users’ online interaction profiles. In the end, we integrate both online and offline layers, and discuss possible applications to further enhance the network performance.

Journal ArticleDOI
Xiaoheng Deng1, Tingting He1, Lifang He1, Jinsong Gui1, Qionglin Peng1 
TL;DR: This paper develops a new Markov chain model and derives a few MAC layer performance metrics such as MAC layer packet dropping probability, the mean throughput and the mean packet delay which contains the queuing delay for IEEE 802.11s wireless mesh networks in the smart grid based on Markov model.
Abstract: The bi-directional communication system is an indispensable component in smart grid (SG) for monitoring and exchanging essential information among the electrical devices. IEEE 802.11s based wireless mesh networks recently have been proposed as an important networking technology to deploy in SG for data collection and remote control purposes, as the cost of networking equipments decreases and performance increases. In this paper, we focus on analyzing the MAC layer performance for IEEE 802.11s wireless mesh networks in the smart grid based on Markov model, taking into account the impact of hidden nodes and different QoS requirements of smart grid applications. We first develop a new Markov chain model to analyze the back-off process for different applications with hidden nodes problem. Then based on the analytical model, we derive a few MAC layer performance metrics such as MAC layer packet dropping probability, the mean throughput and the mean packet delay which contains the queuing delay. Finally, the proposed analytical model is validated via comparing the analytical results with simulation results by ns-3 in NAN scenarios with various applications. We observe a good match between the analytical model and simulations which confirms the veracity of our model.

Proceedings ArticleDOI
31 Oct 2017
TL;DR: A SDN-enabled wireless fog architecture that combines both OpenFlow and distributed wireless protocols is presented, which provides lower latency and efficient load balancing to offload the network load by enabling programmable fog routers.
Abstract: Fog computing has recently emerged as a new cyber foraging technique to offload resource-intensive tasks from mobile devices to mobile cloudlets in close proximity to endusers. Since the one-hop communication in the network edge is predominantly wireless, Wireless Mesh Networks (WMNs) are being considered to build wireless fog networks. However, WMNs use distributed hop-by-hop routing protocols to reflect a partial visibility of the network, which limits their ability to perform global network management and monitoring needed by fog networks. Software Defined Networking (SDN) provides a centralized control and management of the entire network, which makes it a good candidate to support fog communication. Unfortunately, the SDN OpenFlow protocol does not support any functionalities for wireless fog networks as it is primarily targeted to wired networks. To address these issues, this paper presents a SDN-enabled wireless fog architecture that combines both OpenFlow and distributed wireless protocols. The proposed solution provides lower latency and efficient load balancing to offload the network load by enabling programmable fog routers.

Proceedings ArticleDOI
22 Mar 2017
TL;DR: In this paper, a simulation study is conducted to optimize the values of two important parameters; the Beacon and Superframe orders when used with different cluster sizes and different transmission rates.
Abstract: The IEEE 802.15.4 MAC protocol is widely used in mesh wireless sensor networks due to its low energy consumption and long transmission range. In order to achieve the best wireless transmission performance, it is important to optimize the protocol parameters such that a minimum end-to-end delay, minimum packet drop rate and maximum throughput are achieved. In this paper, a simulation study is conducted to optimize the values of two important parameters; the Beacon and Superframe orders when used with different cluster sizes and different transmission rates.

Journal ArticleDOI
28 Feb 2017-Energies
TL;DR: The technique was developed by combining multiple OLSR path selection metrics with the AHP algorithminns-2 and shows improvements of about 23% and 45% in latency and Packet Delivery Ratio (PDR), respectively, in a 25-node grid NAN.
Abstract: Reliable communication is the backbone of advanced metering infrastructure (AMI). Within the AMI, the neighbourhood area network (NAN) transports a multitude of traffic, each with unique requirements. In order to deliver an acceptable level of reliability and latency, the underlying network, such as the wireless mesh network(WMN), must provide or guarantee the quality-of-service (QoS) level required by the respective application traffic. Existing WMN routing protocols, such as optimised link state routing (OLSR), typically utilise a single metric and do not consider the requirements of individual traffic; hence, packets are delivered on a best-effort basis. This paper presents a QoS-aware WMN routing technique that employs multiple metrics in OLSR optimal path selection for AMI applications. The problems arising from this approach are non deterministic polynomial time (NP)-complete in nature, which were solved through the combined use of the analytical hierarchy process (AHP) algorithm and pruning techniques. For smart meters transmitting Internet Protocol (IP) packets of varying sizes at different intervals, the proposed technique considers the constraints of NAN and the applications’ traffic characteristics. The technique was developed by combining multiple OLSR path selection metrics with the AHP algorithminns-2. Compared with the conventional link metric in OLSR, the results show improvements of about 23% and 45% in latency and Packet Delivery Ratio (PDR), respectively, in a 25-node grid NAN.

Journal ArticleDOI
TL;DR: This work proposes an energy-efficient cross-layer design for wireless mesh network (WMN) aided content sharing in OSN as a case study of the interplay between OSNs and technological networks and demonstrates that the composite betweenness based caching strategy is capable of reducing the energy dissipation of the mesh clients by £358 compared to its singular betweennessbased counterpart.
Abstract: Bearing in mind the associated security and privacy concerns, users in an online social network (OSN) normally communicate with their direct friends. We propose an energy-efficient cross-layer design for wireless mesh network (WMN) aided content sharing in OSN as a case study of the interplay between OSNs and technological networks. A power control aided WMN is proposed for energy-efficient content sharing. Based on our power control scheme in the physical layer, an interference-constrained-channel-reuse scheme and a Dijkstra algorithm aided energy-efficient routing protocol are invoked for the medium access control layer and for the network layer, respectively. Inspired by the tool of social network analysis, both the singular and composite betweenness metrics are invoked for quantifying the duty-cycle of mesh routers. The former only considers the topology of the mesh backbone, while the latter considers the topologies of both the OSN and the WMN. Furthermore, the singular/composite betweenness is exploited for designing sophisticated caching strategies in order to improve the content sharing performance. We demonstrate that our caching strategies are capable of reducing the total energy dissipation by as much as ${\text{40}}\%$ . Specifically, the composite betweenness based caching strategy is capable of reducing the energy dissipation of the mesh clients by ${\text{358}}\%$ , compared to its singular betweenness based counterpart.

Proceedings ArticleDOI
18 Apr 2017
TL;DR: The design of a LoRa mesh-networking module for IoT applications (e.g., collecting data from multiple, widely distributed sensors on a university campus) is presented and the results show the LoRaMesh networking module achieved a 88.49% packet delivery ratio (PDR), while the Lo RaWAN in star-network topology was only 58.7% under the same conditions.
Abstract: LoRa, an emerging wireless technology, is examined for long range communication performance in a large area. Although LoRa shows good performance for long-distance transmission in the countryside, its radio signals can be attenuated and interfered with by buildings, trees and other signal sources. In urban areas, our observation shows that LoRa requires a dense deployment of LoRa gateways to ensure that indoor LoRa devices can transfer data back to remote servers. Mesh networking is a solution for increasing the communication range and packet delivery ratio without the need to install additional LoRa gateways. This study presents our design of a LoRa mesh-networking module for IoT applications (e.g.,collecting data from multiple, widely distributed sensors on a university campus). We deployed 19 LoRa mesh-networking devices distributed in an 800m by 600m area on campus to serve as a gateway and to collect data at one-minute intervals. The results show our LoRa mesh networking module achieved a 88.49% packet delivery ratio (PDR), while the LoRaWAN in star-network topology was only 58.7% under the same conditions.

Journal ArticleDOI
TL;DR: Simulation results show that NSR can significantly improve the overall network performance compared to techniques using interference and channel switching, Expected Transmission count or load at gateways as a routing metric, Reinforcement learning-based best path to best gateway (RLBDR), and nearest gateway.

Patent
26 Oct 2017
TL;DR: In this paper, the first scheduling request (SR) process for uplink transmissions requiring uplink resources of at least one first radio resource type was initiated by a wireless device that receives one or more messages comprising configuration parameters for a logical channel in a plurality of logical channels.
Abstract: A wireless device receives one or more messages comprising configuration parameters for a logical channel in a plurality of logical channels. The configuration parameters indicate a mapping restriction of the logical channel to one or more radio resource types in a plurality of radio resource types. The wireless device triggers a first scheduling request (SR) process for uplink transmissions requiring uplink resources of at least one first radio resource type. The wireless device receives an uplink grant indicating uplink radio resources. The wireless device cancels the first SR process if the uplink radio resources are of one of the at least one first radio resource type. Otherwise the wireless device maintains the first SR process pending. The wireless device transmits one or more transport blocks via the uplink radio resources.

Journal ArticleDOI
TL;DR: Simulations results demonstrate that the total transmitting power assigned for nodes is effectively reduced using the graph-cutting algorithm if all computing tasks can be solved by front-end WMNs, and otherwise, the method accepts more virtual networks with the improvement ratio of 77%, through the PON backhaul.
Abstract: As an open integrated environment deployed with wired and wireless infrastructures, the smart city heavily relies on the wireless-optical broadband access network. Smart home data are usually sent to neighbor optical network units (ONUs) through front-end wireless mesh networks (WMNs) and finally reach the optical line terminal (OLT) for decision making via the passive optical network (PON) backhaul. To reduce backhaul bandwidth saturated by this conventional approach, smart edge devices (EDs) should be deployed at sensors and ONUs so that collaborative edge computing can be performed in front-end WMNs. Moreover, the cooperation of EDs at different ONUs is also promising for computing tasks that cannot be handled within front-end WMNs due to the local bottleneck, leading to collaborative edge computing in the PON backhaul. In this paper, network virtualization is utilized to support the coordination of computing and network resources. We also describe the relationship between virtual networks and requirements of computing tasks for substrate resources. First, a graph-cutting algorithm is employed to embed as many virtual networks as possible onto the common network infrastructure in front-end WMNs, aiming at minimizing the total transmitting power. Next, we transform impossibly embedded virtual networks into new ones that must be processed through the PON backhaul where the wavelength consumption will be optimized. Simulations results demonstrate that 1) the total transmitting power assigned for nodes is effectively reduced using the graph-cutting algorithm if all computing tasks can be solved by front-end WMNs; 2) otherwise, our method accepts more virtual networks with the improvement ratio of 77%, through the PON backhaul. In addition, there is a good match between the algorithm result and the optimal number of consumed wavelengths per optical fiber cable.

Book ChapterDOI
24 Aug 2017
TL;DR: A hybrid simulation system based on PSO and SA for solving node placement problem in WMNs is implemented, called WMN-PSOSA, and results show that the LDIWM has better performance than CM.
Abstract: Wireless Mesh Networks (WMNs) have many advantages such as low cost and increased high speed wireless Internet connectivity, therefore WMNs are becoming an important networking infrastructure. In our previous work, we implemented a Particle Swarm Optimization (PSO) based simulation system for node placement in WMNs, called WMN-PSO. Also, we implemented a simulation system based on Simulated Annealing (SA) for solving node placement problem in WMNs, called WMN-SA. In this paper, we implement a hybrid simulation system based on PSO and SA, called WMN-PSOSA. We evaluate the performance of WMN-PSOSA by conducting computer simulations considering two replacement methods: Constriction Method (CM) and Linearly Decreasing Inertia Weight Method (LDIWM). Simulation results show that the LDIWM has better performance than CM.

Book ChapterDOI
08 Nov 2017
TL;DR: A hybrid simulation system based on PSO and SA for solving node placement problem in WMNs is implemented, called WMN-PSOSA and the simulation results show that the LDVM has better performance than RIWM for this scenario.
Abstract: Wireless Mesh Networks (WMNs) have many advantages such as low cost and increased high speed wireless Internet connectivity, therefore WMNs are becoming an important networking infrastructure. In our previous work, we implemented a Particle Swarm Optimization (PSO) based simulation system for node placement in WMNs, called WMN-PSO. Also, we implemented a simulation system based on Simulated Annealing (SA) for solving node placement problem in WMNs, called WMN-SA. In this paper, we implement a hybrid simulation system based on PSO and SA, called WMN-PSOSA. We evaluate the Performance of WMN-PSOSA by conducting computer simulations considering Random Inertia Weight Method (RIWM) and Linearly Decreasing Vmax Method (LDVM). The simulation results show that the LDVM has better performance than RIWM for this scenario.

Patent
20 Oct 2017
TL;DR: In this article, a location of detected motion in a space is determined based on the motion indicator values computed for the respective wireless communication devices, where each individual device represents a degree of motion detected by the individual wireless communication device based on a subset of the wireless signals transmitted or received by the device.
Abstract: In a general aspect, a location of detected motion in a space is determined. In some aspects, motion of an object in a space is detected based on wireless signals communicated through the space by a wireless communication system that includes multiple wireless communication devices. Each wireless signal is transmitted and received by a respective pair of the wireless communication devices. Motion indicator values are computed for the respective wireless communication devices. The motion indicator value for each individual wireless communication device represents a degree of motion detected by the individual wireless communication device based on a subset of the wireless signals transmitted or received by the individual wireless communication device. A location of the detected motion in the space is determined based on the motion indicator values.