Showing papers on "Wireless mesh network published in 2015"

Cloud-based Wireless Network: Virtualized, Reconfigurable, Smart Wireless Network to Enable 5G Technologies

Abstract: In recent years, information communication and computation technologies are deeply converging, and various wireless access technologies have been successful in deployment. It can be predicted that the upcoming fifth generation mobile communication technology (5G) can no longer be defined by a single business model or a typical technical characteristic. 5G is a multi-service and multi-technology integrated network, meeting the future needs of a wide range of big data and the rapid development of numerous businesses, and enhancing the user experience by providing smart and customized services. In this paper, we propose a cloud-based wireless network architecture with four components, i.e., mobile cloud, cloud-based radio access network (Cloud RAN), reconfigurable network and big data centre, which is capable of providing a virtualized, reconfigurable, smart wireless network.

Resilient Routing in Communication Networks

Abstract: Introduction Principles of Communication Networks Resilience Resilience of Future Internet Communications Resilience of Wireless Mesh Networks Disruption-tolerant Routing in Vehicular Ad-hoc Networks

A smart communication architecture for ambient assisted living

Abstract: Intelligent systems and communication technologies have experienced huge advances in the last few years. AAL can benefit from mixing both research fields. This article presents an intelligent communication architecture for AAL. It uses artificial intelligence to process the information gathered from several types of communication (e.g., wireless sensor networks, wireless ad hoc networks, wireless mesh networks) over any type of communication technologies (e.g., deviceto- device, machine-to-machine, sensor-actuator), know what is happening in the network, and detect if elderly people need assistance. The article shows the main intelligent algorithms included in the AAL system and the developed software application. Several real measurements validate the operation of our proposal.

BLEmesh: A Wireless Mesh Network Protocol for Bluetooth Low Energy Devices

Abstract: Bluetooth Low Energy is a highly adopted and anticipated communication solution for the Internet of Things. However, the restriction of data communication topology to point-to-point, limited range of communications, and the lack of IP support make Bluetooth Low Energy less attractive for Internet of Things applications. In Dec. 2014, the Bluetooth SIG standardized the Internet Protocol Support Profile to support the exchanging of IPv6 packets between devices over Bluetooth Low Energy. Still, a mesh networking protocol for multi-hop support is needed for it to overcome the limitations due to short range and restricted topology. This paper introduces Blemish, a wireless mesh network protocol which utilizes the broadcasting capability of wireless transmissions. We identify the available data payload using Bluetooth Low Energy Generic Access Profile -- Non-connectable Advertisement Data for different number of nodes and packets to send in a batch. Then we compare BLEmesh with conventional routing method and flood routing method. Our preliminary evaluation results show that the number of transmissions by BLEmesh is significantly smaller compared to its competitors for some selected network configurations, reducing the aggregated energy consumption within the mesh network.

Software-defined wireless mesh networks: architecture and traffic orchestration

Abstract: SDN has been envisioned as the next generation network paradigm by decoupling control plane and data plane, such that network management and optimization can be conducted in a centralized manner using global network information. In this article, we study how to apply SDN concept to a wireless mesh network that has been widely adopted by various applications. We first propose a novel architecture of SD-WMNs, and identify several critical challenges. Since wireless spectrum is a scarce resource that is shared by both data and control traffic in SD-WMNs, we propose three spectrum allocation and scheduling algorithms, namely FB-NS, NFB-NS, and NFB-S that orchestrate both control and data traffic. Finally, performance is evaluated via extensive simulations.

Bluetooth low energy automation mesh network

Abstract: A system for facilitating communications in a mesh network is provided. One or more devices of the mesh network may participate as routing nodes to provide range extension for any other devices in the mesh network that would otherwise be out of range from one another. In one or more implementations, Bluetooth Low Energy (BLE) may be used as the physical transport of the mesh network.

Data forwarding in hybrid mesh networks

Abstract: A system and method are disclosed for forwarding data in hybrid wireless mesh networks. The method includes configuring a number of mesh network nodes as potential relay nodes (PRNs) in an overlay network associated with a hybrid wireless mesh network, streaming data packets from a source node to a destination node using a native data forwarding algorithm of the hybrid wireless mesh network, dynamically identifying relay nodes (RNs) among PRNs in the overlay network, creating secondary paths for sending data packets towards selected RNs in the overlay network, and relaying data packets from RNs to the destination node using the overlay network.

A Process Algebra for Wireless Mesh Networks

Abstract: We propose a process algebra for wireless mesh networks that combines novel treatments of local broadcast, conditional unicast and data structures. In this framework, we model the Ad-hoc On-Demand Distance Vector (AODV) routing protocol and (dis)prove crucial properties such as loop freedom and packet delivery.

A week in the life of three large Wireless Community Networks

Abstract: Wireless Community Networks (WCNs) are created and managed by a local community with the goal of sharing Internet connection and offering local services. This paper analyses the data collected on three large WCNs, ranging from 131 to 226 nodes, and used daily by thousands of people. We first analyse the topologies to get insights in the fundamental properties, next we concentrate on two crucial aspects: (i) the routing layer and (ii) metrics on the centrality of nodes and the network robustness. All the networks use the Optimized Link State Routing (OLSR) protocol extended with the Expected Transmission Count (ETX) metric. We analyse the quality of the routes and two different techniques to select the Multi-Point Relay (MPR) nodes. The centrality and robustness analysis shows that, in spite of being fully decentralized networks, an adversary that can control a small fraction of carefully chosen nodes can intercept up to 90% of the traffic. The collected data-sets are available as Open Data, so that they can be easily accessed by any interested researcher, and new studies on different topics can be performed. In fact, WCN are just an example of large wireless mesh networks, so our methodology can be applied to any other large mesh network, including commercial ISP networks.

Dominating Set and Network Coding-Based Routing in Wireless Mesh Networks

Abstract: Wireless mesh networks are widely applied in many fields such as industrial controlling, environmental monitoring, and military operations. Network coding is promising technology that can improve the performance of wireless mesh networks. In particular, network coding is suitable for wireless mesh networks as the fixed backbone of wireless mesh is usually unlimited energy. However, coding collision is a severe problem affecting network performance. To avoid this, routing should be effectively designed with an optimum combination of coding opportunity and coding validity. In this paper, we propose a Connected Dominating Set (CDS)-based and Flow-oriented Coding-aware Routing (CFCR) mechanism to actively increase potential coding opportunities. Our work provides two major contributions. First, it effectively deals with the coding collision problem of flows by introducing the information conformation process, which effectively decreases the failure rate of decoding. Secondly, our routing process considers the benefit of CDS and flow coding simultaneously. Through formalized analysis of the routing parameters, CFCR can choose optimized routing with reliable transmission and small cost. Our evaluation shows CFCR has a lower packet loss ratio and higher throughput than existing methods, such as Adaptive Control of Packet Overhead in XOR Network Coding (ACPO), or Distributed Coding-Aware Routing (DCAR).

Wireless Sensor Networks—Node Localization for Various Industry Problems

Abstract: Fast and effective monitoring following airborne releases of toxic substances is critical to mitigate risks to threatened population areas. Electrically powered systems in industrial settings require monitoring of emitted electromagnetic fields to determine the status of the equipment and ensure their safe operation. In situations such as these, wireless sensor nodes (WSNs) at fixed predetermined locations provide monitoring to ensure safety. A challenging algorithmic problem is determining the locations to place these WSNs while meeting several criteria: 1) to provide complete coverage of the domain; 2) to create a topology with problem-dependent node densities; and 3) to minimize the number of WSNs. This paper presents a novel approach, advancing front mesh generation with constrained Delaunay triangulation and smoothing (AFECETS) that addresses these criteria. A unique aspect of AFECETS is the ability to determine WSN locations for areas of high interest (hospitals, schools, and high population density areas) that require higher density of nodes for monitoring environmental conditions, a feature that is difficult to find in other research work. The AFECETS algorithm was tested on several arbitrary shaped domains. AFECETS simulation results show that the algorithm provides significant reduction in the number of nodes, in some cases over 40%, compared with an advancing front mesh generation algorithm; maintains and improves optimal spacing between nodes; and produces simulation run times suitable for real-time applications.

On resilience of Wireless Mesh routing protocol against DoS attacks in IoT-based ambient assisted living applications

Abstract: The future of ambient assisted living (AAL) especially eHealthcare almost depends on the smart objects that are part of the Internet of things (IoT). In our AAL scenario, these objects collect and transfer real-time information about the patients to the hospital server with the help of Wireless Mesh Network (WMN). Due to the multi-hop nature of mesh networks, it is possible for an adversary to reroute the network traffic via many denial of service (DoS) attacks, and hence affect the correct functionality of the mesh routing protocol. In this paper, based on a comparative study, we choose the most suitable secure mesh routing protocol for IoT-based AAL applications. Then, we analyze the resilience of this protocol against DoS attacks. Focusing on the hello flooding attack, the protocol is simulated and analyzed in terms of data packet delivery ratio, delay, and throughput. Simulation results show that the chosen protocol is totally resilient against DoS attack and can be one of the best candidates for secure routing in IoT-based AAL applications.

Systems and methods for determining locations of wireless sensor nodes in a tree network architecture having mesh-based features

Abstract: Systems and methods for determining locations of wireless sensor nodes in a tree network architecture having mesh-based features are disclosed herein. In one embodiment, a system includes a hub having one or more processing units and RF circuitry for transmitting and receiving communications with sensor nodes to enable bi-directional communications. The one or more processing units of the hub execute instructions to configure the system with a tree architecture for communications between the hub and the sensor nodes, to detect a change in range or position of at least one sensor node, and to configure the system temporarily with a mesh-based architecture for determining location information for the sensor nodes based on detecting a change in range or position.

Application of reinforcement learning for security enhancement in cognitive radio networks

Abstract: Cognitive radio leverages on reinforcement learning (RL) to enhance network security.There is lack of reviews on the application of RL to based security schemes.We cover the challenges, characteristics, performance enhancements, and others. Cognitive radio network (CRN) enables unlicensed users (or secondary users, SUs) to sense for and opportunistically operate in underutilized licensed channels, which are owned by the licensed users (or primary users, PUs). Cognitive radio network (CRN) has been regarded as the next-generation wireless network centered on the application of artificial intelligence, which helps the SUs to learn about, as well as to adaptively and dynamically reconfigure its operating parameters, including the sensing and transmission channels, for network performance enhancement. This motivates the use of artificial intelligence to enhance security schemes for CRNs. Provisioning security in CRNs is challenging since existing techniques, such as entity authentication, are not feasible in the dynamic environment that CRN presents since they require pre-registration. In addition these techniques cannot prevent an authenticated node from acting maliciously. In this article, we advocate the use of reinforcement learning (RL) to achieve optimal or near-optimal solutions for security enhancement through the detection of various malicious nodes and their attacks in CRNs. RL, which is an artificial intelligence technique, has the ability to learn new attacks and to detect previously learned ones. RL has been perceived as a promising approach to enhance the overall security aspect of CRNs. RL, which has been applied to address the dynamic aspect of security schemes in other wireless networks, such as wireless sensor networks and wireless mesh networks can be leveraged to design security schemes in CRNs. We believe that these RL solutions will complement and enhance existing security solutions applied to CRN To the best of our knowledge, this is the first survey article that focuses on the use of RL-based techniques for security enhancement in CRNs.

Performance measurement and analysis of long range Wi-Fi network for over-the-sea communication

Abstract: Currently, Indian fishermen use handheld radios or satellite phones for offshore communication. While the former is based on broadcast communication with its range limited by Line-of-Sight, the latter is expensive. Therefore, lack of connectivity-at-sea is a huge problem for many Indian fishermen. Hence, this work prescribes a hierarchical point-to-multi-point backhaul network using long range (LR) Wi-Fi technology. It is a multi-hop network consisting of base stations and clusters of boats. Each boat-cluster forms a wireless mesh access network. A field-trial was conducted at sea to measure and analyze the coverage and connectivity of the P2mP LR Wi-Fi backhaul network, using commercially available 5 GHz base stations, antennas and customer premises equipment (CPE). Several parameters such as transmission power level, mechanical antenna tilt at the base station and channel bandwidth were fine-tuned to maximize the range. This paper discusses the observations and the results obtained.

A mesh network for mobile devices using Bluetooth low energy

Abstract: An important issue of research in wireless networks is to dynamically organize the nodes into a wireless network and route the data from the source to the destination. In most of the existing routing techniques in wireless networks assumes that all nodes are static and do not change their positions till the end of the network. Although it is not a realistic assumption, it eliminates the effects of mobility of nodes in routing the data. In this paper, we present a mesh network for mobile devices using Bluetooth Low Energy (BLE). We propose a weight balancing technique to optimize the communication for routing the data using BLE mesh network. We develop a prototype of BLE mesh network using the Android operating system.

Partially overlapped channel assignment for multi-channel multi-radio wireless mesh networks

Abstract: Partially overlapped channels (POCs)-based design has been identified recently as an emerging technology to further eliminate interference and improve network capacity. However, there are only few studies of channel assignment algorithms for POCs. In this paper, we research on utilizing POCs to improve network capacity and propose a traffic-irrelevant channel assignment algorithm, which assigns channels for all links in the network while minimizing total network interference. Theoretical calculation approach is utilized to obtain the direct relationship between interference ranges and channel separations, which can be easily applied to mesh networks with various configurations without modification. As traffic between the Internet and clients is considered to be dominant, distance from the gateway, number of neighbors, and interference are used to determine the channel assignment order of links. Simulation results reveal that network throughput and end-to-end delay performance can be dramatically improved by fully exploiting POCs as well as orthogonal channels.

A centrality-based topology control protocol for wireless mesh networks

Abstract: Nodes in wireless multi-hop networks establish links with their neighbors, which are used for data transmission. In general, in this kind of networks every node has the possibility of acting as a router, forwarding the received packets when they are not the final destination of the carried data. Due to the routing protocol procedures, when the network is quite dense the overload added by the routing management messages can be very high. To reduce the effects of this overload a topology control mechanism can be used, which can be implemented using different techniques. One of these techniques consists of enabling or disabling the routing functionality in every node. Many advantages result from selecting just a subset of nodes for routing tasks: reduction of collisions, protocol overhead, interference and energy consumption, better network organization and scalability. In this paper, a new protocol for topology control in wireless mesh networks is proposed. The protocol is based on the centrality metrics developed by social network analysts. Our target network is a wireless mesh network created by user hand-held devices. For this kind of networks, we aim to construct a connected dominating set that includes the most central nodes. The resulting performance using the three most common centrality measures (degree, closeness and betweenness) is evaluated. As we are working with dynamic and decentralized networks, a distributed implementation is also proposed and evaluated. Some simulations have been carried out to analyze the benefits of the proposed mechanism when reactive or proactive routing protocols are used. The results confirm that the use of the topology control contributes to a better network performance.

High-Throughput Reliable Multicast in Multi-Hop Wireless Mesh Networks

Abstract: This paper presents a cross-layer approach for enabling high-throughput reliable multicast in multi-hop wireless mesh networks. The building block of our approach is a multicast routing metric, called the expected multicast transmission count (EMTX). EMTX is designed to capture the combined effects of MAC-layer retransmission-based reliability, wireless broadcast advantage, and link quality awareness. The EMTX of single-hop transmission of a multicast packet from a sender is the expected number of multicast transmissions (including retransmissions) required for its next-hop recipients to receive the packet successfully. We formulate the EMTX-based multicast problem with the objective of minimizing the sum of EMTX over all forwarding nodes in the multicast tree, aiming to reduce network bandwidth consumption while ensure high end-to-end packet delivery ratio for the multicast traffic. We provide rigorous mathematical formulations and methods to find near-optimal solutions of the problem computationally efficiently. We present centralized and distributed algorithms, and demonstrate their effectiveness in tackling the EMTX-based multicast problem with a combination of theoretical and numerical results. Simulation experiments show that, in comparison with two baseline approaches, EMTX-based multicast routing reduces the number of hop-by-hop transmissions per packet by up to 40 percent and yet improves the multicast throughput by up to 24 percent.

Improving Channel Assignment in Multi-radio Wireless Mesh Networks with Learning Automata

Abstract: Wireless mesh networks (WMNs) consist of static nodes that usually have one or more radios or media. Optimal channel assignment (CA) for nodes is a challenging problem in WMNs. CA aims to minimize interference in the overall network and thus increase the total capacity of the network. This paper proposes a new method for solving the CA problem that comparatively performs more efficient than existing methods. The link layer in the TCP/IP model is a descriptive realm of networking protocols that operates on the local network link in routers discovery and neighboring hosts. TCP/IP employs the link-layer protocol (LLP) that is included among the hybrid states in CA methods, and learning automata are used to complete the algorithm with an intelligent method for suitable CA. We call this algorithm LLLA, which are short for LLP and learning automata. Our simulation results show that LLLA performs more efficient than ad hoc on-demand distance vector (AODV) types with respect to parameters such as packet drop, end-to-end delay, average goodput, jitter in special applications, and energy usage.

Sequence Numbers Do Not Guarantee Loop Freedom; AODV Can Yield Routing Loops

Abstract: In the area of mobile ad-hoc networks and wireless mesh networks, sequence numbers are often used in routing protocols to avoid routing loops. It is commonly stated in protocol specifications that sequence numbers are sufficient to guarantee loop freedom if they are monotonically increased over time. A classical example for the use of sequence numbers is the popular Ad hoc On-Demand Distance Vector (AODV) routing protocol. The loop freedom of AODV is not only a common belief, it has been claimed in the abstract of its RFC and at least two proofs have been proposed. AODV-based protocols such as AODVv2 (DYMO) and HWMP also claim loop freedom due to the same use of sequence numbers. In this paper we show that AODV is not a priori loop free; by this we counter the proposed proofs in the literature. In fact, loop freedom hinges on non-evident assumptions to be made when resolving ambiguities occurring in the RFC. Thus, monotonically increasing sequence numbers, by themselves, do not guarantee loop freedom.

Mesh network addressing

Abstract: In embodiments of mesh network addressing, a border router receives an address prefix and associated configuration information from an external network. The received address prefix and the configuration information enable the border router to create a provisioning domain that includes the received address prefix and the configuration information, as well as a unique identifier. The border router forwards the created provisioning domain to a leader device in the mesh network that stores the provisioning domain and propagates the provisioning domain to routers to enable packet addressing and routing in the mesh network.

Implementation and Experimental Results of a WMN Testbed in Indoor Environment Considering LoS Scenario

Abstract: Wireless Mesh Networks (WMNs) are attracting a lot of attention from wireless network researchers, because of their potential use in several fields such as collaborative computing and communications. Considering mobility of the terminals, routing is a key process for operation of WMNs. In this paper, we present the implementation of a test bed for WMNs. We analyze the performance of Optimized Link State Routing (OLSR) protocol in an indoor scenario. For evaluation we considered throughput, Packet Delivery Ratio (PDR), hop count, delay and jitter metrics. The experimental results show that the nodes in the test bed were communicating smoothly and we got height values of throughput and PDR and low values of delay and jitter.

Joint link rate allocation, routing and channel assignment in multi-rate multi-channel wireless networks

Abstract: In this paper we address the issue of joint routing, channel assignment, scheduling and link rate allocation in multi-rate multi-channel wireless networks with the goal of increasing network capacity. Many wireless standards support a variety of modulation and coding schemes, which allow devices to choose from several transmission rates. Typically, the highest possible rate is used for transmission, but the potential for increased spatial reuse and capacity exists when using lower rates due to higher interference tolerance. This problem of selecting link rates is further complicated in a multi-channel network. Channel assignment affects the sets of interfering links, and as such also influences the optimal choice of link rates. And there is also an interdependency between routing and both rate and channel assignment. In this work we analyze the joint problem and, due to its hardness, propose a fast heuristic algorithm (JMR) to solve it. We evaluate this algorithm through numerical experiments in a wide variety of configurations, showing that potential for improved capacity via link rate allocation depends on a variety of factors which relate to the capability and need of exploiting spatial reuse, and which include the transmission power, the number of channels and the network architecture and topology. In this work we also propose an architecture for wireless mesh networks with increased capacity and under which optimized rate allocation is shown to notably increase performance. Finally, we evaluate the solutions found by JMR under the ns-3 simulator using the 802.11a protocol stack, where it is shown that physical and MAC layer limitations reduce the performance gain of JMR.

Lighting-Enabled Smart City Applications and Ecosystems based on the IoT

Abstract: The Internet of Things is poised to transform lighting from a simple illumination source, which is most often taken for granted, into a smart and data-rich infrastructure for the cities. To this end, we propose the Lighting-Enabled Smart City APplications and Ecosystems (LENSCAPEs) framework. LENSCAPEs involve i) city-wide wireless Outdoor Lighting Networks (OLNs), to connect the streetlights using either mesh, or cellular networks, ii) sensors, to collect heterogeneous spatio-temporal data about the city, iii) controllers, to actuate physical processes, such as lighting, and iv) other cloud-based applications, to process the data that is collected and disseminated by the city-wide wireless sensor network. Mesh-based networking technologies for OLNs, such as IEEE 802.15.4g, are evaluated by simulating network capacity and comparing with cellular technologies. Light-on-Demand (LoD), an adaptive energy-efficient lighting system based on wireless mesh networks, is presented as the primary application of small-scale OLNs. We also present a case study on a real-world deployment of LoD, which resulted in 92% energy savings over conventional luminaires.