Hybrid Wireless Research Articles

Green Wireless-Optical Broadband Access Network: Energy and Quality-of-Service Considerations

Growing energy demands in the information and communication technology (ICT) sector have been recognized as a major challenge worldwide. Researchers have been actively working to address this challenge, and the major focus centers around improving the energy efficiency of access networks, which are known for consuming about three-quarters of the total network power. Among various access networks, the hybrid wireless–optical broadband access network (WOBAN), which combines a passive optical network (PON) with broadband wireless technology, is highly regarded for its enormous capacity, cost efficiency, and ease of deployment. To develop a green WOBAN, it is important to focus on reducing its power consumption, and in this work, we present an efficient resource management technique for WOBAN that reduces the power consumption of the optical line terminal (OLT) and optical network unit (ONU) by introducing sleep modes for the OLT and ONU, based on the service class and traffic load. Moreover, it considers the quality-of-service requirement of each service class. Simulation results confirm that our proposed solution can save a significant amount of power in the WOBAN network without sacrificing the quality of service of end applications.

A study of a wire–wireless hybrid NoC architecture with an energy-proportional multicast scheme for energy efficiency

The efficiency of interconnect network-on-chip (NoC) design significantly affects the thermal and energy-consumption problems. The wireless interconnect NoC (WiNoC) design provides a promising NoC architecture for multicast in chip multiprocessor (CMP) as compared with fully wired NoC. However, wireless routers (WRs) cost a larger area size as well as larger energy consumption than wired routers do. In this paper, we study a 2-tier wire–wireless hybrid NoC (WHNoC) architecture in an (NS)-processing-element (PE) CMP where N PEs use wires to connect with a wireless-enabled hub forming a star topology subnet and S wireless-enabled hubs form a fully connected WiNoC, named sWHNoC. We first investigate the performance of slotted p-persistent carrier sense multiple access (CSMA) protocol on the fully connected WiNoC. To greatly reduce the energy consumption of WiNoC, we propose an energy-proportional multicast scheme (EMS) by using a power-gating (PG) technique to switch off non-member WRs during the period of multicast transmission. A comprehensive comparison of the star-ring WHNoC, the mesh-based WHNoC, and the proposed sWHNoC is studied. Detailed analyses of the energy consumption of sWHNoC are presented. The correctness of analysis is validated by using Orion 2.0 simulator. Based on our investigation, the sWHNoC with the slotted p-persistent CSMA and the EMS will significantly reduce the energy consumption as well as the transmission latency in CMP.

Improving Capacity and Delay in Directional Hybrid Wireless Networks with Range Extension

With the introduction of directional antennas into wireless networks, the beamwidth decreases and the range extends; thus both the mutual interference and the number of hops are reduced. This paper investigates the asymptotic throughput capacity and delay of hybrid wireless networks equipped with directional antennas. We first present a new scheme combining directional antennas and the same cell routing policy, and then derive the per-node throughput capacity and average delay in the proposed scheme, which mainly depend on the number of base stations m, the beamwidth of directional antennas θ, and the path loss exponent α. The discussions that how our directional hybrid wireless network explores the transmission range extension of directional antennas and how each parameter influences the throughput and delay are further elaborated. Moreover, our analytic results and experiments demonstrate that the substantial improvements on throughput capacity and the obvious reduction of average delay are achieved in hybrid wireless networks with directional antennas.

Interface and results visualization of WMN-GA simulation system: Evaluation for Exponential and Weibull distributions considering different transmission rates

In this paper, we present the interface and data visualization of a simulation system for Wireless Mesh Networks (WMNs), which is based on Genetic Algorithms (GAs). We call this system WMN-GA. As evaluation parameters, we consider Packet Delivery Ratio (PDR), throughput and delay metrics. For simulations, we used ns-3 simulator and Hybrid Wireless Mesh Protocol (HWMP). From simulation results, we found that PDR for Weibull distribution is higher than Exponential distribution. But, the throughput of Exponential distribution is higher than Weibull distribution. The delay of Exponential distribution is smaller than Weibull distribution.

Grid-Based Hole Recovery Mechanism Using Virtual Force in Hybrid WSNs

Sensor nodes are typically empowered with scarce energy resources and limited computing functionality in wireless sensor networks. However, nonuniform random deployment, depletion, and failure of sensor nodes will lead to generating coverage hole in the entire network. These hole problems to occur result in reducing the data transmission performance or in additional power consumption. Consequently, the hole problem is an important factor for the coverage completeness to prolong the network lifetime in wireless sensor networks. We have proposed a hole recovery mechanism based on the grid architecture in hybrid wireless sensor networks. Moreover, virtual force theory is utilized to determine which mobile node should enforce the recovery task. Based on the simulation results, the proposed mechanism is demonstrated to be able to prolong the network lifetime more than 10% with other proposed mechanisms. Otherwise, the proposed mechanism could maintain much more rounds for at least 80% network coverage ratio than other mechanisms.

A NOVEL APPROACH TO DEVELOP A RELIABLE ROUTING PROTOCOL FOR WIRELESS MESH NETWORKS USING IEEE 802.11S AND LTE NETWORKS: A SURVEY PAPER

Wireless mesh networks (WMNs) have emerged as a flexible and low-cost network infrastructure, where heterogeneous mesh routers managed by different users collaborate to extend the network coverage. IEEE 802.11s standard was defined as a wireless mesh network which extends IEEE 802.11 MAC standard. The protocols introduced by IEEE 802.11s draft are divided into Proactive, Reactive or Hybrid categories. This paper aims to improve the routing process of HWMP: Hybrid Wireless Mesh Protocol defined by IEEE 802.11s standard by interworking 802.11s network with LTE network. Also, it aims to make the protocol more reliable by providing the QoS to the network. The pre-defined path selection metric is also enhanced to get more accurate information about the path quality. The proposed contribution aims to provide better performance to the 802.11s-LTE network and enhances the network with delay-aware routing. A simulation study will be conducted under NS-3 to observe the impact of the proposed protocol in offloading mechanism. Finally, the performance of overall contribution is compared to HWMP.

Remote Monitoring System for Intelligent Irrigation in Hybrid Wireless Sensor Networks

Aiming at make effective use of variables control, wireless sensor and monitoring, embedded and wireless communications technology in industrial fields to make intelligent precision irrigation in crops the article designed a closed-loop remote monitoring system of distributed precision irrigation by using Citect configuration software, hybrid sensor networks including wireless sensor networks (WSN) and wireless underground sensor networks (WUSN), ARM9 microprocessor and General Packet Radio Service (GPRS) module. The system consists of monitor computer, irrigation monitor controller, wireless sensor networks, GPRS wireless communication module and valves, in which the wireless sensor networks adopt hybrid topology above and below ground, the controllers utilizes embedded technology to control irrigation water yield that applied to each specific unit according to soil water content. The Citect configuration is used to manage data and HMI by the remote monitoring center, which can conduct a more high-level monitoring through web publishing. The results showed that the data sampling interval is set for 30 min, 4 groups WSN nodes were chosen, which the system could get soil temperature, humidity and soil water content in 5cm and 35cm depth, intelligent irrigation can save water about 25% compare with normal irrigation. This system realizes online automatic monitoring of crop precise irrigation, a hybrid wireless sensor network model for both aboveground and underground is creatively established, which is also the foundation for further study.

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

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 joint optimization of data ferry trajectories and communication powers of ground sensors for long-term environmental monitoring

Recently, various hybrid wireless sensor networks which consist of several robotic vehicles and a number of static ground sensors have been investigated. In this kind of system, the main role of the mobile nodes is to deliver the messages produced by the sensor nodes, and naturally their trajectory control becomes a significant issue closely related to the performance of the entire system. Previously, several communication power control strategies such as topology control are investigated to improve energy-efficiency of wireless sensor networks. However, to the best of our knowledge, no communication power control strategy has been investigated in the context of the hybrid wireless sensor networks. This paper introduces a new strategy to utilize the communication power control in multiple data ferry assisted wireless sensor network for long-term environmental monitoring such that the lifetime of the sensor network is maximized. We formally define the problem of our interest and show it is NP-hard. We further prove there exists no approximation algorithm for the problem which can produce a feasible solution for every possible problem instance even though there is a feasible solution. Then, we propose heuristic algorithms along with rigorous theoretical performance analysis for both the single data ferry case and the multiple data ferry case under certain condition.

A reliable QoS-aware routing scheme for neighbor area network in smart grid

A reliable bi-directional communication network is one of the key factors in smart grid (SG) to meet application requirements and improve energy efficiency. As a promising communication infrastructure, wireless mesh network (WMN) can provide high speed and cost-effect communication for SG. However, challenges remain to maintain high reliability and quality of service (QoS) when applying WMNs to SG. In this paper, we first propose a hybrid wireless mesh protocol (HWMP) based neighbor area network (NAN) QoS-aware routing scheme, named HWMP-NQ, to meet the QoS requirements by applying an integrated routing metric to route decision with effective link condition probing and queue optimization. To further improve the reliability of the proposed HWMP-NQ, we present a multi-gateway backup routing scheme along with a routing reliability correction factor to mitigate the impact of routing oscillations. Finally, we evaluate the performances of the proposed schemes on NS3 simulator. Extensive simulations demonstrate that HWMP-NQ can distinguish different applications and satisfy the QoS requirements respectively, and also improve the average packet delivery ratio and throughput with a reduced routing overhead, even with a high failure rate of mesh nodes.

Network Coding-Aware routing protocol in Wireless Mesh Networks

Network coding mechanisms, such as COPE, can improve network throughput effectively in Wireless Mesh Networks (WMN). While the Hybrid Wireless Mesh Protocol (HWMP) is suitable for WMN, its extension with COPE does not provide any added benefits; specifically, HWMP cannot establish paths with more coding opportunities. As a result, the advantages of network coding cannot be exploited sufficiently. This paper proposes improvements upon HWMP with a new, network Coding-Aware routing protocol (CAHWMP) for WMN. In the CAHWMP protocol, we propose a coding criterion based on data streams to devise an algorithm for actively detecting coding opportunities during path discovery. CAHWMP subsequently establishes paths using the coding-aware routing metric, which can balance channel resource consumption and the gain due to sharing resources introduced by network coding. Simulation results show that CAHWMP can establish paths with more coding opportunities; as a result, it improves network performance such as network throughput.

A P2P-Based Market-Guided Distributed Routing Mechanism for High-Throughput Hybrid Wireless Networks

In a hybrid wireless network that combines a mobile ad-hoc network and an infrastructure network, efficient and reliable data routing is important for high throughput. Existing routing schemes that simply combine ad-hoc and infrastructure routings inherit the drawbacks of ad-hoc routing including congestion and high overhead for route discovery and maintenance. Although current reputation systems help increase routing reliability, they rely on local information exchanges between nodes to evaluate node reputations, so they are not sufficiently effective and efficient. A challenge here is if we can coordinately develop an efficient routing algorithm and effective cooperation incentives for reliable routing. To handle this challenge, this paper presents a peer-to-peer (P2P)-based Market-guided Distributed Routing mechanism (MDR). MDR takes advantage of widespread base stations to coordinately realize highly efficient data routing, and effective reputation management and trading market management for reliable data routing. The packets from a source node are distributively transmitted to base stations directly or indirectly, and then they are transmitted to the destination. The base stations form a P2P structure for reputation collection and querying to avoid local information exchanges, and for managing the service transactions between nodes in the trading market. By leveraging the single-relay transmission feature, base stations can monitor the actual transmitted packets of relay nodes to more accurately and efficiently evaluate their reputations and execute trading market management, as well as detect falsely reported reputation information. We further propose market-based policies to strengthen cooperation incentives. Simulation results show that MDR outperforms the traditional hybrid routing schemes and reputation systems in achieving high throughput.

IJARCCE - Computer and Communication Engineering

2 Abstract: With the increasing level of wireless communication in today's environment, people often required QOS for sharing their data between the nodes. For affording QOS to the user, many researchers proposed a very few methods to provide QoS guaranteed routing for hybrid networks, they strive to improve the network capacity and reliability but they evade constrain in QOS. For this problem our main objective of this paper is to improve the QOS and efficiency of routing approach with constrains over hybrid wireless data streaming using QOS_DARP protocol and MAR. This aims to develop the QOS based reliable architecture against the hybrid wireless routing issues. The system also aims at providing both proactive and reactive solutions for effective routing. The goal of this paper is to providing efficient dynamic routing management to deal the challenges of data transmission and data streaming in hybrid mobile environments.

A Parallel Transmission MAC Protocol in Hybrid VLC-RF Network

This paper proposed a parallel transmission MAC protocol for an indoor hybrid wireless network consists of visible light communication (VLC) and radio frequency (RF). Combining the CSMA/CA algorithm and the concept of parallel transmission, the protocol can solve the multiple access problems for nodes in the hybrid network. This paper uses a two-dimensional Markov chain model to construct the channel reservation model and also gives the throughput theory analyzing algorithm of parallel channel. According the numerical results, the proposed mechanism improves the throughput and efficiency of the hybrid network. 

Compressed Sensing Based on the Characteristic Correlation of ECG in Hybrid Wireless Sensor Network

Hybrid wireless sensor network made up of wireless body area networks (WBANs) and cellular network provides support for telemedicine. In order to facilitate early diagnosis and treatment, WBANs collect and transmit crucial biomedical data to provide a continuous health monitoring by using various biomedical wireless sensors attached on or implanted in the human body. And then, collected signals are sent to a remote data center via cellular network. One of the features of WBAN is that its power consumption and sampling rate should be restricted to a minimum. Compressed sensing (CS) is an emerging signal acquisition/compression methodology which offers a prominent alternative to traditional signal acquisition. It has been proved that the successful recovery rate of multiple measurement vectors (MMV) model is higher than the single measurement vector (SMV) case. In this paper, we propose a simple algorithm of transforming the SMV model into MMV model based on the correlation of electrocardiogram (ECG), such that the MMV model can be used for general ECG signals rather than only several special signals. Experimental results show that its recovery quality is better than some existing CS-based ECG compression algorithms and sufficient for practical use.

Distributed Control of Robotized Nodes in a Hybrid Wireless Sensor Network

Over the past decade, wireless sensor networks (WSN) have provoked the interest of specialists from different areas by imposing a large number of theoretical and practical challenges related to their implementation. The inclusion of mobile robots into the WSN structure is a recently observed trend. Robots can provide flexibility with respect to the installation of the network sensors and allow active information gathering. If necessary, robots can perform desired or based on real-time observations interaction with the environment. The present paper describes a work-in-progress aiming to build laboratory prototype of a robotized hybrid WSN. The latter can be used for various distributed control experiments over the network structure and its efficiency and will help to propose solutions that would unlock the full potential of hybrid wireless sensor networks with integrated mobile nodes. The goal is to transform the network into an adaptive sensor system with intelligent behavior. Robotized wireless sensor nodes have been designed and configured and their functionality has been experimentally tested on path planning and multivehicle collaborative control problems. The on-board wireless communications of the robotized nodes allow them to easily communicate with other nodes facilitating the development of collaborative controllers. The basic framework for multivehicle communications between two robotized WSN nodes has been used in the carried on real-time experiments.

High-performance adaptive hybrid wireless NoC architecture based on improved congestion measurement

In view of the high energy consumption and latency problem due to multi-hop wired links between distant cores of traditional large-scale Network-on-Chip, a virtual torus-based adaptive wireless NoC architecture has been proposed when analyzing the existing several wireless NoC architectures. By not only adopting the automatic detection and dynamic bandwidth allocation mechanism to hot wireless link based on the sensing parameter for improved congestion measurement, but also designing the Dynamic Allocation Control Circuit Module (DACCM) for transmitter, the intra-chip topology and link bandwidth could be adaptively adjusted as different traffic patterns. Experimental results show that the proposed architecture has more significant latency improvement and energy saving under different traffic patterns or real application such benchmark as FFT.

Energy Optimized Routing Algorithm for Hybrid Wireless Mesh Networks in Coal Mine

Mesh clients in hybrid wireless mesh networks can participate in networking and routing. When the backbone transmission network is broken, the mesh client can route and forward the data, which will eliminate the absolute dependence on the backbone network of traditional infrastructure wireless mesh networks in mine emergency rescue. However, the energy of mesh clients is limited. Based on the comprehensive consideration of the efficiency and balance of energy consumption of mesh clients for data transmission, a new energy cost criterion is designed. Energy optimized and fault recovered routing algorithm is proposed on account of different network states. At last, the simulation analysis on the performance of routing algorithm is conducted and compared with typical routing algorithms. Simulation results show that the algorithm has effectively extended the network lifetime and achieved optimized combination of energy efficiency and energy balance. When mesh routers in the backbone network are failed, this algorithm can rapidly rebuild the route and shows strong capacity of routing recovery.

A Distributed Motion Algorithm for Mobile Sensor in Hybrid Wireless Sensor Networks

Constructing a hybrid wireless sensor networks comprising a mix of static sensors and mobile sensors can achieve a balance between improving coverage and reducing the cost of the network. In order to achieve high network coverage, mobile sensor move from a small to a big size of coverage hole in the hybrid wireless sensor networks. Due to the energy of the mobile sensor is limited, how to reduce the moving distance of the mobile sensor and reduce the energy consumption in the process of moving is a very important issue. This paper proposes a distributed minimum cost matching algorithm (DMMA) to redeploy mobile sensor, which can make the level of network coverage to meet the requirement of the environment, while effectively reducing the number of sensors. In our method, static sensors detect coverage hole by Voronoi diagrams, coverage holing sensors and mobile sensors by using DMMA to excellently heal the large coverage holes. Simulation results show that our method can effectively improve the coverage rate of the WSNs, while save the energy of mobile sensors.

Cross-Layer Aware Routing Protocol for Hybrid Wireless Mesh Networks

Route selection in hybrid wireless mesh networks (WMNs) that contain mobile mesh clients with constrained energy is a critical research challenge. Existing routing protocols take the advantages of backbone mesh routing protocols but lack of consideration of the characteristics of clients. Most of these protocols capture interference and traffic load, but lack of considering the effect of mobility and energy constraints of clients. In this paper, we propose a Cross-Layer Aware (CLA) routing protocol, which is based on comprehensively considering characteristics of mesh routers and mesh clients for gateway traffic in hybrid WMNs. In CLA, we propose a new routing metric jointly considering four parameters in a cross-layer design: the MAC layer channel condition, the routing layer path length, the application layer mobility and constrained energy of clients. These parameters can capture the interference, traffic load, stability and energy efficiency, so as to select an optimum route. In addition, we develop a constrained forwarding mechanism to reduce flooding overhead by limiting the forwarding number of clients in CLA, which can reduce the energy consumption wasted in overhead. Simulation results show that the proposed CLA protocol can effectively improve the whole network performance. Index Terms—Hybrid WMNs, routing protocol, cross-layer aware, constrained forwarding