Low-rate Wireless Personal Area Networks Research Articles

A Wearable Wireless Sensor Network for Indoor Smart Environment Monitoring in Safety Applications.

This paper presents the implementation of a wearable wireless sensor network aimed at monitoring harmful gases in industrial environments. The proposed solution is based on a customized wearable sensor node using a low-power low-rate wireless personal area network (LR-WPAN) communications protocol, which as a first approach measures CO2 concentration, and employs different low power strategies for appropriate energy handling which is essential to achieving long battery life. These wearables nodes are connected to a deployed static network and a web-based application allows data storage, remote control and monitoring of the complete network. Therefore, a complete and versatile remote web application with a locally implemented decision-making system is accomplished, which allows early detection of hazardous situations for exposed workers.

An Ultra-Low Power CMOS LNA for WPAN Applications

In this letter, an integrated CMOS LNA has been designed for low-rate wireless personal area network applications in $0.18~\mu $ m technology, by employing various low-power techniques. In order to achieve ultra-low power consumption and small chip size, an inductorless LNA with triple cross-coupling technique working in the subthreshold region has been designed. These techniques provide a high gain, low noise figure (NF) and ultra-low power consumption. The trade-off of the circuit has been discussed. Measured results have been shown: an average 17 dB gain, 4.2 dB NF while dissipating only 0.2 mW (LNA core) power from 1 V DC supply voltage and occupies only 0.27 mm2 area. These are considered to be state-of-the-art for 400 MHz~1 GHz CMOS WPAN applications.

Performance Evaluation of Different Backoff Algorithms in IEEE 802.15.4 using Double Sensing

<p>The IEEE 802.15.4 is the standard for Low Rate Wireless Personal Area network (LR-WPAN). It is widely used in many application areas. The standard uses Slotted CSMA/CA mechanism in its contention access period (CAP) for the beacon enabled mode. The protocol has two modes - single sensing (SS) and double sensing (DS). The protocol also adopts a binary exponential backoff (BEB) algorithm. In this paper, we explore the saturation throughput, delay and energy consumption of this standard with double sensing (DS) using the existing BEB algorithm. We also investigate three other backoff schemes - exponential increase exponential decrease (EIED), exponential increase linear decrease (EILD) and exponential increase multiplicative decrease (EIMD). From simulation results, it is found that the EIED, EILD, EIMD perform better than the BEB for higher loads. It shows that the EIED, EILD, EIMD have better throughput and lower delay than the BEB. The EIED outperforms the other schemes in terms of throughput, delay and energy for the higher loads.</p>

Performance Assessment and Feasibility Analysis of IEEE 802.15.4m Wireless Sensor Networks in TV Grayspaces

In this article, we assess the viability of underlay sensor networks in frequencies used by an incumbent digital TV broadcasting system, that is, in the so-called TV grayspaces (TVGS). Grayspace operations are particularly interesting when other unlicensed bands are overcrowded, for example, due to high-volume WiFi operations. We simulate the operational characteristics of the recent IEEE 802.15.4m standard for low-rate wireless personal area networks to evaluate the performance degradation of an incumbent Digital Video Broadcasting - Terrestrial (DVB-T) system if a secondary network of low-power low-rate devices are co-deployed in the same frequency bands. Our results show that short sensor messages will not disrupt the DVB-T service due to the existing error-correction capabilities. Furthermore, if sufficient separation distances to primary transmitters are maintained, transmit powers are sufficient to achieve reasonable connectivity levels of the secondary network. In order to obtain realistic figures on the predicted feasibility of grayspace sensor networks, we study the deployment constraints of a hypothetical secondary network co-located with the TV broadcasting network of Germany. Our analysis shows that if we aim to support a minimum sensor-sensor distance, no universal coverage can be maintained in this country. While our quantitative results are specific to Germany, we deem them indicative for the expected results also in other potential deployments. We found that while a secondary wireless sensor network in TVGS is technically possible, the necessary constraints on operational parameters and service levels for TVGS co-existence will significantly limit its practical viability.

Efficient routing for low rate wireless network - a novel approach

In recent years, Wireless device networks have achieved associate degree attention on a world level. This comprises small sensors with restricted power and restricted resources. The applicability of wireless sensor networks (WSNs) in various fields such as medical research and civilian applications is proliferating enormously. Every routing protocol designed for WSNs should be energy-efficient, reliable and prolong the network lifetime. Due to the resources and energy constraints in WSNs, routing can be considered as a matter of contention in networks. This research proposes a beacon-enabled least-time and energy-efficient routing protocol with single-level data-aggregation using an IEEE 802.15.4. Considering the low complexness and low power consumption it is appropriate for low-rate wireless personal area networks as WSNs. On comparison of the proposed protocol with the popular ad hoc and other WSN routing protocols, the results show that the proposed protocol outperforms the routing protocols in the literature in terms of latency, throughput, and average energy consumption.

Efficient routing for low rate wireless network - a novel approach

In recent years, Wireless device networks have achieved associate degree attention on a world level. This comprises small sensors with restricted power and restricted resources. The applicability of wireless sensor networks (WSNs) in various fields such as medical research and civilian applications is proliferating enormously. Every routing protocol designed for WSNs should be energy-efficient, reliable and prolong the network lifetime. Due to the resources and energy constraints in WSNs, routing can be considered as a matter of contention in networks. This research proposes a beacon-enabled least-time and energy-efficient routing protocol with single-level data-aggregation using an IEEE 802.15.4. Considering the low complexness and low power consumption it is appropriate for low-rate wireless personal area networks as WSNs. On comparison of the proposed protocol with the popular ad hoc and other WSN routing protocols, the results show that the proposed protocol outperforms the routing protocols in the literature in terms of latency, throughput, and average energy consumption.

A Survey on Software-Defined Wireless Sensor Networks: Challenges and Design Requirements

Software defined networking (SDN) brings about innovation, simplicity in network management, and configuration in network computing. Traditional networks often lack the flexibility to bring into effect instant changes because of the rigidity of the network and also the over dependence on proprietary services. SDN decouples the control plane from the data plane, thus moving the control logic from the node to a central controller. A wireless sensor network (WSN) is a great platform for low-rate wireless personal area networks with little resources and short communication ranges. However, as the scale of WSN expands, it faces several challenges, such as network management and heterogeneous-node networks. The SDN approach to WSNs seeks to alleviate most of the challenges and ultimately foster efficiency and sustainability in WSNs. The fusion of these two models gives rise to a new paradigm: Software defined wireless sensor networks (SDWSN). The SDWSN model is also envisioned to play a critical role in the looming Internet of Things paradigm. This paper presents a comprehensive review of the SDWSN literature. Moreover, it delves into some of the challenges facing this paradigm, as well as the major SDWSN design requirements that need to be considered to address these challenges.

Modelling and analysis data fragmentation in IEEE 802.15.4 slotted CSMA/CA protocol without ACK mode

The low-rate wireless personal area networks (WPANs), as wireless sensor networks (WSNs), suffer from many constraints. The IEEE 802.15.4 standard proposes the slotted CSMA/CA as a communication channel access mechanism with collision avoidance that take into account the constraints of WPANs. In this paper, we propose to introduce a data fragmentation mechanism into slotted CSMA/CA to improve a bandwidth utilisation. The novelty, in this paper, is the use of the fragmentation mechanism to replace an acknowledgement frame after the transmission of the fragment and the remaining frame. The beacon frame is used to confirme the success transmission of a data fragment. To evaluate the performances of our proposition, we have developped a three dimension Markov chain which modelises the behaviour of the node using IEEE 802.15.4 with data fragmentation mechanism without using an ACK frame. The analytical results of the network throughput and the transmission success delay demonstrate the improvement of the bandwidth occupation.

Efficient coding schemes for low‐rate wireless personal area networks

The emerging market of Internet of things has created great demand for low-cost, low-power wireless technologies. Existing IEEE 802.15.4 standard is designed for low-rate wireless personal area networks (LR-WPANs). However, current standard does not fully utilise the benefit of the code redundancy. In this study, the authors propose new coding schemes for LR-WPANs with improved coding gain. They first propose a block code based on extended Bose–Chaudhuri–Hocquenghem (BCH) code that increases the minimum Hamming distance compared with the existing code used in LR-WPANs. The computational complexity of the encoder and decoder remains about the same. In addition, by applying the extended BCH code directly to LR-WPANs, the data rate of the system can be increased without sacrificing coding performance. They further propose a tail-biting convolutional (TBC) code with optimum generator polynomials for LR-WPANs. The proposed TBC code enjoys significant performance improvement while preserving the effective code rate as well as a low decoding complexity. Simulation results validate the effectiveness of the proposed coding schemes.

Implementation of Energy Efficiency Based on Time Scheduling to Improve Network Lifetime in Wireless Body Area Network (WBAN)

ZigBee applications of IEEE 802.15.4 Wireless Sensor Network (WSN) with Low Rate Wireless Personal Area Network (LR-WPAN) can be integrated with e-health technology Wireless Body Area Network (WBAN). WBAN are small size and can communicate quickly making it easier for people to obtain information accurately.WBAN has a variety of functions that can help human life. It can be used in the e-health, military and sports. WBAN has the potential to be the future of wireless communication solutions. WBAN use battery as its primary power source. WBAN has limited energy and must be able to save energy consumption in order to operate for a long time. In this study, we propose a method of time scheduling called cycle sleep period (CSP) as WBAN solutions to save energy and improve energy efficiency. The CSP method is implemented in the real hardware testbed using sensor e-health includes temperature body and current sensor. We compared the performance of CSP method with duty cycle management (DCM) time scheduling-based and without using time scheduling.From the measurement results, our proposed idea has decreasingenergy consumption.Keywords: WSN, LR-WPAN, WBAN, e-health, Time Scheduling

Performance Study of IEEE 802.15.4 under OPNET Modeler for Wireless Sensor Networks

The IEEE 802.15.4 protocol has recently been adopted as a communication standard for low-rate wireless personal area networks (LR-WPANs) due to its low data rate, low power consumption and low cost of Wireless Personal Area Networks. This protocol is quite flexible for a wide range of applications if appropriate tuning of its parameters is carried out. Importantly, the protocol also provides real-time guarantees by using the Guaranteed Time Slot (GTS) mechanism. Indeed, the GTS mechanism is quite attractive for Wireless Sensor Network (WSN) applications. The main objective of this paper is to investigate the performance of BPSK (Binary phase shift keying) and QPSK (Quadrature phase shift keying) modulation techniques. Investigations have been reported to compare the performance of the two modulation schemes. Here modulation schemes have been identified which gives significant performance improvement over the other based on network output load, energy consumption and power reception at the WPAN devices. The results have been presented Pan_Coordinator, GTS and Non GTS End Device (CAP device) of Wireless Sensor Network (WSN).

Performance Study of IEEE 802.15.4 under OPNET Modeler for Wireless Sensor Networks

The IEEE 802.15.4 protocol has recently been adopted as a communication standard for low-rate wireless personal area networks (LR-WPANs) due to its low data rate, low power consumption and low cost of Wireless Personal Area Networks. This protocol is quite flexible for a wide range of applications if appropriate tuning of its parameters is carried out. Importantly, the protocol also provides real-time guarantees by using the Guaranteed Time Slot (GTS) mechanism. Indeed, the GTS mechanism is quite attractive for Wireless Sensor Network (WSN) applications. The main objective of this paper is to investigate the performance of BPSK (Binary phase shift keying) and QPSK (Quadrature phase shift keying) modulation techniques. Investigations have been reported to compare the performance of the two modulation schemes. Here modulation schemes have been identified which gives significant performance improvement over the other based on network output load, energy consumption and power reception at the WPAN devices. The results have been presented Pan_Coordinator, GTS and Non GTS End Device (CAP device) of Wireless Sensor Network (WSN).

Performance Evaluation of AODV and DSDV Routing Protocols over Zigbee Network for Different Topologies under CBR Traffic Pattern

Zigbee is an open specification developed by Zigbee Alliance build on the top of IEEE802.15.4 Physical and Media Access Control layer standard, which is one of the global wireless standards of communication protocol for Low-Rate Wireless Personal Area Networks (LR-WPAN). It aims at low power consumption, low data rate, low cost, short range and flexible, reliable, scalable wireless communication. This paper presents overview of IEEE 802.15.4/Zigbee and analyze the performance of AODV and DSDV routing protocols over Zigbee network for different topologies like Random, Star and Peer to Peer (Mesh) under CBR traffic pattern by varying number of nodes, number of sources and range. Performance analysis is carried out using various parameters like Average End-to-End delay, Average Throughput and Packet delivery ratio to determine the Quality of Services (QoS) of the network under different scenarios using NS2 simulator (Version 2.35). Awk scripts are used for analyzing the simulation results and results are shown in graphical forms.

A Markov Model for Characterizing IEEE 802.15.4 MAC Layer in Noisy Environments

The IEEE 802.15.4 standard represents one of the most successful technologies for enabling low-rate wireless personal area networks (LR-WPANs). Accordingly, the properties of its protocols (at physical and MAC layers) have been widely studied in the scientific literature to derive performance bounds on throughput, delays, and frame losses. At the same time, to the best of the authors' knowledge, a complete characterization of the frame-error-rate process, including also the correlation among loss events, is still missing. This kind of investigation is particularly relevant in noisy industrial environments, which, as well known, introduce bursty frame losses. To this end, this paper proposes a Markov model to account for the different changing conditions under which an IEEE 802.15.4 channel is seen at the MAC layer. The model is able to reproduce synthetic traces having a cumulative distribution function and an autocorrelation coefficient that closely resemble experimental measurements. In this way, it becomes a valuable tool for further refining existing theoretical models and simulation platforms for IEEE 802.15.4 LR-WPANs and for helping the designer and researcher working on industrial Internet of things.

A Holistic Approach to Optimizing the Lifetime of IEEE 802.15.4/ZigBee Networks with a Deterministic Guarantee of Real-Time Flows

IEEE 802.15.4 is a global standard designed for emerging applications in low-rate wireless personal area networks (LRWPANs). The standard provides beneficial features, such as a beacon-enabled mode and guaranteed time slots for realtime data delivery. However, how to optimally operate those features is still an open issue. For the optimal operation of the features, this paper proposes a holistic optimization method that jointly optimizes three cross-related problems: cluster-tree construction, nodes’ power configuration, and duty-cycle scheduling. Our holistic optimization method provides a solution for those problems so that all the real-time packets can be delivered within their deadlines in the most energyefficient way. Our simulation study shows that compared to existing methods, our holistic optimization can guarantee the on-time delivery of all real-time packets while significantly saving energy, consequently, significantly increasing the lifetime of the network. Furthermore, we show that our holistic optimization can be extended to take advantage of the spatial reuse of a radio frequency resource among long distance nodes and, hence, significantly increase the entire network capacity. Category: Ubiquitous computing

Adaptive GTS Allocation Scheme with Applications for Real-time Wireless Body Area Sensor Networks

The IEEE 802.15.4 standard not only provides a maximum of seven guaranteed time slots (GTSs) for allocation within a superframe to support time-critical traffic, but also achieves ultralow complexity, cost, and power in low-rate and short-distance wireless personal area networks (WPANs). Real-time wireless body area sensor networks (WBASNs), as a special purpose WPAN, can perfectly use the IEEE 802. 15. 4 standard for its wireless connection. In this paper, we propose an adaptive GTS allocation scheme for real-time WBASN data transmissions with different priorities in consideration of low latency, fairness, and bandwidth utilization. The proposed GTS allocation scheme combines a weight-based priority assignment algorithm with an innovative starvation avoidance scheme. Simulation results show that the proposed method significantly outperforms the existing GTS implementation for the traditional IEEE 802.15.4 in terms of average delay, contention free period bandwidth utilization, and fairness.

On the influence of the hidden and exposed terminal problems on asynchronous IEEE 802.15.5 networks

Hidden and exposed terminal problems are known to negatively impact wireless communications, degrading potential computing services on top. These effects are more significant in Wireless Mesh Sensor Networks (WMSNs), and, particularly, in those based on the IEEE 802.15.5 Low-Rate Wireless Personal Area Network (LR-WPAN mesh) standard, a promising solution for enabling low-power WMSNs. The first contribution of this paper is a quantitative evaluation of these problems under the IEEE 802.15.5 Asynchronous Energy Saving (ASES) mode, which is intended for asynchronous data-collection applications. The results obtained show a sharp deterioration of the network performance. Therefore, this paper also reviews the most relevant approaches that cope with these problems and are compatible with ASES. Finally, a set of these proposals is assessed to find out those more suitable for their potential integration with ASES, which constitutes the second major contribution of the paper.

A low-power ADC with compact AGC loop for LR-WPAN receivers

This paper presents a novel pipelined analog-to-digital converter (ADC) with a dB-linearity automatic gain control (AGC) loop that exhibits both power and area efficiencies for low-rate wireless personal area network (LR-WPAN) receiver applications. The AGC loop is designed based on feedback architecture for high linearity and a full-digitally control method is proposed to simplify the gain adjusting. The sample-and-hold amplifier less (SHA-less) scheme is employing in ADC design, and moreover, an evaluation-time-sharing technique which combined opamp- and capacitor-sharing is presented for low power consumption and elimination of memory effect. The proposed circuit shows a gain error less than ±0.56 dB in a wide dynamic range of about 70 dB by 2 dB/step and achieves a maximum IIP3, SNDR, SFDR of 16.27 dBm, 41.87 dB, 58.72 dB, respectively. Designed in a 0.18 μm CMOS technology, the proposed circuit has been integrated in the LR-WPAN transceiver. The chip area is as small as 0.94 mm2 and the total power consumption is only 7.62 mW from a 1.8 V single supply.

An Adaptive Superframe Duration Allocation Algorithm for Resource-Efficient Beacon Scheduling

Beacon scheduling is considered to be one of the most significant challenges for energy-efficient Low-Rate Wireless Personal Area Network (LR-WPAN) multi-hop networks. The emerging new standard, IEEE802.15.4e, contains a distributed beacon scheduling functionality that utilizes a specific bitmap and multi-superframe structure. However, this new standard does not provide a critical recipe for superframe duration (SD) allocation in beacon scheduling. Therefore, in this paper, we first introduce three different SD allocation approaches, LSB first, MSB first, and random. Via experiments we show that IEEE802.15.4e DSME beacon scheduling performs differently for different SD allocation schemes. Based on our experimental results we propose an adaptive SD allocation (ASDA) algorithm. It utilizes a single indicator, a distributed neighboring slot incrementer (DNSI). The experimental results demonstrate that the ASDA has a superior performance over other methods from the viewpoint of resource efficiency.

System evaluation of a practical IEEE 802.15.4/4e/4g multi‐physical and multi‐hop smart utility network

This study evaluates the performance of a practical IEEE 802.15.4/4e/4g low-rate (LR) wireless personal area network (WPAN) with multiple physical (PHY) layers and multi-hop capabilities for smart utility networks, machine-to-machine networks and other advanced sensor networks. The proposal includes realistic design considerations addressing demands of practical applications, country-specific regulatory requirements and technical specification in international standards. A cross-layer open system interconnection model from the application, transport, network, medium access control, down to the multiple PHY layers is constructed based on the specification in IEEE 802.15.4 LR-WPAN and other layer-specific standards. Employing the cross-layer model, extensive computer simulations were conducted to investigate the performance of the LR-WPAN system in this application domain. As a result, the authors have successfully verified the simulated achievable average throughput in both PHY layer designs, multi-rate and multi-regional frequency shift keying (MR-FSK) and multi-rate and multi-regional orthogonal frequency division multiplexing (MR-OFDM) with the theoretical throughput by calculation. Secondly, in a multi-PHY environment with the presence of 30 interferer devices, throughput degradation of the victim system is observed within 30%. Furthermore, when interferer devices transmit frames with interval beyond 1 s, the degradation to the victim system becomes negligible. Thirdly, MR-FSK PHY has a simpler design with higher energy-efficiency, whereas MR-OFDM PHY is more complicated with more resilience to interference. They have found an interference tolerance capability difference of 15 dB between the MR-FSK and MR-OFDM systems. Fourthly, comparing with their single-hop counterparts, multi-hop systems have lower average throughput in MR-FSK by 25% and MR-OFDM by 10%. Finally, comparing with networks with periodical beacon transmissions, asynchronous networks have more inferior average throughput of 20% in MR-FSK and 3% in MR-OFDM, with the advantage of longer battery lifespan.