Wireless Body Area Sensor Networks Research Articles

CoR-MAC: Contention over Reservation MAC Protocol for Time-Critical Services in Wireless Body Area Sensor Networks.

Reserving time slots for urgent data, such as life-critical information, seems to be very attractive to guarantee their deadline requirements in wireless body area sensor networks (WBASNs). On the other hand, this reservation imposes a negative impact on performance for the utilization of a channel. This paper proposes a new channel access scheme referred to as the contention over reservation MAC (CoR-MAC) protocol for time-critical services in wireless body area sensor networks. CoR-MAC uses the dual reservation; if the reserved time slots are known to be vacant, other nodes can access the time slots by contention-based reservation to maximize the utilization of a channel and decrease the delay of the data. To measure the effectiveness of the proposed scheme against IEEE 802.15.4 and IEEE 802.15.6, we evaluated their performances with various performance indexes. The CoR-MAC showed 50% to 850% performance improvement in terms of the delay of urgent and time-critical data according to the number of nodes.

Performance of Sampling/Resampling-based Particle Filters Applied to Non-Linear Problems

In this work, we propose a wireless body area sensor network (WBASN) to monitor patient position. Localization and tracking are enhanced by improving the effect of the received signal strength (RSS) variation. First, we propose a modified particle filter (PF) that adjusts resampling parameters for the Kullback-Leibler distance (KLD)-resampling algorithm to ameliorate the effect of RSS variation by generating a sample set near the high-likelihood region. The key issue of this method is to use a resampling parameter lower bound for reducing both the root mean square error (RMSE) and the mean number of particles used. To determine this lower bound, an optimal algorithm is proposed based on the maximum RMSE between the proposed algorithm and the KLD-resampling algorithm or based on the maximum mean number of particles used of these algorithms. Finally, PFs based on KLD-sampling and KLD-resampling are proposed to minimize the efficient number of particles and to reduce the estimation error compared to traditional algorithms.

Flexible quality of service model for wireless body area sensor networks.

Wireless body area sensor networks (WBASNs) are becoming an increasingly significant breakthrough technology for smart healthcare systems, enabling improved clinical decision-making in daily medical care. Recently, radio frequency ultra-wideband technology has developed substantially for physiological signal monitoring due to its advantages such as low-power consumption, high transmission data rate, and miniature antenna size. Applications of future ubiquitous healthcare systems offer the prospect of collecting human vital signs, early detection of abnormal medical conditions, real-time healthcare data transmission and remote telemedicine support. However, due to the technical constraints of sensor batteries, the supply of power is a major bottleneck for healthcare system design. Moreover, medium access control (MAC) needs to support reliable transmission links that allow sensors to transmit data safely and stably. In this Letter, the authors provide a flexible quality of service model for ad hoc networks that can support fast data transmission, adaptive schedule MAC control, and energy efficient ubiquitous WBASN networks. Results show that the proposed multi-hop communication ad hoc network model can balance information packet collisions and power consumption. Additionally, wireless communications link in WBASNs can effectively overcome multi-user interference and offer high transmission data rates for healthcare systems.

Wearable Computing for Health Care

In recent years, wearable computing has been proliferating at a rapid pace and has enabled a wide range of applications such as mobile communication, sensory integration, behavioral modeling and health care monitoring, etc. Many challenges need to be addressed to enable the integration of multiple sensing/communication technologies for various applications with low energy consumption and low transmission rate. A key design requirement for future wearable health care services is to be able to provide prompt, reliable, secure ubiquitous access to health care services to users and health care providers anytime, anywhere. This special issue explores recent advances in designing, implementing, and deploying novel protocols, architectures, and applications in wearable computing for health care. This Special issue opens with an article on a big data platform for wearable data in health care, BA Semantic Big Data Platform for Integrating Heterogeneous Wearable Data in Healthcare,^ authored by Mezghani et al. The diversity, variety, and volume of wearable data related to healthcare make data processing and analytics increasingly difficult. The authors introduce a semantic big data architecture that extends the basic NIST Cloud and Big Data reference architectures with smart mechanisms based on ontology to give meaning to the silos of heterogeneous data. Hence, the authors propose a Wearable Healthcare Ontology that enables the aggregation of the distributed heterogeneous data coming from wearables to make better-informed health related decisions and create new valuable information. The second article, BMulti-Level MAC-Layer QoS Design in Wireless Body Area Network^, by Zhang et al., proposes a multiple level-based QoS design at the MAC layer for a tree topology structuredWBAN. The QoS provisioning is divided into three priority levels, i.e., priority of user, priority of data and priority over time. The time slot-based CSMA/CA mechanism in the beacon mode of IEEE 802.15.4 is used for the implementation of the QoS framework. The simulation results demonstrate the effectiveness of the multi-level QoS provisioning in WBAN. Wearable, non-invasive biosensors, with their portability and low cost, have been applied to a variety of clinical scenarios such as post-traumatic stress disorder, drug addiction, HIV therapy, stress and epilepsy. In the article, BiMStrong: Deployment of a Biosensor System to Detect Cocaine Use^, by Carreiro et al., a parameter trajectory description method to analyze the data (such as skin temperature, motion, etc.) collected from bio-sensors is proposed. The authors also presented the detection of drug use by analyzing several parameters. The research is well motivated by the problem of behavior interventions. The authors further prove the feasibility of use the mobile biosensor system in the detection of substance abuse. The authors have collected real data sets. In the future, using mobile bio-sensor system to improve human well-being is a very promising area aimed at reducing health care costs. The objective of wireless body area sensor networks is to make communication at and near the human body possible in order to measure different body attributes. In the article on wireless body area sensor networks, namely BA Fatigue Measuring Protocol for Wireless Body Area Sensor Networks^, Akram et al. propose a fatigue measurement The Special Issue for this editorial can be found at the following link: http://link.springer.com/journal/10916/39/12/page/1

Delay, Reliability, and Throughput Based QoS Profile: A MAC Layer Performance Optimization Mechanism for Biomedical Applications in Wireless Body Area Sensor Networks

Recently, increasing demand for remote healthcare monitoring systems poses a specific set of Quality of Services (QoS) requirements to the MAC layer protocols and standards (IEEE 802.15.6, IEEE 802.15.4, etc.) of Wireless Body Area Sensor Networks (WBASNs). They mainly include time bounded services (latency), reliable data transmission, fair channel distribution, and specified data rates. The existing MAC protocols of WBASNs are lack of a specific set of QoS. To address this, the paper proposes a QoS profile named delay, reliability, and throughput (DRT). The QoS values computed through DRT profile provide maximum reliability of data transmission within an acceptable latency and data rates. The DRT is based on the carrier sense multiple access with collision avoidance (CSMA/CA) channel access mechanism and considers IEEE 802.15.4 (low-rate WPAN) and IEEE 802.15.6 (WBASN). Further, a detailed performance analysis of different frequency bands is done which are standardized for WBASNs, that is, 420 MHz, 868 MHz, 2.4 GHz, and so forth. Finally, a series of experiments are conducted to produce statistical results for DRT profile with respect to delay, reliability, and packet delivery ratio (PDR). The calculated results are verified through extensive simulations in the CASTALIA 3.2 framework using the OMNET++ network simulator.

A Fatigue Measuring Protocol for Wireless Body Area Sensor Networks.

As players and soldiers preform strenuous exercises and do difficult and tiring duties, they are usually the common victims of muscular fatigue. Keeping this in mind, we propose FAtigue MEasurement (FAME) protocol for soccer players and soldiers using in-vivo sensors for Wireless Body Area Sensor Networks (WBASNs). In FAME, we introduce a composite parameter for fatigue measurement by setting a threshold level for each sensor. Whenever, any sensed data exceeds its threshold level, the players or soldiers are declared to be in a state of fatigue. Moreover, we use a vibration pad for the relaxation of fatigued muscles, and then utilize the vibrational energy by means of vibration detection circuit to recharge the in-vivo sensors. The induction circuit achieves about 68 % link efficiency. Simulation results show better performance of the proposed FAME protocol, in the chosen scenarios, as compared to an existing Wireless Soccer Team Monitoring (WSTM) protocol in terms of the selected metrics.

Interference Mitigation Schemes for Wireless Body Area Sensor Networks: A Comparative Survey.

A wireless body area sensor network (WBASN) consists of a coordinator and multiple sensors to monitor the biological signals and functions of the human body. This exciting area has motivated new research and standardization processes, especially in the area of WBASN performance and reliability. In scenarios of mobility or overlapped WBASNs, system performance will be significantly degraded because of unstable signal integrity. Hence, it is necessary to consider interference mitigation in the design. This survey presents a comparative review of interference mitigation schemes in WBASNs. Further, we show that current solutions are limited in reaching satisfactory performance, and thus, more advanced solutions should be developed in the future.

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.

An Energy Efficient Method for Secure and Reliable Data Transmission in Wireless Body Area Networks Using RelAODV

Growing population, sedentary lifestyle and spreading epidemics in today's world have led to a need for ubiquitous healthcare systems. Wireless body area network (WBAN) is one such concept which serves as a health monitoring technology. In a WBAN sensors are attached to various parts of the human body to monitor the health or in general the bodily functions such as heart rate and blood pressure of a person. The readings obtained from the patient are transmitted to a medical professional so that the patient will be constantly and remotely monitored. This gives location flexibility for the patient instead of being in a hospital or being bound at home. But one of the downsides in adopting WBAN is the security and privacy issues. Medical records are sensitive information and hence for a patient to trust the system, data needs to be sent securely. Moreover, every detail captured by the sensors need to be reliably transmitted to the medical authorities concerned. Another issue is the limited battery power of the sensors. A sensor should not be taxed to do too many computations as that will drastically drain the battery. In this work, we propose a power efficient methodology for secure transmission of patient data to the medical authorities. To improve the reliability of the system we propose a modified adhoc on-demand distance vector (AODV) protocol called RelAODV (Reliable AODV). Simulations have shown that the proposed methodology is energy efficient and improves the overall QoS of the system.

Application specific study, analysis and classification of body area wireless sensor network applications

The evolution of wearable computing and advances in wearable sensor devices has motivated various applications of Body Area Sensor Networks (BASN). In the last few years body areas sensor networks have emerged as a major type of wireless sensor networks (WSN). This emerging networking technology can be used in various walks of life. A number of surveys have been published on MAC or the physical layer mechanism of BASN but very few have focused on studying it from the application point of view. In this paper, we first review, from literature, existing use of body area sensor network and classify and then its application domain. Within these application domains of BASN, we propose a feasibility of scenarios where BASN can be used for both application and technical aspects. In addition, we classify the use of BASN from literature, based on certain parameters. Finally, we discuss and highlight issues where further research can be conducted in the future.

A Survey of Routing Protocols for Low Power Sensor Networks

A Wireless Body Area Sensor Network (WBASN) is combination of a set of sensor nodes, placed on/near or inside a human body. Wireless Body Area Sensor Networks (WBASN) is a developing technology which exploits wireless sensor nodes to implement real-time wearable health monitoring of patients to enhance independent living. These sensor nodes can be worn externally to monitor multiple bioparameters (such as blood oxygen saturation (SpO2), blood pressure and heart activity) of multiple patients at a vital location in the hospital. Hence the mission of the WBASN is very critical, increasing the lifetime of nodes is essential in order to maintain both practicality and effectiveness. There are number of routing protocols for WBASN. This paper will discuss the architecture of WBASN. Moreover, this work gives detailed literature review of many different routing protocols belongs to the field of WBAN and also discuss their strengths and weaknesses.

A Low-Power Wearable Dual-Band Wireless Body Area Network System: Development and Experimental Evaluation

Wireless body area network (WBAN) applications benefit extensively from the advantages offered by unique features of ultra-wideband (UWB) wireless communication, such as high data rate, low power consumption, and simple transmitter design. A major disadvantage in using UWB for WBAN applications is the complexities introduced by UWB receivers, such as high power consumption, poor receiver performance due to low sensitivity, and complex hardware implementation. This paper presents hardware implementation of a new communication system, where UWB is used for high data-rate transmission from sensor nodes and a 433-MHz industrial, scientific, and medical (ISM) band receiver is used for receiving low data-rate control messages at the sensor nodes. A full network system for WBAN applications has been implemented including a unique medium access control protocol. The proposed WBAN system is designed to dynamically control the pulses per bit value used for the UWB data communication using control messages received via the narrowband feedback link (i.e., the 433-MHz ISM link). This leads to dynamic bit error rate (BER) and power control at the sensor nodes, which improves the reliability of communication and power efficiency of sensor nodes under dynamic channel conditions. The performance of the system is evaluated in terms of BER, sensor initialization delay, and power consumption. This novel dual-band architecture utilizes the unique advantages offered by UWB communication and narrowband technology to enable high data rate, low-complexity hardware design, low power consumption, and small form factor for WBAN sensor systems.

A Relay Based Routing Protocol for Wireless In-Body Sensor Networks

Efficient energy utilization of in-body sensors is one of the hot areas of current research. In this paper, we present a relay based routing protocol for in vivo wireless body area sensor networks. Firstly, we decrease the communication distance of in-body sensors to its minimum value. Secondly, we do not allow multi-hopping of data among in-body sensors. So, in our proposed protocol, relays along with one coordinator are deployed on the clothes of a patient. As placed on the patients clothes, relays could easily be recharged and replaced. In-body sensors send the sensed data to nearby relay, which forwards the data to the coordinator and finally to the end station. Moreover, the proposed protocol is provided with linear programming based mathematical models for network lifetime maximization and end-to-end-delay minimization. Simulation results show that our proposed protocol performs better than the selected routing protocols in terms of energy efficiency.

The Applicability of Electrocardiogram (ECG) As Biometrics in Securing the Communication of Wireless Body Area Network

A recent trend in the field of biometrics is ECGbased, where electrocardiogram (ECG) signals are used as input to the biometric system. Previous work has shown that ECG has a good potential, which can be used alone as a biometric parameter or in combination with some other parameters for greater accuracy, due to its main key properties. This paper presents a study on the applicability of ECG signals in securing Wireless Body Area Network (WBAN) communications. We study the permanence and the distinctiveness properties of ECG signals on 20 random patients. The Independent Component Analysis (ICA) and Fast Fourier Transform (FFT) are applied on the ECG signals obtained from MITBIH Normal Synus Rhythm (nsrdb) and MIT-BIH Arrhythmia (mitdb) public database. The experimental results are presented, which exhibit that ECG signal can be utilized properly to achieve better security performance under the stringent constraints of WBAN sensors. Thus, it is believed that the system can naturally secure the information transmission within WBAN, where other techniques use hardware and software to achieve the same purpose.

Energy Efficient System-on-chip Design for Wireless Body Area Sensor Network

This article presents a novel energy-efficient on-chip design for wireless body area sensor networks focused towards pervasive healthcare applications. The network adopts a master–slave architecture, where the body-worn slave nodes periodically send sensor readings to a central master node. Unlike traditional peer-to-peer wireless sensor networks, the nodes in this wireless body area sensor networks are not deployed in an ad hoc fashion. The network is centrally managed and all communications are single-hop. A cluster algorithm is also presented so that all slave nodes are within the transmission range of the master nodes. It pretends that all slave nodes can share resources and information over the internet to reduce energy consumption. The design on system-on-chip platform has been simulated for some experiments and implemented. Compared to published and industrially used schemes, the power consumption of the proposed design is over 30 and 99% lower in the simulation and platform implementation, respectively.

RE-ATTEMPT: A New Energy-Efficient Routing Protocol for Wireless Body Area Sensor Networks

Modern health care system is one of the most popular Wireless Body Area Sensor Network (WBASN) applications and a hot area of research subject to present work. In this paper, we present Reliability Enhanced-Adaptive Threshold based Thermal-unaware Energy-efficient Multi-hop ProTocol (RE-ATTEMPT) for WBASNs. The proposed routing protocol uses fixed deployment of wireless sensors (nodes) such that these are placed according to energy levels. Moreover, we use direct communication for the delivery of emergency data and multihop communication for the delivery of normal data. RE-ATTEMPT selects route with minimum hop count to deliver data which downplays the delay factor. Furthermore, we conduct a comprehensive analysis supported by MATLAB simulations to provide an estimation of path loss, and problem formulation with its solution via linear programming model for network lifetime maximization is also provided. In simulations, we analyze our protocol in terms of network lifetime, packet drops, and throughput. Results show better performance for the proposed protocol as compared to the existing one.

A Clique-based WBAN Scheduling for Mobile Wireless Body Area Networks

Wireless-body-area-networks (WBAN) that generally comprises different types of sensors are useful to gather multiple parameters together, such as body temperature, blood pressure, pulse, heartbeat and blood sugar. However, a dense and mobile WBAN often suffers from interference, which causes serious problems, such as degrading throughput and wasting energy. So, the sensors in WBAN are not active together at the same time and they can be partitioned to different groups and each group works in turn to avoid interference. In this paper, we provide a Clique-Based WBAN Scheduling (CBWS) algorithm to cluster sensors of a single or multiple WBAN into different groups to avoid interference. Particularly, we propose a coloring based scheduling method to schedule all groups to work in a sequence of time slots. The experimental results demonstrate the performance of the proposed CBWS algorithm in terms of system throughput.

A novel and efficient user access control scheme for wireless body area sensor networks

Wireless body area networks (WBANs) can be applied to provide healthcare and patient monitoring. However, patient privacy can be vulnerable in a WBAN unless security is considered. Access to authorized users for the correct information and resources for different services can be provided with the help of efficient user access control mechanisms. This paper proposes a new user access control scheme for a WBAN. The proposed scheme makes use of a group-based user access ID, an access privilege mask, and a password. An elliptic curve cryptography-based public key cryptosystem is used to ensure that a particular legitimate user can only access the information for which he/she is authorized. We show that our scheme performs better than previously existing user access control schemes. Through a security analysis, we show that our scheme is secure against possible known attacks. Furthermore, through a formal security verification using the AVISPA (Automated Validation of Internet Security Protocols and Applications) tool, we show that our scheme is also secure against passive and active attacks.

Cost Efficient Deployment and Reliable Routing Modeling Based Multi-Objective Optimization for Dynamic Wireless Body Sensor Networks Topology

Wireless Body Sensor Networks (WBSNs), like any other sensor networks, suffer from limited energy and are highly distributed network, where its nodes organize by themselves and each of them has the flexibility of collecting and transmitting patient biomedical information to a sink. When a knowledge was sent to a sink from a path that doesn't have a definite basis, the routing is a crucial challenge in Wireless Body Area Sensor Networks. Furthermore, reliability and routing delay are the considerable factors in these types of networks. More attention should be given to the energy routing issue and frequent topology's change in WBSNs. That increases the dynamics of network topology, and complicates the relay selection process in cooperative communications. Unreliable communication over the wireless channel complicates communication protocols and results in low data yield (Stathopoulos 2005). The deployment sensors step is a crucial and complex task due to several independent objectives and constraints. This paper presents a Min-Max multi-commodity flow model for WBSNs which allows preventing sensor node saturation and taking best action against reliability and the path loss, by imposing an equilibrium use of sensors during the routing process. This model is based on the authors' optimal sensors deployment method for WBSNs. Simulations results show that the algorithm balances the energy consumption of nodes effectively and maximize the network lifetime. It will meet the enhanced WBSNs requirements, including better delivery ratio, less reliable routing overhead.

SCP: A Simple Communication Protocol for WBASN

In recent years, researchers have increasingly paid more attention to the Wireless Body Area Sensor Network (WBASN) for its potential applications in medical care and health care field. In these applications, the reliable data transmission is the key point. This paper presents a simple protocol for WBASN, and the reliability of data transport is concerned. The protocol design is described in detailed, and then the protocol evaluation is given. The evaluation result shows that the protocol is suitable for the application of WBASN.