# Wearable Wireless Devices
###### Abstract  
We investigate the performance of wireless devices using a single electrocardiogram device for a single electrocardiogram device  
In the paper, 'Movement Noise Cancellation in Second Derivative of Photoplethysmography Signals with Wavelet Transform and Diversity Combining' [5] authors proposed an algorithm to remove movement noise from second derivative of photoplethysmography (SDPPG) signals. Experiment results show that the proposed algorithm outperforms the previous filter-based algorithm, and that movement noise with 30% time duration can be reduced by up to 70.89%.  
In the paper, 'An Anonymous Mutual Authenticated Key Agreement Scheme for Wearable Sensors in Wireless Body Area Networks', [6] authors proposed that Li et al. lightweight protocol for wearable sensors in wireless body area networks is still vulnerable to three types of attacks i.e., the offline identity guessing attack, the sensor node impersonation attack and the hub node spoofing attack. Authors present a secure scheme that addresses these problems, and retains similar efficiency in wireless sensors nodes and mobile phones.  
In the paper, 'Respiration Symptoms Monitoring in Body Area Networks' [7] authors presented a framework that monitors particular symptoms such as respiratory conditions (abnormal breathing pattern) experienced by hyperthyerosis, sleep apnea, and sudden infant death syndrome (SIDS) patients. The rhythmic patterns extracted using S-Band sensing present the periodic and non-periodic waveforms that correspond to normal and abnormal respiratory conditions, respectively.  
In the paper, 'Internet of Things for Sensing: A Case Study in the Healthcare System' [8], authors did a pilot study, to look at narcolepsy, a disorder in which individuals lose the ability to regulate their sleep-wake cycle. Using S-band sensing Classification and validation of various human activities such as walking, sitting on a chair, push-ups, and narcolepsy sleep episodes are done using support vector machine, K-nearest neighbor, and random forest algorithms. The measurement and evaluation were carried out several times with classification values of accuracy, precision, recall, specificity, Kappa, and F-measure of more than 90% that were achieved when delineating sleep attacks.  
In the paper, 'Emergency-Prioritized Asymmetric Protocol for Improving QoS of Energy-Constraint Wearable Device in Wireless Body Area Networks' [9], authors proposed a new MAC protocol to satisfy the higher energy efficiency of nodes than coordinator by designing the asymmetrically energy-balanced model between nodes and coordinator. The proposed scheme loads the unavoidable energy consumption into the coordinator instead of the nodes to extend their lifetime. Additionally, the scheme also provides prioritization for the emergency data transmission with differentiated Quality of Service (QoS). For the evaluations, IEEE 802.15.6 was used for comparison.  
In the paper, 'Virtual Reality-Wireless Local Area Network: Wireless Connection-Oriented Virtual Reality Architecture for Next-Generation Virtual Reality Devices' [10], authors carefully examine the feasibility of wireless VR over WLANs, and proposed an efficient wireless multiuser VR communication architecture, as well as a communication scheme for VR. Extensive simulations have been performed to corroborate the outstanding performance of the proposed scheme.  
The editors hope that this special issue will benefit the scientific community and contribute to the knowledge base.  
The editors would take this opportunity to applaud the contribution of the authors to this special issue. Efforts of the reviewers to enhance the quality of the manuscripts is also much appreciated.  
The authors declare no conflict of interest.