• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.8
• /
• pp.985-994
• /
• 2012

This paper presents the real channel measurements and investigates their statistical characterization in wireless body area network(WBAN). In on-/off body channel, the measurements are performed with some representative human movements for considering human movements. Moreover, three signal transmission schemes with outage constraint are studied for getting total power consumption in each transmission scheme. Using the real channel measurements, between theoretical and realistic simulation are compared. This paper shows that power efficiency is improved through cooperative communication, and how much position of sensor node and human movement affect signal transmission power.

• Journal of Korea Multimedia Society
• /
• v.15 no.10
• /
• pp.1228-1235
• /
• 2012

In this Paper, we propose an energy efficient localization technique based on WUSB (Wireless USB) over WBAN (Wireless Body Area Networks) protocol required for Wearable Computer systems. For this purpose, the proposed localization algorithm minimizes power consumption and estimates location without range information. It is executed independently on the basis of WUSB over WBAN protocol at each sensor node comprising peripherals of a wearable computer system. And it minimizes power consumption by estimating locations of sensor nodes with range-free method fast.

• Journal of Communications and Networks
• /
• v.14 no.3
• /
• pp.296-309
• /
• 2012

In existing middleware for body sensor networks, energy limitations, hardware heterogeneity, increases in node temperature, and the absence of software reusability are major problems. In this paper, we propose an event-based grid middleware component that solves these problems using distributed resources in in vivo sensor nodes. In our multi-hop communication, we use a lightweight rendezvous routing algorithm in a publish/subscribe system of event-based communication. To facilitate software reuse and application development, a modified open services gateway initiative has been implemented in our middleware architecture. We evaluated our grid middleware in a cancer treatment scenario with combined hyperthermia, chemotherapy, and radiotherapy procedures, using in vivo sensors.

• Journal of Sensor Science and Technology
• /
• v.20 no.6
• /
• pp.382-387
• /
• 2011

Whether a person is feeling sleepy or reasonably awake is important safety information in many areas, such as humans operating in traffic or in heavy industry. The changes of body signals have been mostly researched by looking at electroencephalogram(EEG) signals but more and more other medical signals are being examined. In our study, an electrocardiogram(ECG) signal is measured at a sampling rate of 100 Hz and used to try to distinguish the possible differences in signal between the two states: awake and drowsy. Practical tests are conducted using a wireless sensor node connected to a wearable ECG sensor, and an ECG signal is transmitted wirelessly to a base station connected to a server PC. Through the QRS complex in the ECG analysis it is possible to obtain much information that is helpful for diagnosing different types of cardiovascular disease. A program is made with MATLAB for digital signal filtering and graphing as well as recognizing the parts of the QRS complex within the signal. Drowsiness detection is performed by evaluating the R peaks, R-R interval, interval between R and S peaks and the duration of the QRS complex..

• Journal of Korea Multimedia Society
• /
• v.15 no.7
• /
• pp.879-884
• /
• 2012

In this Paper, we propose an Energy Efficient Time Synchronization technique based on WUSB (Wireless USB) over WBAN (Wireless Body Area Networks) protocol required for Wearable Computer systems. For this purpose, the proposed Time Synchronization algorithm minimizes power consumption and estimates time information with accuracy. It is executed on the basis of WUSB over WBAN protocol at each sensor node comprising peripherals of a wearable computer system. It minimizes power consumption by exchanging time stamp packets and forming a hierarchical structure.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.7 no.7
• /
• pp.1547-1568
• /
• 2013

Wireless body area network (WBAN) is an emerging short-range wireless communication network with sensor nodes located on, in or around the human body for healthcare, entertainment and ubiquitous computing. In WBANs, energy is severely constrained which is the prime consideration in the medium access control (MAC) protocol design. In this paper, we propose a novel MAC protocol named Energy-efficient Relay MAC with dynamic Power Control (ERPC-MAC) to save energy consumption. Without relying on the additional devices, ERPC-MAC employs relaying nodes to provide relay service for nodes which consume energy fast. Accordingly the superframe adjustment is performed and then the network topology can be smoothly switched from single-hop to multi-hop. Moreover, for further energy saving and reliability improvement, the dynamic power control is introduced to adjust the power level whenever a node transmits its packets to the coordinator or the relaying node. To the best of the authors' knowledge, this is the first effort to integrate relay, topology adjustment and power control to improve the network performance in a WBAN. Comprehensive simulations are conducted to evaluate the performance. The results show that the ERPC-MAC is more superior to the existing standard and significantly prolongs the network lifetime.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.54 no.2
• /
• pp.16-27
• /
• 2017

IEEE 802.15.6 standard, a Wireless Body Area Network, aims to transfer not only medical data but also non-medical data, such as physical activity, streaming, multimedia game, living information, and entertainment. Services which transfer those data have very various data rates, intervals and frequencies of continuous access to a medium. Therefore, an efficient anti-collision operations and medium assigning operation have to be carried out when multiple nodes with different data rates are accessing shared medium. IEEE 802.15.6 standard for CSMA/CA medium access control method distributes access to the shared medium, transmits a control packet to avoid collision and checks status of the channel. This method is energy inefficient and causes overhead. These disadvantages conflict with the low power, low cost calculation requirement of wireless body area network, shall minimize such overhead for efficient wireless body area network operations. Therefore, in this paper, we propose a medium access scheduling scheme, which adjusts the time interval for accessing to the shared transmission medium according to the amount of data for generating respective sensor node, and a priority control algorithm, which temporarily adjusts the priority of the sensor node that causes transmission concession due to the data priority until next successful transmission to ensure fairness.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.49 no.1
• /
• pp.46-53
• /
• 2012

The WBAN technology means a short distance wireless network which provides each device's interactive communication by connecting devices inside and outside of body located within 3 meters. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. It is necessary to develop the WBAN core technology that sensor node device, WBAN middleware and WBAN application service for WBAN environment. In this paper we designed the medical message structure and implemented medical application for purpose of vital information reliability. The message structure was proposed for WBAN environment and application can be check biometric information from BN on smart device through WBAN gateway.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.3
• /
• pp.499-505
• /
• 2016

In this Paper, we propose a body-area localization technique based on WUSB (Wireless USB) over WBAN (Wireless Body Area Networks) protocol required for wearable computer systems. The proposed localization algorithm is executed on the basis of WUSB over WBAN protocol at each sensor node comprising peripherals of a wearable computer system. To increase the accuracy of input information through various body motions in wearable computer systems, a new localization technique with high precision must be developed. To achieve the goal, This paper proposes a combined TDoA/FDoA/AoA (Time Of Arrival/Time Difference Of Arrival/Angle Of Arrival) localization technique with more than four WUSB over WBAN devices to estimate body-area location accurately. The combined TDoA/FDoA/AoA technique reduces 10mm in location estimation errors comparing with a combined TDoA/FDoA technique. This performance enhancement in location error reduction can be ignored at other systems but is meaningful results in body-area localization-based communications.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.4C
• /
• pp.338-346
• /
• 2012

Wireless sensor network (WSN) technology provides a variety of medical and healthcare solutions to assist detection and communication of body conditions. However, data reliability inside WSN might be influenced to healthcare routing protocol due to limited hardware resources of computer, storage, and communication bandwidth. For this reason, we have conducted various wireless communication experiments between nodes using parameters such as RF strength, battery status, and deployment status to get a optimal performance of mobile healthcare routing protocol. This experiment may also extend the life time of the nodes. Performance analysis is done to obtain some important parameters in terms of distance and reception rate between the nodes. Our experiment results show optimal distance between nodes according to battery status and RF strength, or deployment status and RF strength. The packet reception rate according to deployment status and RF strength of nodes was also checked. Based on this performance evaluation, the optimized sensor node battery and deployment in the developed our mobile healthcare routing protocol were proposed.