We propose a middleware platform built on wireless USB (WUSB) over wireless body area networks (WBAN) hierarchical protocol for wearable health-monitoring systems (WHMS). The proposed middleware platform is composed of time-synchronization and localization solutions. It is executed on the basis of WUSB over WBAN protocol at each wearable sensor node comprising the WHMS. In the platform, firstly, the time-synchronization middleware is executed. After that, a WHMS host calculates the location of a receiving sensor node by using the difference between the times at which the sensor node received different WBAN beacon frames sent from the WHMS host. The WHMS host interprets the status and motion of the wearable body-sensor objects. to a central node, for example, a personal digital assistant (PDA) or a microcontroller board, which may then in turn display the according information on a user interface or transmit the aggregated vital signs to a medical center. The previous illustrates the fact that a wearable medical system may encompass a wide variety of components: sensors, wearable materials, smart textiles, actuators, power supplies, wireless communication modules and links, control and processing units, interface for the user, software, and advanced algorithms for data extracting and decision making. The wireless body area network (WBAN) is a promising technology that can revolutionize next-generation healthcare applications. Developing a unifying WBAN standard that addresses the core set of technical requirements is the quintessential step to unleash the full potential of WBAN and is currently under discussion in the IEEE 802.15.6 Task Group [2] . The IEEE 802.15.6 WBAN standard is used in or around a body [2, 3] . It is designed to serve advanced medical and entertainment options enabled by this standard. It will allow medical equipment manufacturers and consumer electronics manufacturers to have small, power-efficient, and inexpensive solutions to be implemented for a wide range of devices. This standard considers effects on portable antennas due to the presence of a person (varying with male, female, 2 International Journal of Distributed Sensor Networks skinny, heavy, etc.), radiation pattern shaping to minimize specific absorption rate (SAR) into the body, and changes in characteristics as a result of the user motions. WiMedia Alliance is developing the specifications of the PHY, MAC, and convergence layers for Ultrawideband (UWB) systems with participation from more than 170 companies. Also, it has been promoting the standardization and adaptation of UWB for high rate-wireless personal area network (HR-WPAN) that enables the multimedia and highspeed data communication [4, 5] . WiMedia Alliance has completed the specification of WiMedia distributed-MAC (D-MAC), and this enables various applications, such as wireless USB (WUSB) [4], Wireless 1394, and Wireless IP, to operate on WiMedia D-MAC. The WiMedia D-MAC supports a distributed-MAC approach. In contrast to IEEE 802.15.3, D-MAC makes all devices have the same functionality, and networks are self-organized and provide devices with functions such as access to the medium, channel allocation to devices, data transmission, quality of service, and synchronization in a distributed manner [5] . The term middleware refers to the software layer located between the OS and the application layer. Middleware can be further classified based on "submiddleware" functionalities including time synchronization, location, battery power, and network functionalities. As in all distributed systems, time synchronization is very important in a sensor network since the design of many protocols and the implementation of applications require precise timing information. In forming an energy-efficient radio schedule, conducting in-network processing such as data fusion, performing RF ranging, and
In REF , a middleware platform built on WUSB over WBAN hierarchical protocol for wearable health-monitoring systems (WHMS) is proposed.
Novel MAC Protocol and Middleware Designs for Wearable Sensor-Based Systems for Health Monitoring
International Journal of Distributed Sensor Networks
Computer Science