Context-aware Mobility Management with WiFi/3G Offloading for eHealth WBANs El Hadi Cherkaoui, Nazim Agoulmine LRSM/IBISC Laboratory, University of Evry Val d’Essonne, 23 Boulevard de France, 91100 Evry, France. E-mail: {elhadi.cherkaoui,nazim.agoulmine}@ibisc.univ-evry.fr Abstract—Wireless Body Area Network (WBAN) relays on IEEE802.15.6 communication standard optimized for low power and short range communication between wireless medical sensors installed on the patient body that gathers health data (e.g. Heartbeat, SPO2, etc.). In addition, every WBAN has a specific component called gateway that permits to send the measured health datas to remote servers. For long range communications, the gateway is equipped with a 3G/WiFi interfaces. 3G interface allows high Quality transmission of health data during mobility. However, the large amount of 3G data traffic transmitting through this network is expected to grow rapidly with the popularity of mobile applications and therefore degrade the overall service. The aim of this paper is a contribution to improve the Quality of Service (QoS) of ehealth applications to assure an efficient and continuous remote monitoring of patients and elderly. For that, we propose a design of a new context-aware mobility management system that is able to take benefit from multiple available access wireless networks (3G and WiFi) to offload smartly specific traffics and maintain the QoS of critical services such as ehealth services. Index Terms—WBAN, Heterogeneous networks, Traffic of- floading, Energy efficiency, WBAN, ZigBee, 3G, WiFi I. I NTRODUCTION During the last few years there has been a significant in- crease in the number and variety of wearable health monitoring devices, ranging from simple pulse monitors, activity monitors to sophisticated and expensive implantable sensors. Tradition- ally, personal medical monitoring systems have been used only to collect data. Data processing and analysis were per- formed off-line, making such devices impractical for continual monitoring and early detection of medical disorders. Systems with multiple sensors for physical rehabilitation often feature inconvenient wires between the sensors and the monitoring system. These wires may limit the patient’s activity and level of comfort and thus negatively influence the measured results [1]. One of the most promising approaches to improve remote health monitoring is the one build on emerging Wireless Body Area Networks (WBANs) [2] associated with Cloud Computing technology [3] [4]. A WBAN consists on mul- tiple interconnected wireless sensor nodes, each capable of sampling, processing, and communicating one or several vital signs (heart rate, blood pressure, oxygen saturation, activity) or environmental data (location, temperature, humidity, light). Patients are also equipped with a PDA (Personal Digital Assistance) that plays the role of gateway for the WBAN. It gathers the health data sensed by the WBAN sensors and transmits it to remote health provider(s) server(s) for diagnosis using any available long range communication network (3G, WLAN, GPRS or LTE).With Cloud Computing technology, these applications could also run in the Cloud. Indeed Cloud Computing allows the delivery of computing resources as a service. Shared resources, software, and information are typically provided to computers and other devices as a Utility over the Internet network. WBAN usually relays on IEEE802.15.6 communication standard that is optimized for low power and short range communications. However, these wireless communication are expected to relay on integrating heterogeneous networks con- sisting of cellular and backbone networks. Several technical issues and challenges are associated with the integration of WBANs an Cloud Infrastructure in the context heterogeneous wireless access networks. The main issues of this hetero- geneous inter-connectivity are the interworking of the dif- ferent network including seamless Vertical Handover (VHO) mechanisms to guarantee the reliability of critical healthcare data transmission. Solutions based on WiFi offloading are generally used to avoid transporting unnecessary traffic and to maintain a high QoS for users while saving energy con- sumption. The aim of this paper is to design a context-aware mobility management system that can support high mobility in the WBAN/WLAN/3G inter-working environment based on WiFi offloading, while minimizing power consumption for healthcare applications. This paper is organized as follows: in Section II, we present first some related works on wireless Access Network Selection (ANS) and traffic offloading in heterogeneous networks. We highlight also the problem statement when using WBANs. In Section III, we formulate the problem and present the considered scenario. In Section IV, we introduce the pro- posed architecture for Context-Aware Mobility Management System for WBAN (CAMMSW), including the inter-working architecture between WBAN, WLAN, and 3GPP technologies. Section V presents an implementation and evaluation of the proposed architecture in a simulator and discuss the obtained results. Finally, conclusions are presented in the last section. II. RELATED WORKS A. Access Network Selection The problem of wireless Access Network Selection (ANS) and VHO (Vertical HandOver) have been previously addressed 2014 IEEE 16th International Conference on e-Health Networking, Applications and Services (Healthcom) 978-1-4799-6644-8/14/$31.00 ©2014 IEEE 420