# Implementation of Context Aware e-Health Environments Based on Social Sensor Networks
## 1 Introduction  
Population ageing is unprecedented, without parallel in human history--and the twenty-first century will witness even more rapid ageing than did the century just past [1]. This global phenomenon is affecting the whole world, although with different evolution rates of the process, depending on regions or countries. In any case, the main goal for the future is to ensure people everywhere will be ageing actively, making possible their participation in social activities without any restrictions. Hence, to reach the above challenge, an embedded Social-Health care action or strategy where citizen empowerment should be the solution's central point is mandatory [2]. This strategy must take into account all personal and context factors such as personal health, work and economic situation, social networks, _etc._ that affect active aging and assisted living processes. This Social-Health care strategy should be based on massive use of Information and Communication Technologies (ICT) for making possible a service deployment with several main features as cost-effective, plug and play operation, minimal user's intervention, and helpful for the largest number of citizens. Adopted ICT Social-Health care solutions could be included in two possible scenarios [3]. On the one hand, indoor monitoring scenarios, so-called home monitoring is defined where the user's state is controlled at his or her own residence. These scenarios provide more real information about the userdue to the fact that the remote control process is achieved at a comfortable and regular environment. On the other hand, outdoor monitoring scenarios that include all situations where the user is away from home (office, walking on street, gym, _etc._) and is also continuously monitored. These scenarios provide mobility to the user while the control process is performed. In both scenarios, the devices (for medical or behavioral monitoring), are portable or wearable, general purpose, and user-friendly. Moreover, they are equipped with short range (Bluetooth, Zigbee, IrDA, _etc._) and/or large range (GSM-GPRS, UMTS, _etc._) wireless technologies. Currently, the use of Wireless Sensor Networks (WSN) continues to grow in a wide variety of application fields [4; 5; 6], such as agriculture and farming [7], infrastructure state monitoring [8], location and guiding [9], vehicular communications [10] and healthcare monitoring [11; 12], to name a few. The future trend seems to be the increase of the number of wireless nodes in order to collect more information from the surrounding environment, bringing the Internet of Things (IoT) to our daily life. Among WSNs, Mobile Ad-hoc Networks (MANET) have attracted the attention of many research groups around the world, becoming popular due to the unique characteristics they provide: wireless mobile devices with limited resources that can exchange information with each other without any fixed infrastructure. Thus, MANETs provide easier deployment, system maintenance and upgrade. These characteristics make MANETs an adequate solution to solve efficiently many applications, as is the case of the telemedicine and healthcare system presented in this work. In fact, in the literature can be found several works of MANETs applied to healthcare environments, such as hospital and big in-building environments [13], tele-emergency projects [14], tele-care and telemedicine systems [15; 16], real time medical data acquisition and patient monitoring systems [17; 18; 19], and more specific applications such as tele-cardiology [20], emergency telemedicine system in disaster areas [21] and monitoring combat soldiers [22]. In Spain, the Social-Sanitary System term (in Spanish \"_Sistema Socio-Sanitario_\") makes reference to the public or private healthcare system focused on guaranteeing the best population' state regarding general aspects as life quality, well-being, and social integration.