A Novel Hierarchical Group-Based Overlay Healthcare Network

Introduction

Advances and innovations in the ICT domain have enabled the healthcare environment to provide personalized services (e.g. tele-monitoring, tele-medicine, appointment scheduling etc.) remotely to patients and other participants, i.e. doctors, nurses, paramedical staff that are involved into the treatment plans. The increased demand to handle vast amounts of information and provide accurate treatment efficiently and dynamically poses new challenges to the existing communication infrastructures and networks. These challenges cannot be fully addressed by general-purpose information systems since they do not take into consideration the combination of complex requirements of the healthcare domain such as accurate information searching and retrieval, the dynamic nature of the participating users and appliances and large-scale deployment. The existing systems seem to be inappropriate and inefficient for the ubiquitous healthcare environment. Centralized systems exhibit poor scalability as the number of users and the requests for information retrieval increase. Moreover, in large-scale centralized systems, the increased complexity of information retrieval leads to single points of failure and creates many problems known as bottlenecks. In the healthcare domain, these impairments are crucial in patient’s treatment and pose patient’s life at risk in critical conditions. From this point of view, there is a need for scalable, dynamic, robust and secure networks oriented to healthcare purposes.

The peer-to-peer paradigm seems to be the most fertile computing approach to address the previous challenges. Peer-to-peer networks are characterized by distributed, self-organized, scalable, robust and dynamic functionalities that suit well to the prerequisites of the healthcare domain. Recently, some research efforts have proposed healthcare solutions based on the principles of peer-to-peer networking (Geissbuhler, Spahni, Assimacopoulos, Raetzo & Gobet, 2004; Kailasam, Kumar & Dharanipragada, 2010; Maglogiannis, Delakouridis & Kazatzopoulos, 2006). These works are limited either to a theoretical level or they focus on specific aspects like file sharing. They usually rely on existing structured topologies that offer enhanced scalability and they are particularly effective in handling simple queries. However, they do not inherently support complex queries and the maintenance of the overlay structure requires additional computational cost and message exchange, especially in large-scale networks. On the other hand, unstructured overlays can withstand frequent connections and disconnections of users and they can handle complex queries. Nevertheless, their main search mechanism is flooding which causes increased message overhead and they perform poorly when handling simple queries or when searching for rare items. Given the nature of the medical information stored and exchanged through a healthcare network, support for both simple and complex queries is mandatory. Moreover, for accurate treatment, guaranteed information retrieval with low response time is significant. Structured peer-to-peer overlays are more suitable as the basis for the development of novel peer-to-peer networks tailored to the needs of healthcare systems.