# A Network Architecture and Routing Protocol for the MEDIcal WARNING System
###### Abstract  
The MEDIcal WARNING system continuously and automatically monitors the vital parameters of pre-intensive care hospitalized patients and, thanks to an intelligent processing system, provides the medical teams with a better understanding of their patients' clinical condition, thus enabling a prompt reaction to any change. Since the hospital units generally lack a wired infrastructure, a wireless network is required to collect sensor data in a server for processing purposes. This work presents the MEDIWARN communication system, addressing both the network architecture and a simple, lightweight and configurable routing protocol that fits the system requirements, such as the ability to offer path redundancy and mobility support without significantly increasing the network workload and latency. The novel protocol, called the MultiPath Routing Protocol for MEDIWARN (MP-RPM), was therefore designed as a solution to support low-latency reliable transmissions on a dynamic network while limiting the network overhead due to the control messages. The paper describes the MEDIWARN communication system and addresses the experimental performance evaluation of an implementation in a real use-case scenario. Moreover, the work discusses a simulative assessment of the MEDIWARN communication system performance obtained using different routing protocols. In particular, the timeliness and reliability results obtained by the MP-RPM routing protocol are compared with those obtained by two widely adopted routing protocols, i.e., the Ad-hoc On-demand Distance Vector (AODV) and the Destination-Sequenced Distance-Vector Routing (DSDV). health monitoring network architecture; wireless mesh networks; wireless sensor networks [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [35] [36]  
models and advanced fuzzy logic (that exploits specific rules based on medical expertise), provides interpretative elements on the clinical status of patients and its evolution well before the actual deterioration of the vital functions that would trigger the alert according to solutions such as the Early Warning Score (EWS) [9] criteria. Hence, by alerting medical staff when a patient would be starting to get worse, the MEDIWARN system allows earlier intervention with a higher chance of success in treating a patient. The use of such a system requires a network infrastructure in the hospital that would allow the transfer of data from the sensors to a server for subsequent processing. In particular, as the hospital units may lack a wired infrastructure, a wireless network is typically required. The introductory work in ref. [10] briefly presents the MEDIWARN network architecture and discusses some design challenges that such a system poses. Moreover, it shows the results of simulative assessments in realistic scenarios to provide a preliminary evaluation of the system. This paper is meant to significantly extend the work in ref. [10]. In fact, the brief paper [10] simply overviews the MEDIWARN network architecture without exploring how to address each design challenge in a real implementation, and therefore it does not provide any performance assessment on Commercial-Off-The-Shelves (COTS) devices. Moreover, the simulative results in ref. [10] highlight the need for designing a custom routing protocol for MEDIWARN able to reduce the overhead due to the routing control messages. This work therefore focuses on the MEDIWARN communication system. In particular, it addresses: (i) the network architecture; and (ii) a novel routing protocol specifically devised for the MEDIWARN system, which is simple, lightweight and configurable. Specifically, such a protocol provides the MEDIWARN system with path redundancy and mobility support without significantly increasing the network workload and latency. The paper offers both experimental and simulative performance evaluation of the MEDIWARN communication system in a real use-case scenario.