Ricerc@Sapienza

The hepatitis B virus (HBV) infection represents
a global health problem; it can be transmitted through contact
with infected blood or other body fluids and it is dangerous
being highly contagious. Hepatitis B is preventable with effective
vaccine, as it is strongly recommended by the World
Health Organization; its protection is possibly life-long, at least
20 years. Mathematical modelling is a useful tool to study the
evolution of an epidemic spread and possibly to suggest suitable

LoRaWAN is emerging as an attractive network infrastructure for ultra low power Internet of Thing devices. Albeit the technology itself is quite mature and specified, how to effectively allocate wireless resources so as to support a large amount of devices in a same terrestrial area is an open challenge. This paper contributes by proposing two algorithms (of incremental complexity) which are shown to outperform the basic Adaptive Rate Strategy (ADR) so far considered.

To exploit the LoRaWAN (Long-Range Wide Area Network), it is essential to design suitable allocation schemes for the wireless resources. To this aim, strategies for a fair allocation of Spreading Factors (SF) among the network devices have been presented. These strategies greatly outperform the basic Adaptive Data Rate (ADR) scheme. Within these techniques, EXPLoRa-AT yields so far the best results exploiting an 'ordered water-filling' approach which aims to equalize the Air-Time channel usage for each group of devices using the same SF.

In this paper we present two resource allocations techniques in a visible light communication network with overlapping coverage areas due to the use of access points. Particularly, the first approach exploits the rate maximization criteria, and then aims at maximizing the network rate under constraints on minimum and maximum rates, while the other procedure focuses on achieving fairness in the rate of each user accessing the network. The proposed system relays on optical code division multiple access mechanism, and resource allocation is intended in terms of codes assigned to a given user.