In France, long term Non-Invasive Ventilation (NIV) is a widely used treatment modality in COPD patients with chronic alveolar hypoventilation who have frequent exacerbations. The investigators have demonstrated in a previous study that the analysis of parameters from software embedded in the NIV device can reliably predict the occurrence of an exacerbation. The investigators hypothesize that the daily transmission via a telemonitoring platform of the ventilation parameters of patients, together with an ad hoc warning system, would reduce the rate of hospitalization for COPD patients treated at home with NIV thanks to the early detection and early treatment of these exacerbations.