New research areas in the field of terrestrial optical wireless links

The paper deals with the terrestrial optical wireless links (TOWL) operating with coherent laser beams. The contribution discusses two main types of TOWL: data link and test link. Main aspects of constructions are shown. Purely photonic concept of given links is presented and justified. For the TOWL, applications not only in the field of communications, but also in environmental informatics or for synchronisation impulse distribution (time transmission) are given. Paper further discusses phenomena (standard and non-standard) deteriorating the TWOL availability and their monitoring, evaluation and reduction are explained. TOWL modelling is divided with respect to the stationary and statistical point of view and standardisation of the optical link and the atmosphere are proposed. The topic presented in the paper are independent from modulation formats and coding scheme.