ALSN
ALSN (автоматическая локомотивная сигнализация непрерывная, in Latin - avtomaticheskaya lokomotivnaya signalizatsiya nepreryvnaya, meaning Continuous Automatic Train Signalling) is a train control system used widely on the main lines of the ex-Soviet states (Russian Federation, Ukraine, Belarus, Latvia, Lithuania, Estonia). It uses modulated pulses inducted into rails similar to the Italian RS4 Codici and American Pulse Code Cab Signaling.