In addition, electronic logbook requirements are defined thus: catch and effort recording in 'real time' but as a minimum every 24hrs whilst a fishing vessel is at sea. Catch and effort data can be transmitted over whichever communication channel is available (i.e., if the Satellite Communication Service is unavailable, connection will be attempted via GPRS/GSM and vice versa). Electronic logbooks are commonly referred to as 'E-logbooks' and the end to end process and accompanying software is referred to as 'Elogbook Software System or ELSS'.