What is "pactor"

PACTOR is a radio modulation mode used by amateur radio operators, marine radio stations, and radio stations in isolated areas to send and receive digital information via radio. A robust network of PACTOR stations has been established to relay data between radio stations and the Internet, extending Internet access to sea based and other isolated users. PACTOR utilizes a combination of simple FSK modulation, and the ARQ protocol for robust error detection and data throughput. Generational improvements to PACTOR include PACTOR II, PACTOR III, and PACTOR IV which are capable of higher speed transmission. Pactor modes other than level 1 (P1) are not open source and therefore cannot be decoded by anyone who hasn't invested in a proprietary modem.