28 BER for the different SLs with respect to the energy per bit 29 Spectrum of a PACTORIII signal at SL6 with all 18 tones active 2 Typical communication protocol (TBUS) 3 Global Link Network (GLN) General overview The GLN is a network of cooperating coastal radio stations (CRSs) offering data access for the maritime mobile service. Due to the increasing demand for email transfer and internet access on sea going vessels and the decreasing use of narrow-band direct-printing (NBDP) and radio telex, these radio stations now offer data services on shortwave. Organizational structure All CRSs are operated by independent companies. These companies have joined together to form the GLN. They use common technology and common modulation. The CRS are free to offer their own additional services depending on local requirements. If the connection to the network control centre (NCC) fails for political, military or other reasons, every station is able to operate independently. In such cases the CRSs may also offer long-distance communications outside the main communication networks. Technical structure The GLN is based on the so called Pactor IP-Bridge (PIB). PIB enables transparent data connections based on the TCP/IP protocol over 2k4 radio channels in all the maritime MF/HF bands. PIB may be used for any type of data service with a maximum transfer speed up to 5 600 bit/s compressed. All network servers operate with a Linux OS and additional software packages which ensure a high fail-safe performance. NCC The NCC is operated under an agreement with the CRSs. It is responsible for data bases, accounting, backup, data security and development. The NCC also operates a mail server for small stations without their own data infrastructure. The NCC offers basic data services like weather information, email online compression, web mail, tracking and crew email to all customers of the GLN network. CRS The CRSs hold one or more radio channels on standby for automated data links between vessels and the internet. They may offer additional services like data transfer (FTP), credit card services, web
28 BER for the different SLs with respect to the energy per bit 29 Spectrum of a PACTORIII signal at SL6 with all 18 tones active 2 Typical communication protocol (TBUS) 3 Global Link Network (GLN) General overview The GLN is a network of cooperating coastal radio stations (CRSs) offering data access for the maritime mobile service. Due to the increasing demand for email transfer and internet access on sea going vessels and the decreasing use of narrow-band direct-printing (NBDP) and radio telex, these radio stations now offer data services on shortwave. Organizational structure All CRSs are operated by independent companies. These companies have joined together to form the GLN. They use common technology and common modulation. The CRS are free to offer their own additional services depending on local requirements. If the connection to the network control centre (NCC) fails for political, military or other reasons, every station is able to operate independently. In such cases the CRSs may also offer long-distance communications outside the main communication networks. Technical structure The GLN is based on the so called Pactor IP-Bridge (PIB). PIB enables transparent data connections based on the TCP/IP protocol over 2k4 radio channels in all the maritime MF/HF bands. PIB may be used for any type of data service with a maximum transfer speed up to 5 600 bit/s compressed. All network servers operate with a Linux OS and additional software packages which ensure a high fail-safe performance. NCC The NCC is operated under an agreement with the CRSs. It is responsible for data bases, accounting, backup, data security and development. The NCC also operates a mail server for small stations without their own data infrastructure. The NCC offers basic data services like weather information, email online compression, web mail, tracking and crew email to all customers of the GLN network. CRS The CRSs hold one or more radio channels on standby for automated data links between vessels and the internet. They may offer additional services like data transfer (FTP), credit card services, web
R-REC-M.1798-1-201004-I!!MSW-E.docx