Comparison of ISDN and MPDS communication modes via Inmarsat Fleet services

Inmarsat introduced the Fleet family of services in 2002/2003. For the first time mobile packet data service (MPDS) was introduced into maritime communications, allowing continuous connection of ships to terrestrial networks with payment for volume of data exchanged rather than the duration of airtime used. Noting that the Fleet family of services also provides the ISDN option, questions are being raised, both technical and commercial, about the advantages and disadvantages of each option. This paper discusses both technical and commercial issues in that respect.