H.F. maritime mobile services

The paper surveys the developments in the last 15 years of the h.f. ship-shore communication services provided in the United Kingdom by the Post Office. The first part of the paper deals with the radiotelegraphy services: the international planning at the Atlantic City Radio Conference in 1947; frequency-allocation problems; national planning in the United Kingdom; development of better radio equipments for coast and ship stations; the peace-time development of the joint Admiralty-Post Office Area Scheme for Commonwealth communication with British ships; and the new operational methods for handling the increased volume of traffic. The second part of the paper deals with the developments in the corresponding radiotelephone services with ships and the different frequency-planning and operational problems. The last part of the paper mentions briefly probable future trends, such as the introduction of single-sideband working in the telephony service, selective calling of ships by coast stations to minimize human watchkeeping, data transmission and the use of facsimile for transmission of charts and weather data.