SUMMARY:

This paper describes recent and planned developments in satellite technology which can be used to provide reliable communications to ships and other vessels operating offshore.

1 INTRODUCTION:

  1. 1.1 Communications to, from and between ships and other vessels at sea has always been an important requirement. From the very earliest days of seaborne commerce, systems of coded signalling by either flags or lamps were devised. The development of radio technology provided the first reliable "over the horizon" form of communications.

However, with the fairly recent developments in satellite technology, high quality voice and data communications to or from anywhere in the world have become a reality.

This paper will trace the development of satcoms internationally with a particular focus on services available in Australia and close off shore.

2 RADIO SERVICES IN AUSTRALIAN WATERS:

  1. 2.1 The Overseas Telecommunications Commission (OTC) offers two different radio services with 24 hour per day access.

  2. 2.2 The first and longest established is known as OTC's RADPHONE service offering interconnection to the Public Switched Telephone Network (PSTN) via High Frequency (HF) radio links to OTC's network of coastal radio stations. Indicative charges for this service are a connection fee of $3.25 per call and a usage fee of $2.75 per minute.

  3. 2.3 OTC offer a full duplex radio telephone service using the Very High Frequency (VHF) band. This is known as the "Sea-phone" service and provides a virtual telephone service within 30–100 kms offshore from a suitably equipped coastal station.

  4. 2.4 High capacity dedicated radio links are provided by Telecom on a commercial works basis. These are usually limited to line of sight applications with the ability to cover maximum distances of 30 to 40 Kms.

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