Long Range Offshore Radio Link

2009-11-07

Over 80kms Line of Sight Connection

An overseas customer, heavily involved in offshore activities had been restricted in their logistic operations by low bandwidth connectivity to and from their vessels and shore.   This was a few hundred kilobits at best and was via VSAT.  Apart from the restricted bandwidth, the associated maintenance cost of the aging VSAT hardware was adding to concerns and cost.

W&D was asked to provide a digital data link replacement for the VSAT hardware.   The operational requirement was to increase the bandwidth to at least 5Mbps and to have an operational range of up to 80km out to sea.
The solution provided by the W&D engineers used the dVMo COFDM digital link equipment.  It provided an IP interface for computer data traffic and analogue video interfaces for security images.  The total bandwidth of all services was 8Mbps – a dramatic increase.

The system employed a fixed antenna array at the on-shore base station site and directional antennas on the vessels.   High power amplifiers were used on the dVMo transmitters to deliver 30W of COFDM energy.  Diversity reception was used both on the vessels and at the shore station and this greatly enhanced the receive link performance where sea reflections were a problem.

A secondary narrowband telemetry link using Orion radio modems monitored the performance of the key components in the system and reported this data to web based data pages.   This on line facility allowed the customer to view real time where his assets were deployed and the performance of key components.
The system has now been in service for 36 months and has six vessels operating along a 200km stretch of coast and out to sea by up to 80km.   A local W&D team supports the installation on a 24/7 basis with email and SMS based reporting of any degradation in system performance

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