Circular Letter
COMSAR/Circ.35

RECOMMENDATIONS ON MEDIUM FREQUENCY/HIGH FREQUENCY (MF/HF) DIGITAL SELECTIVE CALLING (DSC) TEST CALLS TO COAST STATIONS

(21 May 2004)

1.  The Maritime Safety Committee, at its seventy-eighth session (12 to 21 May 2004), endorsed the view of the Sub-Committee on Radiocommunications and Search and Rescue (COMSAR), which held its eighth session from 16 to 20 February 2004, that the regular use of DSC equipment as described in COMSAR/Circ.17 should be encouraged.  However, the International Telecommunications Union Sector for Radiocommunications had indicated that excessive test calls on DSC distress and safety frequencies were overloading the system to the point where interference to distress and safety calls had become a cause for concern.

2.  In view of the above, and as a matter of urgency, Administrations concerned are urged to co-operate in managing and reducing the number of test calls on the MF/HF DSC distress and safety frequencies.

3.  To achieve this, live testing on DSC distress and safety frequencies with coast stations should be limited to once a week.  A background on the need for DSC test calls is described in COM/Circ.106.

4.  Member Governments and international organizations are invited to bring the above to the attention of their national search and rescue (SAR) Authorities, RCCs, shipowners, shipping companies and shipmasters.