Analysis of Limit Setting Rationales for Protection of Maritime VHF Radio

Abstract

IEC 60533 is a product standard that puts strict requirements on all equipment on board of ships. Except for dedicated bridge equipment, there are hardly any products available that comply. One aspect from this standard is the low emission limit for radio frequency protection of the maritime very high frequency radio telephony system. This limit appears not to be based on a minimum range to receive a distress call, but on the possibility of receiving the lowest possible signal in an assumed placement of equipment. An analysis of the standard and a reconstruction of their rationale have led to an alternative, functional requirement with proper rationale, which can give the system integrator more flexibility in choosing equipment. This novel risk-based approach results in the same objective, i.e., an interference-free environment. Measurements have been performed to demonstrate possible disturbance sources and to investigate the communication range.

Cost-effective electromagnetic compatible installation on ships using a risk based approach

“…In Figure 4 a measurement is shown on board a ship which is in operation and has a significant amount of equipment on board that is not tested according IEC 60533. However the noise level on the receiver input is below 0 dBμV which is an interpretation of SOLAS requirements as explained in [27]. There are a few signals exceeding the 0 dBμV and it is quite easy to determine their source by tuning in on these signals.…”

Satellite Machine-Type Communication for Maritime Internet of Things: An Interference Perspective

“…where ζ I/N = −6 dB. The receiver system noise N consists of both internal and external noise [23]. The internal noise is dominated by thermal noise with equivalent noise temperature of T r = 30 dBK, given the receiver noise figure of 7 dB [21].…”