Friday Jan 19, 2018

Telecommunications Equipment


Equipment name




It is a telecommunication device to connect with ships with short range, which includes radio frequency range between 156.0 and 162.025 MHz. The marine VHF combines a transmitter and a receiver and can be used only within internationally recognized standard frequencies. Its Channel 16 (156.800 MHz) is specific to calling and emergency situation. The transmission power ranges between 1 and 25 watts, the max optimal range is about 60 nautical miles (111 km) between the antennas mounted on tall ships and hills, and 5 nautical miles (9 km) between the antennas mounted on a small boat at sea level. Frequency modulation (FM) is a vertical pole. This means that the antenna must be mounted vertically.



 It is another communication tool for ships and it has global radio coverage. In the event of disruption of satellite communication system for ships, it remains as the only communication channel with the beach. In accordance with the Safety of Lives at Sea (SOLAS) Convention, it must be installed on ships at coastal stations like NAVTEX.



It is a communication tool which must be installed for the safety of vessels. This system allows for tracking and identification of long-range ships. The long-range tracking aims to increase the security of the government by receiving information about the location and specifications of the ships. This information will enable the government to assess the security risks created outside the coastal zone.



The development of ports and increasing maritime traffic and tonnage of ships increased the risk of ship collision, thus maritime safety and seawater health are seriously threatened. To prevent the risk of incidents such as collision with marine obstacles and drowning, ships require a dual system for monitoring and control of navigation to direct them at high risk and heavy traffic places. This system is called Vessel Traffic Services (VTS).



This communication system was established in Bushehr Province for the first time in 1994, with the critical aim of servicing vessels in the Persian Gulf and the Sea of Oman in line with international conventions. Using the international NAVTEX system, the marine communication station of the General Directorate of Ports and Maritime of Bushehr Province (Bushehr Radio) sends messages, containing weather information, notices of navigational aid marks, maritime operations and emergency reports for ships in the Persian Gulf. All these messages start with the name of PERSIAN GULF. Considering the dramatic increase in maritime traffic and efforts of the Persian Gulf states to use ARABIAN GULF in maritime messaging through their NAVTEX system, the international NAVTEX station of Bushehr has a great importance to the government of the Islamic Republic of Iran.



Currently the World Maritime Organization (IMO) has identified 16 marine areas for broadcasting NAVTEX messages. Iran is located in the IX area. This area includes the Persian Gulf, the Sea of Oman and a part of the Indian Ocean. The PMO is in charge of maritime affairs in the country. In line with performing its government duties, it managed to receive the privilege of establishing two NAVTEX transmitter stations in Shahid Rajai and Bushehr in southern Iran. Nevertheless, broadcasting regular messages is also an important point. This requirement is in accordance with Clause 4 of the SOLAS Convention: GMDSS. This monitoring in the IX area is carried out by Pakistan. Obviously, any disruption to regular broadcast of messages cause prejudice to the marine dignity of the country and has irreparable consequences in the international community which cannot be justified by excuses such inter-organizational differences.

Many points should be noted in this section. In short, the most important ones are provided:

1.       The frequency range is 480-520 kHz which is considered the low frequency band and has huge impact on human body based on Faraday and Gauss rules. These effects are much more destructive than the frequency level of the VHF, UHF, HF antennas and mobile band, given the inverse relationship between frequency and wavelength.

2.       The modulation of waves is of amplitude modulation (AM) type. Given amplitude strengthening in this type of modulation, it will have huge amplitude impacts when transmitting.

3.       The allowable distance of the device is 100 meters according to its power (1000 W), related modulation and documentation. According to the UMNI DIRECTIONAL propagation of the antenna, a sphere with a radius of 100 meters is dangerous.

4.       The antenna length is 90 meters. It uses the LONG WIRE system to strengthen the signal. This increases the radius of hazard area 90 times.

5.       Flat areas are the best environment for propagation of transmitters.

6.       Among similar transmitters with minor differences, one can point to the transmitter of Radio Bushehr in the economic special zone (which has a free distance several times this value) and the transmitter of Civil Aviation.

7.       Based on the international conventions, the development of LRIT, VTS, HF and VHF systems is being pursued as relay stations given this location.