Exercise 10. Complete the text with the words give below, translate and retell the text below

Satellite communications are particularly important elements of the____. The INMARSAT system employs ______ satellites and operates in the 1.5 – 1.6 GHz. It provides ships fitted with Ship Earth Stations (SES) a means of _____ and a capability of two-way communications using radio telex and radiotelephone.

The INMARSAT SafetyNET system is used for broadcasts of MSI to areas not covered by the ___ system.

The maritime satellite system has three major components: the ___ segments provided by INMARSAT, the Coast Earth Stations (CES) provided by INMARSAT signatories and SESs.

The INMARSAT system provides ships at sea with the same types and quality of modern communications as are available____. The nerve center of the system is the Operations Control Center (OCC) located at INMARSAT‘s headquarters in the United Kingdom. Four INMARSAT satellites in geostationary orbit 36,000 kilometers above the ____ provide near-global coverage. The coast earth stations CES provide the ____ between the satellites and terrestrial telecommunications networks.

Geostationary, GMDSS, alerting, ashore, INMARSAT, equator, link, NAVTEX, space

Check yourself

1. Please write the acronym SES in full.

2. INMARSAT-C Land Earth Stations can deliver messages via facsimile, telex and e-mail systems.

a) TRUE b) FALSE c) Only INMARSAT-A/B d) I DON’T KNOW

3. Which one of the following INMARSAT services provides communications by telephone, telex, facsimile (fax), and data?

a) INMARSAT-A/B.

b) INMARSAT-C.

c) SafetyNET.

d) VHF-FM.

4.How many GMDSS sea areas are there in the world where you can use Inmarsat station ?

a) 4 b) 3 c) 2 d) 16

5. Which satellite system supports both ship-to-shore and shore-to-ship facsimile (fax) сommunications?

a) INMARSAT-A/B. b) INMARSAT-C. c) COSPAS-SARSAT. d) INMARSAT-E.

6. What is the service code for requesting automatic (unattended) service through INMARSAT-A/B?

a) It depends on which carrier will be used for routing the call. b) 11#. c) 01. d) 00.

7. Which address must you type to send message from your Inmarsat-C terminal to the hospital?

a) Telex ocean region access code + IMN b) Special code 38 c) Any address with distress priority d) Special code 32

8. What is meant by an INMARSAT satellite's "elevation"?

a) The angle of the satellite to the equator.

b) The satellite height above the horizon as seen from the ship.

c) The relative bearing of the satellite to the vessel's course.

d) The height of the antenna above the main deck.

9. 1 kbit= ...

a) 256 bit b) 1000 bit c) 1024 bit d) 100 bit

10. Which one of the following statements concerning INMARSAT-C is true?

a) Telex communications are established in the ARQ mode.

b) Telex communications are conducted with real-time connectivity.

c) Telex communications are less expensive than voice communications.

d) Telex communications are delivered on a store-and-forward basis.

11. Which key must be used to signal the end of a manually-dialed number in a telephone call made via INMARSAT-A?

a) The colon (":") key. b) The "ENTER" key. c) The plus ("+") key. d) The pound ("#") key

12. Which key must be used to signal the end of a manually-dialed number in a telex via sent via INMARSAT-A?

a) The colon (":") key. b) The "ENTER" key. c) The plus ("+") key. d) The pound ("#") key.

13. How is maximum coverage provided by satellites in the GMDSS?

a) There are four satellites in polar orbit.

b) There are four satellites in geostationary orbit.

c) Each service (INMARSAT-A, -B, -C, and -M) has four satellites in orbit.

d) GMDSS optimizes coordinated use of COSPAS-SARSAT satellites.

14. What priority code is associated with routine calls made via INMARSAT-A?

a) 0. b) 1. c) 2. d) 3.

15. Which telephone services are available through INMARSAT-A?

a) Person-to-person calls. b) Collect calls. c) Credit card calls. d) All of these

16. What is an INMARSAT "Subscriber Number"?

a) This identifies the vessel's selective calling (selcall) number.

b) This is the INMARSAT number that is assigned to a unit for incoming calls.

c) This is the vessel's INMARSAT registration number for accounting authority purposes.

d) This number is used for receiving news and other optional services in FleetNET.

17. What do the characters "GA+" mean when they appear in a telex communications sent by INMARSAT-A?

a) "Global Accounting". b) "Go ahead". c) "General Advisory". d) This abbreviation has no meaning to a telex call as the plus ("+") sign is used only in conjunction with voice calls.

18. Which one of the following calls via INMARSAT-A will be the least expensive?

a) All INMARSAT-A calls are made at uniform rates, regardless of mode.

b) Voice calls placed from one ship to another ship.

c) Telex calls placed from a ship to a shore-based location.

d) Telex calls placed from one ship to another ship.

19. Which one of the following calls via INMARSAT-A will be the most expensive?

a) All INMARSAT-A calls are made at uniform rates, regardless of mode.

b) Voice calls placed from one ship to another ship.

c) Telex calls placed from a ship to a shore-based location.

d) Telex calls placed from one ship to another ship.

20. What is meant by "CES"?

a) Coast Earth Satellite. b) Coast Earth Station. c) Central Equatorial Station. d) Coastal Equivalent Station.

21. What is meant by "AOR"?

a) Atlantic Operations b) Atlantic Ocean Region. c) Actual Ocean Region. d) Actual Operator Response..29

22. What will most likely happen if a satellite's elevation becomes very low?

a) Changes in the elevation have no effect on communications.

b) Communications range through the satellite will likely be maximized.

c) Communications through the satellite will likely become difficult or impossible to establish.

d) This indicates that the vessel should effect a course change to minimize shadowing.

23. What dialing sequence must be entered to request Operator Assistance by telex through INMARSAT-A?

a) Operator assistance is not available through INMARSAT-A, but is available through INMARSAT-C.

b) 11#. c) 01#. d) 11+.

24. What is the purpose of including a string of five periods (". . . . .") in an INMARSAT-A telex message?

a) This is an ellipse that is used to signify that certain redundant text has been deleted

b) This instructs the coast earth station to automatically disconnect the telexconnection and sever the satellite communications.

c) A string of five periods will not affect an INMARSAT-A telex transmission.

d) This instructs the coast earth station to automatically disconnect the telex connection and keep the shipboard unit in communications with the satellite.

25. Which one of the following equipment is intended to be interfaced with an INMARSAT-A unit?

a) On-board personal computer.

b) Digital Selective Calling controller.

c) Autoalarm generator.

d) Shipwide signal distribution panel.

26. What dialing sequence must be entered to request Operator Assistance by voice through INMARSAT-A?

a) Operator assistance is not available through INMARSAT-A, but is available through INMARSAT-C.

b) 11#.

c) 01#.

d) 11+.

27. How are charges determined for a ship-to-ship facsimile communication by INMARSAT-A?

a) Fax rates are about one-half that of ship-to-ship voice communications.

b) Fax rates are about twice that of ship-to-ship voice communications.

c) Fax rates are about the same as for ship-to-ship voice communications.

d) Fax communications are not possible through INMARSAT-A.

28. How are charges calculated for a ship-to-ship telex message sent by INMARSAT-C?

a) Charges begin when the vessel being called responds with its answerback.

b) Charges are determined by the size of the telex message.

c) Charges for a telex call are about one half that of a voice call.

d) Charges for all calls are the same, regardless of their mode.

29. How are charges determined for a ship-to-ship voice communication by INMARSAT-C?

a) Voice communication rates for ship-to-ship calls through INMARSAT-C are about twice those for ship-to shore INMARSAT-C calls.

b)Voice communication rates through INMARSAT-C are about half that for voice communications through INMARSAT-A.

c) Voice communication rates are determined by the length of the call through INMARSAT-C.

d) Voice communications are not possible through INMARSAT-C.

30. Which one of the following statements concerning INMARSAT service rates is true?

a) Charges for a voice call placed through INMARSAT-C begin to accrue when the number being called is answered.

b) Charges for a voice call placed through INMARSAT-A begin to accrue when the message reference number is received from the coast earth station.

c) Charges for a voice call placed through INMARSAT-A begin to accrue when the number being called is answered.

d) Charges for a voice call placed through INMARSAT-A begin to accrue when the coast earth station acknowledges the call.

31. Which one of the following statements concerning INMARSAT-C is true?

a) Voice calls through INMARSAT-C are more expensive than telex calls through the same system.

b) A vessel may send and receive fax messages through INMARSAT-C.

c) A vessel can establish voice communications through INMARSAT-C on a dedicated channel.

d) Telex messages can be sent or received through INMARSAT-C.

32. Which one of the following statements concerning INMARSAT-C is true?

a) Telex communications are conducted with real-time connectivity.

b) Two-way real-time telex communications can exist with prior arrangement.

c) Telex messages are delivered on a store-and-forward basis.

d) Fax messages can be both sent and received through INMARSAT-C.

33. Which one of the following best describes a shipboard INMARSAT-C system?

a) A satellite communications system that provides real-time connectivity.

b) A small, lightweight terminal capable of providing satellite store-and-forward message communications.

c) A small, lightweight terminal used to transmit messages over high frequency (HF) bands to communicate through a satellite.

d) A satellite communications system that also provides continuous Digital Selective Calling coverage for all ocean regions.

34. Which action must be taken to ensure that incoming message traffic of all priority levels will be received through INMARSAT-C?

a) The system needs only to be commissioned and switch on.

b) No additional action is necessary after turning on the receiver and aiming the antenna at the desired satellite.

c) The GMDSS Radio Operator must log on to the desired satellite.

d) The GMDSS Radio Operator must log on to the desired satellite and receive the message reference number (MRN) from the CES.

35. Which one of the following actions should be taken once the vessel is berthed and will not leave port again for several weeks?

a) The GMDSS Radio Operator must notify the NCS that the vessel will be off-line, and wait for the NCS to acknowledge with a confirmation number that must be logged.

b) The INMARSAT-C system can be powered down without taking additional steps once the GMDSS Radio Operator has ensured that all incoming SafetyNET messages have been received and stored.

c) The GMDSS Radio Operator must log off of the INMARSAT system.

d) The GMDSS Radio Operator must transmit an all-ships alert to notify all vessels within the satellite's footprint that the vessel will be off-line.

36. What is the average length of time required for a telex sent by INMARSAT-C to be delivered to the addressee?

a) All INMARSAT-C communications are made with real-time connectivity so there is no delay in message delivery.

b) The average delivery time for a telex sent by INMARSAT-C is about 10 minutes.

c) Date/time notification of delivery is possible only through INMARSAT-A.

d) The average delivery time for a telex sent by INMARSAT-C is about 10 minutes, but fax and data messages sent by INMARSAT-C require about 30 minutes for delivery.

37. How are telex messages sent by INMARSAT-C delivered?

a) They are delivered on a store-and-forward basis.

b) Most are delivered on a store-and-forward basis, but can be delivered in real-time that will be more expensive.

c) They are delivered with no time delay if both the sending and receiving parties are using the same satellite.

d) Delivery time is enhanced when the station sending the telex detects a low (minimal) satellite elevation.

38. What comprises an INMARSAT-C subscriber number?

a) Seven digits, beginning with a one (1).

b) Nine digits, beginning with a three (3).

c) Nine digits, beginning with a four (4).

d) Nine digits, beginning with the country code associated with the country in which the vessel is registered.

39. Which one of the following two-way modes of communications are available when

using INMARSAT-C?

a) Telex. b) Fax. c) 14400 BPS Data. d) Voice.

40. How is a distress message normally initiated through INMARSAT?

a) All INMARSAT units have a dedicated key that can be pressed for immediate action.

b) By adding the word "DISTRESS" in the first line of the message's preamble.

c) Certain INMARSAT units have a dedicated key that can be pressed for Immediate action, while other systems provide menu-driven features.

d) By transmitting the distress message on the U.S. Coast Guard's dedicated monitoring channel.

41. Which one of the following statements concerning geostationary satellites is true?

a) They are in a low-earth polar orbit to provide true global coverage.

b) They are in an equatorial orbit to provide true global coverage.

c) They provide coverage to vessels in nearly all of the world's navigable waters.

d) Vessels sailing in equatorial waters are able to use only one satellite whereas other vessels are able to choose between at least two satellites.

44. Which one of the following statements concerning INMARSAT-A is false?

a) Communications require a highly focused, directional antenna.

b) All modes, including data communications, are possible.

c) Standard-A service is available through all INMARSAT satellites.

d) True global coverage is available.