Section-I: Inmarsat Equip. & Comms: Key Topic #64: Inmarsat-b or f77 Equipment and Operations:

64I1 How is a signal radiated from an Inmarsat-B or F77 system's antenna?

A. It is usually radiated in an omni-directional pattern, but an optional feature allows it to be directional for use when the vessel is on the fringe of the satellite's footprint.

B. It is a highly focused directional signal that must be beamed at the desired satellite.

C. It is radiated in an omni-directional pattern.

D. It is radiated in an omni-directional pattern that can be reversed by the Operator to attain directional beaming to an alternate satellite.

64I2 Which mode of Inmarsat-B communications may be possible with a lower received signal strength?

A. Fax

B. Voice Communications

C. TELEX

D. Binary computer file transfers

64I3 What is the purpose of the second I.D. in an Inmarsat-B or F77 SES?

A. To provide an alternate number which may be called if a busy signal is received by the calling party.

B. To provide an additional speech path, which may be used to communicate while the first channel is engaged in active communications.

C. To provide for an emergency working frequency.

D. To provide an additional number which may be dedicated to computers, fax, etc.

64I4 What is the effect of having five periods (e.g. .....) in the text of a TELEX transmission on an Inmarsat-B SES?

A. The transmission will automatically terminate after those characters are transmitted.

B. Only the first period will be routed to the receiving party.

C. Only the first two periods will be routed to the receiving party.

D. This will automatically trigger the reversal of charges to the receiving party.

64I5 Why is the automatic answerback request (WRU) first used by the LES after an Inmarsat-B TELEX call has been placed from a ship?

A. Let the LES operator know the printer is functioning correctly.

B. Get the identity of the ship station and start the channel assignment process.

C. Verify that there is a good connection with no transmission errors.

D. Identify the SES making the request.

64I6 When engaging in voice communications via an Inmarsat-B of F77 terminal, what procedures are used?

A. CODECs are used to digitize the voice signal.

B. Noise-blanking must be selected by the operator.

C. The voice signal must be compressed to fit into the allowed bandwidth.

D. The voice signal will be expanded at the receiving terminal.

Answers: 64I1 - B 64I2 - C 64I3 - D 64I4 - A 64I5 - D 64I6 - A

Section-I: Inmarsat Equip. & Comms: Key Topic #65: Inmarsat-c: Equipment and Operations-1:

65I1 Which mode of communications is NOT possible through an Inmarsat-C SES?

A. Shore-to-ship Facsimile

B. Data

C. TELEX

D. Emergency Activation

65I2 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 message sent by Inmarsat-C is about 10 minutes.

C. Date/time notification of delivery is possible only through Inmarsat-B.

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.

65I3 How is a signal radiated from an Inmarsat-C system's antenna?

A. It is a highly focused directional signal that must be beamed at the desired satellite.

B. It is usually radiated in an omni-directional pattern, but an optional feature allows it to be directional for use when the vessel is on the fringe of the satellite's footprint.

C. It is radiated in an omni-directional pattern.

D. It is radiated in an omni-directional pattern that can be reversed by the Operator to attain directional beaming to an alternate satellite.

65I4 What statement is true regarding Inmarsat-C?

A. There is a propagation delay, but a direct connection is made between the ship and shore users.

B. There are delays in establishing communications. Then a direct real-time connection is maintained with the other party.

C. The TELEX message is stored until the mailbox is accessed by the station desiring to retrieve their message.

D. This is a store and forward network, with an intermediate step that means there is no direct connection between ship and shore users.

65I5 With an Inmarsat-C LES, how are messages routed to receiving stations?

A. All messages are forwarded via a store and forward network.

B. Direct connections are made to the receiving stations via gateways.

C. Intermediary stations are used to connect the sending station with the receiving station in a real-time mode.

D. Messages are stored until the network is polled by the receiving station.

65I6 What are the directional characteristics of the Inmarsat-C SES antenna?

A. Highly directional parabolic antenna requiring stabilization.

B. Omni-directional.

C. Wide beam width in a cardioid pattern off the front of the antenna.

D. Very narrow beam width straight-up from the top of the antenna.

Answers: 65I1 - A 65I2 - B 65I3 - C 65I4 - D 65I5 - A 65I6 - B