Question

Assignment 1

1. If Satellite with a radius of 5.3m transmitted a message at the frequency of 1.3 MHz to

earth station. Determine;

i. The wavelength, and time, in hour of the transmission

ii. The centrifugal force of the satellite

iii. The attenuation of the transmission

2. The wavelength of a signal transmitted at 1000MS-1 is 700M. Determine the period of

the transmission

3. Analyze the conditions that can lead to satellite path diversity

4. Explain handoff and discuss three types of satellite handoff

Answer 1

1)

2) $Period (T) = 1 /Frequency (f)$

$T = 1/700$

= 0.001429

3)

•   The mass of the central body (earth)
• The radius of the orbit affect orbital speed.
• The orbital radius is in turn dependent upon the height of the satellite above the earth.

4)Handoff is the process of transferring an ongoing call or data session from one channel connected to the core network to another channel.

Link-Layer Handover

Link-layer handover occurs when we have to change one or more links between the communication endpoints due to dynamic connectivity patterns of LEO satellites.

Network-Layer Handover

When one o f the communication endpoints (either satellite or user end) changes its IP address due to the change of coverage area of the satellite or mobility of the user terminal, a network or higher-layer handover is needed to migrate the existing connections of higher-level protocols (TCP, UDP, SCTP, etc.) to the new IP address. 

Inter system handover

It is a handover form the satellite network to a terrestrial cellular network. Mobile station can reach a terrestrial network again which might be cheaper, has a lower latency.