Q 1.9 What are the challenges of using satellites for data communication?

Satellite links are prone to bit errors and propagation delay which can be problematic for some types of data applications.

The severity of problem depends on the desired quality of service i.e. acceptable time delay, bit error rate and throughput.

TCP/IP data protocols are in abundant use. These protocols are sensitive to bit error and time lag inherent in satellite systems. Various solutions are commercially available to minimize the impact.

Satellite resource allocation systems are designed to provide the user-negotiated quality of service. For example streaming and interactive applications require a continuous connectivity, unlike E-mails which do not require instant delivery. Bit error rate is reduced to acceptable level through powerful coding techniques, some of which can approach theoretical bound and by automatic request protocols that are based on retransmission requests when an error is detected at the receiver.