Question

(a) Explain five (5) reasons why NCA is migrating
from Analogue to Digital Transmission.

(b) Wireless communication involves transfer of
information without any physical connection between
two or more points. Because of this absence of any
physical infrastructure, wireless communication has
certain advantages and disadvantages. Discuss the
most important ones with examples.

(c) In GSM systems the signal direction from the
mobile station to the network or the base station is
referred to as uplink. Why are lower frequencies given
to the uplink? A mobile network operator was
allocated uplink frequency (890-915MHz) and
downlink frequency (935-960MHz). Calculate the
number of available RF channels for this operator and
the duplex distance if the spectrum has a carrier
separation of 100kHz. Why are Telco’s more
interested in Radio channels?

Answer 1

hi,

ans a) Digital terrestrial television (DTT) offers improvedspectrum efficiency compared to analogue TV. It also offers enhanced video and audio quality, interactivity, as well as increased programme choices.

The migration from analogue to digital is necessary and urgent for the following reasons:

1)To comply with and adopt the tenets of the GE-06 Agreement

.2)To rapidly adopt spectrum efficient methods in the management of the scarce RF spectrum to broaden its utility as a resource in the interest and benefit of stakeholders

.3)To prevent dumping of obsolete analogue transmission equipment into the country to protect the environment, investors and consumers.

4)To enhance the quality and experience of TV viewers in Ghana by improving terrestrial TV transmission and reception.

5)To promote environmental sanity through co-location of broadcast transmission infrastructure

b)

Wireless - Advantages

Wireless communication involves transfer of information without any physical connection between two or more points. Because of this absence of any 'physical infrastructure', wireless communication has certain advantages. This would often include collapsing distance or space.

Wireless communication has several advantages; the most important ones are discussed below −

Cost effectiveness

Wired communication entails the use of connection wires. In wireless networks, communication does not require elaborate physical infrastructure or maintenance practices. Hence the cost is reduced.

Example − Any company providing wireless communication services does not incur a lot of costs, and as a result, it is able to charge cheaply with regard to its customer fees.

Flexibility

Wireless communication enables people to communicate regardless of their location. It is not necessary to be in an office or some telephone booth in order to pass and receive messages.

Miners in the outback can rely on satellite phones to call their loved ones, and thus, help improve their general welfare by keeping them in touch with the people who mean the most to them.

Convenience

Wireless communication devices like mobile phones are quite simple and therefore allow anyone to use them, wherever they may be. There is no need to physically connect anything in order to receive or pass messages.

Example − Wireless communications services can also be seen in Internet technologies such as Wi-Fi. With no network cables hampering movement, we can now connect with almost anyone, anywhere, anytime.

Speed

Improvements can also be seen in speed. The network connectivity or the accessibility were much improved in accuracy and speed.

Example − A wireless remote can operate a system faster than a wired one. The wireless control of a machine can easily stop its working if something goes wrong, whereas direct operation can’t act so fast.

Accessibility

The wireless technology helps easy accessibility as the remote areas where ground lines can’t be properly laid, are being easily connected to the network.

Example − In rural regions, online education is now possible. Educators no longer need to travel to far-flung areas to teach their lessons. Thanks to live streaming of their educational modules.

Constant connectivity

Constant connectivity also ensures that people can respond to emergencies relatively quickly.

Example − A wireless mobile can ensure you a constant connectivity though you move from place to place or while you travel, whereas a wired land line can’t.

ans c) The UL goes from the user phone to a fixed base station. Take, for example, any of the UMTS FDD frequency bands. You will check that the uplink frequencies are always smaller than downlinks'. In this case, it's the user's phone, which has a size constraint and relies on small batteries, while base stations usually have much better electric supplies with not such strigent requirements. Thus, it makes sense that the Uplink in mobile communications employs the lower frequencies, while the base station employs higher ones.

Why are Telco’s more interested in Radio channels?

Digital Radiocan support the progressive transition from analogue AM and FM radio techniques with greater efficiency, better quality sound, offering greater listener choice and functionality and greater diversity of broadcasters. Hybrid digital radio uses the complimentarycapabilitiesof the internetto add value to the primary broadcast content in a cost effective manner.