ITECH2300 Mobile Network and Wireless Communication Assignment 1 2019

This document presents solutions for an ITECH2300 Mobile Network and Wireless Communication assignment. The first solution focuses on the Square Kilometer Array (SKA) project, detailing its international importance, wireless communication features, antenna types, frequency bands, and technical specifications. It explains SKA's design, location in Australia and South Africa, frequency range, antenna types (SKA-low, SKA-mid, and SKA-survey arrays), and challenges in the design process. The second solution compares home office wireless routers, specifically the AC 1900 Nighthawk VDSL/ADSL modem router and a CM 1000 Ultra High Speed Cable Modem, highlighting modulation techniques (Discrete Multi-tone and OFDM), and their applications. It analyzes DSL and cable modem routers, comparing their modulation, interfaces, bit rates, ports, and features. The comparison includes the advantages and disadvantages of DSL and cable internet connections, including speed, cost, coverage, and security. The document concludes by recommending the ADSL router for its speed and security features.

Electrical Engg.
Mobile Network and Wireless Communication
Student Name –
Student ID –

Solution 3:
SKA ( Square Kilometer Array ) is a project that is important internationally and it is one
amongst the biggest projects being planned in Australia. It consists of features related to
wireless communication, antennas ( of various types, sizes and heights ), communication
frequency bands and some other technical specifications related to wireless communication
technology.
SKA refers to a radio telescope project which is intergovernmental in nature. It is related to
the countries of Australia as well as South Africa. The countries have been chosen on the
basis of their location as well as various other features. It will be capable of operating on a
big range of frequencies and the area will be around 1 km sq. The sensitivity will be very
high due to the big size ( almost 50 times sensitive than other instruments used ). It will need
a very high capacity computing engine. It will be located in southern hemisphere to reduce
the ratio interference.
SKA is capable of combining the signals which it receives from a number of small antennas
which are placed in a distance of few thousands of kilometres. They are used for simulating a
giant radio telescope ( which is highly sensitive ).
This process is known as aperture synthesis. Some parts have to view large parts of the sky at
a single moment, so they have very big field of view. Focal plane arrays have been used to
give multiple field of views ( FOV s ). Such technology is called phased array technology.
The frequency range for SKA is 50 MHz to 14 GHz ( in first and second phase ) and till 30
GHz ( in third phase ).
The antennas which can be used are :

SKA-low array: In this case, dipole antennas are used. The frequency range is 50 to 350
MHz. Diameter is about 100m and each station may have 90 elements.
SKA - mid array: In this case, dish antennas are used. The frequency range is 350 MHz to 14
GHz. The height of antenna and the width of antenna are taken as 15m and 12m respectively.
Thousands of antennas may be used in the array.
SKA- Survey array: In this case, parabolic dishes are used. The frequency range is 350 MHz
to 4 GHz. The diameter is taken as 12 - 15 m.
Generally, the location for SKA telescope is selected in such a way that the location has very
low population and any type of man - made interference is minimum. Hence, South Africa
and Australia are chosen.
The various challenges present in the design process are: a very big bandwidth is needed
from telescope for the processor, the processing power is high, the power consumed by
processors is more, it is essential to use pipelining in processing, storing the data and its
duration is very significant, the data must be retrieved by the users, a lot of research is needed
which is data intensive.
Solution 4:
Home Office Wireless Routers
AC 1900 – Nighthawk VDSL / ADSL Modem Router

Figure 1
CM 1000 Ultra High Speed Cable Modem

Figure 2
Table 1
Feature ADSL2 MODEM ROUTER CABLE MODEM ROUTER
Modulation type Discrete Multi tone
Modulation
OFDM
Modulation bit rates
achievable
1 . 9 Gbps High speed
Error control strategy High security Upto 1 Gbps
Sensitivity to cross talk Very secure Reduced latency
Cable / connector type Telephone line Enhanced user experience
Host side interfaces Cable or fibre modem Gigabit Ethernet port
Bit rates 1 . 9 Gbps Upto 1 Gbps
Ports 4 ethernet ports 1 Gigabit Ethernet port

Embedded switching
capability
DSL filter used Auto sensing technology
DHCP 2 USB ports 32 downstream and 8
upstream channels
Comparison :
Modulation
The DSL uses discrete multi tone modulation which is a type of FDM ( frequency division
multiplexing ). The modem frequency is selected in such a manner that there is no
interference with the phone working.
In Cable router , OFDM ( orthogonal frequency division multiplexing ) is used. It helps in
decoding the digital data on different carrier frequencies. OFDM can help in coping with
extreme channel conditions and there is no need of separate filters for equalisation.
Interference is also reduces in the system.
Here, 2 types of routers are considered. One is ADSL2 Modem router and other is Cable
Modem router. Both of them are used for small area applications. In the DSL router, a
modem is present which terminates the phone line type of internet accessing system with 1 or
more than 1 DSL ( Digital Subscriber line ) system. In cable router, the modem terminates the
IP using a coaxial cable interface. Both the types of routers use different management
systems. Both the DSL as well as the cable modem use a different means to connect to the
internet. DSL and ADSL ( Asymmetric Digital Subscriber line ) us the phone lines for
providing internet connection. Cable modem uses the cable TV lines for providing internet
connection.

Both the cable connection as well as the DSL connection provides a high speed internet. DSL
will run at a less speed if our distance from the DSL provider’s main office is large. The
cable’s internet is slow if many users login at the same time. DSL is more costly as compared
to cable system. If a TV connection is present , then no need for separate installation of wires
is there in cable system. If coverage is seen then DSL is not available at all the locations but
cable system has more coverage as cable TV lines were spread to remote places also. Twisted
pair of cables can be used. There is no interference between the TV signal and the internet
signal as both the wires carry different information.
A DSL modem can connect the PC and the telephone line. It contains the DSL service. In
cable modem , the connection is between the PC and the cable TV line. The cable modem can
be inside or outside the PC or may be attached to the receiver of cable TV. DSL is better for
some applications like VoIP, games, videos etc. This is because DSL has a higher speed than
cable system. Latency is the time taken for sending or receiving a single packet of data on a
line. Security can be enhanced for both the systems by addition of a router. It helps to add
certain security features which help to protect the system on the network.
Finally , the ADSL router is recommended due to its speed and security features.
References
Grainge, K., Alachkar, B., Amy, S., Barbosa, D., Bommineni, M., Boven, P., ... & Gabrielczyk, R.
(2017). Square Kilometre Array: The radio telescope of the XXI century. Astronomy Reports, 61(4),
288-296.
Wang, B., Zhu, X., Gao, C., Bai, Y., Dong, J. W., & Wang, L. J. (2015). Square kilometre array
telescope—Precision reference frequency synchronisation via 1f-2f dissemination. Scientific
reports, 5, 13851.