computers, mobile devices and network services for school … · 2014-10-03 · 2. 200m 2. high...
TRANSCRIPT
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Computers, Mobile Devices and Network Services for School
Athletic Day
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Content:
1. Objective
1.1 Background context, needs .............................................................................4
1.2 Current difficulties without the use of IT......................................................5
1.3 Purposes and benefits of the project ..............................................................6
1.4 Target user, situation of use............................................................................7
1.5 User requirements and scope of project ........................................................9
2. Analysis
2.1 Describe understanding of the problem: identify key sub-problems........11
2.2 Alternative ways of developing this network...............................................12
2.3 Comparison of the alternative ways and the selection of approach..........13
2.4 Summary of selected approach.....................................................................24
3. Design and Implementation
3.1 Report about the information collection process for creating the solution
24
3.2 Description of the overall plan or structure of the solution, with indication of
its major parts ....................................................................................................26
3.3 Description of the major parts involved in the solution and their relations of
others...................................................................................................................27
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3.4 Description of problems arising in implementation and how they are dealt
with......................................................................................................................29
3.5 A completed product/ proposal/ design solution.........................................29
4. Testing and Evaluation
4.1 Network Testing Plan ....................................................................................41
5. Conclusion and Discussion
5.1 The achieved requirements and improvements ..........................................47
5.2 Some insights gained on learning about how to learn/ solve problems.....51
5.3 Knowledge discovered which is relevant for other people on similar projects
in the future ........................................................................................................52
6. Documentation
6.1 User instructions ............................................................................................55
6.2 A set of clear simple fault diagnostic flow charts........................................58
6.3 The method of creating the solution.............................................................60
6.4 Acknowledge all resources of assistance ......................................................60
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1. Objective
1.1 Background context, needs
A school is going to organize an Athletics Day at a sports field outside school. I will
define the scenario of the Athletics Day and design its network environment by using
use computers and mobile devices to form a LAN for ‘student attendance taking’,
‘event results recording’, ‘instant communication’, ‘high confidentiality and
availability of the network’ and ‘integrity of the network’.
Scenario of the Athletics Day involves the type and functionality of different
mobile devices, location and distribution of access points, data security and access
control types of network connection, cost of setting up the network, limitations of the
network design and other special network requirements
The floor plan of the whole Kwai Chung Sports Ground
(The picture is captured from the School Sports Day’s brochure)
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Take my own school as an example. As my school is in Kwai Chung District in
New Territories, I use the Kwai Chung Sports Ground as a reference model for doing
this report. I would suggest that the season of Athletic Day should be held in autumn
or winter because there is less rainy day in these two seasons. The rain will lower the
connectivity, minimize the scope of coverage and reception of access points (wireless
network) and affect the performance of whole LAN (Local Area Network).
Again, I will take my own school as a reference for the background. There are
about 960 students and 50 teachers and assistants. Assume 10% of students will apply
for being crew and all teachers and assistants will be the crew. There will be totally
146 crews in the Athletic Day. And there will be 7 kinds of track events and 6 kinds
of field events.
Kinds of Track events Kinds of Field events
1. 100m 1. Long Jump
2. 200m 2. High Jump
3. 400m 3. Triple Jump
4. 800m 4. Shot Put
5. 3000m 5. Discus
6. 4x100m Relay 6. Javelin
7. 4x400m Relay
1.2 Current difficulties without the use of IT
1. Slow speed and rate of data communication
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Without using Information Technology, the speed and rate of data communication
on School Athletic Day will be very slow. As the transmission of messages (involved
information) can only be done by running form one side to another side by crew, it
causes wasting of time, inconvenient for user, which will totally affect and lower the
efficiency of whole Athletic Day.
2. Low accuracy of results of events
Also, the accuracy of results of all events in track events will be lowered and it will
affect the fairness and results of the events. Sometimes, the time difference between
champion and first or second runner-up may be only about 0.1s or even 0.01s. If there
is no Information Technology, crew needs to be the time keeper. As human’s average
reaction time is 0.2s, it may seriously affect the results. Therefore, argument between
runners and time keeper, crew and teachers will occur.
1.3 Purposes and benefits of the project
Purposes:
The purposes of the project are using Information Technology (IT) to take
attendance record, take event’s result record and do the instant communication in the
Athletic Day.
Benefits:
The benefits of the project are as follows:
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1. It can increase the crew and teachers’ productivity and efficiency in the Athletic
Day.
2. It can increase automation and local communications capabilities of Athletic Day.
3. It can provide the means of exchange data between computers.
4. It permits the sharing of resources.
5. The results records of Athletic Day can be backed up and managed easily.
1.4 Target user, situation of use
1. Teachers
Firstly, teachers need to lead and control the whole Athletic Day’s coordination
between the operation of field and track parts, discipline, all teachers and students.
Therefore, microphone is needed for them to give the special or emergency
announcement to the whole sport ground.
Also, a Personal Digital Assistant (PDA) is needed in the student’ and teachers’
attendance taking. One teacher can use PDA to record the attendance of each class
and send it to Headquarter (where coordinates the operation of all group of crew and
teachers, the announcement of results and the roll call of all events) by using wireless
LAN immediately.
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2. Students
For students, a huge LCD monitor is needed for them to watch the magnified live
events and let them to watch the moment of runner breasting the tape. LCD monitor
can also show the time and rank of the runner (which have just finished events) and
reckon by time from the race begun until it is finished.
The announcement of athletics’ results can also be done by the centralized
broadcast system provided by the sport ground.
3. Athletes
For athletes, roll call assembly can also be done the centralized broadcast system. It
can let all athletes to hear roll call wherever they are. LCD monitor is also necessary
for athletes to know their own results immediately.
4. Crew
Due to the importance of crew, walkie-talkie is the best media for instant
communication. Each group of crew can use their own channel in walkie-talkie; it
helps division of labour and the allocation of job. And for the group of crew which
operates on starting of the track events, walkie-talkie and starting pistol is needed for
coordination with the crew at the goals and synchronization of the time begun in event
respectively.
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Electronic timing is also needed to be controlled by crew. When starting pistol is
fired, the timer starts. When an athlete cuts the light beam at the finish line, the timer
will record the time and results. The results recorded by timer can be used to compare
with record taken by crew.
5. Emergency medical team
As accidents may be occur while the competition on Athletics Day, the emergency
medical team needs Walkie-talkie for instant communication in some emergent
situation, for example, some athletics fall down, get heatstroke or suddenly swoon in
the competition. Emergency medical team needs the clear report of how Athlete
getting hurt and the body state of him immediately. It may even affect the live of the
athletics. Therefore, the way of instant communication must be effective.
1.5 User requirements and scope of project
Requirement:
1. Teachers require a good division of labour between students, athletes and crew.
2. Students require a clearly watching view of the events, knowing the sequence of
the Athletes
3. Athletes require clear instructions of the roll call assembly.
4. Crew requires the latest information
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5. Emergency medical team requires a clear report of how Athlete got hurt in
accidents.
Scope of project:
1. File server is used to deliver programs and data files to workstations only.
2. Print server is used to receive files from workstations then send these files to a
network printer.
3. Network Printer is used to print documents (e.g. event result records) through the
network.
4. Firewall is used to separate untrusted Internet locations from trusted internal
network.
5. Notebook computers are used to process event result records.
6. Mobile devices (PDA, mobile phones and smart phones) are used to take student
attendance and do instant communication.
7. Access Points are used to connect the nodes together to form a wireless network.
8. RJ-45 connector is used to connect to the twisted pair cable.
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9. IEEE 802.11n is the modulation standard for Wireless LAN (WLAN)
2. Analysis
2.1 Describe understanding of the problem: identify key sub-problems
1. Topology
Network topology is the arrangement of a network in geometric form. It has three
goals need to achieve while choosing the suitable one. It must provide maximum
reliability of the network, route the traffic across the lowest-cost path and give the
best response time and throughput to need users.
2. Network Model
Network model is the workflow and the interactions between the nodes in a
network.
3. Cable
Networking Cables are used to connect one network device to other or to connect
two or more computers to share printer, scanner etc. Different types of network cables
like Coaxial cable, Optical fiber cable, Twisted Pair cables are used depending on the
network's topology, protocol and size.
4. Connecting Device
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Connecting devices allow hardware devices to communicate with each other. They
bring convenience to our life and work. The choice of connecting devices depends on
their characters, cost, pros and cons.
5. Types of LAN
Types of LAN are classified into Wired LAN and Wireless LAN. The choice of
wired or wireless just depends on the requirement of users, whether the mobility of
network is important or not.
2.2 Alternative ways of developing this network
There are many alternative approaches while developing a network. In different
approaches, different topologies, network models, cables, connecting devices and
firewalls will be used, just depending the situation and requirement of network.
Approach 1 Approach 2 Approach 3
Topology Bus Topology Ring Topology Star Topology
Network Model Client/Server Model Peer-to-Peer Model N/A
Cable Twisted Pair Coaxial Cable Optical Fibre Cable
Connecting Device Switch Router Hub
Types of LAN Wired LAN Wireless LAN N/A
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2.3 Comparison of the alternative ways and the selection of approach
1. Topology
Bus Topology Ring Topology Star Topology
Diagram
Feature 1. Use one long single cable (backbone)
to link the devices on the network
2. Data are sent from any node and
passing through the backbone
1. The nodes are interconnected to
form a close loop.
2. Nodes cannot communicate
directly
1. The nodes are connected to a
central point.
2. The central point is responsible for
data exchange.
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3. It uses coaxial cable.
4. It uses BNC connector.
3. It uses Peer-to-peer connection
4. IEEE802.5 Token ring is an
example of Ethernet access method
using in ring topology network.
3. The nodes cannot communicate
directly to each other.
4. 10/100 BaseT Ethernet is an
example of Ethernet access
method using in star topology
network.
Advantage 1. It requires a lower installation cost as it
is easy to install, resulting in less
required cable.
2. It is easy to expand so it is scalable
1. It has a fast network response
2. It provides a higher bandwidth
1. It is easy to install
2. It is scalable and flexible to resize
the network.
3. Alternation of nodes will not affect
the network except the central
point
Disadvantage 1. Entire network is down if there is a
breaking point along the backbone
2. Network traffic is easy to slow down if
1. It is difficult to install as expensive
installation cost is required.
2. If one of the nodes is down, the
1. It requires a higher installation
cost for more network components
2. If the central point is out of
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the network is busy whole network is down
3. Number of nodes affect the
network performance
service, the entire network is down
From the comparison table of network topologies above, star topology will be preferred. Star topology is easier to install than bus and ring
topology. Also, it is scalable and flexible to resize the network and the alternation of nodes will not affect the network except the central point
Thus, star topology is better than ring topology. Although star topology requires a higher installation cost for more network components, the
main components of designed this network in Athletics Day is the wireless network devices. Thus, the cost is not very high.
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2. Network Model
Client/Server Model Peer-to-peer Model (P2P)
Diagram
Host The host in Client/Server Model is server. The host in Peer-to-peer Model is not
required. Resources Sharing Resources Sharing in Client/Server Model are centralized. Resources Sharing in Peer-to-peer Model
are centralized.
Installation Cost The installation cost is more expensive. The installation cost is cheaper.
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Security Security can be maintained by user authentication. No security is provided among the
network
Advantage 1. It is easy to be managed as resources sharing is centralized and
controlled by a server.
2. It has a high network security with using user authentication.
It is cheaper as it does not require setting
up a server. Therefore, it is simple to set
up
Disadvantage 1. It is expensive for keeping a powerful server
2. It requires an administrator to maintain the network
3. When the server is down, all services are stopped
1. The sharing of resources is
decentralized so it is difficult to
manage.
2. It does not provide the security among
the network
As it is very important to centralize the sharing resources while taking student attendance and recording event results, Client/Server model is
preferred. Also, it has a high network security with using user authentication than Peer-to-peer network (P2P) so the requirement of high
confidentiality is done. Although the Client/Server Model requires an administrator to maintain the network, the teachers who are in charge the
Information and Communication Technology (ICT) Department in school have enough knowledge to be a network administrator.
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3. Cable
Twisted Pair Coaxial Cable Optical Fibre Cable
Diagram
Feature 1. It is categorized to Category 1
(CAT), CAT2, CAT3, CAT4, CAT5
and CAT6.
2. The Shielded Twisted-Pair (STP)
has metal foil wrapping around
each wire.
1. It is usually used in bus topology.
2. It is usually used by cable TV. 1. It is very thin and made up
of a bundle of thin glass
tube with 5 microns to 62
microns in diameter.
2. The data transmission of
Optical Fibre Cable is by
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means of light pulse.
Advantage 1. The cost is low.
2. There are different categories of
twisted cable can be chosen. Thus,
the cost is variable.
3. The metal foil used in Shielded
Twisted-Pair (STP) can reduce
noise (or interference)
It has a higher capacity for data
communication than twisted cable in general.
1. It carries more information
than copper wire.
2. It is not affected by
electromagnetic
interference.
3. It can have a very long
distance.
Disadvantage The maximum bandwidth is only 1000
Mps with 1000BaseTX Gigabit
Ethernet by using CAT 6 cable.
1. The cable is fragile
2. It is more expensive than twisted pair in
cost.
1. It is very fragile and
requires more protection to
the cable.
2. It is labour intensive in
installation
Optical Fibre Cable is preferred among 3 choices in the comparison table above as it carries more information than copper wire (Twisted Pair and
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Coaxial Cable) Also, Optical Fibre Cable is not affected by electromagnetic interference because the data transmission of it is by means of light
pulse.
4. Connecting Device
Switch Hub
Diagram
Feature 1. It is used to separate LAN areas
2. It enables ports to build independent channels
3. It controls multi-nodes data transmission
1. A central connection for devices in a network
2. No amplification of signals
3. All ports are sharing the network bandwidth
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4. It filters and forwards each packet to the required
port only.
Advantage 1. Network performance is improved as LAN areas
are separated.
2. Multi-nodes data transmission is controlled so
network congestion is prevented
3. Bandwidth can be maintained as it filters and
forwards each packet to the required port only.
The cost of hub is cheaper than switch in general.
Disadvantage The cost of switch is more expensive than switch in
general.
1. The signals are not amplified.
2. The bandwidth cannot be maintained as all ports are sharing the
network bandwidth.
Due to the busy data exchange network, high network performance and a maintained bandwidth are required. Also, the multi-nodes data
transmission of Client/Server Model is controlled so network congestion is prevented. Therefore, Client/Server Model is chosen.
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5. Types of LAN
Wired LAN Wireless LAN (WLAN)
Diagram
Feature It requires cables to make the connection between nodes and
nodes or nodes and other network components (e.g. switch).
The choices of cables are twisted pair cables, coaxial cables and
optical fibres.
1. It used EM waves to transmit and receive data.
2. It requires access points to provide wireless coverage
3. It can be used anytime and anywhere.
4. It is usually used in hand-held computer.
5. It requires a Wireless Network Interface Card (WLAN card)
Advantage It is more stable than Wireless LAN (WLAN) as it is less
affected by interference of environment and the weather than
The installation Wireless LAN (WLAN) is simpler than Wired LAN.
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Wireless LAN (WLAN).
Disadvantage 1. Due to the requirement of cables and network components
in the network, the setting cost is higher than Wireless LAN
(WLAN).
2. The area and use of Wired LAN is limited by cables. It
cannot be used anytime and anywhere.
The performance of the Wireless LAN (WLAN) is easier affected by
the interference of environment and the weather than Wired LAN.
By the comparison made between Wired LAN and Wireless LAN (WLAN), Wireless LAN (WLAN) will be preferred. Considering the setting
cost of Wireless LAN (WLAN), it is lower than Wired LAN. Due to the achievement of student attendance taking, event results recording and
instant communication of the scenario of the Athletic Day, mobility of the network is the most important consideration. Therefore, the limitation
of area and use of Wired LAN causes me to choose Wireless LAN (WLAN)
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2.4 Summary of selected approach
Selected Approach
Topology Star Topology
Network Model Client/Server Model
Cable Optical Fibre Cable
Connecting Device Switch
Types of LAN Wireless LAN
3. Design and Implementation
3.1 Report about the information collection process for creating the solution
1. Fieldwork of the Sports ground
I can go to the Sports ground (e.g. Tsing Yi Sports Ground) to do a fieldwork for
collecting information of the environment there. I can draw the floor plan of the sports
ground or get the catalogs (There is a floor plan in the catalogs) from the information
desk there. Floor plan is an important reference for designing the network diagram
and environment as we can know the whole structure of sports ground. Also, by doing
a fieldwork, I can get the idea of the problem-solving solutions of a network and
determine the efficiency and validity of these solutions.
2. Experience from School
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There is Sports Day in my school annually. As a student of the school and
participant of the track or field events, I can observe the position of the (network)
devices and the macro work flow of the whole Sport ground.
As a crew of School Sports Day, I can understand all operations, micro work flow,
all method of data transmission of the student attendance taking, events results
recording and instant communications. Also, I have a chance to try to be a role in the
data transmission and to use the network devices. By being a crew, I can ask teacher
for the problem in setting a network and solution of the problems. Thus, I can take all
these experiences as a reference for creating solution of problems.
3. Knowledge from books and Internet
There are many relevant resources can be found in books and the Internet. I can
find many kinds of problem-solving solution from them. Many alternative suggestions
can be found in books and the Internet. Therefore, I can justify which solution is the
best one for my design.
4. Experience from previous similar reports/projects
If you have done any similar reports/projects before or have other person’s
reports/projects, they can be used as the reference. The formats, patterns, expression
or even the methods of the producer in similar reports/projects can be learned from.
Also, by the others or previous reports/projects, you will know what mistakes,
misconceptions, improvements should be cautioned. Thus, the quality of this
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report/project can be guaranteed.
3.2 Description of the overall plan or structure of the solution, with indication of
its major parts
The design of the whole network environment of School Sports Day
(The network diagram is drawn by using Microsoft Visio)
The network diagram above is the network environment of the Athletics Day.
The router have been divided the network into 3 interfaces (Trusted Area, Untrusted
Area and Semi-trusted Area) and acts as a firewall by filtering packets. Internet is an
untrusted area as its safety is unknown. Due to the less sensitive area (by comparing
with headquarter), the wireless/mobile devices (Notebook computers, Personal Digital
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Assistant (PDA) (s) and Smart phones) should be put in semi-trusted area. This can
still allow outside world to access the area without strict security setting.
The switch centralizes the connection for server, 3 computers and a standalone
printer in the headquarter (Trusted Area).
The firewall at the centre of the network acts as a main communication role
between 3 interfaces (Trusted Area, Untrusted Area and Semi-trusted Area)
There are two repeaters set between the switch and access point 2 and access point
4. As the length between switch and access point 2 and access point 4 are greater than
100m (supported by the vertical view of a sports ground, e) parts - Location and
Distribution of access points), repeaters are needed to amplify the signal received and
resend. This can overcome signal attenuation due to the distant communication.
Also, if the Athletics Day is a rainy day, the rain will lower the connectivity,
minimize the scope of coverage and reception of access points (wireless network) and
affect the performance of whole LAN (Local Area Network). Therefore, repeaters
play a very important role in this bad weather.
3.3 Description of the major parts involved in the solution and their relations of
others
1. For student attendance taking
The student attendance taking will be done by the class teacher of each class and
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the crew (roll call of athletics’ sports item participation). Each teacher has a Personal
Digital Assistant (PDA) or Smart Phone. After the inputting of the attendance, by
clicking the “submit’ bottom, the data (file) will automatically be sent to the server
through the wireless network.
2. For event results recording
The event results recording are divided into two processes. Firstly, teachers in
charged in each small event (e.g. Discus) will input the results immediately after the
Athletics finishing his own event. The data will be transmitted to the notebook
computer of the type of the events. (There are only 2 types of events (Track Events
and Field Events) is held on the Athletics Day). Data centralization and verification
will be done by the notebook computer there. And finally, the data will be sent to the
server (headquarter) for announcement of the event results and prize ceremony.
3. For instant communication
The instant communication can be done by all people (teacher and crew) who have
wireless/mobile devices. The program used in instant communication would divide
the teachers and crew into groups (according the parts in charged on Athletics Day).
Through the wireless network, some emergency message or announcement can be
transit immediately and effectively from server (headquarter) or within the groups.
4. For High Confidentiality, Availability and Integrity of the network
The high confidentiality, availability and integrity of the network are done by
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implementing a firewall. The firewall will determine whether a packet or a connection
request should be allowed to pass through the network. It has divided the network into
3 interfaces (Trusted area, Semi-trusted area and Untrusted area). Thus, the firewall
has a very clear cut security policies.
3.4 Description of problems arising in implementation and how they are dealt
with
High cost of setting up the network
Actually, more mobile devices are required in the network to allow more teachers,
crew to participate student attendance taking, events results recording and instant
communication, in order to increase the efficiency and popularity of wireless network.
However, as the network is just specially designed for Athletic Day use only, it can be
used once a year. Thus, a high cost assessment is not recommended and by using Eee
Notebook PCs, instead of expensive PDAs and smart phones, HK$1000-2000 can be
saved per each mobile PC. In conclusion, the cost of setting up the network is lowered
without greatly affected the network performance.
3.5 A completed product/ proposal/ design solution
1. Type and functionality of different mobile devices
1. Notebook PC
Notebook Computer can be used as a great database which can first centralize the
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data of the event results recording categories of events (track and field) from Personal
Digital Assistants (PDA) or Smart Phones which are used by each part in track and
field respectively. For example, in shot events, the results of the events recorded by
the Personal Digital Assistants (PDA) or Smart Phones of the teachers in charged, will
first be sent to the notebook computer of field events for data centralization and
verification. Finally, the data will be sent to the server (computers in headquarters)
through the network.
2. Personal Digital Assistants (PDAs) and Smart Phones (e.g. iPhone)
Personal Digital Assistant (PDAs) and Smart Phones both have the same
functionality in the network. They are used in taking events results recording of some
small events and student attendance taking. Each teacher and crew in charge of the
School Sports Day will be allocated a Personal Digital Assistant (PDA) or a smart
phone. After the recording of the event results, the data will first be sent to the
notebook computer for data centralization and verification. Again, the data will be
sent to the server (computers in headquarters) through the network finally.
2. Location and distribution of Access Points
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The floor plan of the whole Kwai Chung Sports Ground with the Location and
distribution of Access Points
(The picture is captured from the School Sports Day’s brochure)
This is the vertical view of a general plan of a sports ground (use Kwai Chung
Sports Ground as an example). And the location and distribution of access points are
also shown in the picture. In theory, One IEEE 802.11 WAP (Wireless Access Point)
can typically communicate with 30 client systems located within a radius of 100 m.
However, due to loads of factors, the actual range of communication can vary
significantly. As the sports ground is totally flat except the auditorium, the access
point can communicate with a radius approximately 100m on the field and track. Due
to four division of the track field (100m per 1 division), 4 access points are distributed
at four corners of the track (as the picture shown)
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3. Data security and access control
1. Firewall
Firewall technology will be used as a network security to increase confidentiality
and integrity of the network. It will implement by a router which can determine
whether a connection request should be allowed to pass through the network. Also, it
can filter the data packet which is not authorized to pass through network.
The packet filtering will be done by comparing the packets to a set of filter rules
when packets pass through and examining the TCP to UDP information.
3 interfaces (Trusted Area, Untrusted Area and Semi-trusted Area) in a firewall
(router) will be defined. This can increase the confidentiality and integrity of the
network significantly. This decreases the chance of server getting out of function and
being attacked or hacked.
By the packet filtering technology done by router, it can apply without the risk of
compromising the network. This technology works best as a very clear cut security
policy. These are all pros of the firewall technology.
2. Login account system
For achieving the requirements - high confidentiality and integrity of the network, a
login system can reach these two targets easier and effectively. The network
administrator should create login accounts (with default password) and distribute to
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users (Teachers, Crew and Emergency medical team). Then, he should set these
accounts’ authentication according their identity, parts of job they handle. This kind of
access control can control and supervise the movement of all users easier.
3. Redundant Array of Independent Disk (RAID)
Redundant Array of Independent Disk (RAID) is used to improve the availability of
the network. It is a technology that allowed computer users to achieve
mainframe-class storage availability from low-cost and less reliable PC-class
disk-drive components via the technique of arranging the devices into arrays for
redundancy. It provides fault tolerance and protection to the HDD of file servers.
4. Uninterruptible Power Supply (UPS)
Improvement of availability of the network can be done by using Uninterruptible
Power Supply (UPS). It provides emergency power and, depending on the topology,
line regulation as well to connected equipment by supplying power from a separate
source when utility power is not available. It differs from an auxiliary or emergency
power system or standby generator, which does not provide instant protection from a
momentary power interruption. A UPS, however, can be used to provide
uninterrupted power to equipment, typically for 5–15 minutes until an auxiliary power
supply can be turned on or utility power is restored.
4. Types of network connection
Network Topology
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I will use Star topology to set up the network of Athletics Day. Star topology is
easier to install. Also, it is scalable and flexible to resize the network and the
alternation of nodes will not affect the network except the central point. Although star
topology requires a higher installation cost for more network components, the main
components of designed this network in Athletics Day is the wireless network devices.
Thus, the cost is not very high.
Network Model
I will use Client/Server Network as the model of the network in Sports ground.
Workstations/wireless devices (Clients) are connected to a central computer (server).
In this model, the server can provide services and resources (such as printers, file
space) to client device. Also, centralized resources can be shared in this model.
The network is easy to be managed in Client/Server Network model as resources
sharing is centralized and controlled by a server. And, due to the need of user
authentication, this model can provide a higher network security. These are
advantages of the Client/Server Network.
However, expensive cost of keeping server powerful is one of the cons of
Client/Server Network model. Also, if there is a problem in the server, or even the
server is down, the whole network will be affected or stopped.
5. Cost of setting up the network
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As all computer programs, centralized broadcast, and microphone are all already
provided and available on the sports ground, the budget of money for setting up the
network is the total cost of all remaining network devices.
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Name of wireless/
mobile devices
Parts needed to use Quantity Cost / Each (HK$) Cost (HK$)
Nodes
Track
Goal 1 3000 3000
Field
Shot Put 1 3000 3000
Discus 1 3000 3000
Javelin 1 3000 3000
High Jump 1 3000 3000
Long jump 1 3000 3000
Triple Jump 1 3000 3000
Others
Places of roll call for runner and field event player 1 3000 3000
Eee PC
Besides Server 2 3000 6000
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Network Components
Switch 2 225 450
Access Points 4 500 2000
Repeater 2 400 800
Router 1 2000 2000
File Server 1 12000 12000
Printer 1 600 600
Total Cost HK$47850
In conclusion, the budget of whole Athletic Day is HK$47850.
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6. Limitations of the network design
1. Scalability of the network design
This network design has the limitation of increasing scalability (expansion) of the
network, especially in the increasing number of nodes in the headquarter (the trusted
area of network where the server is). As I need to consider the overloading of the
network and capability for newly adopt technologies.
2. Reliability and availability of the network design
There is also the limitation of the reliability and availability of the network. As
once there is a problem in the server/switch/cables, or even the server/switch is down,
cable(s) is/are cut off, the whole network will be affected or stopped and no longer
available to the client.
7. Functionality of Network Components (except Nodes – Notebook PC)
1. Switch
In this network of Athletic Day, two witches have been used for separating LAN
areas to improve network performance. Also, they are used to enable ports to build
independent channels, in order to control multi-nodes data transmission and prevent
network congestion.
2. Access Point (WAP/AP)
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For building a wireless network in sports ground, four access pointsare required to
allows wireless communication devices to connect to a wireless network using Wi-Fi,
Bluetooth or related standards. The WAP usually connects to a wired network, and
can relay data between the wireless devices (such as computers or printers) and wired
devices on the network.
3. Repeater
As access point 2 and 4 in the network require wires with length longer than 100m,
two repeaters is used to amplify the signal received then resend and overcome signal
attenuation due to distant transmission.
4. Router
A router is used in the network of Athletics Day. It is a connecting device to route
data from one network to another one. In this network design, router is used connect
the whole LAN with the Internet and translate information between them.
5. File server
File server is the server which delivers program and data files to workstations only.
It does not process and run the data and programs for workstations. In the network of
Athletic Day, file server is mainly used to store the event results and the database. It
also helps to centralize the resources in whole network.
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6. Network Printer (Standalone)
The network standalone printer is used to print Athletic Day event results and other
important documents by crew and teachers.
4. Testing and Evaluation
Once the whole network connection is ready, we must first check and test the
functionality of the hardware of the server(s) and nodes and the connection of the
network to keep up the availability of network before it start to be used on School
Athletic Day as “student attendance taking”, “event results recording” and “instant
communication”. This checking and testing will be done according to the testing plans
below.
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4.1 Network Testing Plan
1. Hardware testing
Items Methods of testing Expected Result(s) The identity of the tester Yes/No
1. Cables
(excluding optical fibres)
By connecting both head of
the cable with the cable
tester*1
All of the light on the cable tester light up and
show green.
Developers Yes
2. Backup server By Cutting the power supply
of server to test efficiency
and availability of
Uninterruptible Power
Supply (UPS)*2
1. Back up all data successfully
2. Server shut down by its own.
Developers Yes
3. Access point By switching on The (green) light of “POWER” is on. Users Yes
4. Print server By sending a printing The document is printed successfully and Users Yes
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request of a document from
different computers (clients
or nodes)
completely.
2. Network connection testing
Items Methods of testing Expected Result(s) The identity of the tester Yes/No
1. Mobile devices communicate
with the server via the access
point
1. The communication of server and
mobile devices is successful.
Users Yes 1. Access point
2. Use command program
(cmd.exe) to test*3
2. A reply is received from server Developers Yes
3. Connection between
server and clients
Use command program (cmd.exe) to
test*3
A reply is received from server or
clients
Developers Yes
4. Connection between Use Window program (cmd.exe) to A reply is received from client(s) Developers Yes
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clients test*3
1. Open web browser to try to visit
website in the Internet
1. No error is received and the
webpage is visited successfully
Users Yes 5. Connection between
server, clients and the
Internet 2. Use command program
(cmd.exe) to test*3
2. A reply is received from server of
the web surfed.
Developers Yes
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*1 More about cable tester
A cable tester is used to verify that all of the intended connections exist and that
there are no unintended connections in the cable being tested. When an intended
connection is missing it is said to be "open" (as in Open circuit). When an unintended
connection exists it is said to be a "short" (as in Short circuit). If a connection "goes to
the wrong place" it is said to be "miswired" (the connection has two faults: it is open
to the correct contact and shorted to an incorrect contact).
*2 Uninterruptible Power Supply (UPS)
Uninterruptible Power Supply (UPS) is used to provide electrical power to
computers or network devices during power outage.
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*3 The testing of using command program in Windows:
(WINDOW\system32\cmd.exe)
Step1 picture (From Window Command Program - cmd.exe)
Step1: Type ‘ipconfig’ to ensure that the nodes you are using have got an IP Address
and Default Gateway.
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Step2a picture (From Window Command Program - cmd.exe)
Step2a: For testing the (3.) connection between server and clients or (4.) clients and
clients, type “ping xxx.xxx.xxx.xxx” (xxx.xxx.xxx.xxx stands the IP address
of the server or clients that you want to test). A reply will be given as the
picture 2a shown.
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Step2b picture (From Window Command Program - cmd.exe)
Step2b: For testing the (5.) connection between server, clients and the Internet, type
“ping hk.yahoo.com” (I use the webpage of Yahoo! Hong Kong as the sample
of step). A reply will be given as the picture 2b shown.
5. Conclusion and Discussion
5.1 The achieved requirements and improvements
By setting up this network environment, all requirements have been achieved:
1. Student attendance taking
The requirement of student attendance taking is achieved by setting up a wireless
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network with wireless devices (which connected to the server).
2. Event results recording
The requirement of event results recording is achieved by setting up a wireless
network with wireless devices which connected to the server and also the print server
(printer).
3. Instant communication
The requirement of instant communication are achieved by setting up a chat room
4. High confidentiality and availability of the network
The requirement of High confidentiality and availability of the network is achieved
by using RAID and UPS for server(s), backup server, setting up a firewall and setting
up a own log-in account for each teacher, crew
5. Integrity of the network
The requirement of integrity of the network is achieved by subnetting and setting
up an own log-in account for each teachers, crew.
Improvements still that can be made:
1. Increase confidentiality of the network by Virtual Private Network (VPN)
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A virtual private network (VPN) is a computer network in which some of the links
between nodes are carried by open connections or virtual circuits in some larger
network (e.g., the Internet) instead of by physical wires. The link-layer protocols of
the virtual network are said to be tunneled through the larger network when this is the
case. One common application is secure communications through the public Internet,
but a VPN need not have explicit security features, such as authentication or content
encryption. VPNs, for example, can be used to separate the traffic of different user
communities over an underlying network with strong security features.
A VPN may have best-effort performance, or may have a defined service level
agreement (SLA) between the VPN customer and the VPN service provider.
Generally, a VPN has a topology more complex than point-to-point.
A VPN allows computer users to appear to be editing from an IP address location
other than the one which connects the actual computer to the Internet.
The setting cost of VPN usually lower than other private networks which requires
sets of technology and hardware.
2. Increase confidentiality of the network by Wi-Fi Protected Access (WPA and
WPA2)
Wi-Fi Protected Access (WPA and WPA2), a Wi-Fi standard that was designed to
improve upon the security features of WEP. The technology is designed to work with
existing Wi-Fi products that have been enabled with WEP (i.e., as software upgrade to
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existing hardware), but the technology includes two improvements over WEP.
Wi-Fi Protected Access (WPA and WPA2) improves data encryption through the
temporal key integrity protocol (TKIP). TKIP scrambles the keys using a hashing
algorithm and, by adding an integrity-checking feature, ensures that the keys haven
been tampered with.
Wi-Fi Protected Access (WPA and WPA2) also provides user authentication, which
is generally missing in WEP, through the extensible authentication protocol (EAP).
WEP regulates access to a wireless network based on a computer hardware-specific
MAC address, which is relatively simple to be sniffed out and stolen. EAP is built on
a more secure public-key encryption system to ensure that only authorized network
users can access the network.
It should be noted that WPA is an interim standard that will be replaced with the
IEEE 802.11i standard upon its completion.
3. Increase availability by using Mesh Topology (Mesh network)
Mesh Topology (Mesh network) is a network topology in which devices are
connected with many redundant interconnections between network nodes. In a true
mesh topology every node has a connection to every other node in the network.
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A Network Model with Mesh Topology
(The network diagram is drawn by Microsoft Visio)
There are two types of mesh topologies: full mesh and partial mesh.
Full mesh topology occurs when every node has a circuit connecting it to every
other node in a network. Full mesh is very expensive to implement but yields the
greatest amount of redundancy, so in the event that one of those nodes fails, network
traffic can be directed to any of the other nodes. Full mesh is usually reserved for
backbone networks.
Partial mesh topology is less expensive to implement and yields less redundancy
than full mesh topology. With partial mesh, some nodes are organized in a full mesh
scheme but others are only connected to one or two in the network. Partial mesh
topology is commonly found in peripheral networks connected to a full meshed
backbone.
5.2 Some insights gained on learning about how to learn/ solve problems
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While a problem is discovered, we should define it first and divide the problem into
some small sub-problems partly. Usually, small sub-problems are easier to be solved
and find the mistakes made than the bigger one.
Then, we should try to formulate hypothesis of which part(s) goes/go wrong, what
is/are wrong with that part(s) and test it. The testing of hypothesis can be done
effectively by using the test plan (if the problem(s) is/are about networking)
While the testing of hypothesis, alternatives should be considered and tried to use
other better method instead of the wrong one. Afterwards, we should analyze the
results gotten and determine whether there are improvements or the problem being
solved. Hope for the best, it is solved. If not, the whole flow of problem solving will
return to the step of formulating hypothesis until the problem is solved.
If the loops of problem solving do not have any help on problem-solving, the other
strategies should be done afterwards. I suggest you to ask friends/students and
teachers for help. The most important thing you need to do while facing problems is
to try your best to find solutions with determination and patient.
5.3 Knowledge discovered which is relevant for other people on similar projects in
the future
This project is a good example for other people to make a reference as many
information and knowledge here can be used in any network environment under any
network requirement and uses.
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Also, I have discovered how to develop a network. There are steps to follow:
1. Network Requirement Analysis
First, Network Requirement Analysis is required. We should obtain requirement
from users by interview, communicate with different levels of users and maintain an
updated user requirement. Also, we should know the geographical distribution of the
office layout about the network structure and network topology used and the
applications to be run on the network, the demand of bandwidth.
Then, we need to identify the uses of the network by conducting informational
interviews, quantifying the network to know the number of users and number of
computers and list the application and tasks performed in the network. Server
dependence is also a things need to know, in order to know the numbers and types of
server to be installed. (Domain controller / File server / Print server / Application
server)
2. Network Design
The step next is the network design. The designer needs to draw up the logical and
physical network diagram for the network, network configuration and network
planning and diagram.
There are Four Considerations on Network Design. They are User Concerns,
Geographical Consideration, Future expansion and Cost assessment.
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2.1 User Concerns
Users always concern with the response time (which means the time for the
network response after users’ instructions) and the reliability of applications
2.2 Geographical Consideration
Maps and floor plans are needed to determine the distance limit between the nodes
and data flow of the whole network.
2.3 Future Expansion
Future Expansion is also needed, like the migration plan which avoids disruption of
network services.
2.4 Cost Assessment
The designer should use a brief list of the overall costs to estimate the cost required.
All costs used in this Athletic Day about the network is one-time costs (Fixed costs).
They are the cost of purchasing and installing of network hardware and the cabling of
the LAN.
2.5 Network Configuration
In this scenario, subnet and router are used to break the network into segments to
reduce network traffic for a whole network
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2.6 Network Planning and Diagram
Finally in designing step, a network diagram is required to outline the logical and
physical connections.
3. Network Installation
Cabling will be done during physical installation and configuration of the network,
the connection of data nodes to other connecting devices like hubs, switches and
routers will be done.
4. Network Maintenance and Upgrading
To maintain a stable working environment for users, network administrators are
responsible for doing this. In this scenario of the Athletic Day, teachers of
Information and Communication Technology (ICT) Department in school can play
this role.
Network administrators need to serve users’ requests about the network account
login problem and the performing routine data backup and data archiving.
6. Documentation
6.1 User instructions
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For crew and teachers
1. How to login to the network (computer/wireless devices)?
i) Switch on the computer
ii) Wait until a login requested is shown on the page
iii) Click “Ctrl”, “Alt” and “Del” button
iv) Input your user name/ user ID (which is provided by School IT Department)
v) Input your default password (which is also provided by School IT Department)
vi) Complete
2. How to submit student attendance taking?
i) Launch the web browser
ii) Go to the Intranet page
iii) Input your user name/ user ID (which is provided by School IT Department)
iv) Input your default password (which is also provided by School IT Department)
v) Select the class you are taking attendance
vi) Tick the box in front of the student name for student(s) who is/are present
vii) Just leave the box empty if the student(s) is/are absent
viii) Type the number of student(s) presented
ix) Click “submit” button
x) Complete
3. How to submit event results recording?
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i) Open the event results recording program (which provided by the school)
ii) Choose the name of events or the number of events you are going to record
iii) Type the event result record of the participants just besides their names
iv) Click “confirm” button
v) Confirm and check the correctness of the typed data
vi) Click “submit” button
vii) Complete
For Network Administrator
What is the range of IP, subnet mask, Network ID of all nodes and Network
Components?
The range of IP of whole network is default as the Class C network with starting
Network ID 192.168.0.1 and subnet mask 255.255.255.0. The range of IP subnet
mask, Network ID of all nodes and Network Components are as follows:
Nodes/Network
Components
Parts needed to use IP address Subnet Mask Network ID
Nodes
Track
Goal 192.168.1.1 255.255.255.0 192.168.1.0
Field
Shot Put 192.168.1.2 255.255.255.0 192.168.1.0
Eee Notebook PC
Discus 192.168.1.3 255.255.255.0 192.168.1.0
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Javelin 192.168.1.4 255.255.255.0 192.168.1.0
High Jump 192.168.1.5 255.255.255.0 192.168.1.0
Long jump 192.168.1.6 255.255.255.0 192.168.1.0
Triple Jump 192.168.1.7 255.255.255.0 192.168.1.0
Others
Places of roll call for
runner and field
event player
192.168.1.8 255.255.255.0 192.168.1.0
Besides Server 192.168.1.9 255.255.255.0 192.168.1.0
Other Network Components (except Nodes)
Switch 1 192.168.1.10
Switch 2 192.168.1.11
Access Point 1 192.168.1.12
Access Point 2 192.168.1.13
Access Point 3 192.168.1.14
Access Point 4 192.168.1.15
Repeater 1 192.168.1.16
Repeater 2 192.168.1.17
Router 192.168.1.18
File Server 192.168.1.19
Printer
N/A
192.168.1.20
N/A
6.2 A set of clear simple fault diagnostic flow charts
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1. Flow chart of Troubleshooting Process
If problem/problems is/are realized and concerned, I will search/find the relevant
information/knowledge/solution(s) in the Internet by using search engines or books.
Due to the Web 2.0 generation, under the interactive actions between the developer
and Internet users, it is important for me to criticize the accuracy of the relevant
information/knowledge/solution(s) found and determine the feasibility of them. I will
ask teacher(s) to confirm information/knowledge/solution(s) when there is suspicion
with them.
Define problem
Analyze the results
Consider alternatives
Testing hypothesis
Formulate
Problem solved?
NoYes
Success
Define problem
Formulate hypothesis
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2. Flow chart of a Network Life Cycle
The flow chart above shows a general network life cycle. Or in other words, this is
the whole image of setting up a network from the very beginning to the “mature” state.
Accept the last step of the flow chart – Training and End-user support; all previous
steps can be revisable if error(s) is/are found during the network “development”.
Following this flow charts, the network can be corrected many times until it is perfect.
Therefore, performance and efficiency of the network can be guaranteed.
6.3 The method of creating the solution
There are three method of creating solution, Fieldwork (of the Sports ground),
Experience from School and Knowledge from books and Internet. For more details of
these three solutions, please refer to previous section 3.1 (Report about the
information collection process for creating the solution).
6.4 Acknowledge all resources of assistance
Network Requirement Analysis
Network Design
Network Installation
Training and End-user Support
Network Maintenance and Upgrade
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Website:
http://www.hp.com
http://www.dell.com
http://www.webopedia.org
http://www.wikipedia.org
http://www.microsoft.com
http://www.cisco.com
Book/Magazine
1. E-zone magazine
2. Data Communication and Networking (published by Radian)
Teacher
School Computer and Information Technology Subject Teacher – Mr XXX