Wireless Networking Technology And Wifi Protocols Computer Science Essay

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The Wireless networking technology, which uses radio waves to provide wireless network connection and high speed internet. Wi-Fi works with no wired connection between sender and receiver by using radio frequency technology and it's similarly to cordless phone they transmit data from one point to another point .A frequency within the electromagnetic associated with radio wave propagation. It requires staying within the wireless network range to connect a computer. The Wi-Fi products are based on the (IEEE) Institute of Electrical and Electronics Engineers 802.11 standards.

Wi-Fi networks transmit in the unlicensed public 2.4 GHz or 5GHz radio bands, so you don't need to get a federal license or take a test to use Wi-Fi equipment. You can find Wi-Fi equipment available for three different protocols: 802.11a, 802.11b, and the 802.11g. Usually all that you need do add a wireless client is install a Wi-Fi network adapter and configure the client to access the network. Mobility is another advantage of Wi-Fi. The wireless networking technology which uses radio waves to provide wireless network connection and high speed internet.

Wi-Fi protocols:

IEEE 802.11b:

It was appear in late 1999. It operates at 2.4GHz radio spectrum. The theoretical speed is 11 mbps within 30m range. The actual speed is 4-6 mbps it operates 100 - 150 feet range. This standard is most popular it was least expensive.

IEEE 802.11a:

It was introduced in 2001. It operates at 5 GHz. The standard is less popular and more expensive. The theoretical speed is 54 mbps and actual speed is 15-20 mbps and the feet range is 50-75m. it was not compatible with 802.11b.

IEEE 802.11g:

Introduced in 2003 it combines the future of both standards (a, b). it operates 100-150 feet range and the speed is 54 mbps with 2.4 GHz radio frequencies. It was compatible with 'b'.

Chosen technology:

In this step we got select a IEEE 802.11g. because it operates 100-150 range it is higher than other protocol and the speed range is 54 mbps with the 2.4 GHz radio frequencies and it was compatible with 'b'.


Ring topology:

It also known as ring network and it is a computer network configuration. The network computer and device are connected to each other and forming a large circle. For example;

Description: http://www.computerhope.com/jargon/r/ring.gif

Bus topology:

It is a multi-drop transmission medium it allows only one device to transmit at a time determines which station is to transmit. The data frames contain source and destination addresses. For example;

Description: http://homepages.uel.ac.uk/u0116771/bus_topology_files/image002.gif

It connects each computer to a single line, coax cable that is referred to as 'bus'. The signal transmits one end to other. The computer on the bus simply listens for the signal that no need to moving the signal along.

Chosen technology:

For the city campus we have to use both ring and bus topology. Because for bus we have to use for the class room and the ring is for outside.


In this network we choose the fiber optics;

Description: http://www.nanonics.co.il/imgtemp/lensfiber4.jpg 

it is a single mode fiber from 488 nm to 1550 nm. The working distance is 5-50 microns.

Specification of topology:

Specification of topology:

Core diameter - wavelength-dependent 50 µm

Working Distance


5 µm (λ=1.5 µm)

20 µm


50 µm (λ=1.5 µm)

60 µm

Depth of Focus

±1 µm

±1 µm

Spot Size Tolerance

Without near-field optical characterization

±0.5 µm

±0.5 µm

With near-field optical characterization

±0.25 µm

±0.25 µm

Coating Dimensions


1.0-1.5 µm

1.0-1.5 µm

Minimum Length

0.5 mm

0.5 mm

Maximum Length

5 cm

5 cm

Minimum Strip Distance

2 mm ± 0.1 mm

2 mm ± 0.1 mm

Maximum Strip Distance

No limitation

No limitation

Advantage of Ring Topology:

Data transmitted between two nodes are passes through all the intermediate nodes.

The central server is not required for the management of this topology.

Disadvantages of Ring Topology:

The failure of a single node can cause the entire network fail.

The movements or changes to the network nodes cause the performance of the entire network.

Advantages of Bus Topology:

Bus topology is easy to handle and implement.

Bus topology is the best suited for small networks.

Disadvantages of Bus Topology:

Cable length is limited and it limits the number of station that can be connected.

It can perform well only if limited number of nodes.

Threats of business operations:


Because they use radio waves, wireless LANs are open to hackers trying to access sensitive information or spoil the operation of the Network. In fact, most wireless LANs do not implement any form of reliable security, enabling an access to just about anyone. It is proven that large cities using 802.11 wireless LANs can be hacked easily. It is also found that many major corporations, retail stores, airports, and homes are highly venerable of being hacked.

The Evil Twin

The Evil Twin is one of the trendiest threats to Wi-Fi users. It can also be known as Wi-Fi Phishing. Network names such as of hot-spot's or even secure networks' are being duplicated by the rouge access point, Evil Twin. Once a consumer sign in erroneously into the incorrect access point, it instantly captures the data and might also harass the computer.(as told by experts)

Solution for the evil twin:

Leader of Interlink Networks, Inc, an Ann Arbor, Mich. It has been proposed and recommended by Klein to use an application like the free Lucid Link Wireless Client. It is competent in detecting the changes of security settings spontaneously and furthermore provides a warning to the user to alert him from being assailed by an Evil Twin. He says that" it is also preferable to reside away from any open, or unsecured, wireless networks".

The Promiscuous Client

The Evil Twin has an accomplice acknowledged as Promiscuous Clients. They are the opportunistic perils to anyone's work and business. The promiscuous client is not exploited for any malicious purposes nor does it correlate with any access point that is located near any public hotspot deliberately. It is basically present for only one reason or another, accommodating a beguilingly strong signal. "802.11 wireless cards frequently search for a sturdier signal to bond and as well as hunt to hook up with a similar SSID name."(as told by experts)

Solution for the promiscuous client:

The head of Newbury Networks, Inc a Boston IT security firm, says that he genuinely come across a Promiscuous Client in his recent trip. It was one that was supplying a tremendous signal and speed. Auspiciously, his laptop and he both managed to pull through the meeting. Maggie recommended using a wireless "sniffer" (Microsoft Windows XP) which will facilitate one in monitoring and analyzing the network airspace. The head of Newbury Networks, Inc a Boston IT security firm, also says that one should be familiar with the layout which is placed inside offices, across the hallway, on the floors on top of and beneath someone and as well as on the exterior of the bricks and business thus improving his idea on the desirable locations where security breaches might occur.

Wireless Network Viruses 

Viruses can be classified under various categories. One of it is wireless viruses. According to the expert, chief technological officer for Net Labs and, a St. Louis networking company, he declares that the virus worm MVW-Wi-Fi, bucks itself into a laptop through a wireless network and emits wireless search request packets to detect other available local wireless networks. It further forwards itself to contiguous wireless network devices. Its vicious aptitudes are very numeric in nature. Running the antivirus software and keeping it updated is an advice given by him.

One is able to repudiate from most nuisances by ascertaining the security the settings despite if you are using a Bluetooth-enabled Personal Digital Assistant, a cell phone or a computer. It is applicable for small business wireless networks too. According to Single Click Systems, A Toms River, N.J., networking company for small businesses, he pronounces that almost two-third of all wireless users are on an unsecured network.

If there is a necessity that small businesses should gain knowledge about wireless networking, it is essential for them to know that encryption is their excellent form of defense.

Neither virus nor hacker attack is the prime security threat yet. An expert of president of Razor point Security Technologies, Inc., a New York Company declares that they depict themselves as "professional hackers" for contentment. He also articulates that "we're not a target" or "we only need to secure the important machines" are some famous lines that we hear incessantly. Attentiveness is the most decisive point of protection. If users are alert of the real risks and the threats that could possibly take place, everything else could be assembled on subsequently.


RFID means for Radio-frequency identification (RFID). It is type of technology that uses radio waves to recognize an object. RFID can also be used as a Tag and attached on the Equipments for safety concern. The RFID is applied to a product for the function of identification and tracking them from thefts by means of using the radio waves. These tags can be read from several meters away and further away than the line of view of the reader.

Most RFID tags contains at least two parts. One of which is the integrated circuit for storing and processing the information, amending and demodulating a radio-frequency signal, and other focused functions. The second is the antenna to receive and transmit the signals.

In general there are three types of RFID tags:

Passive RFID tags, which does not a battery and also does not need of an outdoor supply to aggravate the signal transmission.

Active RFID tags, which contains a battery and a can, transmit signals once an exterior resource has been fully effectively recognized

Battery assisted passive (BAP) RFID tags, which needs an exterior resource to come around and also has important and advanced forward link capability in providing a greater range.

RFID has many functions; for example, it is commonly used in the infrastructure of a school to improve the schools efficiency of inventory tracking and managing of the equipments from theft and from outside attackers.

There are lot of ways to access point configuration interfaces from outside attackers .


Smart card is one way to secure company's equipment from theft . using smart card will provide minimum security. For example the door of a computer lab will be locked until a authorized person places the card to the sensor and the door will unlock itself) this system can also be used to guard restricted places. This system will be useful to secure valuable equipments from people to enter.

A smart card is similar to a credit card in shape and size, but inside it's completely different. Inside it is a normal credit card which is a simple piece of plastic that does contain an embedded microprocessor for viewing its details. The microprocessor is under a gold contact pad on other side of the card. Think of a microprocessor as replacing the usual magnetic stripe on a credit card or debit card.

Smart cards play a heavy role in Europe than in United States. In Europe, certain industries like health insurance and banking industries use these types of smart cards. Everyone in that country has their own smart card for their health insurance. Even though smart cards have been available in their modern form for at least a decade but they are just starting to expand in the United States.

In popular countries the Magnetic stripe technology plays a important role. There are some disadvantages in the magnetic stripe technology such as the data on a stripe can easily be read, written, deleted or changed with off-the-shelf equipment. Therefore, the stripe is not really the best place to store sensitive information. To protect the consumer from these activities and some businesses, they have invested in extensive on the online mainframe-based is computer networks for verification and processing. Certain countries are developing by using the types of securities

The microprocessor on the smart card plays an important role in an aspect of the security. The host computer and the card reader actually communicate to the microprocessor. The microprocessor enforces a access to the data on the card. If the host computer is read and wrote the smart card's random access memory, it would be no different but a Diskette. The smart card uses a serial interface and receives its power from external sources like a card reader.


Security cameras are improving all over the world. They play a important role in all aspect of the business. The Security Cameras are either wired or wireless, and which setup you will need depends on where you'll want to put the cameras or how visible you want them to be. Wired cameras might be trickier to install, where as stray wires can hamper your attempts to be discreet. They do, however, have typically higher-quality picture than a wireless cameras, since their signals are not travelling through the air.

Wireless cameras are more flexible, but broadcasts from other device such as wireless Internet, cordless phones or baby monitors which can interrupt a wireless camera's signal. Also, we must keep in mind that if we decide on a wireless system, there is a possibility that your video feeds could be intercepted by others. Having someone else monitoring your activity around the house or finding out whether or not you are at home defeats the purpose of having security cameras. If you are worried about your personal security, you can check with the manufacturer to see whether or not they encrypt their wireless systems.

Large cameras will be visible, and people typically will install them outside or in an area where people know they are under video surveillance. You can also find smaller, hidden cameras online in many different ways and forms -- a tiny camera hidden inside of an alarm clock for a instance, or a small pinhole camera that fits inside of an intercommunication system.

But before you install any type of security system in your home -- especially the small, "hidden" type one you should note the legal restrictions on video surveillance. In most places, anyone recording either audio or video in a specified area must need to alert anyone in range of the surveillance device that he or she is being recorded. For instance, if you record someone else does telephone conversation without them know it, that is illegal. It's also true that if you install any tiny camera into a room in your house without letting anyone know it is there, you're technically breaking the law. If anyone found out the camera and wasn't previously aware of its existence, you could potentially face charges.

Security Cameras has many types of functions; for example, it is used in the infrastructure of a school to improve the efficiency of inventory tracking and management of the equipments from theft and from a outside attackers by means of CCTV. The CCTV cameras can help if there is any problem going on in the school premises by outside attackers will be reported to the Security people. Thus these Latest technology play a vital role in providing efficiency to the schools


Firewall is a device or software that controls a flowing of data in the network. Can be used to filter a content from the internet. It can limit a connection in and out of a network. It is a part of a computer system or a network that is designed to block the unauthorized access. Firewall can be implemented in hardware and software. It inspects each message and blocks those do not meet the security criteria. Firewall having a routing capability that allows honey pots to keep a local users from internet.

Question 4:



D-link DCM 630

D-link DCM 630

D-link DCM 630

Server 1

Serves 2

Server room CISCO 1465


Ring topology:

It is divided point to point links is being set up to make a ring.

Technology allows a break to occur at any point in the fiber optic ring and communication remains unaffected.

Each node's network interface card has one input and one output connection. So each node is connected to two links.

When a node receives a signal on its input connection and its repeater circuitry retransmits that signal, immediately and without buffering to its output connection.

Data flows only in one direction

To send a message, a node transmits new bits onto the ring. If a message is addressed to a node that node copies bits off the ring as they go by. If node receives a message that is not addressed to it, it repeats the message without copying it.

Cable: CAT 5 (100 mbps, 100 meter)

Router: DLINK DCM 604 (Wi-Fi access point, 54 mbps )

It is a voice over IP wireless residential gateway integrated. It got 4 ports switch and IEEE 802.11g. The range of the router is 100-150 meter.

CISCO ROUTER: 1465 (100/1000 mbps, VLAN supported)