WiFi Case Study

Case Study On

WIFI

Submitted By

AQEEL ANSARI 101P044FAISAL AHMED 101P043ILYAS SAYYED 101P039

Under the guidance of

Prof. SHIBURAJ PAPPU

Bachelor of Engineering[T. E. Computer Engineering]

[2013 - 2014]at

Department of Computer Engineering

Rizvi College of EngineeringNew Rizvi Educational Complex, Off-Carter Road,

Bandra(w), Mumbai - 400050

Affiliated to

University of Mumbai

CERTIFICATEThis is to certify that

AQEEL ANSARIFAISAL AHMEDILYAS SAYYED

of T.E. Computer Engineering have successfully submitted report on “WIFI”, in partial fulfillmentof the Degree of Bachelor of Engineering in Computer Engineering under the guidance of“Prof. SHIBURAJ PAPPU”, from Rizvi College of Engineering, Bandra(W),Mumbai in the year2013-14.

Prof. Shiburaj Pappu Prof.Internal Guide External Guide

Prof. Dinesh B. Deore Dr. Varsha ShahHOD, Computer Department Principal RCOE

Internal Examiner External Examiner

Date:

ABSTRACT

Wi-Fi is a trademark of the Wi-Fi Alliance that may be used with certified products that belong to aclass of wireless local area network (WLAN) devices based on the IEEE 802.11 standards. Because ofthe close relationship with its underlying standard, the term Wi-Fi is often used as a synonym for IEEE802.11 technology. The Wi-Fi Alliance is a global, non-profit association of companies that promotesWLAN technology and certifies products if they conform to certain standards of interoperability. Notevery IEEE 802.11-compliant device is submitted for certification to the Wi-Fi Alliance, sometimes be-cause of costs associated with the certification process and the lack of the Wi-Fi logo does not imply adevice is incompatible with Wi-Fi devices. Today, an IEEE 802.11 device is installed in many personalcomputers, video game consoles, smartphones, printers, and other peripherals, and virtually all laptopor palm-sized computers.

Keywords : Wi-Fi,IEEE 802.11,WLAN.

Index

1 Introduction 11.1 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 The Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 Wi-Fi certification 32.1 Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.1.1 Internet access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.1.2 Direct computer-to-computer communications . . . . . . . . . . . . . . . . . . 4

3 Types 53.1 Airport Wi-Fi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.2 City-wide Wi-Fi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.3 Campus-wide Wi-Fi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53.4 Future directions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Advantages and Limitations 74.1 Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.2 Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.3 Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Risks 95.1 Data security risks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.2 Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.3 Network Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.4 Securing Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105.5 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

6 IEEE Paper 11

References 13

APPENDICES 13

A eReport Details 14

List of Figures

1.1 LAN card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2 Router . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3.1 City-wide Wi-Fi antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

6.1 IEEE Paper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Chapter 1 Introduction

Chapter 1

Introduction

Wi-Fi, also spelled Wifi or WiFi, is a technology that allows an electronic device to exchange data orconnect to the internet wirelessly using microwaves in the 2.4 GHz and 5 GHz bands. The name is atrademark name, and was stated to be a play on the audiophile term Hi-Fi. The Wi-Fi Alliance definesWi-Fi as any ”wireless local area network (WLAN) products that are based on the Institute of Electricaland Electronics Engineers’ (IEEE) 802.11 standards”. However, since most modern WLANs are basedon these standards, the term ”Wi-Fi” is used in general English as a synonym for ”WLAN”. Only Wi-Fi products that complete Wi-Fi Alliance interoperability certification testing successfully may use the”Wi-Fi CERTIFIED” trademark. Many devices can use Wi-Fi, e.g., personal computers, video-gameconsoles, smartphones, some digital cameras, tablet computers and digital audio players. These canconnect to a network resource such as the Internet via a wireless network access point. Such an accesspoint (or hotspot) has a range of about 20 meters (66 feet) indoors and a greater range outdoors. Hotspotcoverage can comprise an area as small as a single room with walls that block radio waves, or as largeas many square miles achieved by using multiple overlapping access points.

Depiction of a device sending information wirelessly to another device, both connected to the localnetwork, in order to print a document.Wi-Fi can be less secure than wired connections such as Ether-net because an intruder does not need a physical connection. Web pages that use SSL are secure butunencrypted internet access can easily be detected by intruders. Because of this, Wi-Fi has adoptedvarious encryption technologies. The early encryption WEP, proved easy to break. Higher quality pro-tocols (WPA, WPA2) were added later. An optional feature added in 2007, called Wi-Fi Protected Setup(WPS), had a serious flaw that allowed an attacker to recover the router’s password. The Wi-Fi Al-liance has since updated its test plan and certification program to ensure all newly certified devices resistattacks.

1.1 History

Wi-Fi uses both single-carrier direct-sequence spread spectrum radio technology (part of the larger fam-ily of spread spectrum systems) and multi-carrier orthogonal frequency-division multiplexing (OFDM)radio technology. The deregulation of certain radio-frequencies for unlicensed spread spectrum deploy-ment enabled the development of Wi-Fi products, its onetime competitor HomeRF, Bluetooth, and manyother products such as some types of cordless telephones. Unlicensed spread spectrum was first madeavailable in the US by the FCC in rules adopted on May 9, 1985 and these FCC regulations were latercopied with some changes in many other countries enabling use of this technology in all major coun-tries. The FCC action was proposed by Michael Marcus of the FCC staff in 1980 and the subsequentregulatory action took 5 more years. It was part of a broader proposal to allow civil use of spread spec-trum technology and was opposed at the time by mainstream equipment manufacturers and many radio

Rizvi College of Engineering, Bandra, Mumbai. 1

Chapter 1 Introduction

system operators.

Figure 1.1: LAN card

1.2 The Name

The term Wi-Fi, commercially used at least as early as August 2000, was coined by a brand-consultingfirm called Interbrand Corporation. The Wi-Fi Alliance had hired Interbrand to determine a name thatwas ”a little catchier than ’IEEE 802.11b Direct Sequence’”. Phil Belanger, a founding member ofthe Wi-Fi Alliance who presided over the selection of the name ”Wi-Fi”, also stated that Interbrandinvented Wi-Fi as a play on words with Hi-Fi, and also created the Wi-Fi logo. The Wi-Fi Allianceused the ”nonsense” advertising slogan ”The Standard for Wireless Fidelity” for a short time after thebrand name was invented, leading to the misconception that Wi-Fi was an abbreviation of ”WirelessFidelity”.The yin-yang Wi-Fi logo indicates the certification of a product for interoperability. Non-Wi-Fi technologies intended for fixed points such as Motorola Canopy are usually described as fixedwireless. Alternative wireless technologies include mobile phone standards such as 2G, 3G or 4G.

Figure 1.2: Router

2

Chapter 2 Wi-Fi certification

Chapter 2

Wi-Fi certification

The IEEE does not test equipment for compliance with their standards. The non-profit Wi-Fi Alliancewas formed in 1999 to fill this void to establish and enforce standards for interoperability and backwardcompatibility, and to promote wireless local-area-network technology. As of 2010, the Wi-Fi Allianceconsisted of more than 375 companies from around the world. The Wi-Fi Alliance enforces the useof the Wi-Fi brand to technologies based on the IEEE 802.11 standards from the IEEE. This includeswireless local area network (WLAN) connections, device to device connectivity (such as Wi-Fi Peerto Peer aka Wi-Fi Direct), Personal area network (PAN), local area network (LAN) and even somelimited wide area network (WAN) connections. Manufacturers with membership in the Wi-Fi Alliance,whose products pass the certification process, gain the right to mark those products with the Wi-Fi logo.Specifically, the certification process requires conformance to the IEEE 802.11 radio standards, theWPA and WPA2 security standards, and the EAP authentication standard. Certification may optionallyinclude tests of IEEE 802.11 draft standards, interaction with cellular-phone technology in convergeddevices, and features relating to security set-up, multimedia, and power-saving. Not every Wi-Fi deviceis submitted for certification. The lack of Wi-Fi certification does not necessarily imply that a device isincompatible with other Wi-Fi devices. If it is compliant or partly compatible, the Wi-Fi Alliance maynot object to its description as a Wi-Fi device[citation needed] though technically only certified devicesare approved. The Wi-Fi Alliance may or may not sanction derivative terms, such as Super Wi-Fi, coinedby the US Federal Communications Commission (FCC) to describe proposed networking in the UHFTV band in the US.

2.1 Uses

2.1.1 Internet access

A Wi-Fi enabled device such as a personal computer, video game console, mobile phone, MP3 player or-personal digital assistant can connect to the Internet when within range of a wireless network connectedto the Internet. The coverage of one or more interconnected access points called a hotspot can comprisean area as small as a few rooms or as large as many square miles covered by a group of access pointswith overlapping coverage. Wi-Fi technology has been used in wireless mesh networks, for example,in London. In addition to private use in homes and offices, Wi-Fi can provide public access at Wi-Fihotspots provided either free of charge or to subscribers to various commercial services. Organizationsand businesses such as airports, hotels and restaurants often provide free hotspots to attract or assistclients. Enthusiasts or authorities who wish to provide services or even to promote business in selectedareas sometimes provide free Wi-Fi access. As of 2008 there are more than 300 metropolitan-wide Wi-Fi (Muni-Fi) projects in progress. There were 879 Wi-Fi based Wireless Internet service providers in


Chapter 2 Wi-Fi certification

the Czech Republic as of May 2008. Routers that incorporate a digital subscriber line modem or a cablemodem and a Wi-Fi access point, often set up in homes and other premises, provide Internet-access andinternetworking to all devices connected (wirelessly or by cable) to them. One can also connect Wi-Fi devices in ad hoc mode for client-to-client connections without a router. Wi-Fi also enables placesthat would traditionally not have network to be connected, for example bathrooms, kitchens and gardensheds.

2.1.2 Direct computer-to-computer communications

Wi-Fi also allows communications directly from one computer to another without the involvement of anaccess point. This is called the ad-hoc mode of Wi-Fi transmission. This wireless ad-hoc network modehas proven popular with multiplayer handheld game consoles, such as the Nintendo DS, digital cameras,and other consumer electronicsdevices. A similar method is a new specification called Wi-Fi Directwhich is promoted by the Wi-Fi Alliance for file transfers and media sharing through a new discoveryand security methodology.

4

Chapter 3 Types

Chapter 3

Types

3.1 Airport Wi-Fi

In September of 2003, Pittsburgh International Airport became the first airport to allow and offer freeWi-Fi throughout its terminal.[7] It is now commonplace.

3.2 City-wide Wi-Fi

In the early 2000s, many cities around the world announced plans for a city wide Wi-Fi network. Thisproved to be much more difficult than their promoters initially envisioned with the result that most ofthese projects were either canceled or placed on indefinite hold. A few were successful, for example in2005, Sunnyvale, California became the first city in the United States to offer city wide free Wi-Fi. Fewof the Municipal Wi-Fi firms have now entered into the field of Smart grid networks.

Figure 3.1: City-wide Wi-Fi antenna

3.3 Campus-wide Wi-Fi

Carnegie Mellon University built the first wireless Internet network in the world at their Pittsburghcampus in 1994, long before the Wi-Fi standard was adopted.

3.4 Future directions

As of 2010 Wi-Fi technology had spread widely within business and industrial sites. In business environ-ments, just like other environments, increasing the number of Wi-Fi access-points provides redundancy,support for fast roaming and increased overall network-capacity by using more channels or by definingsmaller cells. Wi-Fi enables wireless voice-applications (VoWLAN or WVOIP). Over the years, Wi-Fiimplementations have moved toward ”thin” access-points, with more of the network intelligence housed


Chapter 3 Types

in a centralized network appliance, relegating individual access-points to the role of mere ”dumb” ra-dios. Outdoor applications may utilize true mesh topologies. As of 2007 Wi-Fi installations can providea secure computer networking gateway, firewall, DHCP server, intrusion detection system, and otherfunctions.

6

Chapter 4 Advantages and Limitations

Chapter 4

Advantages and Limitations

4.1 Advantages

Wi-Fi allows local area networks (LANs) to be deployed without wires for client devices, typically re-ducing the costs of network deployment and expansion. Spaces where cables cannot be run, such asoutdoor areas and historical buildings, can host wireless LANs. Wireless network adapters are now builtinto most laptops. The price of chipsets for Wi-Fi continues to drop, making it an economical networkingoption included in even more devices. Wi-Fi has become widespread in corporate infrastructures. Dif-ferent competitive brands of access points and client network interfaces are inter-operable at a basic levelof service. Products designated as ”Wi-Fi Certified” by the Wi-Fi Alliance are backwards compatible.Wi-Fi is a global set of standards. Unlike mobile phones, any standard Wi-Fi device will work anywherein the world. Wi-Fi is widely available in more than 220,000 public hotspots and tens of millions ofhomes and corporate and university campuses worldwide. The current version of Wi-Fi Protected Ac-cess encryption (WPA2) is considered secure, provided a strong passphrase is used. New protocols forQuality of Service (WMM) make Wi-Fi more suitable for latency-sensitive applications (such as voiceand video), and power saving mechanisms (WMM Power Save) improve battery operation.

4.2 Limitations

Spectrum assignments and operational limitations are not consistent worldwide. Most of Europe allowsfor an additional 2 channels beyond those permitted in the U.S. for the 2.4 GHz band. (113 vs. 111);Japan has one more on top of that (114). Europe, as of 2007, was essentially homogeneous in thisrespect. A very confusing aspect is the fact that a Wi-Fi signal actually occupies five channels in the2.4 GHz band resulting in only three non-overlapped channels in the U.S.: 1, 6, 11, and three or fourin Europe: 1, 5, 9, 13 can be used if all the equipment on a specific area can be guaranteed not to use802.11b at all, even as fallback or beacon. Equivalent isotropically radiated power(EIRP) in the EU islimited to 20 dBm (100 mW).

4.3 Range

Wi-Fi networks have limited range. A typical wireless access point using 802.11b or 802.11g with astock antenna might have a range of 35 m (115 ft) indoors and 100 m (330 ft) outdoors. IEEE 802.11n,however, can more than double the range. Range also varies with frequency band. Wi-Fi in the 2.4 GHzfrequency block has slightly better range than Wi-Fi in the 5 GHz frequency block which is used by802.11a and optionally by 802.11n. On wireless routers with detachable antennas, it is possible to im-prove range by fitting upgraded antennas which have higher gain in particular directions. Outdoor ranges


Chapter 4 Advantages and Limitations

can be improved to many kilometers through the use of high gain directional antennas at the router andremote device(s). In general, the maximum amount of power that a Wi-Fi device can transmit is limitedby local regulations, such as FCC Part 15 in the US. Due to reach requirements for wireless LAN ap-plications, Wi-Fi has fairly high power consumption compared to some other standards. Technologiessuch as Bluetooth (designed to support wireless PAN applications) provide a much shorter propagationrange between 1 and 100m and so in general have a lower power consumption. Other low-power tech-nologies such as ZigBee have fairly long range, but much lower data rate. The high power consumptionof Wi-Fi makes battery life in mobile devices a concern. Researchers have developed a number of ”nonew wires” technologies to provide alternatives to Wi-Fi for applications in which Wi-Fi’s indoor rangeis not adequate and where installing new wires (such as CAT-6) is not possible or cost-effective. Forexample, the ITU-T G.hn standard for high speed Local area networks uses existing home wiring (coax-ial cables, phone lines and power lines). Although G.hn does not provide some of the advantages ofWi-Fi (such as mobility or outdoor use), it’s designed for applications (such as IPTV distribution) whereindoor range is more important than mobility. Due to the complex nature of radio propagation at typicalWi-Fi frequencies, particularly the effects of signal reflection off trees and buildings, algorithms canonly approximately predict Wi-Fi signal strength for any given area in relation to a transmitter. Thiseffect does not apply equally to long-range Wi-Fi, since longer links typically operate from towers thattransmit above the surrounding foliage. The practical range of Wi-Fi essentially confines mobile useto such applications as inventory-taking machines in warehouses or in retail spaces, barcode-readingdevices at check-out stands, or receiving/shipping stations. Mobile use of Wi-Fi over wider ranges islimited, for instance, to uses such as in an automobile moving from one hotspot to another. Otherwireless technologies are more suitable for communicating with moving vehicles.

8

Chapter 5 Risks

Chapter 5

Risks

5.1 Data security risks

The most common wireless encryption-standard, Wired Equivalent Privacy (WEP), has been shown to beeasily breakable even when correctly configured. Wi-Fi Protected Access (WPA and WPA2) encryption,which became available in devices in 2003, aimed to solve this problem. Wi-Fi access points typicallydefault to an encryption-free (open) mode. Novice users benefit from a zero-configuration device thatworks out-of-the-box, but this default does not enable any wireless security, providing open wirelessaccess to a LAN. To turn security on requires the user to configure the device, usually via a softwaregraphical user interface (GUI). On unencrypted Wi-Fi networks connecting devices can monitor andrecord data (including personal information). Such networks can only be secured by using other meansof protection, such as a VPN or secure Hypertext Transfer Protocol (HTTPS) over Transport LayerSecurity.

5.2 Interference

Wi-Fi connections can be disrupted or the internet speed lowered by having other devices in the samearea. Many 2.4 GHz 802.11b and 802.11g access-points default to the same channel on initial startup,contributing to congestion on certain channels. Wi-Fi pollution, or an excessive number of access pointsin the area, especially on the neighboring channel, can prevent access and interfere with other devices’use of other access points, caused by overlapping channels in the 802.11g/b spectrum, as well as with de-creased signal-to-noise ratio (SNR) between access points. This can become a problem in high-densityareas, such as large apartment complexes or office buildings with many Wi-Fi access points. Addi-tionally, other devices use the 2.4 GHz band: microwave ovens, ISM band devices, security cameras,ZigBee devices, Bluetooth devices, video senders, cordless phones, baby monitors, and (in some coun-tries) Amateur radio all of which can cause significant additional interference. It is also an issue whenmunicipalities or other large entities (such as universities) seek to provide large area coverage.

5.3 Network Security

The main issue with wireless network security is its simplified access to the network compared to tradi-tional wired networks such as Ethernet, with wired networking one must either gain access to a building(physically connecting into the internal network) or break through an external firewall. To enable Wi-Fi,one merely needs to be within the wireless range of the Wi-Fi network. Most business networks protectsensitive data and systems by attempting to disallow external access. Enabling wireless connectivity


Chapter 5 Risks

reduces security if the network uses inadequate or no encryption. An attacker who has gained accessto a Wi-Fi network router can initiate a DNS spoofing attack against any other user of the network byforging a response before the queried DNS server has a chance to reply

5.4 Securing Methods

A common measure to deter unauthorized users involves hiding the access point’s name by disabling theSSID broadcast. While effective against the casual user, it is ineffective as a security method becausethe SSID is broadcast in the clear in response to a client SSID query. Another method is to only allowcomputers with known MAC addresses to join the network,[55] but determined eavesdroppers may beable to join the network by spoofing an authorized address. Wired Equivalent Privacy (WEP) encryptionwas designed to protect against casual snooping but it is no longer considered secure. Tools such asAirSnort or Aircrack-ng can quickly recover WEP encryption keys.[56] Because of WEP’s weaknessthe Wi-Fi Alliance approved Wi-Fi Protected Access (WPA) which uses TKIP. WPA was specificallydesigned to work with older equipment usually through a firmware upgrade. Though more secure thanWEP, WPA has known vulnerabilities. The more secure WPA2 using Advanced Encryption Standardwas introduced in 2004 and is supported by most new Wi-Fi devices. WPA2 is fully compatible withWPA. A flaw in a feature added to Wi-Fi in 2007, called Wi-Fi Protected Setup, allows WPA and WPA2security to be bypassed and effectively broken in many situations. The only remedy as of late 2011 is toturn off Wi-Fi Protected Setup,[58] which is not always possible.

5.5 Safety

Further information: Wireless electronic devices and health The World Health Organization (WHO)says ”there is no risk from low level, long-term exposure to Wi-Fi networks” and the United Kingdom’sHealth Protection Agency reports that exposure to Wi-Fi for a year results in the ”same amount of ra-diation from a 20-minute mobile phone call”. A small percentage of Wi-Fi users have reported adversehealth issues after repeat exposure and use of Wi-Fi, though there has been no publication of any ef-fects being observable in double-blind studies. A review of studies involving 725 people that claimedelectromagnetic hypersensitivity found no evidence for their claims.

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Chapter 6 IEEE Paper

Chapter 6

IEEE Paper

Figure 6.1: IEEE Paper


Chapter 6 IEEE Paper

12

References

References

[1] ”Wi-Fi Alliance: White Papers”. www.wi-fi.org. Retrieved 2009-10-22.

[2] ”What is the True Meaning of Wi-Fi?”. Teleclick. Retrieved 2007-08-31.

[3] ”Long Distance WiFi Trial” (PDF). Retrieved 2008-03-10.

[4] ”Free Wi-Fi? User beware: Open connections to Internet are full of security dangers, hackers, IDthieves”. Larry Higgs Asbury Park Press.

[5] ”Wi-Fi (wireless networking technology)”. Encyclopdia Britannica. Retrieved 2010-02-03.


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