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  • 1. Implementation of Wireless Fidelity Technology: Affordable, Practical, and Future-Proof Matt Geis Johnson Wei May 11, 2010
  • 2. 2 Introduction Wireless Fidelity, widely know as “Wi-Fi” is simply a standard for wireless certification for the connectivity of wireless networks with respective mobile devices. However, there is much mystery, myth, and confusion surrounding this new technology. Is Wi-Fi secure? How easy is it able to be implemented into a business? Is it costly to maintain? History of Wi-Fi Wi-Fi was not an overnight sensation. Years of events have shaped the evolution and maturation of what it is today. In 1993, Advanced Micro Device’s (AMD) Director of Corporate Development, Brett Stewart, entertained the idea of his own company as the original 802.11 MAC technology was licensed to Xircom. Two years later in 1995, Plancom was founded. This new company intended to open public spaces with wireless access. Wayport was created a year later along with its first new hotel. The entire infrastructure of the hotel was based on linux and the system incorporated the Breezecom frequency hopping. All the rooms in the hotel were wired with the exception of a wireless lobby and bar area. June of 1997 heralded the finalization of the 802.11 technology. The Institute of Electrical and Electronic Engineers (IEEE) finalized the initial standard for wireless LANs, IEEE 802.11. This standard specified a 2.4GHz operating frequency with data rates of 1 and 2Mbps. When deploying a wireless LAN using the initial version of 802.11, there was a choice in using either the frequency hopping spread spectrum (FHSS) or a direct sequence spread spectrum (DSSS). Since the ratification of the initial 802.11 standard, the IEEE 802.11 Working Group (WG) has made several revisions.
  • 3. 3 Three months from the finalization of the 802.11 specification, Wayport receives Series A funding on September 27th. Shortly afterwards Wayport switches to Aironet and begins manufacturing Aironet 11 Mbps gear. In the summer of 1998, Apple Airpot became mainstream. Computer using Lucent Technologies Orinoco (formerly WaveLAN) equipment became the first operating system maker to include support for Wi-Fi, which they called AirPort. Apple also shipped the necessary hardware for clients for $100, and the AirPort Base Station, an access point, for $300, a price they managed to maintain until 2002 while revising the product only once. In September of 1999, Nokia began ambitious plans for massive wireless deployment. Nokia, in conjunction with ZD Events, created wireless access zones in selected areas of the Atlanta Congress Center including the Congress Center's Conference Club, the Omni and Weston Hotels. In a similar effort with Laptop Lane, Nokia implemented wireless access zones in selected areas of the Atlanta Airport. Most importantly, Nokia, along with 5 other industry leaders; 3Com, Aironet, Intersil, Lucent Technologies, and Symbol Technologies, united to form the Wireless Ethernet Compatibility Alliance (WECA). WECA's mission was to certify interoperability of IEEE 802.11 High Rate products and promote that standard for the enterprise, small business, public hot spots and home. Just two months later, Cisco acquired Aironet. During this timeframe, Jesse R. Walker of Intel published Unsafe at any key size; An analysis of the WEP encapsulation, citing the inefficacy of WEP and dispelled the notion that simply increasing the WEP key size would increase security. Walker stated: “it is infeasible to achieve privacy with the WEP encapsulation by simply increasing key size. The submission reports easily implemented, practical attacks against WEP that
  • 4. 4 succeed regardless of the key size or the cipher. In particular, as currently defined, WEP’s usage of encryption is a fundamentally unsound construction; the WEP encapsulation remains insecure whether its key length is 1 bit or 1000 or any other size whatsoever, and the same remains true when any other stream cipher replaces RC4. The weakness stems from WEP’s usage of its initialization vector. This vulnerability prevents the WEP encapsulation from providing a meaningful notion of privacy at any key size.” Competition tightened as companies fell out of business while others jumped on Wi-Fi bandwagon. AerZone, a contender for the leading airport hot spot wireless ISP, shut down despite having signed contracts to offer service at United and Delta waiting areas, and across certain major airports. On the other hand, Starbucks picked MobileStar as its wireless partner. Starbucks announced that MobileStar would build out all of its freestanding stores over a course of three years. During this time, Musenki was founded with intent of building open-source wireless networking equipment. New York Times Circuits cover story for February 21, 2000, entailed public space wireless ISPs. Wi-Fi blogger Glenn Fleishman authored an enormous piece on wireless ISPs. Several of the companies mentioned disappeared over the next six months. Exactly one month later on March 21, Nokia launched a new generation access point, the A030 Wireless LAN Access Point, which offered fast mobile access to Internet and corporate intranet. It was optimized for mobile operation, enterprise and corporate use, providing 11 Mbit/s broadband mobility and allowing wireless offices to be set up anywhere. At the 7th Annual International Conference on Mobile Computing and Networking in July, a team of researchers from Berkeley (Nikita Borisov, Ian Goldberg, and David Wagner) published the first serious paper that received a great deal of press attention about problems with WEP, titled Intercepting Mobile Communications: That of 802.11. This was immediately followed by a practical demonstration as Avi Rubin announced that he was part of a team that has broken WEP, with Adam Stubblefield and
  • 5. 5 John Ioannidis. The paper, AT&T Labs Technical Report TD-4ZCPZZ, was the first disclosed attack against WEP which used the Fluhrer, Mantin, and Shamir attack. A year later, CTIA, Boingo, SmartCity and the Orange County Convention Center worked together to bring Wi-Fi to the CTIA conference in Orlando. Hot spot encompassed more than one million square feet of wireless access — believed to be the largest indoor deployment of Wi-Fi to date. In the meantime WECA changed its name to Wi-Fi Alliance, recognizing the power of its trademark. On October 4, 2001, Wi-Fi added 802.11a to its arsenal specifications. The newly renamed Wi-Fi Alliance changed the Wi-Fi trademark to serve as an overall symbol of interoperability coupled with specific annotations below the mark on products to say whether they are 2.4 GHz or 5 GHz band based. Due to the inability of WEP to insure security, a new security protocol Wi-Fi Protected Access (WPA) was to replace WEP. The Wi-Fi Alliance announced WPA as an “interim solution for link-layer security based on the work in progress at the IEEE 802.11i task group.” WPA fixed most of WEP’s fundamental problems, while also requiring 802.1x and EAP support to be included. Certification of WPA as part of Wi-Fi was scheduled to begin in February 2003; mandatory inclusion was scheduled for the following fall 2003. Shortly afterwards, on November 4, 2001, Vivato demonstrated the abilities of the phased-array antenna. Vivato took unveiled its secret project and showed how its antenna and access point solution could light up entire buildings or parts of a city from a single location instead of requiring individual access points densely arrayed. The creation of 802.11g soon followed and was quickly ratified.
  • 6. 6 Current Technology Four IEEE WLAN standards mainstream Wi-Fi technology: 802.11b, 802.11g, 802.11n, and 802.11a. As noted earlier, 802.11b became the first wireless standard to be implemented widely. It was not, however, the first form of the 802.11 specification. The 802.11b standard arrived after 802.11 Legacy, the first version of the IEEE standard. With a speed increase and price reduction over 802.11 Legacy, 802.11b quickly became an accepted technology, making Wi-Fi more mainstream. Officially ratified in 1999, 802.11b operated on the 2.4 gigahertz band. This became a disadvantage for 802.11b users, as the 2.4 gigahertz band was shared by many other appliances, including cordless phones, microwave ovens, and Bluetooth technology. This led to considerable interference and degradation of the signal and ultimately slower connection speeds. Capable of “point-to-multipoint” abilities, an 802.11b access point sends out a signal from one location to be potentially received in multiple locations simultaneously. The data transfer speeds can reach as high as 11 megabits per second, assuming only the absolute best conditions. As the signal grows weaker, transfer speeds diminish accordingly. In such cases, the data transfer speed will be reduced from 11 megabits per second to 5 megabits per second, then 2 megabits per second, and then finally 1 megabit per second as the signal continues to weaken. Additionally, the access point may be configured for point-to-point as opposed to point-to-multipoint, allowing for the transfer of data to only one user faster over a much greater distance, facilitating traveling from the access point and still remain connected. The 802.11b standard was immediately compatible with 802.11g, which was introduced several years later.
  • 7. 7 The second IEEE standard introduced, 802.11a, was ratified in 1999. Unlike 802.11b, 802.11a operated on the 5 gigahertz band as opposed to 802.11b’s 2.4 gigahertz band, which meant interference no longer interfered with other electronic appliances as it had done for those on 2.4 gigahertz frequency. Ultimately, this suggested better signals and increased speeds over the previous specification. However, one significant problem occurred with the utilization of the 5 gigahertz band. It was known that operating at the frequency gave a different signal than with 2.4 gigahertz. Obstacles absorbed the signal much more than the previous band. Thus, the signal did not penetrate as far, and it required a better line-of-sight. This however, only meant more access points were needed to operate the network efficiently. Regarding speed, 802.11a offered a potential data transfer speed of 54 megabits per second, almost five times faster than that of 802.11b. As the 802.11a signal diminished, the data transfer speed was reduced to 48 megabits per second, 36 megabits per second, 24 megabits per second, 18 megabits per second, 12 megabits per second, 9 megabits per second, and finally 6 megabits per second. Oddly, this standard was not as well received as 802.11b. It was released to the public shortly after the 802.11b, but due to its short range effectiveness and government regulations, it did not become nearly as widely implemented as the 802.11b had been. Technological improvements have led better signals, almost comparable to that of 802.11b, and the governments around the world have facilitated the technology for people to use. The 802.11a standard is only compatible with itself. One of the newer Wi-Fi technologies was the 802.11g, ratified in 2003, became the third standard to be introduced. Like the 802.11b specification, 802.11g returned to
  • 8. 8 the 2.4 gigahertz band, only with the speed of the 802.11a. The 802.11g had a potential data transfer speed of 54 megabits per second. It appeared to combine the best parts of its two predecessors, 802.11b’s strong signal range coupled with 802.11a’s faster data transfer speeds. Of course it inherited the flaws of the 802.11b’s interference from the other appliances on the 2.4 gigahertz band as well; nonetheless, it was hoped that the increased speed would make up for it shortcomings. As the signal weakened, the data transfer speed was reduced to 48 megabits per second, 36 megabits per second, 24 megabits per second, 18 megabits per second, 12 megabits per second, 9 megabits per second, and finally 6 megabits per second. This is the same speed degradation pattern seen from the 802.11a standard. 802.11g, while widely adopted, had its fair share of problems. It appeared that the interference caused by other appliances on the 2.4 gigahertz band had a greater affect on the 802.11g than it did with 802.11b, because of its higher speeds. This interference causes the speed to drop to extremely low levels, meaning 802.11g users were not seeing speeds that much greater than someone using 802.11b. This technology became widely adopted by the public as it was backwards compatible with 802.11b as they both used the 2.4 gigahertz band. While the two were compatible, having an 802.11b on an 802.11g network would nonetheless slow bandwidth considerably. The most current IEEE standard, was a new concept, which theoretically improved greatly over the flaws of the previous standards. The 802.11n standard was developed by TGn, with help from several other companies, including Intel and the Wi-Fi Alliance. With the 802.11n standard, it was hoped that the technology would be
  • 9. 9 improved in every area. The industry desired the new standard to be faster, have a much stronger signal, and continue the pattern of compatibility and interoperability with past standards, promising it would work with standards a, b, and g. This became a challenge for engineers of 802.11n. Clearly, as seen, from the previous standards, there has always been some drawback to the next standard. However, 802.11n sought to improve in every area, and be the clear choice of any wireless user, all while cutting non-influential variable costs where applicable. While the data transfer speed has not been fully confirmed, current estimates range from a conservative 100 megabits per second, to a potential of 540 megabits per second. Increasing the data transfer speeds to such a level, and to make 802.11n compatible with past standards, new technology needed to be developed. Current technologies being further developed for use in 802.11n include multiple-input multiple- output (MIMO) and orthogonal frequency division multiplexing (OFDM). MIMO, otherwise known as a “smart antenna system,” uses several signals sent and received by the wireless medium. MIMO has the potential to benefit 802.11n greatly. First, MIMO will help with the problem of other objects absorbing the signals sent from one medium to another. Signals that hit objects, and are no longer in the line of sight from the source, are known as “Multipath” signals. Multipath signals are usually degraded, however with MIMO the multipath signals are “spacially resolved” and thus deliver information as intended. This technology will aid 802.11n in sending and receiving data faster and at greater distances than the other standards were able to manage.
  • 10. 10 Orthogonal Frequency Division Multiplexing (OFDM0 involves a single source sending out multiple signals on different frequencies. The main benefit from OFDM is that it creates a resistance against multipath signals, thus giving users a better signal. OFDM had been used in previous standards, however engineers designing the new standard are hoping that it will be more effective with 802.11n. There are many more standards, as 802.11 goes from a to w. Each standard is a little different, and some are better than others, however a, b, g, and n are the most important as they are the mainstream standards. Due to the multiple standards, companies manufacture Wireless Network Adapters than will work with multiple signals. These “dual-mode” and “tri-mode” cards can handle multiple standards with no problems. Security Many have questioned if data on Wi-Fi networks is secure. Now this is frequently asked, as it is important to keep personal and confidential information from getting into the hands of others. Computers are sending data through the air to one another, so how can any of it be protected? Often computer users surfing the internet over Wi-Fi connections enter numerous user names, passwords, credit card numbers, and banking information. Malicious users can “sniff” using programs called “wardrivers” to detect Wi-Fi networks that might be wide open to the public. This allows them access to the network. Once on the networks, it is possible for them to use specialized programs to intercept signals being sent through the wireless network, gaining access to anything transmitted and received by the user.
  • 11. 11 This may sound scary; however, there is good protection from it. For personal users, protecting yourself can be simple as adding a firewall, turning off auto-connect to servers, encrypting data, and using anti-virus protection. For businesses, administrators need to activate the built-in encryption ability of the computers right away. It is also recommended that the businesses use a Virtual Private Network (VPN) connection to create a connection that cannot be intercepted by any other computers than the ones intended to receive the data. Businesses should also use the latest version of the Wi-Fi Protected Access (WPA2), which will keep all confidential data safe. It would also be a good idea to set up a Secure Sockets Layer (SSL) when using web services. Disadvantages of Wi-Fi It is known that there are a few clear shortcomings of Wi-Fi technology. While 802.11n provides significant increase in range for wireless networks, many of the estimates are generous. Similarly Wi-Fi will never be as fast or stable as a wired ethernet network. Roaming also becomes an issue. True mobility cannot be achieved with out proper roaming capabilities, allowing the transition from one wireless access point to another. As previously mentioned, weakened signal strength further worsened through frequency interference provides a system of diminishing returns. Lastly, security has been constant issue. It takes a competent computer user to properly configure the security settings for any wireless network. Wireless networks have often been compared to walking outside without wearing any clothes. Anyone is able to use unsecured wireless networks and thus have potential access to sensitive information. Furthermore, the most popular security measure WEP, has been proven
  • 12. 12 ineffective through many sources. Currently, there are even websites that provide detailed guides and tools for successfully cracking a WEP “secured” network. However, the advancement of the WPA security measure is a positive step for a secure wireless environment. However, it has not been implemented widely. Advantages over a Wired Network For years the world has been using wires and cables browse the world-wide web. The world has evolved since then, and internet users have found a better alternative, Wi- Fi. It has many advantages over cables and wires, and what disadvantages it has are negligible. Wi-Fi is the technology of the future, and if it continues to improve, the traditional Ethernet cable linked networks will be obsolete in no time. To do a comparison of the two, it is obvious that Wi-Fi will one day be able to almost completely replace the use of cables. Installing Wi-Fi is much easier. Assume a start up business desired to set up a new network. If they chose to go the traditional way, using ethernet cables to hook up all of their machines, they will most likely need professional help in the form of skilled technicians. This of course will be on top of the numerous cables and network cards that must be purchased as well. Such a job could take many days to complete. If the company were to choose Wi-Fi, things would be much simpler. With Wi-Fi, the company may simply install access points throughout the area and put Wireless Network Adapters (WLANs) into the computers that are to be on the network. Due to the increased use of Wi-Fi, the costs have been decreasing steadily, opening up many opportunities for Wi-Fi access.
  • 13. 13 In terms of speed, Wi-Fi once was far behind using Ethernet cables, however these days things have changed. Basic 10BaseT wired Ethernet cables have a potential data transfer speed of 100 megabits per second. Currently, 802.11a and 802.11g are capable of 54 megabits per second, which is getting up there. When 802.11n is finally introduced as promised into the mainstream, it should be able to surpass the speed of an Ethernet network easily. With a minimum potential speed prediction speed of 100 megabits per second, it is most likely that it will be able to move data much faster than any Ethernet cable can. Moving away from an access point will damage the signal with wireless, however moving a cable networked computer a decent distance can result in pulled cables and other more serious damage. Also, a wireless laptop may go from receiving a wireless signal from one access point, to walking into a stronger signal from another access point, boosting their transfer speed back up. There really is no comparison when it comes to mobility. With cables, one is stuck in the same spot. One must also find locations with cable access, or they will not be able to log onto the internet. With Wi-Fi, one must simply venture into an area that can be reached by an access point. This has become increasingly easier the past few years as well. There are a growing number of access points popping up around the world, meaning mobility can only improve. Therefore, while Wi-Fi may not be faster than an ethernet connection or not yet as secure, the ease of use and portability are undeniable in a society which values such traits above all else. The future is “business on the go” and if one were stuck on ethernet cables, the world will simply pass you by.
  • 14. 14 Advantages over WiMAX WiMAX (Worldwide Interoperability for Microwave Access), sometimes called wireless broadband, is the latest wireless innovation. While WiMAX may someday be the standard, it currently has little advantage over Wi-Fi. Currently, WiMAX is still only being tested. There are different estimates on the data transfer speed, but most estimate this figure at about 70 megabits per second. The great claim of WiMAX is that it can cover extremely long distances, those of up to 30 miles. People have been talking about such technology for about a decade now, and this seems to be the first to have a real shot at it. Currently, it seems that they have not met the hype however. In tests done by AT&T in October 2005, things did not look as good as promised. The signal only managed to reach a three to five mile range, with speeds going from 500 kilobytes per second to 2 megabits per second, far off from the 70 megabits per second over 30 miles that were claimed. With the costs of implementing such a technology being so high, it seems unreasonable to install it in most places in the United States, especially with the ease most companies and consumers can set up Wi-Fi networks. It become apparent that the United States has no need for implementation of WiMAX networks, increasing the number of access points is more than sufficient. WiMAX seems more appropriate for wide range broadband applicable in third world countries. Why Go Wi-Fi? Wi-Fi is practical. Wireless technology has been closely associated with a clutter less, clean, and efficient environment for good reason. Could one ever imagine a Starbucks jumbled with Ethernet cables? Not only does a wire free environment promote
  • 15. 15 cleanliness, it is more cost efficient as well. A wired network usually involves expanding areas of the property for cables route through. “If your business grows and you need to move, you don't have to abandon your network infrastructure investment or hire a networking company to rewire the new location. And there's no network downtime—you can be up and running even before the furniture arrives. Simply plug the system into a power outlet and you'll be operational in minutes.” ( Wi-Fi also enables users the freedom of location—complete mobility with access to office files on the network. Additionally, Wi-Fi can be easily added onto any existing wired network technology. Furthermore, it is prime time to invest in Wi-Fi technology. Currently the market is almost over saturated with Wi-Fi products. Such saturation indicates strong competition among vendors and thus lowers prices for the consumer. All Wi-Fi products are compatible, regardless of the vendor. Lastly, Wi-Fi has expanded. The number of wireless hotspots, locations where you can connect using 802.11 wireless technology, is growing so fast that market research firm IDC estimates there will be 100,000 public hotspots globally by 2006. Wi-Fi in Business Wi-Fi has been a recent big hit in the business world. Companies are realizing how the technology can benefit them, and are making profits because of it. A great example is UPS. In setting up a $120 million worldwide system, they are able to transfer information at incredible speeds, leading to a 35% gain in productivity. Many companies are getting in on Wi-Fi, as setting up a powerful enough access point for business costs only about $2,000. Many large companies, such as Microsoft and General Motors, have begun to invest in Wi-Fi, as they see the benefits it brings.
  • 16. 16 Wi-Fi is not just for laptop computers. It can be put into just about any machine. Once installed, that machine will become part of a larger network, being able to send and receive large amounts of data almost instantaneously. The interesting thing is that the use of Wi-Fi in the business world will only increase. There are scored of businesses that are extremely interested in Wi-Fi, but are holding back to make absolutely sure that it is secure enough to protect their confidential data. With new technologies being implemented, there is no doubt that many of those businesses that were holding out are beginning to take action, and beginning to integrate Wi-Fi technology into their business.
  • 17. 17 Works Cited Green, Heather, Steve Rosenbush, Roger Crockett, and Stanley Holmes. "Wi-Fi Means Business." BW Online. 28 Apr. 2003. 20 Nov. 2005 <>. "IEEE 802.11." Wikipedia. 28 Nov. 2005. 20 Nov. 2005 <http>. Orlowski, Andrew. "AT&T lifts kimono on WiMAX trials." The Register. 27 Oct. 2005. 11 Nov. 2005 <>. Wilson, James M. "The Next Generation of Wireless LAN Emerges with 802.11n." Device Forge. 9 Aug. 2004. 25 Nov. 2005 <>. Wright, Maury. "WiMax wireless broadband: Fixed-flavor questions abound, mobile lurks." Voices of Electronics Engineer. 13 Mar. 2005. 3 Nov. 2005 <>.