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  • 1. Wireless 1 Wireless: Today Technological Advancement Student1-02 Indiana-University Purdue-University Fort Wayne Computer in Society CS306, Section 2 For Jacques Chansavang Fall 2007
  • 2. Wireless 2 As you know, technology has grow and blossom so much that no one can ever imagine. The role and impact of technology in both our personal and working lives is ever growing. Understanding how people shape technology and how technology shapes people's interactions with each other and the natural world is important not only for those who research, develop and implement new technologies but also for all those people and organizations that have to use those technologies in their working and personal lives. The world technological advancement has reach this point today simply because of the wireless technology. The term "wireless" was first publicly use to refer to a radio receiver or transceiver (a dual purpose receiver and transmitter device), establishing its usage in the field of wireless telegraphy at the early age; now you can find the term is being used to describe modern wireless connections such as in cellular networks and wireless broadband Internet (Hamilton, 2007). In addition, it is also used in a general sense to refer to any type of operation that is implemented without the use of wires, such as for example wireless remote control, wireless energy transfer, and so on. In this aspect, it is broadly use regardless of the specific technology (e.g., radio, infarred, ultrasonic, etc.) that is used to accomplish the operation (Athens, 2007). Furthermore, wireless can also be used to describe telecommunications in which electromagnetic waves, rather than some form of wire, carry the signal over part or the entire communication path (“Electromagnetic fields”, 2000). Some monitoring devices, such as intrusion alarms, employ acoustic waves at frequencies above the range of human hearing; these are also sometimes classified as wireless. The first wireless transmitters went on the air in the early 20th century using radiotelegraphy of the Morse code (Goldsmith, 2005). Later, as modulation made it possible to transmit voices and music via wireless, the medium came to be called "radio." With the advent of television, fax, data communication, and the effective use of a larger portion of the spectrum, the term "wireless" has been resurrected.
  • 3. Wireless 3 Technically, how old is wireless technology, anyway? Most people are surprised to find that it goes back well over 200 years. Wireless communication technologies have existed and been utilized for over a hundred years (Tse, 2005). It all started in 1819, the Danish physicist Hans Christian Oersted noted that a compass needle would move in the presence of an electric field, thus establishing the fundamental relationship between electricity and magnetism. We call the entire field electromagnetic to this day. Then in 1831, Michael Faraday demonstrated electromagnetic induction and built the first direct-current generator (“Electromagnetic fields”, 2000). While this wasn't useful for wireless communications, it did provide a way to generate electricity. The next big leap forward was the result of theoretical work by James Clerk Maxwell, the great Scottish physicist. He published "On a Dynamical Theory of the Electromagnetic Field" in 1865, and in 1873 "A Treatise on Electricity and Magnetism," which became what is known Maxwell's Equations (Athens, 2007). These are a series of very difficult differential equations which describe the movement of electromagnetic waves through space (“Electromagnetic fields”, 2000). Remarkably, we use them to this day. Maxwell, by the way, had never seen a radio; they did not exist then, and he had no actual experience with radio waves themselves. But the theory he developed paved the way for the next set of critical inventions. Building on Maxwell's work, Heinrich Hertz in 1887 invented the oscillator (an alternating-current generator) and created radio waves (Goldsmith, 2005). He contributed by demonstrating of the theory of electromagnetic waves which was very important and trigger what we have today as wireless technology. Hertz put his study in practice so he demonstrated that electromagnetic waves could be transmitted and caused to travel through space at straight lines and that they were able to be received by an experimental apparatus (“Electromagnetic fields”, 2000). Though, Hertz didn’t follow up his experiments any further but Nikola Telsa continued to implement the practical applications of the wireless communication and remote control technology. It is noted that
  • 4. Wireless 4 Oersted, Faraday, and Maxwell all had units of physical measurement named in their honor as well. Another contribution to wireless technology is David E. Hughes who induced electromagnetic waves in a signaling system and it was eight years before Hertz's experiments. Hughes transmitted Morse code by an induction equipment (Tse, 2005). In 1878, Hughes's induction transmission method utilized a "clockwork transmitter" to transmit signals. Then in 1885, T.A. Edison uses a vibrator magnet for initiation transmission. By 1888, Edison positions a system of signaling on the Lehigh Valley Railroad. Finally in 1891, Edison attains the wireless patent for this method using inductance (Athens, 2007). Not to forget Guglielmo Marconi, he played an important role in the wireless technology. He was the Italian founder of wireless technologies, developed an interest in technology and communications as a child. He had read about and understood the work of Heinrich Rudolf Hertz and began to see the significance that wireless communication would have for the modern world (Tse, 2005). In 1894 Marconi began experimentations, and in 1899 sent a telegraphic message across the English Channel and in 1901 a transmission across the Atlantic, without needing to use wires. This achievement has signaled a major advance and presented evidence that it was a system of real practical value (Athens, 2007). Only three years later, Marconi’s wireless devices were able to send and receive a telegraph across the Atlantic Ocean. The wireless technology that Marconi developed was a cross between traditional wired telegraphy and Hertzian waves, named after Heinrich Hertz who discovered them (Goldsmith, 2005). Hertz sudden and premature death in 1894 signaled the start of Marconi intense trialing of wireless technologies. Matter of fact, in the years before Marconi, numerous people had already experimented with wireless communication, many of them utilizing antennas that were as long as, if not longer than, the distance across which they wanted a to send signal (Athens, 2007).
  • 5. Wireless 5 In the early years of Marconi wireless telegraphy, the main uses for it were for military purposes. The first war that Marconi wireless communications systems were used was the Boer War in 1899, and in 1912, a wireless device set sail with the Titanic. It was the best system in the world, and without it, the tragedy of the Titanic could have been worse, because it was the device that alerted other ships in the area of the sinking Titanic (Goldsmith, 2005). Even though there was no physical unit was named for Marconi, but he did win the Nobel Prize in 1909 (Athens, 2007). By the 1920s, wireless telegraphy had taken off and became a mass medium, and its popularity soared with the public discovery that it could send personal messages across continents. With the introduction of broadcast radio, wireless technology became commercially available for everyone. There have been so many great contributions since then, from Edwin Armstrong who created FM radio to Lee De Forest who invented the electron tube and Andrew Viterbi who came up with digital decoding and CDMA (Tse, 2005). There are now more people working in wireless communications than at any other time in history. So as the computer industry suffers, to some degree, from the pains of maturity, wireless shows no such trend towards slowing down. In the last thirty years wireless communication technologies have seen a revolution, as people rediscover the uses for it, and its advantages. In the 1980s, wireless technologies were analogue signals (1G), in the 1990s they changed to digital (2G), in the nineties they remained digital but became better quality and faster, and now the future is heading rapidly for 4G communications (Goldsmith, 2005). In 1994, the Ericsson telecommunications company began devising and developing a technology that would connect portable devices while replacing cables (Moher, Michael, and Simon Haykin, 2004). They named this device Bluetooth after King Harald I of Norway, who joined Denmark and Norway. Under the aims of the Ericsson company for Bluetooth, this paralleled the objective of Bluetooth technology, which aims to unite the computer and telecommunication industry (Athens, 2007). After its initial development, Ericsson
  • 6. Wireless 6 realized that the product had huge potential worldwide, and from the Bluetooth Special Interest Group, which now includes over 1000 companies from around the world. The on demand nature of today society has seen technologies like Bluetooth becoming an extremely popular alternative to wired communications and cables (Athens, 2007). Below Table 1.1 demonstrates a simple timeline of Wireless Technologies evolution. Table 1. A simple timeline in Wireless Technologies evolution (this is not to be considered an ‘all inclusive’ timeline) ______________________________________________________ 1896 Guglielmo Marconi develops the first wireless telegraph system 1927 First commercial radiotelephone service operated between Britain and the US 1946 First car-based mobile telephone set up in St. Louis, using ‘push-to-talk’ technology 1948 Claude Shannon publishes two benchmark papers on Information Theory, containing the basis for data compression (source encoding) and error detection and correction (channel encoding) 1950 TD-2, the first terrestrial microwave telecommunication system, installed to support 2400 telephone circuits 1950s Late in the decade, several ‘push-to-talk’ mobile systems established in big cities for CB-radio, taxis, police, etc. 1950s Late in the decade, the first paging access control equipment (PACE) paging systems established 1960s Early in the decade, the Improved Mobile Telephone System (IMTS) developed with simultaneous transmit and receive, more channels, and greater power 1962 The first communication satellite, Telstar, launched into orbit 1964 The International Telecommunications Satellite Consortium (INTELSAT) established, and in 1965 launches the Early Bird geostationary satellite
  • 7. Wireless 7 Table 1 (continued) _____________________________________________________ 1968 Defense Advanced Research Projects Agency – US (DARPA) selected BBN to develop the Advanced Research Projects Agency Network (ARPANET), the father of the modern Internet 1970s Packet switching emerges as an efficient means of data communications, with the X.25 standard emerging late in the decade 1990 Motorola files FCC application for permission to launch 77 (revised down to 66) low earth orbit communication satellites, known as the Iridium System (element 77 is Iridium) 1992 One-millionth host connected to the Internet, with the size now approximately doubling every year 1993 Internet Protocol version 4 (IPv4) established for reliable transmission over the Internet in conjunction with the Transport Control Protocol (TCP) 1994–1995 FCC licenses the Personal Communication Services (PCS) spectrum (1.7 to 2.3 GHz) for $7.7 billion 1998 Ericsson, IBM, Intel, Nokia, and Toshiba announce they will join to develop Bluetooth for wireless data exchange between handheld computers or cellular phones and stationary computers 1990s Late in the decade, Virtual Private Networks (VPNs) based on the Layer 2 Tunneling Protocol (L2TP) and IPSEC security techniques become available 2000 802.11(b)-based networks are in popular demand 2000–2001 Wired Equivalent Privacy (WEP) Security is broken. The search for greater security for 802.11(x)-based networks increases "If I have seen further it is by standing on ye shoulders of Giants," Isaac Newton wrote that in a famous letter of his to Robert Hooke, the great English scientist and inventor (Goldsmith, 2005). Today, after well over 200 years, we continue to build on the work of an
  • 8. Wireless 8 amazing number of inspiring people who were fascinated with the concept of communication through the air. And the innovations continue at a remarkable pace. Wireless technologies represent a rapidly emerging area of growth and importance for providing ubiquitous access to the network for everyone over the world. People everywhere increasingly want un-tethered network access from general-purpose classrooms, meeting rooms, auditoriums, and even the hallways of work or school buildings (Goldsmith, 2005). There is interest in creating mobile computing labs utilizing laptop computers equipped with wireless Ethernet cards. Recently, industry has made significant progress in resolving some constraints to the widespread adoption of wireless technologies. Some of the constraints have included disparate standards, low bandwidth, and high infrastructure and service cost (Tse, 2005). Wireless technologies can both support the institution mission and provide cost-effective solutions. Wireless is being adopted for many new applications: to connect computers, to allow remote monitoring and data acquisition, to provide access control and security, and to provide a solution for environments where wires may not be the best solution (Athens, 2007). What follows is an overview of existing wireless technologies, its applications, the benefits, and the related issues. Before getting into the benefits and the issues aspect of wireless technology, we need to get a better understanding of the wireless infrastructure and its applications. Infrastructure wireless networking bridges a wireless network to a wired Ethernet network. Infrastructure wireless also supports central connection points for Wireless Local Area Network (WLAN) clients. A wireless access point (AP) is required for infrastructure mode wireless networking. To join the WLAN, the AP and all wireless clients must be configured to use the same Service Set Identifier (SSID) (Tse, 2005). The AP is then cabled to the wired network to allow wireless clients access to, for example, Internet connections or printers. Additional APs can be added to the WLAN to increase the reach of the infrastructure and support any number of wireless clients.
  • 9. Wireless 9 Below are couples of figures that explain how satellite communicates, wireless infrastructure, and the Fixed Broadband Wireless Access Network. Figure 1. Satellite Communications and Wireless Infrastructure Figure 2. Simplified Fixed Broadband Wireless Access Network
  • 10. Wireless 10 There are numerous applications for all the different wireless technologies. First there is voice and messaging application. Cell phones, pagers, and commercial two-way business radios can provide voice and messaging services. These devices may be based on analog or digital standards that differ primarily in the way in which they process signals and encode information (Goldsmith, 2005). The analog standard is the Advanced Mobile Phone Service (AMPS). Digital standards are Global System for Mobile Communications (GSM), Time Division Multiple Access (TDMA), or Code Division Multiple Access (CDMA). Normally, devices operate within networks that provide metropolitan, statewide, or nationwide coverage. These large and costly networks are operated by carriers such as AT&T, Sprint, Verizon, local phone companies, etc. and operate in different frequency bands which are allocated by the FCC (Tse, 2005). Throughput depends on the standard being used, but presently in the U.S., these networks operate throughput rates up to 16 kilobits per second (Kbps). New digital standards, also referred to as "Third-Generation Services" or 3G, are already expected in 2004, and will provide 30 times faster transfer rates and enhanced capabilities (Athens, 2007). Because of the many standards, there are interoperability issues between networks, carriers, and devices. Generally, charges are based on per minute utilization or per number of messages. Another application is hand-held and internet-enabled devices. Internet-enabled cell phones and Personal Digital Assistants (PDAs) have emerged as the newest products that can connect to the Internet across a digital wireless network. New protocols, such as Wireless Application Protocol (WAP), and new languages, such as WML (Wireless Markup Language) have been developed specifically for these devices to connect to the Internet (Goldsmith, 2005). However, the majority of current Internet content is not optimized for these devices; presently, only email, stock quotes, news, messages, and simple transaction-oriented services are available. Other limitations include low bandwidth (less than 14 Kbps), low quality of service, high cost, the need for additional equipment, and high utilization of devices' battery power (Hamilton,
  • 11. Wireless 11 2007). Nevertheless, this type of wireless technology is growing rapidly with better and more interoperable products. The last popular wireless application is the data networking. There is a differentiation between pure data applications in wireless local area networks (WLANs) and data, voice, and video converged in broadband wireless (Tse, 2005). In addition, there is also the new and advance Bluetooth, an emerging wireless technology. Wireless Local Area Networks (WLAN) are implemented as an extension to wired LANs within a building and can provide the final few meters of connectivity between a wired network and the mobile user (Athens, 2007). WLANs are based on the IEEE 802.11 standard. There are three physical layers for WLANs: two radio frequency specifications (RF - direct sequence and frequency hopping spread spectrum) and one infrared (IR) (Goldsmith, 2005). Most WLANs operate in the 2.4 GHz license-free frequency band and have throughput rates up to 2 Mbps. The new 802.11b standard is direct sequence only, and provides throughput rates up to 11 Mbps. Currently the predominant standard, it is widely supported by vendors such as Cisco, Lucent, Apple, etc. By the middle of 2002, a new standard, 802.11a, will operate in the 5 GHz license-free frequency band and is expected to provide throughput rates up to 54 Mbps. WLAN configurations vary from simple, independent, peer-to-peer connections between a set of PCs, to more complex, intra-building infrastructure networks. There are also point-to- point and point-to-multipoint wireless solutions. A point-to-point solution is used to bridge between two local area networks, and to provide an alternative to cable between two geographically distant locations (up to 30 miles) (Goldsmith, 2005). Point-to-multi-point solutions connect several, separate locations to one single location or building. Both point-to- point and point-to-multipoint can be based on the 802.11b standard or on more costly infrared- based solutions that can provide throughput rates up to 622 Mbps (OC-12 speed). In a typical WLAN infrastructure configuration, there are two basic components:
  • 12. Wireless 12 1. Access Points - An access point/base station connects to a LAN by means of Ethernet cable. Usually installed in the ceiling, access points receive, buffer, and transmit data between the WLAN and the wired network infrastructure. A single access point supports on average twenty users and has a coverage varying from 20 meters in areas with obstacles (walls, stairways, elevators) and up to 100 meters in areas with clear line of sight. A building may require several access points to provide complete coverage and allow users to roam seamlessly between access points. 2. Wireless Client Adapter - A wireless adapter connects users via an access point to the rest of the LAN. A wireless adapter can be a PC card in a laptop, an ISA or PCI adapter in a desktop computer, or can be fully integrated within a handheld device. Broadband wireless (BW) is an emerging wireless technology that allows simultaneous wireless delivery of voice, data, and video. BW is considered a competing technology with Digital Subscriber Line (DSL). It is generally implemented in metropolitan areas and requires clear line of sight between the transmitter and the receiving end. BW comes in two flavors: Local multi-point distribution service (LMDS) and Multi-channel multi-point distribution service (MMDS) (Moher, Michael, and Simon Haykin, 2004). Both operate in FCC-licensed frequency bands. LMDS is a high bandwidth wireless networking service in the 28-31 GHz range of the frequency spectrum and has sufficient bandwidth to broadcast all the channels of direct broadcast satellite TV, all of the local over-the-air channels, and high speed full duplex data service. Average distance between LMDS transmitters is approximately one mile apart. As for MMDS, it operates at lower frequencies, in the 2 GHz licensed frequency bands. MMDS has wider coverage than LMDS, up to 35 miles, but has lower throughput rates (Goldsmith, 2005).
  • 13. Wireless 13 Companies such as Sprint and WorldCom own MMDS licenses in the majority of U.S. metropolitan areas. Broadband wireless still involves costly equipment and infrastructures. However, as it is more widely adopted, it is expected that the service cost will decrease. Finally, there is the new and innovation technology of Bluetooth. Bluetooth is a technology specification for small form factor, low-cost, short-range wireless links between mobile PCs, mobile phones, and other portable handheld devices, and connectivity to the Internet (Tse, 2005). The Bluetooth Special Interest Group (SIG) is driving development of the technology and bringing it to market and it includes promoter companies such as 3Com, Ericsson, IBM, Intel, Lucent, Motorola, Nokia, and over 1,800 Adopter/Associate member companies. Bluetooth covers a range of up to ten meters in the unlicensed 2.4GHz band (Hamilton, 2007). Because 802.11 WLANs also operate in the same band, there are interference issues to consider. Bluetooth technology and products started being available in 2001, but interoperability seems to be a big problem. By the time and if Bluetooth becomes an adopted technology, current WLANs will already be migrating to the 5 GHz band (mid 2002). In today's fast moving world of technology, everyone's talking about going "wireless". But what does that mean and what are the benefits of wireless computing? Wireless working in company premises enables staff with notebook computers to connect to company systems, email and the internet as they move around the office. In addition, wireless enables a wide spectrum of business applications that integrate with ‘head office’ to be used remotely – from sales force automation, to field service engineering, to financial services (Moher, Michael, and Simon Haykin, 2004). Even more, wireless creates a productive environment in remote locations, including satellite offices and workers’ homes, to enable staff to utilize their time effectively and to manage their work/life balance. Also, you should know that wireless enables information to be sent and received on the move – via hotspots in airports, hotels, service stations and even coffee shops and on mobile phone networks via GPRS and 3G (Hamilton, 2007). There are a lot of
  • 14. Wireless 14 benefit aspects you can look at when it comes to wireless mobility. With the enterprise users, you can say that they have the freedom and flexibility in where and when they work. It’s extremely convenience for them to be able to have access to live data enabling better decision-making. Not to mention, wireless allows users to empower away from the office as Enterprise information becomes available at the client site. Also, it has a positive affect permitting mobile devices that work in a familiar way, anywhere and at anytime Wireless brings a great deal of benefits to the enterprise business aspect as well. It helps businesses increased sales from more, and better, informed customer meetings. Certainly, it reduced total cost of ownership as familiar costs, such as cabling and office space, are dramatically reduced. It also increased return on investments as business processes improve and efficiencies are rapidly made as productivity rises (Tse, 2005). The customer satisfaction obviously improved from immediate information availability and better decision-making. Wireless can brings company competitive advantage in responding to customer’s requirements without being restricted by geography or time. A few recent technical advances have made wireless LANs (WLANs) more attractive. Support for the 802.11g standard enabled vendors to boost the networking option's top speed to 54 Mbps. IT recently identified how wireless technology can measurably improve worker productivity and lead to positive impacts on time, schedules, and quality (“What is Wireless?” 2006). They linked return on investment (ROI) to productivity gains from wireless network access. Through rigorous data-gathering techniques, they demonstrated how wireless LANs could deliver business benefits to the organization. They found significant benefits to wireless technology, resulting from the advantages that wireless has over wired network access, including increased access, flexibility, and lower cost. In particular, there were a lot of significant benefits that were found. Company will save tremendously for the costs of installing wireless in a 3,000 employee building, about half as
  • 15. Wireless 15 much as installing wired connections (Moher, Michael, and Simon Haykin, 2004). Consider the 52 minutes that can be saved per user per week through multitasking during meetings. Another big plus is the financial benefits of implementing a wireless infrastructure in conference rooms. These benefits resulted from the advantages that wireless technology has over wired network access, including increased access, flexibility, and lower cost (Hamilton, 2007). There were also sign of qualitative benefits found in the following areas: like perceived productivity, spontaneous meetings enabled by wireless, wireless at home. Of course, the benefit that organizations receive from wireless will differ. The greatest benefits will likely materialize in environments where collaboration needs are high, where fast access to information and rapid decision making are important (Tse, 2005). In addition to the quantifiable benefits mentioned above, there were other identified benefits that are worth talking. These include additional benefits of multitasking in meetings, spontaneous collaborative meetings, and wireless at home. Wireless user comments indicated that wireless connectivity allows greater flexibility to connect to the network at work. In fact 47 percent of the wireless users in the study reported that greater flexibility was a key benefit of wireless over wired network connections. Access points were installed everywhere so employees can gather and have meetings anywhere even in isolated location that does not have any wired network connections and still be connected to the network. One factor that may contribute to this flexibility is greater ease of connectivity and wireless users stated that wireless made it quicker and easier to connect to the network. In addition, wireless users stated that wireless enabled them to respond to important situations more quickly. Wireless workers can be connected a higher percentage of the time in meetings or in other locations and be more available to respond to important situations (Hamilton, 2007). Of those who use wireless at work, 66 percent also have wireless networks at home. 36 percent of those who have wireless at home expressed how wireless at home gave them greater flexibility. User comments indicated that this flexibility included being able to work in a quieter location, a more comfortable
  • 16. Wireless 16 location, a more enjoyable location. It also included being able to multitask with home activities like watching the kids. This flexibility also helped some people keep up with heavy workloads (Tse, 2005). It enabled some people to work from home in spite of competing factors that would have otherwise prevented it. Wireless users also perceived that wireless helped them be more productive. Wireless LAN technology, while replete with the conveniences and advantages described above, has its share of downfalls. For a given networking situation, wireless LANs may not be desirable for a number of reasons. Most of these have to do with the inherent limitations of the technology. First, there is security. Wireless LAN transceivers are designed to serve computers throughout a structure with uninterrupted service using radio frequencies. Because of space and cost, the antennas typically present on wireless networking cards in the end computers are generally relatively poor (Moher, Michael, and Simon Haykin, 2004). In order to properly receive signals using such limited antennas throughout even a modest area, the wireless LAN transceiver utilizes a fairly considerable amount of power. What this means is that not only can the wireless packets be intercepted by a nearby adversary's poorly-equipped computer, but more importantly, a user willing to spend a small amount of money on a good quality antenna can pick up packets at a remarkable distance; perhaps hundreds of times the radius as the typical user. In fact, there are even computer users dedicated to locating and sometimes even cracking into wireless networks, known as war drivers (Tse, 2005). On a wired network, any adversary would first have to overcome the physical limitation of tapping into the actual wires, but this is not an issue with wireless packets (Hamilton, 2007). To combat this consideration, wireless networks users usually choose to utilize various encryption technologies available such as Wi-Fi Protected Access (WPA). Some of the older encryption methods, such as WEP are known to have weaknesses that a dedicated adversary can compromise.
  • 17. Wireless 17 In addition, range is another downfall for wireless. The typical range of a common 802.11g network with standard equipment is on the order of tens of meters. While sufficient for a typical home, it will be insufficient in a larger structure (“What is Wireless?” 2006). To obtain additional range, repeaters or additional access points will have to be purchased. Costs for these items can add up quickly. Other technologies are in the development phase, however, which feature increased range, hoping to render this disadvantage irrelevant. Next, the reliability of wireless is another problem that has consider. Like any radio frequency transmission, wireless networking signals are subject to a wide variety of interference, as well as complex propagation effects that are beyond the control of the network administrator. In the case of typical networks, modulation is achieved by complicated forms of phase-shift keying (PSK) or quadrate amplitude modulation (QAM), making interference and propagation effects all the more disturbing (Moher, Michael, and Simon Haykin, 2004). As a result, important network resources such as servers are rarely connected wirelessly. Not to forget, speed is also counted as a negative aspect for wireless. The speed on most wireless networks, typically 1-108 Mbit/s, is reasonably slow compared to the slowest common wired networks, 100 Mbit/s up to several Gbit/s (Moher, Michael, and Simon Haykin, 2004). There are also performance issues caused by TCP and its built-in congestion avoidance. For most users, however, this observation is irrelevant since the speed bottleneck is not in the wireless routing but rather in the outside network connectivity itself. A major obstacle for deployment of wireless networks is the existence of multiple standards. As it was mentioned previously, there are analog and digital standards in wireless telephony. While GSM is the only widely supported standard in Europe and Asia, multiple standards are in use in the U.S. As a result, the U.S. has lagged in wireless networks deployment. Just recently, organizations have been formed to ensure network and device interoperability (Tse,
  • 18. Wireless 18 2005). For example, the adoption of the 802.11b standard has made wireless data networks one of the hottest newcomers in the current wireless market. Recently there have been concerns risen and research conducted concerning usage of wireless communications and its possible relation to poor concentration, memory loss, nausea, premature senility and even cancer (“Bees Vanish and Scientists Race for Reasons”, 2006). On the PBS show Nature there was a show dedicated to Colony Collapse Disorder where there was mention of some blame on the phenomenon of missing bees particularly due to the wide use of cellphones as the cause of the collapse (“Bees Vanish, and Scientists Race for Reasons”, 2006). As for my opinion, I think that wireless is one of the greatest and beneficial innovations in history. Though it does have a few downfalls but I think its positive aspect of wireless has helped everyone who is in touch with technology. The way I see it is that popularity of wireless is a testament primarily to their convenience, cost efficiency, and ease of integration with other networks and network components (“What is Wireless?” 2006). The majority of computers sold to consumers today come pre-equipped with all necessary wireless LAN technology so this mean everyone favor it. The wireless nature of such networks allows users to access network resources from nearly any convenient location within their primary networking environment from home to office. With the increasing saturation of laptop-style computers, this is particularly relevant. With the emergence of public wireless networks, users can access the internet even outside their normal work environment. Most chain coffee shops, for example, offer their customers a wireless connection to the internet at little or no cost. Additionally, users connected to a wireless network can maintain a nearly constant affiliation with their desired network as they move from place to place (“What is Wireless?” 2006). For a business, this implies that an employee can potentially be more productive as his or her work can be accomplished from any convenient location. If anyone work or set up a wireless network before, they all know that initial setup of an infrastructure-based wireless network requires little more than a single access point.
  • 19. Wireless 19 Furthermore, wireless networks can serve a suddenly-increased number of clients with the existing equipment. Of course, wireless networking hardware is considerably cheap compare to wire. With all that aspects, I think wireless has come a long way and still room for improvements to serve the people of the world. Therefore, I think wireless has brought at lot of positive results every environment and I don’t see why you wouldn’t agree with me also.
  • 20. Wireless 20 References Athens, Gary. (2007). Wireless Wises Up. Computerworld, 33. Retrieved October 23, 2007, from EbscoHost database. Bees Vanish and Scientists Race for Reasons. (2006, October 10). New York Times. Retrieved on November 8, 2007, from the World Wide Web: http://www.nytimes.com/2007/04/24/science/24bees.html? _r=2&ex=1184904000&en=ee092759055eb302&ei=5070&oref=slogin&oref=slogin Electromagnetic fields. (2000, June 2). World Health Organization. Retrieved October 12, 2007, from World Wide Web: http://www.who.int/peh-emf/en/ Goldsmith, Andrea. (2005). Wireless Communications. New York: Cambridge University Press. Hamilton, Anita. (2007). Wireless Street Fight. Time, 48. Retrieved November 6, 2007, from EbscoHost database. Moher, Michael, and Simon Haykin. (2004). Modern Wireless Communications. New Jersey: Prentice Hall. Tse, David. (2005). Fundamentals of Wireless Communication. Cambridge: Cambridge University Press. “What is Wireless?” (2006, April 10). Whatis.com. Retrieved on September 19, 2007, from the World Wide Web: http://searchmobilecomputing.techtarget.com/sDefinition/0,,sid40_gci213380,00.html

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