Wi-fi Wireless Technology

Wi-fi Wireless Technology Business data network and telecommunications Wi-fi has entered in to our lives some years now. It solves some problems that wire networks have but generate new. At the moment there are few advantages and a lot of disadvantages. Wi-fi can be very useful in many cases and I think it deserves a deep look in to it. Also wi-fi has many prospects for further development. Wi-fi needs specified devices in order to work properly. History The term wi-fi (wireless fidelity) is used in order to determine the appliances that are based on specification IEEE 802.11 and faction of ISM band, that is frequencies 2.4Ghz for Europe .Wi-Fi uses single carrier DSSS (direct sequence spread spectrum) radio technology but also multi-carrier OFDM (Orthogonal Frequency Division Multiplexing) radio technology. These regulations that enabled the development of Wi-Fi, are HomeRF, and Bluetooth. Unlicensed spread spectrum was available for first time by the Federal Communications Commission in 1985 and the FCC regulations were copied later with some changes in other countries and made the use of this technology enable in all major countries. Michael Marcus of the FCC staff proposed the FCC action in 1980 and the subsequent regulatory action in 5 more years. It was part of a proposal to allow civil use of spread spectrum technology and was opposed by the mainstream equipment manufacturers and many radio system operators. (Federal Communications Commission. 1985). The Wi-Fi was invented in 1991 by NCR Corporation/ATT. Initially the use was for cashier systems. The first wireless products that were brought on the market was under the name â€Å"WaveLAN† with speeds of 1 Mbit/s up to 2 Mbit/s. Vic Hayes, was involved in designing standards such as IEEE 802.11b, and 802.11a. He has been named as â€Å"the father of Wi-fi†. (Vic Hayes at 1st Home Networking Conference, 2007). Uses A device with Wi-Fi enabled, such as a PC, PDA, cell phone, game console, or MP3 player can connect to the Internet within the range of a wireless network connected to the Internet (Access point). The interconnection between one or more access points in a certain area is called a hotspot. Hotspots can cover a single room up to many squares covered by overlapping access points. The devices can network each other and connect to the Internet, share files and digital cameras can transfer video wirelessly. Wi-Fi also allows devices to connect directly with each other (peer-to-peer mode). This connectivity mode is useful most in gaming applications. When the technology released in the market there were many problems because consumers were not sure if the products from companies would work together. The Wi-Fi Alliance began as a community to solve this and to address the needs of the end user and allow the technology to mature. The Alliance created the branding Wi-Fi CERTIFIED to show to the consumers that products are interoperable with other products displaying the same branding. (Wi-fi alliance, 2000). Routers and Wi-Fi access points are used most in homes to provide Internet access and networking to all devices that are connected wirelessly or by cables into them. Devices can also be connected in ad-hoc mode for client-to-client connections without using a router. In Business and industrial environments, as increasing the number of Wi-Fi access points we get faster roaming and increased network capacity by creating smaller cells or by using more channels. Wi-Fi can enable wireless voice applications such as WVOIP. Wi-Fi installations can provide a secure computer network, firewall, DHCP server and other functions. In addition to home and office use, Wi-Fi is publicly available also at Wi-Fi hotspots provided either free of charge or under a certain price. Sometimes free Wi-Fi is provided by organizations or authorities who wish to promote business in their area. Metropolitan-wide WiFi (Mu-Fi) already has more than 300 projects in process. (Muniwireless, 2007). Standard devices Wireless access points can connect wireless devices to a wired LAN. An access point is something like an Ethernet hub, relaying data between the connected devices. Wireless adapters are connecting in the devices, externally or internally such as usb, pci and allow devices to connect to the wireless network. Wireless routers integrate a firmware application that provides IP Routing, NAT, and DNS forwarding through an interface. Wireless range extenders (repeaters) can extend the range of the wireless network. Ig the repeaters are placed in the area smart then the signal can be excellent. The devices that are connected through repeaters may have an increased latency for each hop. Each device will get signal from the device that gives better signal. With wireless bridges we can connect two or more networks between them. This is different from an access point because an access point works at the data-link layer. We can use two wireless bridges when a wired connection may be unavailable, such as a connection between two separate buildings. Most devices (routers, access points, bridges, repeaters) are designed for home or business environments. Pci cards use antenna connectors and usb only have internal antennas while some have external connections in addition to an internal antenna. In laptops it is commonly used mini pci cards. In a network between two buildings that the distance is a matter it is usually used big antennas in the roof of the buildings, so the signal can be remain strong enough. Advantages of Wi-Fi Wi-Fi allows LANs to be deployed while it reduces the cost of the network deployment. WLANS can be hosted in areas that cannot be run by cables, such as outdoor areas or even historical buildings. The prices for wireless products continue to drop, making it a fair networking option. Wi-Fi has become widespread and more and more devices obtain wi-fi technology. Wi-Fi is a global set of standards. Products designated as Wi-Fi Certified by the Wi-Fi Alliance are backwards inter-operable. Except mobile phones, any device with wi-fi standard will work anywhere in the world. Wi-Fi use WPA encryption and it is not easily cracked if the passwords are strong enough. Nowadays it is used WPA2 also, an encryption that has no known weaknesses. A new protocol for Qos is WMM and makes Wi-Fi better for voice, video applications, and power saving methods. To make enable the WMM feature all devices in the network must support it. Disadvantages of Wi-Fi Wifi in Europe use for the 2.4 GHz band (1-13) channels, in US (1-11) and Japan (1-14). A Wi-fi signal occupies around five channels in the 2.4 GHz resulting in only 3 non-overlapped channels in the US: 1, 6, 11, and four in Europe: 1,5,9,13 Power consumption is too high compared to with other low bandwidth standards, such as Bluetooth, making a concern about devices batteries life of the. WEP (Wired Equivalent Privacy) is the most usual wireless encryption standard that is used, but shown that can be easily breakable. Wi-Fi Protected Access (WPA, WPA2), solved this problem and its available on most products. Most Wi-Fi Access Points have default the security disabled thought, providing open wireless access to their LAN. You can always turn on the security by configuring the device, usually via the graphical user interface (GUI) of the router/access point. Unencrypted networks can be used to read and copy data that are transmitted over the network, unless we have a security method to secure the data, such as VPN The wireless networks have limited range. A typical Wi-Fi home router using 802.11g with a stock antenna might have a range of 35 m indoors and 95 m outdoors. Range also varies with frequency band. Wi-Fi in the 2.4 GHz frequency block has slightly better range than Wi-Fi in the 5 GHz frequency block. Outdoor range with improved (directional) antennas can be several kilometres or more with line-of-sight. IEEE 802.11g-(2003) When the range increases the performance of a wireless network is decreased. Ethernet or other cables are more reliable then wi-fi. An Ethernet connection can reach speed up to 1Gbit/s and in the other hand 802.11g networks have a maximum of 54 Mbit/s. Protocol 802.11n try to improve the speeds, but still does not achieve Ethernets reliability. People with adsl2+ can understand an increase in performance using wired connection rather than WiFi. Wi-Fi in many cases has problems with the signal-to-noise ratio (SNR). SNR compares the level of the desired signal to the background noise. This can be a huge problem in high-density areas. All the devices must support the same protocol for example 802.11g. And in case there are other access points in the network, the name (SSID) must maintain the same. In Wireless networks there are many times incompatibility problems between brands. Different standards may disrupt connections or low speeds. The new protocol 802.11n use 5 GHz band and have more channels available. Each node (access point, repeater) on the network is able to see the communication between other devices, allowing network traffic to be easily captured. When a WiFi network is not encrypted it is vulnerable to attacks. Wi-fi is a new technology and still under development. Many people may adopt it cause it produce a non wire environment and others not. I think wi-fi will give better quality in the future and maybe it will get pass some main problem that it have at the moment. References Authorization of Spread Spectrum Systems Under Parts 15 and 90 of the FCC Rules and Regulations (TXT). Federal Communications Commission (June 18, 1985). Retrieved on 2007-12-01. Wi-Fi Alliance Certified Products. (2000) certifications.wi-fi.org. Retrieved on 2007-11-01. from http://certifications.wi-fi.org/wbcs_certified_products.php V.Hayes at (November 04 2007). 1st Home Networking Conference Retrived on 2007-12-03 from http://lirne.net/2007/11/vic-hayes-at-1st-home-networking-conference/ Muniwireless (2007). Muniwireless-technology Retrieved on 2007-12-01 from http://www.muniwireless.com/ IEEE 802.11g-(2003) 802.11g Retrieved on 2007-12-03 from http://en.wikipedia.org/wiki/IEEE_802.11g-2003

Dreams and Aspirations :: essays research papers

I have a dream†¦ you have a dream†¦ our nation has a dream†¦ our world has a dream. We all have a dream. We all have a dream, but the difference is how we realise our dream, how we obtain our dream, and how our dream changes us. This is evident in our learning of dreams and aspirations through the texts Flowers for Algernon by Daniel Keys, What’s Eating Gilbert Grape? by Lasse Hallstrà ¶m, and through my own studies of Million Dollar Baby by Clint Eastwood. These three highly acclaimed texts represent the same ideas on dreams and aspirations, which can be defined as hope, desire or the longing for a condition or achievement, but these texts express the same ideas differently, shaping our understanding of dreams and aspirations. â€Å"If you can imagine it you can create. If you can dream it, you can become it.† William Arthur Ward These three texts contain the search for dreams, whether they be absurd, simple, or take you on a journey. Throughout the texts, the protagonists realise their dreams, each represented in a different way. In Flowers for Algernon by Daniel Keys, Charlie’s dream is to be intelligent, not so that he can be normal, but so people will like him. Charlie knows that his retardation has cut him off from most of society, and has limited his ability to connect with people, but he does not mind. Charlie does not long to join society to increase his social standing; rather, he longs to join primarily because he is lonely. In Charlie’s mind, intelligence is the quality that will gain him entry into a world of friends. The resulting irony is that when Charlie does become incredibly intelligent, he finds himself even lonelier than before.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã¢â‚¬Å"I just want to be smart like other pepul so I can have lots of frends who like me.† progris riport 6th page 10 It is also Charlie’s innocence of his dream that allows him to be exploited. It is Professor Nemur that has allowed Charlie’s innocence to be vandalised through the operation, as Professor Nemur expresses his own motivations in comforting Charlie that he will be famous, and will make the history books. However, these are Professor Nemurs’ dreams not Charlies, and Nemur is only using Charlie to reach his dreams. â€Å"And he said that meens Im doing something grate for sience and Ill be famus and my name will go down in the books.

Tourism Course Issue

INTRODUCTIONThis chapter presents an overview of the current study which discusses the reasons of BS Tourism Management Students why they choose the course. Researcher’s from University of the East Caloocan focuses their attention on the student’s reason they choose, it is to identify the number one reason of the students why do they took Tourism Management. This chapter includes the background of the study, plan of the thesis and its conclusion.BACKGROUND OF THE STUDYAccording to the research of Guangpeng Siriwan (2011), the tourism industry is one of the fastest growing industries worldwide. It is reported that the industry represented approximately 3 percent of the world’s total labour force in 1999 (International Labour Organization 2001) and rose to approximately 8 percent and created more than 235 million jobs globally in 2010 (International Labour Organization 2010).As of today, many students choose the course Tourism Management without any possible reason , but only few students expressed little interest in pursuing the career because of their regrets in getting the course. That is why the researchers conducted a study to be able to understand what drives the students in choosing the course. As a result, it is important to develop the career-decision-making of the students, to identify the factors that pursue their decision making in taking the course.PLAN OF THE THESISThe primary purpose of the study is to identify and to understand the factors why do students choose their Tourism Management course. The researchers conducted a survey in the University of the East Caloocan that the BSTM 1st-4th year students answered. There are 40 participants every year is consist of 10 participants. The survey contains some of the possible reasons of taking up the course and they are only allowed to answer one possible  reason. As the researchers gathered the surveys, they started to gather the results.CONCLUSIONThis chapter provides an overview of the current study. It introduces the research background of the study and the plan of the thesis. Later, it describes the primary purpose of the study, which is to investigate what drives the students to take the Tourism Management course and to understand the possible reasons.

Analyzing Julius Caesars Motives - 1685 Words

From a young age, Julius Caesar was introduced to the politics of Rome through his family’s connection to Marius. Growing through his adolescence in both the proscription period of Marius and the dictatorship of Sulla, Caesar gained a lesson in extra constitutional advancement in the early career of Gaius Pompeius Magnus. Both Marius and Sulla distinguished themselves in the Social War, and both wanted command of the war against Mithridates, which was initially given to Sulla; but when Sulla left the city to take command of his army, a tribune passed a law transferring the appointment to Marius. Sulla responded by marching his army on Rome, which was believed to be an influence on Caesar’s crossing of the Rubicon. Caesar became the head of his family at the age of sixteen, and managed to have himself elected as the new High Priest of Jupiter. The priests needed to be of patrician family, and married to a patrician, so Caesar broke off his engagement to a young plebeian, and married Cornelia, the daughter of Lucius Cinna. When Roman ruler Sulla declared himself dictator, he began a systematic purge of all Maria connections within Rome, and any who held the Populares ideology, including Julius Caesar. The marriage between Caesar’s aunt to Marius gave the family a connection with a potentially important political group, regarding the family as Populares. Sullas proscriptions saw hundreds of his political enemies killed or exiled. Caesar, as the nephew of Marius andShow MoreRelatedWilliam Shakespeare s Julius Caesar961 Words   |  4 Pagesmorals are. So by analyzing Julius Caesar, Shakespeare’s core values and moral will shine through. Although there are many characters in Julius Caesar that are vastly different in nature, the way in which Shakespeare highlights any individual points to what he stands for. Starting with Marcus Brutus, Shakespeare focuses the attention on his honor. Brutus sided with Pompey in the civil war with Caesar in which Caesar won. Funk and Wagnall’s New World Encyclopedia report that â€Å"After Caesar’s victory at PharsalusRead MoreRoman Aristocracy Essay4218 Words   |  17 Pagesattainments defined the Roman aristocrat in the Republic? How, if at all, did this conception of the aristocrat change during the empire? The aristocracy of Rome has changed with the transition from the Republic to the Empire. This can be seen through analyzing funeral epitaphs, such as the epitaph of the Scipionic family and the epitaph of Publius Plautius Pulcher. Virtues of the aristocracy in the Republic were mainly focused on virtus and gloria; they attained such precedence by maintaining the achievements