The Limitations Of 4G

The Limitations Of 4G Although the concept of 4G communications shows much promise, there are still limitations that must be addressed. One major limitation is operating area. Although networks are becoming more ubiquitous, there are still many areas not served. Rural areas and many buildings in metropolitan areas are not being served well by existing wireless networks. This limitation of todays networks will carry over into future generations of wireless systems. The hype that is being created by 3G networks is giving the general public unrealistic expectations of always on, always available, anywhere, anytime communications. The public must realize that although high-speed data communications will be delivered, it will not be equivalent to the wired Internet at least not at first. If measures are not taken now to correct perception issues, 4G services are deployed, there may be a great deal of disappointment associated with the deployment of the technology, and perceptions could become negative. If thi s were to happen, neither 3G nor 4G may realize its full potential. Another limitation is cost. The equipment required to implement a next generation network is still very expensive. Carriers and providers have to plan carefully to make sure that expenses are kept realistic. Some issue expected with the implementation of 4G with multiple heterogeneous networks are issues such as; †¢ access, †¢ handoff, †¢ location coordination, †¢ resource coordination to add new users, †¢ support for multicasting, †¢ support for quality of service, †¢ wireless security and authentication, †¢ network failure and backup, and †¢ pricing and billing. Network architectures will play a key role in implementing the features required to address these issues. POSSIBLE ARCHITECTURES One of the most challenging problems facing deployment of 4G technology is how to access several different mobile and wireless networks. Figure 1 shows three possible architectures: using a multimode device, an overlay network, or a common access protocol. Multimode devices One configuration uses a single physical terminal with multiple interfaces to access services on different wireless networks. Early examples of this architecture include the existing Advanced Mobile Phone System/Code Division Multiple Access dual-function cell phone, Iridiums dual function satellite-cell phone, and the emerging Global System for Mobile telecommunications/Digital Enhanced Cordless Terminal dual-mode cordless phone. The multimode device architecture may improve call completion and expand effective coverage area. It should also provide reliable wireless coverage in case of network, link, or switch failure. The user, device, or network can initiate handoff between networks. The device itself incorporates most of the additional complexity without requiring wireless network modification or employing interworking devices. Each network can deploy a database that keeps track of user location, device capabilities, network conditions, and user preferences. The handling of quali ty-of-service (QoS) issues remains an open research question. Overlay network In this architecture, a user accesses an overlay network consisting of several universal access points. These UAPs in turn select a wireless network based on availability, QoS specifications, and userdefined choices. A UAP performs protocol and frequency translation, content adaptation, and QoS negotiation-renegotiation on behalf of users. The overlay Issues in network, rather than the user or device, performs handoffs as the user moves from one UAP to another. A UAP stores user, network, and device information, capabilities, and preferences. Because UAPs can keep track of the various resources a caller uses, this architecture supports single billing and subscription. Common access protocol This protocol becomes viable if wireless networks can support one or two standard access protocols. One possible solution, which will require interworking between different networks, uses wireless asynchronous transfer mode. To implement wireless ATM, every wireless network must allow transmission of ATM cells with additional headers or wireless ATM cells requiring changes in the wireless networks. One or more types of satellite-based networks might use one protocol while one or more terrestrial wireless networks use another protocol. QUALITY OF SERVICE Supporting QoS in 4G networks will be a major challenge due to varying bit rates, channel characteristics, bandwidth allocation, fault-tolerance levels, and handoff support among heterogeneous wireless networks. QoS support can occur at the packet, transaction, circuit, user, and network levels. †¢ Packet-level QoS applies to jitter, throughput, and error rate. Network resources such as buffer space and access protocol are likely influences. †¢ Transaction-level QoS describes both the time it takes to complete a transaction and the packet loss rate. Certain transactions may be timesensitive, while others cannot tolerate any packet loss. †¢ Circuit-level QoS includes call blocking for new as well as existing calls. It depends primarily on a networks ability to establish and maintain the end-to-end circuit. Call routing and location management are two important circuit-level attributes. †¢ User-level QoS depends on user mobility and application type. The new location may not support the minimum QoS needed, even with adaptive applications. In a complete wireless solution, the end-to-end communication between two users will likely involve multiple wireless networks. Because QoS will vary across different networks, the QoS for such users will likely be the minimum level these networks support. End-to-End QoS Developers need to do much more work to address end-to-end QoS. They may need to modify many existing QoS schemes, including admission control,dynamic resource reservation, and QoS renegotiation to support 4G users diverse QoS requirements. The overhead of implementing these QoS schemes at different levels requires careful evaluation. A wireless network could make its current QoS information available to all other wireless networks in either a distributed or centralized fashion so they can effectively use the available network resources. Additionally, deploying a global QoS scheme may support the diverse requirements of users with different mobility patterns. The effect of implementing a single QoS scheme across the networks instead of relying on each networks QoS scheme requires study. Handoff delay Handoff delay poses another important QoS-related issue in 4G wireless networks. Although likely to be smaller in intranetwork handoffs, the delay can be problematic in internetwork handoffs because of authentication procedures that require message exchange, multiple-database accesses, and negotiation-renegotiation due to a significant difference between needed and available QoS. During the handoff process, the user may experience a significant drop in QoS that will affect the performance of both upper-layer protocols and applications. Deploying a priority-based algorithm and using location-aware adaptive applications can reduce both handoff delay and QoS variability. When there is a potential for considerable variation between senders and receivers device capabilities, deploying a receiver-specific filter in part of the network close to the source can effectively reduce the amount of traffic and processing, perhaps satisfying other users QoS needs. Although 4G wireless technology of fers higher bit rates and the ability to roam across multiple heterogeneous wireless networks, several issues require further research and development. It is not clear if existing 1G and 2G providers would upgrade to 3G or wait for it to evolve into 4G, completely bypassing 3G. The answer probably lies in the perceived demand for 3G and the ongoing improvement in 2G networks to meet user demands until 4G arrives.

A Discussion of Heroism in Literature and Film Essay

Defining Heroism Each individual has their own personal definition of heroism or more specifically the characteristics of a true hero. Some may believe that a hero must be a person of high morals, while others may believe that a hero must a brave person, and yet others may believe that a hero can conceivably be a hero by chance and must not possess any specific qualities. Dictionary.com defines a hero or heroine as a person of distinguished courage or ability, admired for his or her brave deeds and noble qualities. The Greek philosopher Aristotle defined heroism in his book titled Poetics. According to Anthony Ubelhor, an instructor at the University of Kentucky, â€Å"Aristotle describes the tragic hero as a protagonist who is otherwise perfect except for a tragic or fatal flaw that eventually leads to his demise. In fact, an Aristotelian tragic hero must have four characteristics: goodness, superiority, a tragic flaw, and a realization of both his flaw and his inevitable demise†. However, it is important to note that different societies have different values, and the values of a society do change over time. These differences and changes will affect the concept of heroism. â€Å"Many people who may have been heroes during their time may not be looked upon as heroes today. Davy Crocket, for example, chased away the Indians, raped the land and killed animals. He might not be considered a hero today, but he was during another time in history† (Pendharkar). This author will attempt to define heroism while making an allowance for societal differences and changes. Therefore, this author’s definition of a hero or heroine is a person who performs a legal or ethical act that is of benefit to another entity without first considering any personal gain or  harm that may be received due to said act. In this author’s opinion, this definition means that a firefighter is a hero, a man who rescues abused animals is a hero, and a pimp who happens to catch a stumbling man and prevent him from falling in front of a moving bus is a hero. Of these three examples, the first two are what could be called the conventional types of hero, while the third is what this author believes to be an â€Å"accidental† hero. Examples of Heroism in Literature There are many examples of heroism in literature. Atticus Finch, a character in Harper Lee’s novel To Kill a Mockingbird, is viewed by many as a hero. In the novel, which takes place in Alabama during 1935, the lawyer Atticus Finch defends a black man accused of raping a white woman. The reader learns through the actions of Atticus Finch â€Å"what it means to behave morally – to do the right thing – in the face of tremendous social pressure. In short, To Kill a Mockingbird reveals the heroic nature of acting with moral courage when adhering to social mores would be far less dangerous† (Profiles in Courage). Nancy Drew is another example of heroism in literature. The character Nancy Drew appeared in several books written by Carolyn Keene. A young girl helping others by solving mysteries, Nancy Drew â€Å"came along in 1930 when girls needed a new kind of heroine, a perfectly groomed teenage sleuth at the wheel of a blue roadster — unflappable and brave in the face of a modern world full of dangers and mysteries† (Otto). A third hero in literature is Robin Hood, who has appeared in countless novels written by various authors. Robin Hood is often considered â€Å"the first hero of the common people of England† (Keen). He fought against the corrupt Sheriff of Nottingham for the benefit of the residents who had been subjected to the evil deeds of the Sheriff. The tales of Robin Hood endorse the â€Å"old-fashioned virtues of altruism and swashbuckling heroism† (Roush). Father Merrin in William Peter Blatty’s novel The Exorcist is a fourth example of heroism in literature. In the novel, a young girl is possessed by demons. Father Karras enlists the help of Father Merrin in exorcising the demons from the girl. While performing the exorcism, the demons leave the  girl and possess Father Merrin. Realizing this, the priest jumps out the window to his death. In a classic example of heroism in the face of good versus evil, Father Merrin saves the girl by becoming possessed himself, and then gives his life in order to prevent the demons from leaving his body and entering another. Examples of Heroism in Film Examples of heroism in film are also numerous. However, they are a bit harder to identify, because many films are adapted from novels. For example, The Exorcist, mentioned above, was adapted to a 1973 film that won several awards, including Oscars and Golden Globes. One example of heroism in film is Batman. Originally appearing in comic books, the character Bruce Wayne takes on the identity of Batman in order to fight evil in Gotham City. In the original Batman film, as well as the sequels, Batman fights various evil characters, saves innocent people, and restores order in the city of Gotham. Neither Batman, nor Bruce Wayne, receives any form of compensation for, or personal benefit from, performing these heroic tasks. Buffy Summers from the film Buffy the Vampire Slayer is another example of heroism in film. Buffy discovers that she has been chosen to protect humanity by destroying evil vampires. She does not receive any compensation for her heroic acts. As a matter of fact, Buffy gives up the normal, teenage life that she would prefer in order to protect others. Continuing on this theme, the film was later adapted to television and was a popular series for seven seasons. Conclusion These examples of heroism in literature and film illustrate an important point. There is no list of required acts or characteristics that define a hero. Atticus Finch, Nancy Drew, Robin Hood, Father Merrin, Batman, and Buffy Summers are very different characters, and they are all heroic in different ways. In the end, each of these characters helped others without personal gain as a determining factor. http://voices.yahoo.com/a-discussion-heroism-literature-film-218006.html References â€Å"Hero.† Dictionary.com website. URL: http://Dictionary.reference.com/browse/hero Keen, M. â€Å"Robin Hood a Peasant Hero.† EBSCOhost database. URL: http://search.ebscohost.com/login.aspx?direct=true&db=aph&AN=9110210460&loginpage=Login.asp&site=ehost-live Otto, M. â€Å"Girl Sleuth and the Fountain of Youth; At 75, Nancy Drew Continues to Enchant Readers–and Now Academics, Too.† ProQuest database. URL: http://proquest.Umi.com/pqdweb?did=899780321&Fmt=3&clientId=65562&RQT=309&VName-PQD Pendharkar, L. â€Å"The Hero Chronicles.† The Heroism Project website. URL: http://www.heroism.org/decades.html â€Å"Profiles in Courage: Harper Lee’s to Kill a Mockingbird.† National Endowment for the Humanities EDSITEment website. URL: http://edsitement.neh.gov/view_lesson_plan.asp?id=525 Roush, M. â€Å"Rockin’ Robin.† TV Guide. Vol. 55, No. 9, p. 21. Ubelhor, A. â€Å"Fairy Tales, Myths & Other Archetypal Stories.† University of Kentucky website. URL: http://www.uky.edu/~aubel2/eng104/myth/essay2.html

Operating System common on the Internet Essay

This paper discusses the various types of operating systems that are commonly used for the internet. The paper explains the general meaning of the operating systems and then discusses the various types of operating systems which support the internet applications. An operating system is a software component of a computer system that is responsible for the management of various activities of the computer and the sharing of computer resources. Operating Systems provide a base software platform on top of which other programs called application programs can run. Operating systems enable user to interact with the computer systems by acting as an interface between users or the application programs and the computer hardware. The different operating systems available in the market offer a wide choice for the user. However, with the increasing internet usage, the choice of operating system greatly depends on how well the OS supports the activities of the internet based applications. The different operating systems provide different types of browsers to enable internet usage. Linux is the most popular operating system for the internet and is based on UNIX, just like the Mac OS X. Linux offers larger amount of free space and open source software and is more equipped than any of the other counterparts. Comparing the features of the various OS, Hughes states that one of the most important features of the Linux operating system is its set of internet clients and servers including mail, news, FTP, web as well as the proxy clients and servers. Owing to the range of Linux distributions to offer, Linux is easily customizable. The use of compatibility layers such as Wine, makes Linux attuned with the windows programs and hence a good choice for the internet. The system is less prone to viruses and hence more reliable, especially for the internet. The system is freely available and far less expensive. This advanced operating system is most popular and recommended for internet users. BSD operating systems are very similar to Linux operating systems and fully support internet access. Both Linux and BSD come with full functionality for regular dial-up, PPP-based, cable modem, and Ethernet connections. Sun Operating system, which is a part of Sun Microsystems Solaris, is yet another OS commonly used for internet networked applications (Linfo, 2004). Although not so commonly used, BSD and IRIX also considered as good operating systems for the internet applications. Linux is considered to be safer for web hosting servers. It is found to b more reliable, stable and efficient (Internet-Web Hosting). Microsoft Windows has been the most common operating system. The series of operating systems started with MS_DOS, Windows 95, Windows NT, XP and the now popular Windows Vista. Owing to the largest library of programs and applications, and the ease of hardware compatibility that it renders, Windows continues to be one of the commonly opted operating systems. However, considering the performance speed and security issues, Windows might not be the best choice for the internet. Windows operating system is prone to viruses and spy ware because of which it necessitates the installation and maintenance of the internet security software. Apple’s Mac OS X is the second most popular operating system based on UNIX. The OS is relatively simpler and more compatible. It offers many advanced features along with an intuitive interface. Mac OS X supports second largest selection of software and is the most reliable operating system. Unlike the Windows Operating system, Mac OS X is not prone to virus or malware and is a better choice for the internet when compared to Windows for certain cases. However, the limited compatibility with the Apple hardware imposes a constraint on the system being used across the internet. Unlike the Windows, the Mac OS X does not require the frequent expenditure on the internet security software subscriptions and is thus less expensive as compared to the Windows. The choice of Operating Systems for running Internet applications primarily depends on the type of user. While Windows may be the choice of home and leisure users, Linux is generally used by professionals. Windows offers ease of use whereas Linux provides Security and Open source. References Hughes, P. , Operating Systems Comparison. Retrieved on April 14, 2009 from http://netshooter. com/linux/oscomp. html The Most Popular Operating Systems. 2004. Linux Information Project Retrieved on April 14, 2009 from http://www. linfo. org/operating_systems_list. html Internet-Web Hosting. Retreived on April 14, 2009 from http://www. internet-webhosting. com/whichplan. php

Saint Jerome A Concise Biography

Jerome (in Latin, Eusebius Hieronymus) was one of the most important scholars of the early Christian Church. His translation of the Bible into Latin would become the standard edition throughout the Middle Ages, and his viewpoints on monasticism would be influential over the centuries. Childhood and Education Jerome was born at Stridon (probably near Ljubljana, Slovenia) sometime around 347 C.E. The son of a well-off Christian couple, he began his education at home, then continued it in Rome, where his parents sent him when he was about 12 years old. Seriously interested in learning, Jerome studied grammar, rhetoric, and philosophy with his teachers, read as much Latin literature as he could get his hands on, and spent a great deal of time in the catacombs under the city. Toward the end of his schooling, he was formally baptized, possibly by the pope himself (Liberius). His Travels For the next two decades, Jerome traveled widely. In Treveris (present-day Trier), he became extremely interested in monasticism. In Aquileia, he became associated with a group of ascetics who congregated around Bishop Valerianus; this group included Rufinus, a scholar who translated Origen (a 3rd-century Alexandrian theologian). Rufinus would become Jeromes close friend and, later, his adversary. Next, he went on a pilgrimage to the East, and when he reached Antioch in 374, he became a guest of the priest Evagrius. Here Jerome may have written De septies percussa (â€Å"Concerning Seven Beatings†), his earliest known work. A Dream That Would Have a Profound Impact on Him In early spring of 375, Jerome became severely ill and had a dream that would have a profound impact on him. In this dream, he was hauled in front of a heavenly court and accused of being a follower of Cicero (a Roman philosopher from the first century B.C.), and not a Christian; for this crime, he was horribly whipped. When he woke up, Jerome vowed that he would never again read pagan literature -- or even own it. Soon after, he wrote his first critical interpretive work: a commentary on the Book of Obadiah. Decades later, Jerome would minimize the importance of the dream and disown the commentary; but at the time, and for years afterward, he would not read the classics for pleasure. A Hermit in the Desert Not long after this experience, Jerome set off to become a hermit in the desert of Chalcis in the hopes of finding inner peace. The experience proved to be a great trial: He had no guide and no experience in monasticism; his weak stomach rebelled against desert food; he spoke only Latin and was terribly lonely among Greek- and Syriac-speakers, and he was frequently plagued by temptations of the flesh. Yet Jerome always maintained he was happy there. He dealt with his troubles by fasting and praying, learned Hebrew from a Jewish convert to Christianity, worked hard to practice his Greek, and kept in frequent correspondence with the friends hed made in his travels. He also had the manuscripts hed brought with him copied for his friends and acquired new ones. After a few years, however, the monks in the desert became involved in a controversy concerning the bishopric of Antioch. A Westerner among Easterners, Jerome found himself in a difficult position and left Chalcis. Becomes a Priest but Doesnt Take on Priestly Duties He returned to Antioch, where Evagrius once again served as his host and introduced him to important Church leaders, including Bishop Paulinus. Jerome had developed a reputation as a great scholar and serious ascetic, and Paulinus wanted to ordain him as a priest. Jerome only agreed on the conditions that he be allowed to continue his monastic interests and that he would never be forced to take on priestly duties. Jerome spent the next three years in intensive study of the scriptures. He was heavily influenced by Gregory of Nazianzus and Gregory of Nyssa, whose ideas about the Trinity would become standard in the Church. At one point, he traveled to Beroea where a community of Jewish Christians had a copy of a Hebrew text that they understood to be the original Gospel of Matthew. He continued to improve his understanding of Greek and came to admire Origen, translating 14 of his sermons into Latin. He also translated Eusebius Chronicon (Chronicles) and extended it to the year 378. Returns to Rome, Becomes Secretary to Pope Damasus In 382 Jerome returned to Rome and became secretary to Pope Damasus. The pontiff urged him to write some short tracts explaining the scriptures, and he was encouraged to translate two of Origens sermons on the Song of Solomon. Also while in the employ of the pope, Jerome used the best Greek manuscripts he could find to revise the Old Latin version of the Gospels, an attempt that wasnt entirely successful and, furthermore, wasnt very well received among the Roman clergy. While in Rome, Jerome led classes for noble Roman women -- widows and virgins -- who were interested in the monastic life. He also wrote tracts defending the idea of Mary as a perpetual virgin and opposing the idea that marriage was just as virtuous as virginity. Jerome found much of the Roman clergy to be lax or corrupt and did not hesitate to say so; that, along with his support of monasticism and his new version of the Gospels, provoked considerable antagonism among the Romans. After the death of Pope Damasus, Jerome left Rome and headed to the Holy Land. The Holy Land Accompanied by some of the virgins of Rome (who were led by Paula, one of his closest friends), Jerome journeyed throughout Palestine, visiting sites of religious importance and studying both their spiritual and archaeological aspects. After a year he settled in Bethlehem, where, under his direction, Paula completed a monastery for men and three cloisters for women. Here Jerome would live out the rest of his life, only leaving the monastery on short journeys. Jeromes monastic lifestyle did not keep him from getting involved in the theological controversies of the day, which resulted in many of his later writings. Arguing against the monk Jovinian, who maintained that marriage and virginity should be viewed as equally righteous, Jerome wrote Adversus Jovinianum. When the priest Vigilantius wrote a diatribe against Jerome, he responded with Contra Vigilantium, in which he defended, among other things, monasticism and clerical celibacy. His stand against the Pelagian heresy came to fruition in the three books of Dialogi contra Pelagianos. A powerful anti-Origen movement in the East influenced him, and he turned against both Origen and his old friend Rufinus. Latin Translation of the Bible and The Vulgate In the last 34 years of his life, Jerome wrote the bulk of his work. In addition to tracts on monastic life and defenses of (and attacks on) theological practices, he wrote some history, a few biographies, and many biblical exegeses. Most significantly of all, he recognized that the work hed begun on the Gospels was inadequate and, using those editions considered most authoritative, he revised his earlier version. Jerome also translated books of the Old Testament into Latin. While the amount of work he did was considerable, Jerome didnt manage to make a complete translation of the Bible into Latin; however, his work formed the core of what would become, eventually, the accepted Latin translation known as The Vulgate. Jerome died in 419 or 420 C.E. In the later Middle Ages and Renaissance, Jerome would become a popular subject for artists, often depicted, incorrectly and anachronistically, in the robes of a cardinal. Saint Jerome is the patron saint of librarians and translators.