Southwest Airlines research paper Essay Example for Free

Southwest Airlines research paper Essay Southwest Airlines, since the beginning has struggle and fight to get in the airline business. Starting with Dallas, Texas. Southwest had to fight to stay at Love field airport, when all the airlines moved to the new Airport of Dallas-Fort worth International airport. Winning this battle gave Southwest the opportunity to get all the customers they wanted, from the near downtown airport, instead of driving 15 miles for the new airport, pay for expensive parking and having to arrive one hour earlier. However the other airlines did not like it, like American Airlines and Braniff International. They would have to pay higher fees for use of the new airport and Southwest Airline did not. The other great battle was when Southwest applied to fly from Houston to New Orleans, the application of Southwest Airlines was opposed by local government and by the airlines that flew that route and were operating from the new airport of Dallas-Fort worth, DFW, they felt this could divert customer that could change flying from Houston better than DFW . Jim Wright who was Forth Worth Congressmen was ask by Southwest opponents to help, and as he was a majority of the U. S. House of Representatives, Wright took it to Washington and a new law emerged. The Wright Amendment of 1979 said that â€Å"No airline may provide nonstop or through-plane service from Dallas Love Field to any city in any state except for location in Texas, Louisiana, Arkansas, Oklahoma and New Mexico. † (Thompson, A Gamble, J. (2010). Southwest could only advertise flights out of Dallas Love Field to these five states. The Wright Amendment continue for 18 years, then in 1997 three more states were added to the â€Å"Wright Zone† Alabama, Mississippi and Kansas , and in 2005 Missouri. On 2006 Congress legislation was passed and signed into law that repealed the Wright Amendment beginning in 2014. â€Å"The legal regulatory and competitive battles that Southwest fought in its early years produced a strong esprit de corps among Southwest personnel and a drive to survive and proper despite the odds. † â€Å"They have the warrior mentality, they are here in the airline business to stay and will fight for their share of the market†. (Thompson, A Gamble, J. (2010) The idea of having ticketless help the airline to saved money on paper and accounting for all these tickets. And the idea came from one of the employees. Southwest Airlines places their employees before the customers, this idea has given Southwest Airlines and advantage in customer service that other airlines do not have. In this company the employees feel free to come with ideas and implemented them, if the ideas do not work they will not be reprimand or fired, the failure will be used as example and experience. That gives the employees empowerment and the courage to keep looking for new ideas to improve the service and the company. Herb Kelleher has been an important figure in the culture of Southwest Airlines, with his background; majored in philosophy and law graduating with honors on both. Herb, as everybody called him in Southwest Airlines has given this company a unique culture, where the employees sing and dance with the customers and they give friendship and love more than just customer service. This style has worked for more than 40 years, the airline is love by their customer, who do not really care that there is no first class or preferred seating. They just want the good service and to be transported from point to point safe, on time and with a better price. Even their stock name reflects love. NYSE LUV is Southwest financial name. (Thompson, A Gamble, J. (2010) Southwest Strategic planning for the future, and buying fuel in advance for their planes, gave them the opportunity to save millions of dollars. Southwest was the first airline to negotiate these prices with the oil companies. Southwest Airlines has its own school for flight attendants and training for employees, there is no other University that can train them with the special Southwest Airline Culture. Other airlines have the training schools too, what happen is that the culture is different. Other airlines like United trained the flight attendants for First Class and Business class, besides economy, their training takes longer and their uniforms are more expensive. Southwest uniforms are less expensive and they only have one class, economy. Their flight attendants are also trained to clean the plane on turn around. Other airlines have a cleaning crew that gets into the plane and clean it while the flight attendants are resting; however some airlines have adopted this plan since 9/11. This has saved Southwest salaries on each city for cleaning. Only on cities that the planes stay overnight they have a special cleaning crew that gives the plane a complete service. (Thompson, A Gamble, J. (2010) The idea of having only one type of equipment has given great savings, comparing with other airlines that have different aircrafts and need mechanics specialized on each different aircraft and to have different kinds of plane pieces of maintenance according to each plane. Southwest has all his mechanics highly trained for only one kind of aircraft and the maintenance inventory of their pieces for maintenance in their planes are all the same and this means that they do not need millions of dollars in equipment and train mechanics for each different type of aircraft. After 9/11, Southwest shines like a start as the only airline that do not lose money in 2001 or 2002 and the only airline that did not furlough any of its employees during this time that the rest of the airlines furlough about 500,000 employees among them. It was here when all the eyes of the analyst look at Southwest as the marvelous company that has been doing the right thing all the time, and that was prepared with enough cash, for any eventuality. Southwest Airlines is name in every management book as example of how to conduct an airline and what strategy they have to hold their employees and have very low turn around. Strategy which gives their passengers what they want, and also the strategy has made Southwest a profitable airline since 1973. (Thompson, A Gamble, J. (2010) Company Mission Southwest Airline’s Mission, Vision and Triple Bottom Line Commitment to Performance, People and Planet. (See Exhibit 1) â€Å"Southwest Mission is dedication to the highest quality of Customer Service delivered with a sense of warmth, friendliness, individual pride and Company Spirit† (Southwest Airlines). For Southwest Airlines the employees come first and customer second. By having employees satisfied with their job, and treated like family, they will be able to give the best customer service with warmth, friendliness and keep all customer satisfied too. The airline has pursued low fares to make affordable travel to a majority of middle class customers. By charging low fares, and no charging extra fees on baggage, and changing tickets, the customers know exactly what they are paying without paying any extra charges. Southwest serves 72 airports in 37 states and transports 89. Million passengers annually. Southwest had a revenue of $89. 08 billion from November 2012 to November 2013. (Bureau of Transportation Statistics) Internal/External Analysis Strengths  Southwest Airlines firm operating strategy has given profit for 40 years, flying from point to point instead of having a â€Å"hub† like other airlines do, has given Southwest the opportunity to utilized their hours flying for each plane more than others. With their 20 minutes turn over on each point, the airline has on the air their planes most of the time. This capacity utilization makes their cost down and has a competitive advantage over other airlines whose turnaround times were more than 30 minutes. Their bargaining power with suppliers like fuel prices paying in advance and saving millions of dollars over other airlines. Their labor efficiency and pay scales. By training their employees to perform the best and guarantee them good pay and becoming more important than customers, Southwest has economized in having fewer employees per aircraft than other airlines. Employees have in average the same salary as other airlines, employees get profit sharing plan, however they work more. In economies el scale, Southwest Airlines operates only jets Boing 737-300 with 173 planes, Boeing 737-700 with 343 and Boing 737-500 with 25 planes. Having the same kind of planes they operated with very low cost. Widespread Reach: As of the end of 2011, the company serviced 72 cities in 37 states, stretching across the entire United States, and their AirTran acquisition now extends their reach into international skies, mostly over Mexico and the Caribbean islands. Southwest announce 15 more nonstop services from Dallas Love field Airport. Online systems and software, Southwest Airlines invested in next-generation technology and software to improve its ticketless system and its back-office accounting, payroll and human resource information. Previously they have invested in its management information systems to speed data flows and upgrade its customer capabilities. In 2001 implemented new software to generate optimal crew schedules it help improve on-time performance and reduce employees in the schedule department. Southwest operating cost had been lowers than other airlines. (Thompson, A.p. C-294. 2012). Successful differentiation from other airlines is their employees culture, which is transmitted to the customers, employees give a warmth customer service, normally calling the passengers by their first name, singing and hugging and kissing. No other airline does this. †(Guenette, R. November 13, 2013) By giving the same product at a better price than other more expensive airlines, Southwest Airlines has been able to have a larger share of the market. Southwest has a reputable brand with excellent record of safety, this is a major advantage. For the first Quarter of 2013, Southwest reported earnings and revenue that exceeded Wall Street expectations (EPS: $0. 07 per share, Revenue: $4. 08 billion vs. EPS: $0. 02 per share, Revenue: 4. 07 billion). Additionally, average passenger revenue per available seat mile rose 1. 8% along with an increase in passenger traffic by 0. 3%. Keeping the strong numbers in mind from the last quarter, analysts are optimistic about Q2 2013 earnings ($0. 39 a share, up from $0. 36 during Q2 2012). (Ing, S. July 24, 2013). Weaknesses Operating Expenses: The average cost per gallon of fuel from 2005 to 2011 grew 182.  30%, the consumer is constantly demanding added services and amenities to their flights, and the unions are viscously battling for more money for their members; at the end of the day the company does not have much money left over (net profit margin is 1. 14%). Debt: The Company is estimated to possess $361 million of debt on their balance sheet, and until they pay down these debts it will drag significantly on their business. Depending on only one company as supplier for their planes can be a problem if the supplier fails or stop their production. Although Boeing is a robust company, changes can affect Southwest Airlines. The economy, even though Southwest is a low cost airline, until the economy continues low, people cannot fly unless is business or emergency. Achieving sustainable competitive advantage for Southwest is becoming harder as operating costs are going up and the company has a low net profit margin. (Guenette, R. November 13, 2013) Opportunities The industry attractiveness is a strength and an opportunity for Southwest Airlines, the only major airline that do not charge for baggage, many customer look into this as they are also attracted for the price the service, safety and excellent rate on time performance. As a complementary strategy function, Southwest Airlines acquisition of Air Tran gives them the option to fly international for the first time. This acquisition strategy strengthens competitiveness for Southwest Airlines, and gives the opportunity to enter into international markets. Customers that look at how the companies treat their customers and employees, Southwest Airlines have won awards every year for customer satisfaction and by putting their employees first and second their customers. Other airlines that treat the employees as if they were only a number are losing money every year. Example American, United Airlines and Delta Airlines. (Thompson, A Gamble, J. (2010) Threats. The culture establish by Herb Kelleher may not be followed by Gary Kelly and Southwest Executives. Another airlines that are following the pattern of Southwest Airlines, like Jet Blue and Allegiant could get a better share of the Market The airline industry is incredibly competitive, and the race to get the consumer’s business often leads to margin contraction Weather Uncertainty: As we have seen most recently with snow storms in the North east, natural disasters can cause major losses in business for the airlines, and because Mother Nature is so unpredictable, there is always major uncertainty revolving around the company When jet fuel prices rise, airline companies are faced with the decision of passing the pain onto their customers and possibly losing business, or swallowing the costs and ruining their margins The company operates mainly in the United States of America, and thus any economic slowdown exclusive to the American economy could drastically hurt Southwest’s business, while other international companies possess the ability to overcome American decline economy if internationally the economy is better. Goals and Long-term Objectives The analysis shows that Southwest Airlines should seek International market share to gain access to new customers and to spread business risk across a wider market area. Actually Southwest is solely business is within the United States, with the acquisition of Air Tran which was already flying to Mexico, and the Caribbean, Southwest Airlines attempt to fly international is one of the goals and long term objectives. The company has measures their steps into new markets after studying the market and the possibilities, Southwest Airlines will do the same with flight to international markets. Air Tran is already flying to Cancun in Mexico and Puerto Rico in the Caribbean, soon other cities could be added, like Acapulco and Puerto Vallarta in Mexico and other Islands in the Caribbean. Southwest Airlines should not follow an aggressive strategy as the economy is not strong enough. It should continue marketing in the cities where these flights are going to depart from the United States and on their international destination. Southwest Strategy of acquisition has saved the company of all the expenses and complex structure to work in a foreign market. All these procedures and permits and agreements with international governments and the IATA. (International Air Transport Association) are already done by Air Tran. Strategy Selection Southwest Airlines should use the â€Å"Think Global act Global Strategy†, as an International Airline. Southwest Airlines has a brand that is recognized International mainly by the way this company has performed during its 40 years since they start flying. Customers around the world know about their code of ethic, their mission and the way they have run the company by employees first then customers, their safety record and on time performance, and very important their low cost. Should also continue with the Ethical and Cultural Strategy that has been core of the company culture. As the social Responsibility and Corporate Citizenship Strategy. The company Social Responsibility Strategy has been example to many companies not only in the United States, but in other countries too. . (Thompson, A Gamble, J. (2010) Southwest action to enhance employees well-being, by treat them like family and putting their employees first, even before its customers, has given them the merit of recognition of one of the best companies to work for. The company has an ethical strategy and operates honorably and ethically, this was clear when Southwest Airlines was the only Airlines after 9/11 crisis, that did not furlough any of its employees. The airline showed with this example the ethic and honorability which has been their Strategy since the beginning of the company 40 years ago. (Thompson, A Gamble, J. (2010). Southwest Airlines supports several charitable causes, participates in community service activities and contributes to the overall betterment of society. (Thompson, A Gamble, J. (2010) Southwest should continue with these Strategies, as they have shown how well they work for the company, their employees, their customers and their community. These Strategies of Social responsibility and the Strategies stated before about the Vision, Mission, objectives and basic competitive Strategies. Southwest as a low-cost carrier has seen its cost base edge up over the years as it has matured and gained in scale. In response Southwest has modified its business model and has started to fly from crowded markets, such as New York’s LaGuardia . The 2011 Air Tran acquisition, the biggest in Southwest history, has accelerated the process of expansion, and has given the company a larger share in the Atlanta domestic market, and also the international destinations in the Caribbean and Mexico. (Sing, C. 2013) Recommendations/Implementation The above analysis shows that the best recommendation for Southwest is to continue opening new routes in Mexico and the Caribbean. Having already open the door with Air Tram to Cancun, it is feasible that the same permits can be used to fly to the same country. The two destinations we suggest are Acapulco and Puerto Vallarta, following with Los Cabo’s after one year. All these three cities have facilities and International Airports. The affluent of Tourists to these cities is year round. Southwest Airlines could fly these routes with 2 aircrafts. The Company has a contract with Boing for 25 planes during the next 10 years. (Southwest Airlines One Report (February 3, 2013) The persons in charge of this venture will have to be trained to handle international law and all the complex regulations that an airline has to comply, however among the employees of Air Tran; there must be the experience person or persons, needed to handle the opening of the new route. The hiring of ground personnel at the airport of the new destinations, have to be done locally, and the operation manager can be an American. Mexican Immigration Law requires that employees should be of Mexican Nationality, However the Manager can be an American with a job permit up to 2 years (Mexican Immigration Law). Marketing for these two new destinations has to be done principally on the cities that fly nonstop to the new destination. Marketing has to be done also at the new destination, to gain international market share for the airline. The company has the sufficient funds to open these two cities and start operations by next year 2015. (Annex 3) The Company has already a reservations office established and all the ground support for the International service from Air Tran.

Understand employment responsibilities and rights in health and social care Essay Example for Free

Understand employment responsibilities and rights in health and social care Essay Unit 201 – Understand employment responsibilities and rights in health, social care or children and young people’s settings. Describe the terms and conditions of own contract of employment. Probation period: When I joined Children 4 Most I was told I was on a 6 month probation period, This means that the management are able to terminate my contract if the company is unsatisfied with my working standards. Place of Work: I was also told that I may have to work at other locations for the nursery’s needs. Pay arrangements: My pay is  £433 a month which is paid Into my bank account in or around the 23rd of each month. I am also entitled to  £150 bonus every 3 months; this is given to each staff member if they haven’t had a sick day or been late to work in the 3 month period. Contracted Hours: My hours of work are 35 hours a week, A Monday to Friday arrangement. Holidays: My holiday year runs from the 1st of April to the 31st of March. I am entitled to 28 days holidays which include the days I have to take for Bank Holidays. Holiday Pay: Holiday pay will be at the normal rate pay. Notice period: If I choose to leave within my first month of being with the company a notice period is not permitted, However If I have been working with the company longer than 1 month a 1 week period will be provided, If I will have been with the company longer than 6 month’s a 4 week notice is required. Confidentiality: Should I breach this it may result in my contract being terminated. However if a child is believe to be in need or at risk of suffering harm, Legal advice should be obtained. Describe the information which needs to be shown on your pay slip. My salary should be shown and the hours which I have worked, Also the rate of my pay for example 433.3300. Also the date of the payslip, the tax code and employee number, The net pay and also my name. Total gross pay, Gross for tax, Tax paid, Earnings for National Insurance and also My National Insurance number. Explain what could happen when not carrying out the correct requirements of your role. If I didn’t carry out the correct requirements the children may not get the correct care that should be given. The nursery may also receive a visit from OFSTED and they may close down the nursery or change the rating for example from outstanding to pass, Parents may also take their children out of the nursery which may cause the nursery to close down. Explain how your role contributes to the overall delivery of then service provided. I provide all the correct care to ensure all the children’s needs are all correctly met and that they are happy and learning to all of their abilities. I have lots of responsibilities around the nursery from maintaining care of the children to protecting them and encouraging them with their learning. I also have to monitor the children and check the register frequently and carry out head count checks every 30 minutes. I also have close bonds with the parents and when carrying out activities making sure the safety aspects are all addressed and followed. If the correct care wasn’t provided, overall care may be dropped and accidents may happen. Explain how you could influence the quality of the service provided by – following the best practice within your work role. In a great position to influence a quality of care by setting standards of care, I show respect towards the children at all I times, I allow each child to have one and one time with me and I also allow each child to talk when they would like something. I deal with private situations with great respect for a example toilet routines, I encourage each child to close the toilet door behind them and I encourage each child to wipe themselves independently and pull up their clothing before they have opened the toilet door. Identify the personal information that must be kept up to date with your employer. The information includes: * name * address * date of birth * sex * education and qualifications * work experience * National Insurance number * tax code * details of any known disability * emergency contact details Explain agreed ways of working with employer. Without a job description you wouldn’t be able to apply for the job as you wouldn’t know what roles and responsibilities the job would entitle. Your employer will also have agreed on your pay and the benefits you may or may not get within the job for example a company car, you will have agreed to this by signing a contract.

Multipath Fading Channels And Transmitted Signals Computer Science Essay

Multipath Fading Channels And Transmitted Signals Computer Science Essay Multipath fading is a phenomenon of fading of transmitted signals due to refraction, reflection and diffraction from objects or obstacles present in the line or way of transmission. In this article, we have be realized an example of multipath fading channels such as in case of Rayleigh fading channels using MATLAB and would be analysing the variations incurred after varying system parameters such as samples per second and Doppler shift of the respective blocks of the Rayleigh fading system. Also, here screen shots of the respective variations have been provided for clear understanding of induced variations. 1. Introduction As mentioned earlier as well, multipath fading is the occurrence of fading of transmitted signals by refraction, reflection and diffraction due to obstacles present in the line or path of transmission and channels affected due to this type of fading are called multipath fading channels. Rayleigh fading is nothing but the statistical model that communication engineers use to study the characteristics propagation of radio signals, in case of wireless propagation channels. In general, Rayleigh fading model is used for studying ionospheric and tropospheric signals propagation and such that the signals are transmitted in a widespread manner i.e. they are transmitted in form of concentric rings throughout the atmosphere. Thus, these are not used to study the fading that occurs in line of sight propagation (for that Rician is preferred over it). The Rayleigh fading channel can be used to study fading characteristics such as in cases of densely populated cities with a large number of skyscrapers (such as Central London and NYC). The central limit theorem limits this concept such that the amount of scatter can be considered as a function of irrespective of individual function of Gaussian distribution. The impulse response can be modelled a random function varying from 0 to 2pie [1]. The probability distribution function R(of Rayleigh fading) can be given as; Where, ÃŽÂ © =  E(R2). [1] As mentioned in abstract that we would be varying the Doppler shift in case of Rayleigh fading and will be explaining the observed variations in the generated output, its better to have an understanding of what Doppler shift actually means as well for better understanding of concepts. Doppler effect (or Doppler shift) can be described as the increase or decrease in Doppler frequency in case of a moving object (for e.g. the Doppler frequency increases when the object is moving towards the stationary or moving object and vice versa for moving away from the desired moving or stationary object). The mathematical expression for Doppler frequency can be given as; f = left( frac{v + v_r}{v + v_{s}} right) f_0 , Where Vr is the velocity of receiver relative to the medium and Vs is the velocity of source relative to the medium and V is the velocity of waves in the medium [2]. Also, Doppler power spectral density which is also an important parameter of Rayleigh fading is the measure of spectral broadening caused in the waveform characteristics of the transmitted signal (such that the received signals appears to be faded and broadened as compared to the actual signal sent). The mathematical expression for Doppler power spectral density can be shown as [3]; S(nu) = frac{1}{pi f_d sqrt{1 left(frac{nu}{f_d}right)^2}} Realization of Rayleigh fading using MATLAB A sample program of Rayleigh fading can be accessed in MATLAB 2010a by typing the command doc_qpsk_rayleigh_derotated in the command window. The MATLAB operator gives us a block diagram of the Rayleigh fading. It consists of a Bernoulli binary sequence generator, two QPSKs, one error rate calculator, one Rayleigh fading block (where adjustments regarding Doppler shift can be made), one phase removal of path gain block and in the end an AWGN block for simulation of faded signal (4). The screenshot of block diagram for Rayleigh fading had been shown below; Figure 1. MATLAB screenshot of the block diagram for simulating the Rayleigh fading 2.1 Simulation with basic values of Doppler shift and sample rate The simulation results into three possible outputs. These are transmitter output, Rayleigh channel output with no phase component and Rayleigh noisy channel output with no phase component. These outputs for sample simulation with bit sample rate/sec of 100logbase2 (M) and maximum Doppler shift of 1000 hertz is shown below. The screenshots of respective output of QPSK modulator output, Rayleigh channel output and noisy Rayleigh channel output has been shown below; Figure 2.screenshot of MATLAB simulated QPSK modulator output for Rayleigh fading Figure 3.screenshot of Rayleigh channel output for Rayleigh fading (simulated using MATLAB) Figure 4.screenshot of the noisy Rayleigh channel output for Rayleigh fading (simulated using MATLAB) 2.2. Simulation with changed values of Doppler shift and sample rate In the second simulation i have changed the values in Doppler shift and sample rate per second. The Doppler shift can be changed by changing masking parameters in the Rayleigh fading channel. Here, in this simulation I have kept the Doppler shift to 10000Hz while in previous case it was 1000Hz. Also, in Bernoulli bit sequence generator the value of samples per second had been changed to 1000logbase2 (M). The observed variations have been shown below. Figure 5. QPSK modulator output of the Rayleigh fading (simulated using MATLAB) Figure 6. Rayleigh channel output for the Rayleigh fading (simulated using MATLAB). Figure 7. Noisy Rayleigh channel output for Rayleigh fading (simulation using MATLAB) 2.3. Explanation of the observed variations It can be seen that in first case the outputs (amplitude) of QPSK modulator lies in the range of -1 to 0 and 0 to +1 while it varies from -2 to 0 and 0 to +2 which obviously should be observable as the samples per second gets increased from 1000 to 10000 samples per second. However, as the Doppler shift is increased the fading becomes more visible in case of the Rayleigh fading and noisy Rayleigh fading channels. The explanation can be given using Jakes model which relates the Doppler shift and Rayleigh fading. Jakes model relates the Rayleigh fading for kth wave to Doppler shift in following manner; R(t,k) = 2sqrt{2}left[sum_{n=1}^{M}left(cos{beta_n} + jsin{beta_n}right)cos{left(2 pi f_n t + theta_{n,k}right)} + frac{1}{sqrt{2}}left(cos{alpha} + jsin{alpha}right)cos{2 pi f_d t}right] Also, fn=fd(cosa) [5] Hence, it can be said that the amount of Rayleigh fading is directly proportional to the cosine of Doppler shift experienced by the transmitted wave. Also, worth mentioning over here is that is cosine decreases from 0 to increasing values of angle. It can be also seen that from expression mentioned above for power spectral density for Doppler shift that if the Doppler shift is increased the corresponding power spectral density is also increased. Thus, the results shown in the screenshots are explained and justified and it can be said that with the increase of Doppler shift the transmitted waves the Rayleigh fading is increased and so is the power spectral density related to it. Conclusion Rayleigh fading is an important phenomenon used to explain multipath fading in case of the dense populated areas. Rayleigh fading affects a transmitted signal by making broadened and faded in nature and it also does effects its power spectral density in a big way. Also, with increase in Doppler shift the Rayleigh is increased as well. In this setup, channel distortion parameters such as gain and phase are defined as a complex number consisting of real and imaginary parts. Thus, Rayleigh fading can be said to be composed of two paths (real and imaginary) and can be considered as independent paths which can be added in order to get net magnitude of Rayleigh fading occurred in the transmission [6]. To counter the effects of Rayleigh fading a number of techniques were used in the past but the most common one used these days is using a White Gaussian simulator for maintaining bearable effects of Rayleigh fading. This had been shown in the block diagram shown above. References Proakis John. G (1995).  Digital Communications  (3rd Ed.). Singapore: McGraw-Hill Book Co. pp.  767-768.  ISBN  0-07-113814-5 Rosen, Joe; Gothard, Quinn Lisa (2009). Encyclopedia of Physical Science. Infobase Publishing. p. 155. ISBN 0-816-07011-3., available on page 155 Clarke.H.R. (July-August 1968). A Statistical Theory of Mobile Radio Reception. Bell Systems Technical Journal, page number 957-1000 Arsal. A, Ozen. S(2008), A Rayleigh fading  ¬Ã‚ lter design for multipath Rayleigh fading simulation and comparisons to other simulators Jakes. C. Williams, Editor (February 1, 1975). Microwave Mobile Communications. New York: John Wiley Sons Inc. ISBN 0-471-43720-4. Proakis John. G (1995).  Digital Communications  (3rd Ed.). Singapore: McGraw-Hill Book Co. pp.  767-768.  ISBN  0-07-113814-5 Spread Spectrum Models Abstract Spread spectrum is a statistical modulation technique that is been used for increasing the available channel bandwidth. In this article we have focussed on the one the spread spectrum models i.e. two users real spreading with BPSK modulation using MATLAB. Also, a brief study of variations and the explanation of such observations are made in this article. Here, Ill be varying the SNR value of the AWGN block in the given block diagram for the spread spectrum model and would be observing and explaining the variations occurred. 1. Introduction Spread spectrum modulation is a type of modulation in which we intentionally increase the available bandwidth in frequency domain i.e. we stretch the available bandwidth. This leads to a broadened or widened signal for with increased bandwidth. This is generally done to increase bandwidth for signals that require more bandwidth for transmission (it has an effect similar to aliasing but the difference we take anti-aliasing measures against the later). The system models that use such spread spectrum techniques are called spread spectrum models. Two user model for real spreading with BPSK modulation basically utilizes two different orthogonal codes for spreading of the codes. The process of spreading is independent in nature i.e. a different pn sequence for each of the two users. This model uses the orthogonal frequency division multiplexing access technology (OFDM) for communication between the two users simultaneously. In this scheme, there are a large number of orthogonal sub carriers separated by a very small distance. The data is then divided into small but same sized chunks and then are loaded (modulated) on these orthogonal sub carriers through multiple paths [1]. The subcarriers then can use any of the conventional technologies for modulating these data packets (such as QAM or PSK) for transmission over the channel. Also, the symbol rates for individual data packets are maintained such that those comparable to its conventional counterparts. However, OFDM is more popular with wireless systems. 2.1. Realization of spread spectrum model using MATLAB Two user orthogonal real fading with BPSK can be realized in MATALAB by typing commspreading_orthobpsk2u in the MATLAB command video. The result shown on the MATLAB simulation window is a block diagram of two user real spreading with BPSK. The screenshot of this has been shown below; Figure 1- Two-user orthogonal real spreading with BPSK modulation (simulated in MATLAB) As shown in the block diagram here the system setup can be broadly classified into three sections. These are transmitter section, the channel and then receiver section. Receiver section is further extended into one more section known as error calculation section. Let us have a brief look into each of the sections mentioned above. 2.1.1 Transmitter section The transmitter section is responsible for transmitting signals to receiver section via channel section of the system setup. Transmitter section is basically made up 5 major components, these are Random integer (signal generator), real BPSK modulator, Hadamard code generator, normalized gain and spreader blocks. Random integer block is used for the generation of signals that could be used for sending over the channel. These signals are then BPSK modulated where it is also mixed with the actual user signals and sent to spreader section. The sequence generated is of 64 bits length. Then on the lower side of the transmitter contains Hadamard code generator which generates unique Hadamard codes for the signals encryption and security to protect it from hacking and noise addition over the channel. The gain of the Hadamard code is then normalized and mixed with the BPSK modulated signal in the spreader section. The spreader is responsible for the deliberate spreading of signals in the frequency domain to increase the bandwidth of transmitted signal. 2.1.2. Channel section Channel section here refers to actual channel or medium through which transmission is done. But here its not wireless as it is an experimental setup. This section here contains AWGN correction blocks. These are responsible for deciding SNR values for the transmitted signals as to gain knowledge about the actual signal transmission through wireless medium. Here, a person can set values of SNR such that to determine the low and high noise environment and the results of these variations of the error rate at receiver section. 2.1.3. Receiver section The receiver section is responsible for the reception, decryption, de-spreading and calculation of error rate in the received signals after travelling through the physical medium. The process carried out here is just opposite as of transmitter section of the setup. The received signal is first sent to de-spreader for removing the spreading done in transmitter section. The integrator and dump section is used to detect or separate out RZ and NRZ parts of bit sequence [3]. Then the sequence is sent to demodulating BPSK section and then to error rate determination section for error rate estimation. 2.2. Effects of Variations in SNR on the Error rate The effects of variations of SNR on the error rate have been summarized below. The table below shows the variations in values of SNR and the corresponding changes in error rate i.e. eRx/Rx (number of erroneous bits transferred /total bits received [2]) with de-spreading. Also, worth mentioning here is that the time period for which the simulation is carried by the system is set to 0.125 seconds in this sample spread spectrum modulation. The table is as under; Figure 2. Table above depicts the effect of variation of SNR on the error rate of the system setup explained above (all values are realized in MATLAB and written down in the table) The table above shows that with increasing values of signal to noise ratio the value of bit error rate is reduced. But it is different in first two readings for receiver1 and receiver2 while it ends out to be zero for SNR value 100 dB for all of the values simulated in a time defined range of 0.125 seconds. This pretty understandable that the dispreading used is here is of ideal nature thus the value of erroneous bits goes down as value of SNR increases. The difference in the error rates between the first two readings of receiver1 and receiver2 is pretty understandable as the two different signals have different error rates when they are transmitted through two different Hadamard codes (i.e. initial seed for first receiver was set to 37 and for second it was set 631). 3. Conclusion Two user orthogonal real fading with BPSK modulation is used as an experimental to study the characteristics of spread spectrum. The OFDMA as we know splits the large data into small equally sized fragments and transmits it through multiple paths thus is also affected by multipath fading. This particularly affects wireless channels even makes is even more difficult to maintain SNR and low error rates. To counter the effects AWGN simulator is used such that the effects of multipath fading are neutralized. The observations made with this system setup prove that value of SNR affects the error rate percentage in the transmission. As the value of SNR is increased the value of error rate goes down and vice versa for a lower value of SNR. References 1. Robertson. P; Kaiser .S; The effects of Doppler spreads in OFDM(A) mobile radio systems, Vehicular Technology Conference, 1999. VTC 1999 Fall. IEEE VTS 2. Shah .Gaurav ; Molina. Andres ; Blaze. Matt (2006); Keyboards and Covert Channels 3. Sadr, R.; Hurd, W. J.; The Telecommunications and Data Acquisition Report, page 158-173 (ISBN N88-12679 04-32) 4. Aurthur. Ross (1997); CA Patent 2228131; data available on http://www.mathworks.com/products/commblockset/demos.html?file=/products/demos/shipping/commblks/commspreading_m.html#1 5. MATLAB code available at http://www.mathworks.com/products/commblockset/demos.html?file=/products/demos/shipping/commblks/commspreading_m.html#1 IEEE 802.11 WLAN Abstract IEEE 802.11 is the standard adopted by IEEE for design of wireless network systems. Here, in this article a sample simulation of 802.11 standard is done using MATLAB and Simulink. Also, a brief description of operation and functional characteristics of blocks (i.e. components) used for attaining and maintaining wireless networks have been made. Also, certain parameters of WLAN system setup are varied to make a brief study of changes that incur in the system due to these variations. 1. Introduction Secure, dependable and fast wireless systems have become a need of current growing world that touches everyone ranging from individuals to large organizations. Wireless networks are needed for small private area networks such as Bluetooth and Ad Hoc and large networks for wider network coverage such as 3G and 4G networks are currently being employed for providing internet and communication services to people with mobility. The WLAN 802.11 standard is used for wireless communication networks in 2.4, 3.6 and 5 GHz frequency bands [1]. There is a complete family of 802.11 which uses a number of over the air modulation techniques for transmission and reception of signals. There a number of versions launched by IEEE under the name of 802.11, this includes 802.11a, 802.11b, 802.11g and 802.11n. The most frequently employed among these are 802.11b and 802.11g. The data to be transmitted is first broken in small and equally sized packets and then modulated and transmitted on multiple channels (through different paths) to the destination. Thus, it uses OFDMA access for setting up communication. 802.11 standard has a complete frame stack for secure and dependable communication. These include certain frames for controlling and maintaining the wireless connection among wirelessly connected hosts. These are Protocol version, Type, Sub type, ToDS and FromDS, More fragment, Retry, Power management, More data and WEP [2]. All these play important part in setting, maintaining, controlling and releasing the wireless connection among a number of wirelessly connected hosts on 802.11 system. Below is shown a sample example of how 802.11 WLAN standard system looks like. Figure 1. The Linksys WRT54G contains an 802.11b/g radio with two antennas [3]. 2.1. Realization of IEEE 802.11 WLAN standard in MATLAB A sample MATLAB program for IEEE 802.11 WLAN can be realized in MATLAB by typing the same in help command box of the MATLAB. The output shows an experimental setup containing block diagram of the IEEE 802.11 WLAN system. This has been shown below. Figure 2- The screenshot above shows the block diagram of the sample IEEE 802.11 WLAN standard simulated in MATLAB The block diagram broadly contains variable-rate data source, BPSK modulator and demodulator, OFDM symbol generation block and disassemble OFDM frame block, multipath channel and a packet error calculation block. Also, the signal visualization block for opening the signal characteristics of such setup. These signals characteristics are shown below. Figure 3-The signals transmission and receiver characteristics of the 802.11 system setup using sample settings (simulated in MATLAB) 2.2. Operations and working of the Block diagram The signal characteristics can be visualized in the above screenshot. The transmitted data consists of a binary stream of data send with OFDMA modulation. In this model shown above the variable rate data source is used to generate a binary string of variable data rates which could be considered as similar to the real life scenario as data rates vary with time and need of the users. This binary string is then BPSK modulated using BPSK modulator which is the case with OFDMA as it uses any other general modulation technique for the modulation of signals and then OFDMA codes are added to it. The signals are now undergo a number of alterations before reaching the multipath channels. These include adding a cyclic code to the signals and going through IFFT which is inverse fast Fourier transform to the signal. The signals are then sent through multiple paths which is the case with the OFDMA. This completes transmitter section. After all these processes the signal enters the receiver section of the WLAN. The signals go through cyclic code removal block and then FFT or fast Fourier transform block to anti the effects of IFFT. Then signals are equalised in frequency domain as these get disturbed in frequency domain as shown in the figure 2 signal equalization. The disassemble OFDM block takes off the OFDM codes from the signals and then the signals is demodulated using a BPSK demodulator after which the signal output is sent to the error collection block where the original and received signals are compared to get error rate in the transmission. Also, one more output wire goes to adaptive modulation control block where the degree of modulation is controlled according to the bit error rate achieved by the system. Also, the value of SNR is varied according to the values entered in the stack. This also changes the adaptive modulation control. 2.3. Effects of variations in certain parameters of IEEE 802.11 WLAN setup The effects of inducing variations in certain parameters such as SNR or hysteresis are visible in the transmission characteristics of the block diagram shown below. These values are achieved after changing the value of hysteresis value for adaptive modulation to 10dB from 3dB and lower SNR threshold values to [10 11 14 18 22 24 26 32] decibels from earlier value of [10 11 14 18 24 26] decibels. It can be seen from the two figures 3 and 4 that the unequalized signal spreads out more. Also, the per i.e. packet error rate is increased from 6% to 12%. This due to increased hysteresis for adaptive modulation control. Conclusion The IEEE 802.11 standard for wireless LAN is used as a standard for setting up the wireless network for communication of multiple numbers of hosts. Also, in this sample simulation we concluded that with varying values of SNR and hysteresis the BER and PER also changes. Thus, it can be also concluded that data rates and packet loss rates are also variable at variable places in the parts of networks. This due to different distances, landscapes and congestion is different for different areas as the signal transmission follows multiple paths for transmission and every single path has a different type of obstacles available. Also, the system is greatly affected by noise present in free space. The reception quality always decreases with increase in distance between the service provider and host.

Effective Use of the First Person in First Confession Essay -- First C

Effective Use of the First Person in First Confession "I decided that, between one thing and another, I must have broken the whole ten commandments, all on account of that old woman, and so far as I could see, so long as she remained in the house I had no hope of ever doing anything else," (page 189). This quote from the text of "First Confession" by Frank O'Connor exquisitely shows which point of view O'Connor selected for his story. Frank O'Connor chose the first-person point of view to tell his tale. One can determine this by three factors: the use of the word "I", the use of grammatical voice and the use of conveying the story through the characters. These three techniques are shown vividly throughout O'Connor's novella. The use of the word "I" in O'Connor's short story is in the text continuously with an unquestionable presence. A prime example of the usage of "I" in O'Connor's tale is first seen in the second paragraph as Jackie talks about his grandmother favoring Nora, his older sister, over him: "Nora, my sister, just sucked up to the old womanÖI was too honest, that was my trouble; and when I was playing around with Bill ConnellÖand saw my grandmother steering up the path with the jug of porter I was mortified. I made excuses not to let him into the house, because I could never be sure what she would be up to when we went in," (page 188). The application of the word "I" is an obvious and well-known method of the first-person point of view, as well as using another compatible method such as grammatical voice. Grammatical voice is a conventional technique of guiding the reader through the story using a first-person point of view. This is a... ...s. The reader is also shown that Jackie's mother dislikes her mother-in-law's mannerisms. This use of conveying the story through the characters is another method that is primarily used in first-person point of view, conventionally for its simplicity and advantage of giving several details in a short amount of time. O'Connor shows first-person point of view unremittingly in the short story "First Confession." By his usage of the word "I," O'Connor announces to the reader that he is writing in first-person, by using the method of grammatical voice O'Connor shows another technique of writing in first-person and, intertwined with grammatical voice, his conveyance of the story through the characters is his last usage of writing in the first-person point of view. These three applications of writing give the reader a sure perception of O'Connor's point of view.

Impact of the Writers of Antiquity on Modern Times Essay -- History Li

Impact of the Writers of Antiquity on Modern Times History is riddled with the names of various intellectuals and descriptions of their theories. Born of brilliant men like Marx and Machiavelli, to name a few, these theories are preserved in books, illustrated in day-to-day domestic and international affairs, and immortalized in modern theories and documents. They are the predecessors of present theories that have been reinterpreted for a different era and reapplied in a new context. In his most famous work, The Prince, Niccolà ³ Machiavelli discusses the ways in which to not only attain, but also retain, political power. His works deal heavily with methods for creating and maintaining a defensive state—one that is capable of withstanding attack—and the ways in which a ruler can rule. According to Machiavelli, a ruler may violate the moral norm—throw away the ethical rulebook, so to speak—so long as it benefits his state. These theories still resound in many modern policies. Cruel birth control practices, like those of Indira Gandhi in the 1970’s and those of China much more...

Fredrick Douglas Essay -- essays research papers

In Douglas Monroy’s essay â€Å"The Creation and Re-creation of California Society,† the thesis is that studying history of California is not just about changes in state’s political concerns but is more about relation with human existence. First, he talks about land and liberty and how Californians settled at the landscape. Second, Douglas explains about the life in present day California. Last, he talks about Californios and Indios. Douglas Monroy’s purpose in writing this essay is to inform readers of how California and the inhabitants were in the 1800s by showing detailed life style. The author provides a couple of interesting evidences about land and liberty in California. The first thing that I found interesting is a story about Governor Echeandia and his administration. He arrived in California and formed study groups back in 1825. This actually got some young men involved and excited about the ideas of liberty and equality. An ironic fact is that male children born to original settlers and presidial soldiers maintained control over the concerns in California, which in today’s society is hard to believe. The life on the Ranchos was perhaps the most interesting out of all, because of how one family took care of Sonoma area, Mariano Vallejo, which husbanded twenty-five thousand cows, twenty-four thousand sheep and two thousand horses. It is unbelievable to a present day Californian like me. There was one sentence that actually surprised me. I thought that boys were more impo...

College Students Cheating on Exams Essay

In today’s age when you look at the word â€Å"Cheating†, you may find many different definitions or meanings. Whether you cheat at work; known as fraud, cheat at home; known as dishonesty, or at school, this act of conduct can lead to many consequences made by ones choice. Cheating as a word to me means to not follow rules or standards brought up as a person. As we focus today on students cheating, the first thing that comes to my mind is cheating on an exam. As much as we hate to believe it, students in these days have followed the path of trying to do anything to get that grade. I believe many students today are driven to cheat when there is too much emphasis to ace an exam from both parents and school staff. It’s difficult to dismiss why students cheat, but I think if you eliminate pressure, students are less likely to engage in such conduct. Cheating leads to breaking the rules in many cases. Sometimes cheating can also lead to students finding someone else to help take one another’. No matter how careful teachers or programs are designed to prevent it, students will always find ways to get around obstacles and cheat at one point. Students may think cheating on an exam might seem like an easy way for a student to get a good grade and get ahead in his or her career, but the end result is when students cheat on exams, everyone is affected in many ways. When a student cheats or decides to cheat on an exam, they forget to think about the consequences that occur as a result of the decision made. Have you ever stopped and thought of the different consequences that occur? Consequences can vary depending on the student getting caught cheating. Some professors may issue a grade of a zero as a standard consequence; other professors may report the cheating to school board depending on the kind of test taken. In most cases, the student will be put on academic probation for repeat offenses which can affect the student’s career development. The student may be able to get a job with more responsibilities and more pay, but they may not be able to keep it, or might even harm people. Whether the student’s career is medical assistant, a teacher, or a lawyer, the exams are supposed to show the level of knowledge required for them to perform well and how can one show that when they are cheating on studies or exams. Another consequence of students cheating is that students, who cheat and get caught, cause other current and future students who do not cheat to become penalized for honesty. When students cheat they change the rules of education in favor of themselves. At the same time changing rules for themselves also cause changing rules for those that choose not to cheat, end result at one point or another someone will be affected. When you think of cheating, the question you should ask yourself should be; â€Å"Are you willing to take a huge risk and possibly affect your future? † The end result to cheating is obviously not a good turnout that leads to many different wrong roads. Many people say once a cheater, always a cheater meanings if you cheat once, are you bound to cheat again or will you learn from your mistakes. On the basis of predictability of human conduct, when you think of exams your first perception would be who is going to cheat on the exam. There are many different reasons why people cheat, just as there are differences in individuals who may cheat. For some, cheating is a way of life, one may cheat for some relief and in other cases others may cheat and be caught off guard causing a momentary slipup, which in end result may never happen again. Now what causes a person to act in that behavior, and determine what caused that behavior. What factors lead a person to cheat is what many ask. Eventually one can make a change and not cheat again. I believe schools should organize speakers, programs and workshops in the framework of â€Å"helping a student to cope with stress†. As part of these programs, parents should be made aware of how they often teach their children to cheat by increasing the pressure or demonstrating that success is the ultimate value in life. Students need to learn that you can cheat your way through school, graduate without learning anything, then get a profession and cause another person to get hurt due to not knowing anything in school due to cheating. Next time if you should cheat to make that extra grade, think again because it may result in hurting yourself and your future or the future of others.